JP6485760B2 - Transmission method, transmission apparatus, reception method and reception apparatus - Google Patents

Description

  The present invention particularly relates to a precoding method, a precoding apparatus, a transmission method, a transmission apparatus, a reception method, and a reception apparatus for performing communication using multiple antennas.

  Conventionally, as a communication method using multiple antennas, for example, there is a communication method called Multiple-Input Multiple-Output (MIMO). In multi-antenna communication represented by MIMO, transmission speed of data is increased by modulating transmission data of a plurality of sequences and transmitting each modulated signal simultaneously from different antennas.

  FIG. 28 shows an example of the configuration of the transmission / reception apparatus when the number of transmission antennas is 2, the number of reception antennas is 2, and the number of transmission modulation signals (transmission streams) is 2. The transmitting apparatus interleaves the encoded data, modulates the interleaved data, performs frequency conversion and the like to generate a transmission signal, and the transmission signal is transmitted from the antenna. At this time, a system in which different modulated signals are transmitted from the transmitting antenna to the same frequency at the same time is the space multiplex MIMO system.

  At this time, Patent Document 1 proposes a transmitter having a different interleaving pattern for each transmit antenna. That is, in the transmitting apparatus of FIG. 28, two interleavings (πa, πb) have different interleaving patterns. Then, as shown in Non-Patent Document 1 and Non-Patent Document 2 in the receiving apparatus, reception quality is improved by repeatedly performing a detection method using soft values (MIMO detector in FIG. 28). It will be done.

A non-line of sight (NLOS) environment represented by a Rayleigh fading environment and a LOS (line of sight) environment represented by a rice fading environment exist as a model of an actual propagation environment in wireless communication. When transmitting a single modulated signal in a transmitter, performing maximum ratio combining on signals received by a plurality of antennas in a receiving device, and performing demodulation and decoding on a signal after maximum ratio combining, LOS environment, In particular, in an environment with a large Rice factor indicating the magnitude of the direct wave reception power relative to the scattered wave reception power, good reception quality can be obtained. However, depending on the transmission scheme (for example, the spatial multiplexing MIMO transmission scheme), there is a problem that the reception quality is degraded as the rice factor increases. (See Non-Patent Document 3)
(A) and (B) in FIG. 29 show low-density parity-check (LDPC) coded data 2 × 2 in a Rayleigh-fading environment and a Rice-fading environment with Rice factor K = 3, 10, 16 dB. (2-antenna transmission, 2-antenna reception) BER (Bit Error Rate) characteristics (vertical axis: BER, horizontal axis: SNR (signal-to-noise power ratio)) in the case of space-multiplexed MIMO transmission is shown an example of simulation results ing. (A) of FIG. 29 shows BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (APP: a posteriori probability) without iterative detection, and (B) of FIG. The BER characteristic of Max-log-APP (refer nonpatent literature 1 and nonpatent literature 2) (it was 5 times of repetition number) which detected is shown. As can be seen from FIGS. 29 (A) and 29 (B), it can be confirmed that reception quality deteriorates as the Rice factor increases in the spatial multiplexing MIMO system, regardless of whether or not iterative detection is performed. From this, there is a problem unique to the space multiplex MIMO system that is not present in a system transmitting a single modulation signal in the past, that "in space multiplex MIMO systems, the reception quality deteriorates when the propagation environment becomes stable". Recognize.

  Broadcasting and multicast communication are services for users in line-of-sight, and the radio wave propagation environment between the receiver possessed by the user and the broadcasting station is often the LOS environment. When a spatial multiplexing MIMO system having the above-mentioned problems is used for broadcasting or multicast communication, a phenomenon occurs that the receiver can not receive service due to deterioration of reception quality although the reception electric field strength of radio waves is high there is a possibility. That is, in order to use a space multiplex MIMO system for broadcast and multicast communication, development of a MIMO transmission scheme that can obtain a certain degree of reception quality in any of the NLOS environment and the LOS environment is desired.

  Although Non-Patent Document 8 describes a method of selecting a codebook (precoding matrix) to be used for precoding from feedback information from a communication partner, as described above, as in broadcast and multicast communication, the communication partner There is no description at all about how to perform precoding in a situation where feedback information from H. can not be obtained.

  On the other hand, Non-Patent Document 4 describes a method of switching precoding matrices with time, which can be applied even when there is no feedback information. Although this document describes using a unitary matrix as a matrix used for precoding and switching unitary matrices at random, the application method for degradation of reception quality in the LOS environment described above is described. Not described at all, only random switching is described. As a matter of course, there is no description about the precoding method for improving the degradation of reception quality in the LOS environment, and the method of constructing the precoding matrix.

WO 2005/050885

"Achieving near-capacity on a multiple-antenna channel" IEEE Transaction on communications, vol. 51, no. 3, pp. 389-399, March 2003. “Performance analysis and design optimization of LDPC-coded MIMO OFDM systems” IEEE Trans. Signal Processing. , Vol. 52, no. 2, pp. 348-361, Feb. 2004. “BER performance evaluation in 2 × 2 MIMO spatial multiplexing systems under Rician fading channels,” IEICE Trans. Fundamentals, vol. E91-A, no. 10, pp. 2798-2807, Oct. 2008. "Turbo space-time codes with time varying linear transformations," IEEE Trans. Wireless communications, vol. 6, no. 2, pp. 486-493, Feb. 2007. "Likelihood function for QR-MLD suitable for soft-decision turbo decoding and its performance," IEICE Trans. Commun. , Vol. E88-B, no. 1, pp. 47-57, Jan. 2004. "Signpost to the Shannon limit:" Parallel concatenated (Turbo) coding "," Turbo (iterative) decoding "and its surroundings" The Institute of Electronics, Information and Communication Engineers, Information Technology IT98-51 “Advanced signal processing for PLCs: Wavelet-OFDM,” Proc. of IEEE International symposium on ISPLC 2008, pp. 187-192, 2008. D. J. Love, and R. W. heath, Jr. “Limited feedback unitary precoding for spatial multiplexing systems,” IEEE Trans. Inf. Theory, vol. 51, no. 8, pp. 2967-1976, Aug. 2005. DVB Document A122, Framing structure, channel coding and modulation for a second generation digital terrestrial television broadcasting system, m (DVB-T2), June 2008. L. Vangelista, N. Benvenuto, and S. Tomasin, "Key technologies for next-generation terrestrial digital television standard DVB-T2," IEEE Commun. Magazine, vo. 47, no. 10, pp. 146-153, Oct. 2009. T. Ohgane, T. Nishimura, and Y. Ogawa, “Application of space division multiplexing and those performance in a MIMO channel,” IEICE Trans. Commun. , Vo. 88-B, no. 5, pp. 1843-1851, May 2005. R. G. Gallager, “Low-density parity-check codes,” IRE Trans. Inform. Theory, IT-8, pp-21-28, 1962. D. J. C. Mackay, “Good error-correcting codes based on very sparse matrixs,” IEEE Trans. Inform. Theory, vol. 45, no. 2, pp 399-431, March 1999. ETSI EN 302 307, “Second generation framing structure, channel coding and modulation systems for broadcasting, interactive services, news gathering and other broadband satellite applications,” “v. 1.1.2, June 2006. Y. -L. Ueng, and C. -C.I. Cheng, “a fast-convergence decoding method and memory-efficient VLSI decoder architecture for irregular LDPC codes in the IEEE 802.16e standards,” IEEE VTC-2007 Fall, pp. 1255-1259.

  An object of the present invention is to provide a MIMO system capable of improving reception quality in an LOS environment.

  In order to solve such problems, a transmission method according to an aspect of the present invention is characterized in that a first transmission signal and a first transmission signal are generated from a basic modulation signal consisting of a basic stream and an expansion modulation signal consisting of an extension stream of data different from the basic stream. (2) A transmission method of generating transmission signals and transmitting the generated transmission signals in the same frequency band and at the same timing from one or more different output ports by different transmitting devices, with respect to the extension modulation signal Select one precoding matrix from among the precoding matrices on a regular basis and perform precoding using the selected precoding matrix to generate a precoded extended modulation signal, and the basic modulation A first transmission signal and a second transmission signal from a signal based on the signal and the pre-modulated extension modulation signal , And transmits the first transmission signal from one or more first output ports, and transmits the second transmission signal from one or more second output ports different from the first output port. I assume.

  Further, a transmitting apparatus according to one aspect of the present invention generates a first transmission signal and a second transmission signal from a basic modulation signal consisting of a basic stream and an expansion modulation signal consisting of an extension stream of data different from the basic stream. A transmitting apparatus for transmitting each of the generated transmission signals from one or more different output ports at the same frequency band and at the same timing, and one of a plurality of precoding matrices for the extension modulation signal. A weighting / combining unit that selects one precoding matrix while switching regularly and performs precoding using the selected precoding matrix to generate a precoded extended modulation signal, and a signal based on the basic modulation signal And generating the first transmission signal and the second transmission signal from the precoded extended modulation signal, Providing a transmitter configured to transmit a first transmission signal from one or more first output ports, and transmit the second transmission signal from one or more second output ports different from the first output port. It features.

  In the reception method according to one aspect of the present invention, the reception device receives the first transmission signal and the second transmission signal transmitted by the transmission device from one or more different output ports at the same frequency band and at the same timing. A receiving method, wherein the first transmission signal and the second transmission signal are the basic modulation signal consisting of a basic stream and an expansion modulation signal consisting of an extension stream of data different from the basic stream with respect to the expansion modulation signal And selecting one precoding matrix from among a plurality of precoding matrices while regularly switching, and performing precoding using the selected precoding matrix to generate an enhanced modulation signal after precoding; It is generated from a signal based on the basic modulation signal and an extended modulation signal after the precoding, Demodulating each of the received first transmission signal and the second transmission signal according to a demodulation scheme corresponding to the modulation scheme used for the basic modulation signal and the extension modulation signal, performing error correction decoding, and obtaining data It features.

A receiving device according to one aspect of the present invention is a receiving device that receives a first transmission signal and a second transmission signal transmitted by the transmitting device from one or more different output ports at the same frequency band and at the same timing. The first transmission signal and the second transmission signal are a plurality of basic modulation signals of a basic stream and extended modulation signals of an extension stream of data different from the basic stream with respect to the extension modulation signals. Select one precoding matrix from among the precoding matrices on a regular basis and perform precoding using the selected precoding matrix to generate a precoded extended modulation signal, and the basic modulation Signal generated from the signal based on the signal and the extended modulation signal after the precoding, and Each of the first transmission signal and the second transmission signal is demodulated by a demodulation method corresponding to the modulation method used for the basic modulation signal and the extended modulation signal, and error correction decoding is performed to obtain data. .

  According to the above aspects of the present invention, it is used for precoding by transmitting and receiving a signal precoded by one precoding weight matrix selected while switching regularly among a plurality of precoding weight matrices. Since the precoding weight matrix to be used is any one of a plurality of precoding weight matrices determined in advance, reception quality in the LOS environment can be improved according to the design of the plurality of precoding weight matrices.

  As described above, according to the present invention, it is possible to provide a precoding method, a precoding device, a transmission method, a reception method, a transmission device, and a reception device for improving the degradation of reception quality in the LOS environment, so broadcast and multicast communication It is possible to provide high quality service to users in line of sight.

Example of transmitter / receiver configuration in space multiplexed MIMO transmission system Example of frame configuration Example of transmitter configuration when applying precoding weight switching method Example of transmitter configuration when applying precoding weight switching method Frame configuration example Example of precoding weight switching method Configuration example of receiver Configuration example of signal processing unit of receiving apparatus Configuration example of signal processing unit of receiving apparatus Decryption processing method Reception status example BER characteristic example Example of transmitter configuration when applying precoding weight switching method Example of transmitter configuration when applying precoding weight switching method Frame configuration example Frame configuration example Frame configuration example Frame configuration example Frame configuration example Position of reception quality inferiority Position of reception quality inferiority Example of frame configuration Example of frame configuration Example of mapping method Example of mapping method Example of configuration of weighting combining unit An example of symbol sorting method Example of transmitter / receiver configuration in space multiplexed MIMO transmission system BER characteristic example An example of a space multiplexed 2x2 MIMO system model Poor location of reception Poor location of reception Poor location of reception Poor location of reception Poor location of reception Characteristic example of minimum distance in complex plane of reception bad point Characteristic example of minimum distance in complex plane of reception bad point Poor location of reception Poor location of reception An example of configuration of transmitting apparatus according to Embodiment 7 Example of frame configuration of modulated signal transmitted by transmitting device Poor location of reception Poor location of reception Poor location of reception Poor location of reception Poor location of reception An example of frame configuration in time-frequency axis An example of frame configuration in time-frequency axis Signal processing method Structure of modulation signal when space-time block code is used Example of frame configuration details in time-frequency axis Example of transmitter configuration An example of the configuration of modulation signal generation units # 1 to #M in FIG. 52 A diagram showing a configuration of an OFDM system related processor (5207_1 and 5207_2) in FIG. Example of frame configuration details in time-frequency axis Example of configuration of receiving device A diagram showing a configuration of an OFDM system related processor (5600_X, 5600_Y) in FIG. Example of frame configuration details in time-frequency axis Broadcast system example Poor location of reception Example of configuration of transmitting apparatus when hierarchical transmission is applied Example of configuration of transmitting apparatus when hierarchical transmission is applied An example of precoding to a basic stream An example of precoding for an extension stream Example of arrangement of symbols of modulated signal when hierarchical transmission is applied Configuration example of signal processing unit in receiving apparatus when hierarchical transmission is applied Example of configuration of transmitting apparatus when hierarchical transmission is applied Example of configuration of transmitting apparatus when hierarchical transmission is applied Example of symbol configuration of baseband signal Example of arrangement of symbols of modulated signal when hierarchical transmission is applied Example of configuration of transmitting apparatus when hierarchical transmission is applied Example of configuration of transmitting apparatus when hierarchical transmission is applied Example of symbol configuration of baseband signal after space-time block coding Example of arrangement of symbols of modulated signal when hierarchical transmission is applied Example of arrangement of symbols of modulated signal when hierarchical transmission is applied Example of change in the number of symbols and slots required for one encoded block when using a block code Example of changing the number of symbols and slots required for two encoded blocks when using a block code Overall configuration of digital broadcasting system Block diagram showing a configuration example of a receiver Diagram showing the structure of multiplexed data Diagram showing schematically how each stream is multiplexed in multiplexed data A detailed diagram showing how video streams are stored in PES packet sequences Diagram showing the structure of TS packets and source packets in multiplexed data Diagram showing data structure of PMT Diagram showing internal structure of multiplexed data information Diagram showing the internal structure of stream attribute information Configuration diagram of video and audio output device A diagram showing the configuration of a baseband signal replacing unit

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
The transmission method, transmission apparatus, reception method, and reception apparatus of the present embodiment will be described in detail.

Before performing this description, an outline of a transmission method and a decoding method in a space multiplexing MIMO transmission system which is a conventional system will be described.
The configuration of the N _{t x} N _r space multiplexed MIMO system is shown in FIG. The information vector z is encoded and interleaved. Then, as an output of the interleaving, a vector u of encoded bits u = (u ₁ ,..., U _Nt ) is obtained. Here, u _i = (u _i1 ,..., U _iM ) (M: number of transmission bits per symbol). Assuming that the transmission vector s = (s ₁ ,..., S _Nt ) ^T , the transmission signal s _i = map (u _i ) is expressed from the transmission antenna #i, and if the transmission energy is normalized E {| s _i | ² } = Es It is expressed as / Nt (E _s : total energy per channel). Then, assuming that the reception vector is y = (y ₁ ,..., Y _Nr ) ^T , it is expressed as Expression (1).

At this _{time, H NtNr} channel _{matrix, n = (n 1, ...} , n Nr) T is the noise vector, _{n i} is zero mean, variance sigma ² of i. i. d. Complex Gaussian noise. From the relationship between transmit and receive symbols introduced at the receiver, the probability for the receive vector can be given in a multi-dimensional Gaussian distribution as in equation (2).

  Here, consider a receiver that performs iterative decoding as shown in FIG. 1 consisting of an outer soft-in / soft-out decoder and MIMO detection. The vector (L-value) of the log likelihood ratio in FIG. 1 is expressed as equations (3)-(5).

<Repetitive detection method>
Here, the iterative detection of the MIMO signal in the N _{t x} N _r space multiplexed MIMO system will be described.

The log likelihood ratio of x _mn is defined as equation (6).

  From the Bayes theorem, equation (6) can be expressed as equation (7).

However, it is set as _{Umn, ± 1} = {u | _umn = ± 1}. And ln a a _j ~ max
When approximated by ln _aj , the equation (7) can be approximated as the equation (8). In addition, the symbol of above "-" means an approximation.

P (u | u _mn ) and ln P (u | u _mn ) in equation (8) are expressed as follows.

  By the way, the logarithmic probability of the equation defined by the equation (2) is expressed as the equation (12).

  Therefore, in Equation (7) and (13), in the case of MAP or APP (a posteriori probability), the L-value after the posterior is expressed as follows.

  Hereinafter, it is called iterative APP decoding. Further, from Equations (8) and (12), in the log-likelihood ratio (Max-Log APP) based on the Max-Log approximation, the posterior L-value is expressed as follows.

Hereinafter, it is called iterative Max-log APP decoding. Then, external information required in the iterative decoding system can be obtained by subtracting the prior input from equation (13) or (14).
<System model>
FIG. 28 shows the basic configuration of the system leading to the following description. Here, a 2 × 2 spatial multiplexing MIMO system is used, and in each of streams A and B, there are outer encoders, and two outer encoders are encoders of the same LDPC code (here, an encoder using an LDPC code is used as the outer encoder) The error correction code used by the outer encoder is not limited to the LDPC code, and the same applies to other error correction codes such as turbo code, convolutional code, and LDPC convolutional code. In addition, although the outer encoder is configured to have each transmit antenna, the present invention is not limited to this, and there may be a plurality of transmit antennas or one outer encoder, and transmission Has more outer encoders than antennas Even if it is.). And, in the streams A and B, there are interleavers (π _a and π _b ) respectively. Here, the modulation scheme is 2 ^h- QAM (h bits will be transmitted in one symbol).

  At the receiver, it is assumed that iterative detection (repeated APP (or Max-log APP) decoding) of the above-mentioned MIMO signal is performed. Then, as decoding of an LDPC code, for example, sum-product decoding is performed.

FIG. 2 shows a frame configuration and describes the order of symbols after interleaving. At this time, (i _a , j _a ) and (i _b , j _b ) are represented as in the following formulas.

At this time, i _a , i _b : the order of symbols after interleaving, j _a , j _b : bit positions in the modulation scheme (j _a , j _b = 1,..., H), π _a , π _b : stream The interleavers A and B, Ω ^a _{ia, ja} , and Ω ^b _{ib, j} ^b indicate the order of data before interleaving of the streams A and B. However, FIG. 2 shows the frame configuration when i _a = i _b .
<Iterative decoding>
Here, an algorithm for sum-product decoding and iterative detection of a MIMO signal used for decoding an LDPC code in a receiver will be described in detail.

Sum-product decoding A binary MxN matrix H = {H _mn } is used as a parity check matrix of an LDPC code to be decoded. Subsets A (m) and B (n) of the set [1, N] = {1, 2,..., N} are defined as follows.

At this time, A (m) means a set of column indexes which is 1 in the mth row of parity check matrix H, and B (n) is a set of row indexes which is 1 in nth row of parity check matrix H . The algorithm for sum-product decoding is as follows.
Step A · 1 (initialization): A priori value log ratio β _mn = 0 is set for all pairs (m, n) satisfying H _mn = 1. A loop variable (number of iterations) _lsum = 1 is set, and a loop maximum number is set as _{lsum, max} .
Step A · 2 (row processing): For all pairs (m, n) satisfying H _mn = 1 in the order of m = 1, 2 _,. Update the ratio α _mn .

At this time, f is a Gallager function. And how to obtain λ _n will be described in detail later.
Step A · 3 (row process): For all pairs (m, n) satisfying H _mn = 1 in the order of n = 1, 2 _,. Update the ratio β _mn .

Step A · 4 (calculation of log likelihood ratio): Log likelihood ratio L _n is obtained as follows for nε [1, N].

Step A · 5 (counting the number of iterations): If l _sum <l _{sum, max,} then l _sum is incremented and the process returns to step A · 2. If _lsum = _{lsum, max} , this round of sum-product decoding ends.

The above is the operation of one sum-product decoding. Thereafter, iterative detection of the MIMO signal is performed. Variable m used in the description of the operation of the aforementioned sum-product _{decoding, n, α mn, β mn} , at λ _{n, L n,} the variables in the stream _{A m a, n a, α} a mana, β a mana, It is _assumed that variables in λ _na and L _na and stream B are represented by m _b , n _b , α ^b _mbnb , β ^b _mbnb , λ _nb and L _nb .
<Iteration detection of MIMO signal>
Here, how to determine λ _n in iterative detection of a MIMO signal will be described in detail.

    From the equation (1), the following equation is established.

  From the frame configuration of FIG. 2, the following relational expressions hold from Equations (16) and (17).

At this time, n _a , n _b ∈ [1, N]. In the following, λ _na , L _na , λ _nb , and L _nb at the number of iterations k of the iterative detection of the MIMO signal are _{denoted as} λ _{k, na} , L _{k, na} , λ _{k, nb} , L _{k, nb} , respectively I assume.

Step B · 1 (initial detection; k = 0): In the initial detection, λ _{0, na} and λ _{0, nb} are determined as follows.
In case of iterative APP decoding:

In case of iterative Max-log APP decoding:

However, it is assumed that X = a, b. Then, the number of iterations of MIMO signal iterative detection is set to l _mimo = 0, and the maximum number of iterations is set to l _{mimo, max} .
Step B · 2 (iterative detection; iteration number k): λ _{k, na} and λ _{k, nb} when the number of iterations is _{k are given by Eqs} . (11) (13)-(15) (16) (17) 31)-(34). However, (X, Y) = (a, b) (b, a).
In case of iterative APP decoding:

In case of iterative Max-log APP decoding:

Step B · 3 (counting of the number of iterations, code word estimation): If l _mimo <l _{mimo, max} , increment l _mimo and return to step B · 2. In the case of l _mimo = l _{mimo, max} , the estimated codeword is also fixed as follows.

However, it is assumed that X = a, b.
FIG. 3 is an example of a configuration of transmitting apparatus 300 in the present embodiment. Coding section 302A receives information (data) 301A and frame configuration signal 313 as input, and frame configuration signal 313 (error correction method used by coding section 302A for error correction coding of data, coding rate, block length etc. The error correction method may be switched, for example, according to the convolutional code, the LDPC code, the turbo code, etc. Error correction coding is performed, and data 303A after coding is output.

Interleaver 304A receives encoded data 303A and frame configuration signal 313, performs interleaving, that is, rearranges the order, and outputs interleaved data 305A. (The method of interleaving may be switched based on the frame configuration signal 313.)
Mapping section 306A receives interleaved data 305A and frame configuration signal 313, and has QPSK (Quadrature Phase Shift Keying), 16 QAM (16 Quadrature Amplitude Modulation), 64 QAM (64 Quadrature Amplitude Modula)
modulation) to output a baseband signal 307A. (Based on the frame configuration signal 313, the modulation scheme may be switched.)
FIG. 24 shows an example of a method of mapping the in-phase component I and the quadrature component Q constituting the baseband signal in QPSK modulation in the IQ plane. For example, as shown in FIG. 24A, when the input data is "00", I = 1.0 and Q = 1.0 are output, and similarly, when the input data is "01", I = I -1.0, Q = 1.0 is output,... FIG. 24B is an example of a mapping method in the IQ plane of QPSK modulation which is different from FIG. 24A, and FIG. 24B differs from FIG. 24A in that FIG. The signal point shown in FIG. 24B can be obtained by rotating the signal point about the origin. Non-patent document 9 and non-patent document 10 show such a constellation rotation method, and cyclic Q delay shown in non-patent document 9 and non-patent document 10 may be applied. Good. As another example different from FIG. 24, FIG. 25 shows signal point arrangement in the IQ plane in the case of 16 QAM, and an example corresponding to FIG. 24 (A) is FIG. 25 (A), FIG. 24 (B) An example corresponding to is shown in FIG.

  The encoding unit 302B receives the information (data) 301B and the frame configuration signal 313 as input, and the frame configuration signal 313 (includes information such as error correction method to be used, coding rate, block length, etc. Also, according to the error correction method, error correction coding such as convolutional code, LDPC code, turbo code, etc. is performed in accordance with the error correction method. Output 303B.

Interleaver 304B receives encoded data 303B and frame configuration signal 313 as input, performs interleaving, that is, rearranges the order, and outputs interleaved data 305B. (The method of interleaving may be switched based on the frame configuration signal 313.)
Mapping section 306B receives interleaved data 305B and frame configuration signal 313, and performs modulation such as QPSK (Quadrature Phase Shift Keying), 16 QAM (16 Quadrature Amplitude Modulation), 64 QAM (64 Quadrature Amplitude Modulation), etc. The signal 307B is output. (Based on the frame configuration signal 313, the modulation scheme may be switched.)
The weighting and combining information generation unit 314 receives the frame configuration signal 313, and outputs information 315 on a weighting and combining method based on the frame configuration signal 313. The weighting and combining method is characterized in that the weighting and combining method is switched regularly.

  The weighting synthesis unit 308A receives the baseband signal 307A, the baseband signal 307B, and the information 315 on the weighting synthesis method as input, and weights and synthesizes the baseband signal 307A and the baseband signal 307B based on the information 315 on the weighting synthesis method, The signal 309A after weighting and combining is output. In addition. Details of the method of weighting and combining will be described in detail later.

  Radio section 310A receives weighted signal 309A as input, performs processing such as orthogonal modulation, band limitation, frequency conversion, amplification, etc., and outputs transmission signal 311A, and transmission signal 511A is output as a radio wave from antenna 312A. Ru.

  The weighting synthesis unit 308B receives the baseband signal 307A, the baseband signal 307B, and information 315 on the weighting synthesis method as input, and weights and synthesizes the baseband signal 307A and the baseband signal 307B based on the information 315 on the weighting synthesis method, The signal 309B after weighted combination is output.

  FIG. 26 shows the configuration of the weighting and combining unit. The baseband signal 307A is multiplied by w11 (t) to generate w11 (t) s1 (t) and multiplied by w21 (t) to generate w21 (t) s1 (t). Similarly, the baseband signal 307B is multiplied by w12 (t) to generate w12 (t) s2 (t) and multiplied by w22 (t) to generate w22 (t) s2 (t). Next, z1 (t) = w11 (t) s1 (t) + w12 (t) s2 (t) and z2 (t) = w21 (t) s1 (t) + w22 (t) s2 (t) are obtained.

The details of the method of weighting and combining will be described in detail later.
Radio section 310B receives weighted signal 309B as input, performs processing such as orthogonal modulation, band limitation, frequency conversion, amplification, etc., and outputs transmission signal 311B, and transmission signal 511B is output as a radio wave from antenna 312B. Ru.

FIG. 4 shows a configuration example of a transmitting apparatus 400 different from that of FIG. In FIG. 4, portions different from FIG. 3 will be described.
Coding section 402 receives information (data) 401 and frame configuration signal 313, performs error correction coding based on frame configuration signal 313, and outputs data 402 after coding.

  Distribution section 404 receives encoded data 403 as input, distributes it, and outputs data 405A and data 405B. In addition, although the case where one encoding part was one was described in FIG. 4, the encoding part was not limited to this, and the encoding part is made into m (m is an integer greater than or equal to 1), The code produced by each encoding part The present invention can be implemented similarly even in the case where the distribution unit divides the data into two series of data and outputs the divided data.

  FIG. 5 shows an example of a frame configuration on the time axis of the transmission apparatus in this embodiment. The symbol 500_1 is a symbol for notifying the receiving apparatus of the transmission method. For example, an error correction method used to transmit data symbols, information on the coding rate, and a modulation method used to transmit data symbols Transmit information, etc.

  A symbol 501_1 is a symbol for estimating channel fluctuation of the modulated signal z1 (t) (where t is time) transmitted by the transmission apparatus. The symbol 502_1 is a data symbol transmitted by the modulation signal z1 (t) to the symbol number u (in the time axis), and the symbol 503_1 is a data symbol transmitted by the modulation signal z1 (t) to the symbol number u + 1.

  A symbol 501_2 is a symbol for estimating channel fluctuation of the modulated signal z2 (t) (where t is time) transmitted by the transmission apparatus. The symbol 502_2 is a data symbol transmitted by the modulation signal z2 (t) to the symbol number u, and the symbol 503_2 is a data symbol transmitted by the modulation signal z2 (t) to the symbol number u + 1.

The relationship between the modulation signal z1 (t) and the modulation signal z2 (t) transmitted by the transmission device and the reception signals r1 (t) and r2 (t) in the reception device will be described.
In FIG. 5, reference numerals 504 # 1 and 504 # 2 denote transmitting antennas in the transmitting apparatus, and 505 # 1 and 505 # 2 denote receiving antennas in the receiving apparatus. The transmitting apparatus transmits the modulated signal z 1 (t) as the transmitting antenna 504. # 1, the modulated signal z2 (t) is transmitted from the transmitting antenna 504 # 2. At this time, it is assumed that the modulation signal z1 (t) and the modulation signal z2 (t) occupy the same (common) frequency (band). Channel fluctuation of each transmitting antenna of the transmitting apparatus and each antenna of the receiving apparatus is h11 (t), h12 (t), h21 (t), h22 (t), respectively, and reception received by the receiving antenna 505 # 1 of the receiving apparatus Assuming that the signal is r1 (t) and the received signal received by the receiving antenna 505 # 2 of the receiving device is r2 (t), the following relational expression is established.

FIG. 6 is a diagram related to the weighting method (precoding method) according to the present embodiment, and weighting combining section 600 is a weighting combining section combining weighting combining sections 308A and 308B of FIG. 3. is there. As shown in FIG. 6, the streams s1 (t) and s2 (t) correspond to the baseband signals 307A and 307B in FIG. 3, that is, according to the mapping of modulation schemes such as QPSK, 16 QAM, 64 QAM, etc. It becomes band signal in-phase I, quadrature Q component. Then, as in the frame configuration of FIG. 6, the stream s1 (t) represents a signal of symbol number u as s1 (u), a signal of symbol number u + 1 as s1 (u + 1),. Similarly, the stream s2 (t) represents a signal of symbol number u as s2 (u), a signal of symbol number u + 1 as s2 (u + 1),. Then, weighting combining section 600 receives as input baseband signals 307A (s1 (t)) and 307B (s2 (t)) in FIG. 3 and information 315 related to weighting information, and uses a weighting method according to information 315 related to weighting information. , And outputs the signals 309A (z1 (t)) and 309B (z2 (t)) after the weighting and combining of FIG. At this time, z1 (t) and z2 (t) are expressed as follows.
For symbol number 4i (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

As described above, it is assumed that the weight combining unit in FIG. 6 regularly switches precoding weights in a 4-slot cycle. (However, here, the precoding weight is switched regularly at four slots, but the number of slots switched regularly is not limited to four.)
Non-Patent Document 4 describes switching precoding weights for each slot, and Non-Patent Document 4 is characterized by randomly switching precoding weights. On the other hand, the present embodiment is characterized in that a certain period is provided and precoding weights are switched regularly, and four rows of two-row precoding weight matrix composed of four precoding weights are selected. It is characterized in that each absolute value of one precoding weight is equal (1 / sqrt (2)), and the precoding weight matrix having this feature is switched regularly.

  In the LOS environment, using a special precoding matrix may greatly improve the reception quality, but the special precoding matrix is different depending on the direct wave situation. However, in the LOS environment, there is a rule, and if the special precoding matrix is regularly switched in accordance with this rule, the reception quality of data is greatly improved. On the other hand, when precoding matrices are switched at random, there is a possibility that there will be precoding matrices other than the above-mentioned special precoding matrices, and it is only with one-sided precoding matrix which is not suitable for the LOS environment. There is also the possibility of performing precoding, which does not necessarily lead to good reception quality in the LOS environment. Therefore, there is a need to realize a precoding switching method suitable for LOS environment, and the present invention proposes a precoding method related thereto.

  FIG. 7 shows an example of the configuration of receiving apparatus 700 in the present embodiment. Radio section 703 _X receives as input reception signal 702 _X received by antenna 701 _X, performs processing such as frequency conversion and quadrature demodulation, and outputs baseband signal 704 _X.

Channel fluctuation estimation section 705_1 in modulated signal z1 transmitted by the transmitter receives baseband signal 704_X as input, extracts reference symbol 501_1 for channel estimation in FIG. 5, and extracts a value corresponding to h11 of equation (36). Channel estimation signal 70
Output 6_1.

  Channel fluctuation estimation section 705_2 in modulated signal z2 transmitted by the transmission apparatus receives baseband signal 704_X as input, extracts reference symbol 501_2 for channel estimation in FIG. 5, and obtains a value corresponding to h12 of equation (36). It estimates and outputs channel estimation signal 706_2.

Radio section 703 _Y receives as input received signal 702 _Y received by antenna 701 _Y, performs processing such as frequency conversion and quadrature demodulation, and outputs baseband signal 704 _Y.
Channel fluctuation estimation section 707_1 in modulated signal z1 transmitted by the transmitter receives baseband signal 704_Y as input, extracts reference symbol 501_1 for channel estimation in FIG. 5, and extracts a value corresponding to h21 of equation (36). It estimates and outputs a channel estimation signal 708_1.

  Channel fluctuation estimation section 707_2 in modulated signal z2 transmitted by the transmitter receives baseband signal 704_Y as input, extracts reference symbol 501_2 for channel estimation in FIG. 5, and obtains a value corresponding to h22 in equation (36). It estimates and outputs channel estimation signal 708_2.

  Control information decoding section 709 receives baseband signals 704 X and 704 Y, detects symbol 500 _ 1 for notifying the transmission method of FIG. 5, and outputs signal 710 regarding the information of the transmission method notified by the transmission apparatus.

  The signal processing unit 711 receives the baseband signals 704 X, 704 Y, channel estimation signals 706_1, 706_2, 708_1, 708_2, and the signal 710 related to the transmission method information notified by the transmission apparatus, performs detection and decoding, and receives received data. Output 712_1 and 712_2.

Next, the operation of the signal processing unit 711 in FIG. 7 will be described in detail. FIG. 8 shows an example of the configuration of the signal processing unit 711 in the present embodiment. FIG. 8 mainly includes an INNER MIMO detection unit, a soft-in / soft-out decoder, and a weighting coefficient generation unit. The iterative decoding method in this configuration is described in detail in Non-Patent Document 2 and Non-Patent Document 3, but the MIMO transmission scheme described in Non-patent 2 and Non-Patent Document 3 is a space multiplex MIMO transmission scheme However, the transmission scheme in this embodiment is a MIMO transmission scheme in which the precoding weight is changed with time, which is a point different from Non-Patent Document 2 and Non-Patent Document 3. The channel matrix in equation (36) is H (t), the precoding weight matrix in FIG. 6 is W (t) (where the precoding weight matrix changes with t), and the received vector is R (t) = Assuming that (r1 (t), r2 (t)) ^T and stream vector S (t) = (s1 (t), s2 (t)) ^T , the following relational expression holds.

At this time, the receiving apparatus may apply the decoding methods of Non-Patent Document 2 and Non-Patent Document 3 to R (t) by considering H (t) W (t) as a channel matrix. it can.
Therefore, the weighting coefficient generation unit 819 in FIG. 8 receives the signal 818 (corresponding to 710 in FIG. 7) related to the transmission method information notified by the transmission apparatus, and outputs the signal 820 related to the weighting coefficient information.

  The INNNER MIMO detection unit 803 receives the signal 820 related to the information of the weighting factor, and uses this signal to perform the operation of equation (41). And although it will perform repetition detection and decoding, the operation is explained.

  In the signal processing unit of FIG. 8, in order to perform iterative decoding (iterative detection), it is necessary to perform the processing method as shown in FIG. First, one code word (or one frame) of the modulation signal (stream) s1 and one code word (or one frame) of the modulation signal (stream) s2 are decoded. As a result, from the soft-in / soft-out decoder, one codeword (or one frame) of the modulation signal (stream) s1 and one codeword (or one frame) of the modulation signal (stream) s2 are obtained. A Log-Likelihood Ratio (LLR) of bits is obtained. Then, detection and decoding are performed again using the LLR. This operation is performed multiple times (this operation is called iterative decoding (iterative detection)). The following description will focus on a method of generating log likelihood ratios (LLRs) of symbols of a specific time in one frame.

  In FIG. 8, a storage unit 815 includes a baseband signal 801X (corresponding to the baseband signal 704_X in FIG. 7), a channel estimation signal group 802X (corresponding to the channel estimation signals 706_1 and 706_2 in FIG. 7), and a baseband. In order to realize iterative decoding (iterative detection), the signal 801Y (corresponding to the baseband signal 704_Y in FIG. 7) and the channel estimation signal group 802Y (corresponding to the channel estimation signals 708_1 and 708_2 in FIG. 7) are input. Then, H (t) W (t) in Equation (41) is executed (calculated), and the calculated matrix is stored as a deformed channel signal group. Then, when necessary, the storage unit 815 outputs the above signals as a baseband signal 816X, a modified channel estimation signal group 817X, a baseband signal 816Y, and a modified channel estimation signal group 817Y.

The subsequent operation will be described separately for the case of initial detection and the case of iterative decoding (iterative detection).
<In case of initial detection>
The INNER MIMO detection unit 803 receives the baseband signal 801X, the channel estimation signal group 802X, the baseband signal 801Y, and the channel estimation signal group 802Y as input. Here, the modulation scheme of the modulation signal (stream) s1 and the modulation signal (stream) s2 will be described as 16 QAM.

The inner MIMO detection unit 803 first executes H (t) W (t) from the channel estimation signal group 802X and the channel estimation signal group 802Y to obtain candidate signal points corresponding to the baseband signal 801X. The situation at that time is shown in FIG. In FIG. 11, ● (black circle) is a candidate signal point on the IQ plane, and since the modulation scheme is 16 QAM, there are 256 candidate signal points. (However, because FIG. 11 shows an image diagram, 256 candidate signal points are not shown.) Here, four bits transmitted in the modulation signal s1 are b0, b1, b2, b3, and the modulation signal s2. Assuming that four bits to be transmitted are b4, b5, b6 and b7, candidate signal points corresponding to (b0, b1, b2, b3, b4, b5, b6 and b7) are present in FIG. Then, a squared Euclidean distance between the reception signal point 1101 (corresponding to the baseband signal 801X) and each of the candidate signal points is obtained. Then, each square Euclidean distance is divided by the noise variance σ ² . Therefore, (b0, b1, b2, b3
, B4, b5, b6, b7) and the Euclidean distance between the candidate signal point and the received signal point Euclidean distance divided by the variance of the noise E _X (b0, b1, b2, b3, b4, b5, b6, b7) ) Will be determined. The baseband signals and the modulation signals s1 and s2 are complex signals.

Similarly, H (t) W (t) is executed from channel estimation signal group 802X and channel estimation signal group 802Y to obtain candidate signal points corresponding to baseband signal 801Y, corresponding to reception signal point (baseband signal 801Y The squared Euclidean distance is calculated, and this squared Euclidean distance is divided by the noise variance σ ² . Therefore, E _Y (b0, b1, b2) is a value obtained by dividing the squared Euclidean distance between the candidate signal point and the received signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) by the noise variance. , B3, b4, b5, b6, b7).

_{Then, E X (b0, b1,} b2, b3, b4, b5, b6, b7) + E Y (b0, b1, b2, b3, b4, b5, b6, b7) = E (b0, b1, b2, b3 , B4, b5, b6, b7).

The INNER MIMO detection unit 803 outputs E (b0, b1, b2, b3, b4, b5, b6, b7) as a signal 804.
Log-likelihood calculating unit 805A receives signal 804, calculates the log likelihood of bits b0, b1, b2, and b3 and outputs a log-likelihood signal 806A. However, in the calculation of the log likelihood, the log likelihood for “1” and the log likelihood for “0” are calculated. The calculation method is as shown in the equation (28), the equation (29), and the equation (30), and the details are shown in Non-Patent Document 2 and Non-Patent Document 3.

Similarly, log likelihood calculation unit 805 B receives signal 804, calculates the log likelihood of bits b 4 and b 5 and b 6 and b 7, and outputs log likelihood signal 806 B.
Deinterleaver (807A) receives log likelihood signal 806A as input, performs deinterleaving corresponding to the interleaver (interleaver (304A) in FIG. 3), and outputs deinterleaved log likelihood signal 808A.

  Similarly, deinterleaver (807 B) receives log likelihood signal 806 B as input, performs deinterleaving corresponding to the interleaver (interleaver (304 B) in FIG. 3), and outputs deinterleaved log likelihood signal 808 B.

  Log likelihood ratio calculator 809 A receives log likelihood signal 808 A after deinterleaving and calculates log likelihood ratio (LLR: Log-Likelihood Ratio) of the bits encoded by encoder 302 A of FIG. 3. , And outputs a log likelihood ratio signal 810A.

  Similarly, log likelihood ratio calculation unit 809 B receives log likelihood signal 808 B after deinterleaving and receives log likelihood ratio (LLR: Log-Likelihood Ratio) of the bits encoded by encoder 302 B of FIG. 3. ) And outputs a log likelihood ratio signal 810B.

Soft-in / soft-out decoder 811A receives log likelihood ratio signal 810A as input, performs decoding, and outputs decoded log likelihood ratio 812A.
Similarly, Soft-in / soft-out decoder 811B receives log likelihood ratio signal 810B as input, performs decoding, and outputs decoded log likelihood ratio 812B.

<In the case of iterative decoding (iterative detection), the number of iterations k>
The interleaver (813A) receives as input the decoded log likelihood ratio 812A obtained by the k−1th soft-in / soft-out decoding, performs interleaving, and outputs the interleaved log likelihood ratio 814A. . At this time, the interleaving pattern of the interleaving (813A) is the same as the interleaving pattern of the interleaver (304A) of FIG.

  The interleaver (813B) receives as input the decoded log likelihood ratio 812B obtained by the k−1th soft-in / soft-out decoding, performs interleaving, and outputs the interleaved log likelihood ratio 814B. . At this time, the interleaving pattern of interleaving (813B) is the same as the interleaving pattern of interleaver (304B) in FIG.

  The INNER MIMO detection unit 803 receives the baseband signal 816X, the deformed channel estimation signal group 817X, the baseband signal 816Y, the deformed channel estimation signal group 817Y, the interleaving logarithmic likelihood ratio 814A, and the interleaving logarithmic likelihood ratio 814B. I assume. Here, instead of the baseband signal 801X, the channel estimation signal group 802X, the baseband signal 801Y, and the channel estimation signal group 802Y, the baseband signal 816X, the modified channel estimation signal group 817X, the baseband signal 816Y, the modified channel estimation signal group 817Y Is used because a delay time is generated because of iterative decoding.

  The difference between the operation during iterative decoding of INNER MIMO detection section 803 and the operation during initial detection is that the interleaved log likelihood ratio 814A and the interleaved log likelihood ratio 814B are used in signal processing. It is. The INNNER MIMO detection unit 803 first obtains E (b0, b1, b1, b2, b3, b4, b5, b6, b7) as in the case of the initial detection. In addition, the coefficients corresponding to the equations (11) and (32) are determined from the interleaving in log likelihood ratio 814A and the interleaving in log likelihood ratio 914B. Then, the value of E (b0, b1, b2, b3, b4, b5, b6, b7) is corrected using this calculated coefficient, and the value is corrected to E '(b0, b1, b2, b3, b4, b5). , B6, b7) and output as a signal 804.

  Log-likelihood calculating unit 805A receives signal 804, calculates the log likelihood of bits b0, b1, b2, and b3 and outputs a log-likelihood signal 806A. However, in the calculation of the log likelihood, the log likelihood for “1” and the log likelihood for “0” are calculated. The calculation method is as shown in Formula (31), Formula (32), Formula (33), Formula (34), and Formula (35), and is shown in Non-patent documents 2 and 3 There is.

  Similarly, log likelihood calculation unit 805 B receives signal 804, calculates the log likelihood of bits b 4 and b 5 and b 6 and b 7, and outputs log likelihood signal 806 B. The operation after the deinterleaver is similar to the initial detection.

Although FIG. 8 shows the configuration of the signal processing unit in the case of performing iterative detection, iterative detection is not necessarily an essential configuration for obtaining good reception quality, and components necessary only for iterative detection. The configuration may not have the interleavers 813A and 813B. At this time, the INNNER MIMO detection unit 803 does not perform repetitive detection.
The important part in the present embodiment is to calculate H (t) W (t). As shown in Non-Patent Document 5 etc., initial detection and iterative detection may be performed using QR decomposition.

In addition, as shown in Non-Patent Document 11, even if linear calculation of Minimum Mean Square Error (MMSE) and Zero Forcing (ZF) is performed based on H (t) W (t), initial detection is performed. Good.

  FIG. 9 is a configuration of a signal processing unit different from that of FIG. 8, and is a signal processing unit for a modulated signal transmitted by the transmission apparatus of FIG. A difference from FIG. 8 is the number of soft-in / soft-out decoders, and the soft-in / soft-out decoder 901 receives log likelihood ratio signals 810A and 810B as input, performs decoding, and then decodes. The log likelihood ratio 902 is output. The distributing unit 903 receives the decoded log likelihood ratio 902 as input, and performs distribution. The other parts are the same as in FIG.

  FIG. 12 shows BER characteristics when the transmission method is the transmission method using the precoding weights of the present embodiment under the same conditions as in FIG. (A) of FIG. 12 shows BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (APP: a posteriori probability) without iterative detection, and (B) of FIG. The BER characteristic of Max-log-APP (refer nonpatent literature 1 and nonpatent literature 2) (it was 5 times of repetition number) which detected is shown. When FIG. 12 and FIG. 29 are compared, it can be understood that, when the transmission method of the present embodiment is used, the BER characteristic when the Rice factor is large is significantly improved over the BER characteristic when spatial multiplexing MIMO transmission is used. The effectiveness of the method of the present embodiment can be confirmed.

  As described above, when transmitting apparatus of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas as in this embodiment, by switching precoding weights regularly with time, switching is performed regularly, In the LOS environment in which the direct wave is dominant, the effect of improving the transmission quality can be obtained as compared to when using the conventional space multiplex MIMO transmission.

  In the present embodiment, in particular, the configuration of the receiving apparatus has been described by limiting the number of antennas and the operation has been described. However, even if the number of antennas increases, the embodiment can be implemented similarly. That is, the number of antennas in the receiving apparatus does not affect the operation and effects of the present embodiment. Further, in the present embodiment, the LDPC code has been particularly described as an example, but the present invention is not limited to this, and as to the decoding method, as a soft-in / soft-out decoder, only sum-product decoding is exemplified. There are other soft-in / soft-out decoding methods, such as the BCJR algorithm, the SOVA algorithm, the Msx-log-MAP algorithm, etc. Details are shown in Non-Patent Document 6.

  Further, although the single carrier scheme has been described as an example in the present embodiment, the present invention is not limited to this, and the embodiment can be implemented similarly even when multicarrier transmission is performed. Thus, for example, spread spectrum communication system, orthogonal frequency-division multiplexing (OFDM) system, single carrier frequency division multiple access (SC-FDMA) system, single carrier orthogonal frequency-division multiplexing (SC-OFDM) system, etc. The same applies to the case of using the wavelet OFDM method or the like shown in FIG. Also, in the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, etc.), symbols for transmission of control information, etc. may be arranged in a frame.

Below, an example at the time of using an OFDM system is explained as an example of a multicarrier system.
FIG. 13 shows the configuration of a transmitter when using the OFDM scheme. The same reference numerals as in FIG. 3 denote the same parts in FIG.

  OFDM method related processing section 1301 A receives weighted signal 309 A, performs processing related to OFDM method, and outputs transmission signal 1302 A. Similarly, the OFDM scheme related processor 1301B receives the weighted signal 309B as an input, and outputs a transmission signal 1302B.

  FIG. 14 shows an example of the configuration of the OFDM system related processing units 1301A, 1301B and after in FIG. 13. The parts related to 1301A through 312A in FIG. 13 are 1401A through 1410A and the parts related with 1301B through 312B. Are 1401B to 1410B.

  The serial-to-parallel converter 1402A performs serial-to-parallel conversion on the weighted signal 1401A (corresponding to the weighted signal 309A in FIG. 13), and outputs a parallel signal 1403A.

Rearranger 1404A receives parallel signal 1403A as input, performs rearrangement, and outputs rearranged signal 1405A. The sorting will be described in detail later.
The inverse fast Fourier transform unit 1406A receives the rearranged signal 1405A, performs inverse fast Fourier transform, and outputs the inverse Fourier transformed signal 1407A.

Radio section 1408 A receives signal 1407 A after inverse Fourier transform, performs processing such as frequency conversion and amplification, and outputs modulated signal 1409 A, and modulated signal 1409 A is output as a radio wave from antenna 1410 A.
The serial-to-parallel converter 1402 B performs serial-to-parallel conversion on the weighted signal 1401 B (corresponding to the weighted signal 309 B in FIG. 13), and outputs a parallel signal 1403 B.

Rearranger 1404B receives parallel signal 1403B as input, performs rearrangement, and outputs rearranged signal 1405B. The sorting will be described in detail later.
Inverse fast Fourier transform unit 1406B receives rearranged signal 1405B as input, performs inverse fast Fourier transform, and outputs inverse Fourier transformed signal 1407B.

  Radio section 1408B receives signal 1407B after inverse Fourier transform, performs processing such as frequency conversion and amplification, and outputs modulated signal 1409B, and modulated signal 1409B is output as a radio wave from antenna 1410B.

  In the transmission apparatus of FIG. 3, since it is not a transmission method using multicarrier, as shown in FIG. 6, precoding is switched so as to be four cycles, and symbols after precoding are arranged in the time axis direction. In the case of using a multicarrier transmission scheme such as the OFDM scheme as shown in FIG. 13, as a matter of course, symbols after precoding are arranged in the time axis direction as shown in FIG. In the case of the multicarrier transmission method, a method of arranging using the frequency axis direction or both of the frequency axis and the time axis can be considered. Hereinafter, this point will be described.

FIG. 15 shows an example of a symbol rearrangement method in the rearrangement units 1401A and 1401B of FIG. 14 at the horizontal axis frequency and the vertical axis time, and the frequency axis is from (sub) carrier 0 to (sub) carrier 9 The modulation signals z1 and z2 use the same frequency band at the same time (time), and FIG. 15 (A) shows a method of rearranging symbols of the modulation signal z1, FIG. 15 (B). Shows a method of rearranging symbols of the modulation signal z2. The symbols of the weighted signal 1401A input to the serial-to-parallel converter 1402A are numbered as # 1, # 2, # 3, # 4,. At this time, as shown in FIG. 15A, symbols # 1, # 2, # 3, # 4, ... are arranged in order from carrier 0, and symbols # 1 to # 9 are arranged at time $ 1. , And then regularly arrange symbols # 10 to # 19 at time $ 2.

  Similarly, the symbols of the weighted signal 1401 B input to the serial-to-parallel converter 1402 B are numbered as # 1, # 2, # 3, # 4,. At this time, as shown in FIG. 15B, symbols # 1, # 2, # 3, # 4, ... are arranged in order from carrier 0, and symbols # 1 to # 9 are arranged at time $ 1. , And then regularly arrange symbols # 10 to # 19 at time $ 2. The modulation signals z1 and z2 are complex signals.

  Further, symbol group 1501 and symbol group 1502 shown in FIG. 15 are symbols for one cycle when the precoding weight switching method shown in FIG. 6 is used, and symbol # 0 is the precoding weight of slot 4i in FIG. Symbol # 1 is a symbol when the precoding weight of slot 4i + 1 of FIG. 6 is used, and symbol # 2 is a symbol when the precoding weight of slot 4i + 2 of FIG. 6 is used. Symbol # 3 is a symbol when the precoding weight of slot 4i + 3 of FIG. 6 is used. Therefore, in symbol #x, when x mod 4 is 0, symbol # x is a symbol when the precoding weight of slot 4i of FIG. 6 is used, and when x mod 4 is 1, symbol # x is a symbol. 6 is a symbol when the precoding weight of slot 4i + 1 is used, and when x mod 4 is 2, symbol #x is a symbol when the precoding weight of slot 4i + 2 of FIG. 6 is used, x mod 4 When is 3, symbol #x is a symbol when the precoding weight of slot 4i + 3 of FIG. 6 is used.

  As described above, in the case of using a multicarrier transmission method such as the OFDM method, unlike the single carrier transmission, the symbols can be arranged in the frequency axis direction. The arrangement of the symbols is not limited to the arrangement as shown in FIG. Another example will be described using FIG. 16 and FIG.

  FIG. 16 shows an example of a method of rearranging symbols in the rearranging sections 1401A and 1401B of FIG. 14 at a horizontal axis frequency and a vertical axis time different from that of FIG. 15. FIG. 16 (A) shows a modulation signal z1. FIG. 16B shows a method of rearranging symbols of modulated signal z2. 16A and 16B differ from those in FIG. 15 in that the symbol rearrangement method of the modulation signal z1 and the symbol rearrangement method of the modulation signal z2 are different, and in FIG. 0 to # 5 are allocated to carrier 4 to carrier 9, symbols # 6 to # 9 are allocated to carriers 0 to 3, and then symbols # 10 to # 19 are allocated to each carrier according to the same rule. At this time, as in FIG. 15, the symbol group 1601 and the symbol group 1602 shown in FIG. 16 are symbols for one cycle when the precoding weight switching method shown in FIG. 6 is used.

  FIG. 17 shows an example of a method of rearranging symbols in rearranging sections 1401A and 1401B of FIG. 14 at a horizontal axis frequency and a vertical axis time different from FIG. 15, and FIG. 17 (A) shows modulation signal z1. The symbol rearrangement method is shown in FIG. 17B, which shows the symbol rearrangement method of the modulated signal z2. 17 (A) and (B) differs from FIG. 15 in that symbols are sequentially arranged on the carrier in FIG. 15, while symbols are not sequentially arranged on the carrier in FIG. It is a point. Of course, in FIG. 17, as in FIG. 16, the symbol rearrangement method of the modulation signal z1 and the rearrangement method of the modulation signal z2 may be different.

  FIG. 18A shows an example of a symbol rearrangement method in the rearrangement units 1401A and 1401B of FIG. 14 with respect to horizontal axis frequency and vertical axis time different from FIGS. 18 and 15 to 17; FIG. FIG. 18B shows a method of rearranging symbols of z1, and FIG. 18B shows a method of rearranging symbols of modulated signal z2. Although symbols are arranged in the frequency axis direction in FIGS. 15 to 17, symbols are arranged using both the frequency and time axes in FIG. 18.

  Although the example in the case of switching the switching of the precoding weight by 4 slots has been described in FIG. 6, here, the case of switching by 8 slots will be described as an example. Symbol group 1801 and symbol group 1802 shown in FIG. 18 are symbols of one cycle (therefore, 8 symbols) when the precoding weight switching method is used, and symbol # 0 uses the precoding weight of slot 8i. The symbol # 1 is a symbol when the precoding weight of slot 8i + 1 is used, the symbol # 2 is a symbol when the precoding weight of slot 8i + 2 is used, and the symbol # 3 is a slot 8i + 3. The symbol # 4 is a symbol when the precoding weight of slot 8i + 4 is used, and the symbol # 5 is a symbol when the precoding weight of slot 8i + 5 is used. , Symbol # 6 is the symbol when using the precoding weight of slot 8i + 6 symbols # 7 is a symbol when using the precoding weight of slot 8i + 7. Therefore, in symbol #x, when x mod 8 is 0, symbol # x is a symbol when the precoding weight of slot 8 i is used, and when x mod 8 is 1, symbol # x is a pre for slot 8 i + 1. The symbol is a symbol when a coding weight is used, and when x mod 8 is 2, symbol # x is a symbol when a precoding weight of slot 8i + 2 is used, and when x mod 8 is 3, symbol # x is It is a symbol when the precoding weight of slot 8i + 3 is used, and when x mod 8 is 4, symbol #x is a symbol when the precoding weight of slot 8i + 4 is used, and when x mod 8 is 5, Symbol #x is precoding weight of slot 8i + 5 When x mod 8 is 6, symbol # x is the symbol when the precoding weight of slot 8 i + 6 is used. When x mod 8 is 7, symbol # x is the slot 8 i + 7 It is a symbol when a coding weight is used. In the arrangement of symbols in FIG. 18, one cycle of symbols is arranged using four slots in the time axis direction and two slots in the frequency axis direction, for a total of 4 × 2 = 8 slots. The number of symbols per minute is m × n symbols (that is, there are m × n types of precoding weights) n slots in the frequency axis direction (number of carriers) used to arrange symbols for one period, time Assuming that a slot used in the axial direction is m, it is preferable to set m> n. This is because the phase of the direct wave, the fluctuation in the time axis direction is slow compared to the fluctuation in the frequency axis direction. Therefore, since the precoding weight change of this embodiment is performed in order to reduce the influence of the steady direct wave, it is desirable to reduce the fluctuation of the direct wave in the period in which the precoding weight is changed. Therefore, it is preferable to set m> n. Also, considering the above points, it is better to rearrange symbols using both the frequency axis and the time axis as shown in FIG. 18 rather than rearranging the symbols only in the frequency axis direction or only the time axis direction. Is likely to be steady, and the effect of the present invention can be obtained. However, if arranged in the direction of the frequency axis, there is a possibility that diversity gain can be obtained because the fluctuation of the frequency axis is steep, so the method of performing rearrangement using both the frequency axis and the time axis is necessarily optimal. It is not always the case.

FIG. 19 shows an example of a method of rearranging symbols in the rearranging sections 1401A and 1401B of FIG. 14 at a horizontal axis frequency and a vertical axis time different from that of FIG. 18; FIG. 19A shows a modulation signal z1. FIG. 19 (B) shows a method of rearranging symbols of modulated signal z2. In FIG. 19, as in FIG. 18, symbols are arranged using both the frequency and the time axis. However, in FIG. 18, different from FIG. 18, the frequency direction is prioritized in FIG. While symbols are arranged, in FIG. 19, priority is given to the time axis direction, and thereafter, symbols are arranged in the time axis direction. In FIG. 19, a symbol group 1901 and a symbol group 1902 are symbols for one cycle when the precoding switching method is used.

  In FIG. 18 and FIG. 19, similarly to FIG. 16, the same arrangement can be performed even if the arrangement method of symbols of modulation signal z1 is different from the arrangement method of symbols of modulation signal z2 and the method is high. The effect that the reception quality can be obtained can be obtained. In addition, in FIG. 18 and FIG. 19, even if symbols are not arranged one after another as in FIG. 17, the same effect can be obtained, and an effect that high reception quality can be obtained can be obtained. it can.

  FIG. 27 shows an example of a method of rearranging symbols in the rearranging sections 1401A and 140B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which is different from the above. Consider the case where the precoding matrix is switched regularly using four slots as in equations (37) to (40). The characteristic point in FIG. 27 is that the symbols are arranged in order in the frequency axis direction, but when advancing in the time axis direction, the point is cyclically shifted by n (n = 1 in the example of FIG. 27) symbol cyclically It is. It is assumed that switching of the precoding matrices of Equations (37) to (40) is performed for four symbols indicated in symbol group 2710 in the frequency axis direction in FIG.

  At this time, precoding using the precoding matrix of equation (37) for the symbol # 0, precoding using the precoding matrix of equation (38) for # 1, and precoding matrix of equation (39) for # 2 It is assumed that precoding using equation (40) is performed using precoding using equation (40) in # 3.

  Similarly for the symbol group 2720 in the frequency axis direction, precoding using the precoding matrix of equation (37) for symbol # 4, precoding using the precoding matrix for equation (38) for # 5, # 6 It is assumed that precoding using the precoding matrix of Equation (39) is performed, and precoding using the precoding matrix of Equation (40) is performed at # 7.

  Although switching of the precoding matrix as described above is performed for symbols of time $ 1, since cyclic shifts are performed in the time axis direction, symbol groups 2701, 2702, 2703, and 2704 are pre-processed as follows. It will switch the coding matrix.

  In symbol group 2701 in the time axis direction, symbol # 0 precoding using the precoding matrix of equation (37), symbol # 9 precoding using the precoding matrix of equation (38), and equation # 18 (# 18) It is assumed that precoding using the precoding matrix of 39) and precoding using the precoding matrix of equation (40) are performed in # 27.

  In symbol group 2702 in the time axis direction, precoding using the precoding matrix of equation (37) for symbol # 28, precoding using the precoding matrix for equation (38) at # 1, and equation (10) It is assumed that precoding using the precoding matrix of 39) and precoding using the precoding matrix of equation (40) are performed in # 19.

  In symbol group 2703 in the time axis direction, precoding using the precoding matrix of equation (37) for symbol # 20, precoding using the precoding matrix for equation (38) at # 29, and equation (1) for symbol # 1 It is assumed that precoding using the precoding matrix of 39) and precoding using the precoding matrix of equation (40) are performed in # 10.

  In symbol group 2704 in the time axis direction, precoding using the precoding matrix of equation (37) for symbol # 12, precoding using the precoding matrix for equation (38) at # 21, and equation (30) It is assumed that precoding using the precoding matrix in 39) and precoding using the precoding matrix in equation (40) in # 3 are performed.

  As for the feature in FIG. 27, for example, in the case of focusing on the symbol # 11, both neighboring symbols (# 10 and # 12) on both sides in the frequency axis direction at the same time use precoding matrix different from # 11 By performing precoding on both symbols (# 2 and # 20) on both sides in the time axis direction of the same carrier of the # 11 symbol by using a precoding matrix different from # 11. is there. And this is not limited to the symbol of # 11, and all symbols in which symbols exist on both sides in the frequency axis direction and the time axis direction have the same characteristics as the symbol of # 11. As a result, the precoding matrix is effectively switched, and it becomes less likely to be affected by the steady state of the direct wave, and there is a high possibility that data reception quality will be improved.

  Although FIG. 27 is described as n = 1, the present invention is not limited to this, and the embodiment can be implemented similarly as n = 3. Further, in FIG. 27, when the symbols are arranged on the frequency axis and the time passes in the axial direction, the above feature is realized by providing the feature of cyclic shift of the arrangement order of symbols, but the symbols are random There are also methods that realize the above features by arranging them (which may be regular).

Second Embodiment
In the first embodiment, the case where precoding weights are regularly switched as shown in FIG. 6 has been described, but in the present embodiment, a specific precoding weight design method different from the precoding weights shown in FIG. Will be explained.

In FIG. 6, the method of switching the precoding weight of Formula (37)-Formula (40) was demonstrated. If this is generalized, the precoding weights can be changed as follows. (However, the switching cycle of the precoding weight is 4 and the same description as in the equations (37) to (40) is made.)
For symbol number 4i (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

Then, from Expression (36) and Expression (41), the reception vector R (t) = (r1 (t), r2 (t)) ^T can be expressed as follows.
At symbol number 4i:

At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

At this time, in channel elements h ₁₁ (t), h ₁₂ (t), h ₂₁ (t), h ₂₂ (t), it is assumed that only a direct wave component exists, and the amplitude component of the direct wave component is It is assumed that all are equal and that no variation occurs in time. Then, the equations (46) to (49) can be expressed as follows.
At symbol number 4i:

At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

However, in Equations (50) to (53), A is a positive real number, and q is a complex number. The values of A and q are determined according to the positional relationship between the transmitting device and the receiving device. And Formula (50)-Formula (53) shall be represented as follows.
At symbol number 4i:

At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

Then, when q is expressed as follows, a signal component based on either one of s1 and s2 is not included in r1 and r2, so it is not possible to obtain a signal of either s1 or s2.
At symbol number 4i:

At symbol number 4i + 1:

For symbol number 4i + 2:

At symbol number 4i + 3:

  At this time, if q has the same solution in symbol numbers 4i, 4i + 1, 4i + 2, 4i + 3, the channel element of the direct wave does not have a large fluctuation, so that reception is performed with the channel element whose value of q is equal to the above same solution. Since the device can not obtain good reception quality at any symbol number, it is difficult to obtain error correction capability even if an error correction code is introduced. Therefore, if q does not have the same solution, focusing on the solution not including δ among the two solutions of q, the following conditions are necessary from equations (58) to (61) It becomes.

(X is 0, 1, 2, 3, y is 0, 1, 2, 3, and x ≠ y.)

As an example satisfying Condition # 1,
(Example # 1)
<1> θ11 (4i) = θ11 (4i + 1) = θ11 (4i + 2) = θ11 (4i + 3) = 0 radian,
<2> θ21 (4i) = 0 radian <3> θ21 (4i + 1) = π / 2 radian <4> θ21 (4i + 2) = π radian <5> Consider a method to set as θ21 (4i + 3) = 3π / 2 radian Be (The above is an example, and a set of (θ21 (4i), θ21 (4i + 1), θ21 (4i + 2), θ21 (4i + 3) is 0 radian, π / 2 radian, π radian, 3π / 2 radian At this time, particularly under the condition <1>, there is no need to apply signal processing (rotation processing) to the baseband signal S1 (t), so the circuit size can be reduced. It has the advantage of being able to Another example is
(Example # 2)
<6> θ11 (4i) = 0 radian <7> θ11 (4i + 1) = π / 2 radian <8> θ11 (4i + 2) = π radian <9> θ11 (4i + 3) = 3π / 2 radians
<10> θ21 (4i) = θ21 (4i + 1) = θ21 (4i + 2) = θ21 (4i + 3) = 0 radian. (The above is an example, and a set of (θ11 (4i), θ11 (4i + 1), θ11 (4i + 2), θ11 (4i + 3)) is 0 radian, π / 2 radian, π radian, 3π / 2 radian At this time, particularly under the condition of <6>, there is no need to apply signal processing (rotation processing) to the baseband signal S2 (t), so the circuit scale can be reduced. It has the advantage of being able to As another example, the following is given.
(Example # 3)
<11> θ11 (4i) = θ11 (4i + 1) = θ11 (4i + 2) = θ11 (4i + 3) = 0 radians,
<12> θ21 (4i) = 0 radian <13> θ21 (4i + 1) = π / 4 radian <14> θ21 (4i + 2) = π / 2 radian <15> θ21 (4i + 3) = 3π / 4 radian (The above is an example (0 21 (4 i), θ 21 (4 i + 1), θ 21 (4 i + 2), θ 21 (4 i + 3)), 0 radian, π / 4 radian, π / 2 radian, 3π / 4 radian one by one It should just exist.)
(Example # 4)
<16> θ11 (4i) = 0 radian <17> θ11 (4i + 1) = π / 4 radian <18> θ11 (4i + 2) = π / 2 radian <19> θ11 (4i + 3) = 3π / 4 radian
<20> θ21 (4i) = θ21 (4i + 1) = θ21 (4i + 2) = θ21 (4i + 3) = 0 radian (The above is an example and (θ11 (4i), θ11 (4i + 1), θ11 (4i + 2), θ11 (4i)) In the set of 4i + 3), 0 radian, π / 4 radian, π / 2 radian, and 3π / 4 radian should be present one by one.
Although four examples are given, the method for satisfying the condition # 1 is not limited to this.

  Next, design requirements for not only θ11 and θ12 but also λ and δ will be described. For λ, it may be set to a certain value, and the requirement is to give the requirement for δ. Therefore, a method of setting δ when λ is 0 radian will be described.

In this case, if .pi. / 2 radians.ltoreq..vertline..delta..ltoreq..pi. Radians, then good reception quality can be obtained, particularly in the LOS environment.
By the way, in the symbol numbers 4i, 4i + 1, 4i + 2, 4i + 3, there are two points q which are bad reception quality. Therefore, there will be 2 × 4 = 8 points. In the LOS environment, all eight points should be different solutions in order to prevent degradation of reception quality at a particular receiving terminal. In this case, in addition to <condition # 1>, the condition of <condition # 2> is required.

  In addition, it is preferable that the phases of these eight points be uniformly present. (Because it is considered that the phase of the direct wave is likely to have a uniform distribution) In the following, a method of setting δ that satisfies this requirement will be described.

In the case of (Example # 1) and (Example # 2), by setting δ to ± 3π / 4 radians, the points having poor reception quality have phases uniformly. For example, assuming (example # 1) and δ is 3π / 4 radian, there is a point that the reception quality is deteriorated once every four slots as shown in FIG. 20 (A is a positive real number). In the case of (Example # 3) and (Example # 4), by setting δ to ± π radian, the phase is uniformly present at a point where the reception quality is bad. For example, assuming that (example # 3) and δ is π radian, there is a point that the reception quality is deteriorated once every four slots as shown in FIG. (If the element q in the channel matrix H exists at the points shown in FIGS. 20 and 21, the reception quality will be degraded.)
By doing as described above, good reception quality can be obtained in the LOS environment. Although the example in which the precoding weights are changed in four slot cycles has been described above, the case in which the precoding weights are changed in N slot cycles will be described below. Considering the same as in the first embodiment and the above description, the processing shown below will be performed on the symbol numbers.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

Therefore, r1 and r2 are expressed as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
In the case of symbol number Ni + N-1:

At this time, in channel elements h ₁₁ (t), h ₁₂ (t), h ₂₁ (t), h ₂₂ (t), it is assumed that only a direct wave component exists, and the amplitude component of the direct wave component is It is assumed that all are equal and that no variation occurs in time. Then, the equations (66) to (69) can be expressed as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

However, in Equations (70) to (73), A is a real number, and q is a complex number. The values of A and q are determined according to the positional relationship between the transmitting device and the receiving device. And Formula (70)-Formula (73) shall be represented as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
In the case of symbol number Ni + N-1:

Then, when q is expressed as follows, a signal component based on either one of s1 and s2 is not included in r1 and r2, so it is not possible to obtain a signal of either s1 or s2.
In case of symbol number Ni (i is an integer of 0 or more):

For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

  At this time, if q has the same solution in the symbol numbers N to Ni + N-1, the channel element of the direct wave does not have a large fluctuation, so that the receiver having the same value of q as the above same solution does not have any symbol Even in the case of numbers, good reception quality can not be obtained, so even if an error correction code is introduced, it is difficult to obtain error correction capability. Therefore, if q does not have the same solution, focusing on the solution not including δ among the two solutions of q, the following conditions are required from equations (78) to (81) It becomes.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Next, design requirements for not only θ11 and θ12 but also λ and δ will be described. For λ, it may be set to a certain value, and the requirement is to give the requirement for δ. Therefore, a method of setting δ when λ is 0 radian will be described.

  In this case, as in the method of changing the precoding weight in a 4-slot cycle, if .pi. / 2 radians.ltoreq..vertline..delta..ltoreq..pi. Radians with respect to .delta., Good reception quality can be obtained particularly in the LOS environment. You can get it.

  In the symbol numbers Ni to Ni + N-1, there are two points q each of which causes poor reception quality, and hence there are points of 2N points. In the LOS environment, in order to obtain good characteristics, all these 2N points should be different solutions. In this case, in addition to <condition # 3>, the condition of <condition # 4> is required.

In addition, the phases of these 2N points should be uniform. (Because the phase of the direct wave in each receiver is considered to be likely to have a uniform distribution)
As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the LOS environment in which direct waves are dominant by switching precoding weights regularly and performing switching regularly. In the above, it is possible to obtain the effect that the transmission quality is improved as compared with the case of using the conventional space multiplex MIMO transmission.

  In the present embodiment, the configuration of the receiving apparatus is as described in the first embodiment. In particular, with regard to the configuration of the receiving apparatus, the operation has been described by limiting the number of antennas, but the number of antennas increases. Can be implemented similarly. That is, the number of antennas in the receiving apparatus does not affect the operation and effects of the present embodiment. Further, in the present embodiment, as in the first embodiment, the error correction code is not limited.

  Further, in the present embodiment, the precoding weight changing method on the time axis has been described in contrast to the first embodiment, but as described in the first embodiment, using the multicarrier transmission method, the frequency axis, frequency By arranging symbols on the time axis, the precoding weight changing method can be implemented similarly. In the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, etc.), symbols for control information, etc. may be arranged in a frame.

Third Embodiment
In the first embodiment and the second embodiment, the case where the amplitudes of the elements of the matrix of precoding weights are equal in the method of regularly switching the precoding weights has been described. However, in this embodiment, this condition is satisfied. An example will be described.
In order to compare with Embodiment 2, the case where precoding weights are changed in N slot periods will be described. In the same manner as in the first and second embodiments, the symbol number will be subjected to the processing represented below. Where β is a positive real number and β ≠ 1.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

Therefore, r1 and r2 are expressed as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

At this time, in channel elements h ₁₁ (t), h ₁₂ (t), h ₂₁ (t), h ₂₂ (t), it is assumed that only a direct wave component exists, and the amplitude component of the direct wave component is It is assumed that all are equal and that no variation occurs in time. Then, formulas (86) to (89) can be expressed as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

However, in Equations (90) to (93), A is a real number and q is a complex number. And Formula (90)-Formula (93) shall be represented as follows.
In case of symbol number Ni (i is an integer of 0 or more):

However, j is an imaginary unit.
For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
· ·
For symbol number Ni + N-1:

Then, when q is expressed as follows, it becomes impossible to obtain any signal of s1 and s2.
In case of symbol number Ni (i is an integer of 0 or more):

For symbol number Ni + 1:

・
・
・
When the symbol number Ni + k (k = 0, 1, ..., N-1):

・
・
・
For symbol number Ni + N-1:

  At this time, if q has the same solution in the symbol numbers N to Ni + N-1, the channel component of the direct wave does not have a large fluctuation, so that no good reception quality can be obtained in any symbol number. Therefore, even if the error correction code is introduced, it is difficult to obtain the error correction capability. Therefore, if q does not have the same solution, focusing on the solution not including δ among the two solutions of q, the following conditions are required from equations (98) to (101) It becomes.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Next, design requirements for not only θ11 and θ12 but also λ and δ will be described. For λ, it may be set to a certain value, and the requirement is to give the requirement for δ. Therefore, a method of setting δ when λ is 0 radian will be described.

  In this case, as in the method of changing the precoding weight in a 4-slot cycle, if .pi. / 2 radians.ltoreq..vertline..delta..ltoreq..pi. Radians with respect to .delta., Good reception quality can be obtained particularly in the LOS environment. You can get it.

  In the symbol numbers Ni to Ni + N-1, there are two points q each of which causes poor reception quality, and hence there are points of 2N points. In the LOS environment, in order to obtain good characteristics, all these 2N points should be different solutions. In this case, in addition to <condition # 5>, β is a positive real number, and considering that β 考慮 す る 1, the condition of <condition # 6> is required.

  As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the LOS environment in which direct waves are dominant by switching precoding weights regularly and performing switching regularly. In the above, it is possible to obtain the effect that the transmission quality is improved as compared with the case of using the conventional space multiplex MIMO transmission.

  In the present embodiment, the configuration of the receiving apparatus is as described in the first embodiment. In particular, with regard to the configuration of the receiving apparatus, the operation has been described by limiting the number of antennas, but the number of antennas increases. Can be implemented similarly. That is, the number of antennas in the receiving apparatus does not affect the operation and effects of the present embodiment. Further, in the present embodiment, as in the first embodiment, the error correction code is not limited.

  Further, in the present embodiment, the precoding weight changing method on the time axis has been described in contrast to the first embodiment, but as described in the first embodiment, using the multicarrier transmission method, the frequency axis, frequency By arranging symbols on the time axis, the precoding weight changing method can be implemented similarly. In the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, etc.), symbols for control information, etc. may be arranged in a frame.

Embodiment 4
In the third embodiment, in the method of regularly switching precoding weights, the case of two types of amplitudes of 1 and β of each element of the matrix of precoding weights has been described as an example.

  Here,

Is ignored.

Subsequently, an example of switching the value of β by the slot will be described.
In order to compare with the third embodiment, the case of changing the precoding weight in 2 × N slot cycle will be described.

In the same manner as in the first embodiment, the second embodiment, and the third embodiment, the following processing is performed on the symbol numbers. Where β is a positive real number and β ≠ 1. Further, α is a positive real number, and α ≠ β.
At symbol number 2Ni (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
For symbol number 2Ni + 1:

・
・
・
When the symbol number 2Ni + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + N-1:

In case of symbol number 2Ni + N (i is an integer of 0 or more):

However, j is an imaginary unit.
In the case of symbol number 2Ni + N + 1:

・
・
・
In the case of symbol number 2Ni + N + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + 2N-1:

Therefore, r1 and r2 are expressed as follows.
At symbol number 2Ni (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
For symbol number 2Ni + 1:

・
・
・
When the symbol number 2Ni + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + N-1:

In case of symbol number 2Ni + N (i is an integer of 0 or more):

However, j is an imaginary unit.
In the case of symbol number 2Ni + N + 1:

・
・
・
In the case of symbol number 2Ni + N + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + 2N-1:

At this time, in channel elements h ₁₁ (t), h ₁₂ (t), h ₂₁ (t), h ₂₂ (t), it is assumed that only a direct wave component exists, and the amplitude component of the direct wave component is It is assumed that all are equal and that no variation occurs in time. Then, Equations (110) to (117) can be expressed as follows.
At symbol number 2Ni (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
For symbol number 2Ni + 1:

・
・
・
When the symbol number 2Ni + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + N-1:

In case of symbol number 2Ni + N (i is an integer of 0 or more):

However, j is an imaginary unit.
In the case of symbol number 2Ni + N + 1:

・
・
・
In the case of symbol number 2Ni + N + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + 2N-1:

However, in Equations (118) to (125), A is a real number, and q is a complex number. And Formula (118)-Formula (125) shall be expressed as follows.
At symbol number 2Ni (i is an integer greater than or equal to 0):

However, j is an imaginary unit.
For symbol number 2Ni + 1:

・
・
・
When the symbol number 2Ni + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + N-1:

In case of symbol number 2Ni + N (i is an integer of 0 or more):

However, j is an imaginary unit.
In the case of symbol number 2Ni + N + 1:

・
・
・
In the case of symbol number 2Ni + N + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + 2N-1:

Then, when q is expressed as follows, it becomes impossible to obtain any signal of s1 and s2.
At symbol number 2Ni (i is an integer greater than or equal to 0):

For symbol number 2Ni + 1:

・
・
・
When the symbol number 2Ni + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + N-1:

In case of symbol number 2Ni + N (i is an integer of 0 or more):

In the case of symbol number 2Ni + N + 1:

・
・
・
In the case of symbol number 2Ni + N + k (k = 0, 1, ..., N-1):

・
・
・
In the case of symbol number 2Ni + 2N-1:

  At this time, if q has the same solution in symbol numbers 2N to 2Ni + N-1, the channel component of the direct wave does not have a large fluctuation, so that no good reception quality can be obtained for any symbol number. Therefore, even if the error correction code is introduced, it is difficult to obtain the error correction capability. Therefore, if q does not have the same solution, focusing on one of the two solutions of q not including δ, from equations (134) to (141) and α お よ び β <Condition # 7> or <Condition # 8> is required.

  At this time, <condition # 8> is the same condition as that described in the first to third embodiments, but since <condition # 7> is α ≠ β, 2 of q Of the two solutions, the solution that does not contain δ will have a different solution.

  Next, design requirements for not only θ11 and θ12 but also λ and δ will be described. For λ, it may be set to a certain value, and the requirement is to give the requirement for δ. Therefore, a method of setting δ when λ is 0 radian will be described.

  In this case, as in the method of changing the precoding weight in a 4-slot cycle, if .pi. / 2 radians.ltoreq..vertline..delta..ltoreq..pi. Radians with respect to .delta. You can get it.

  In the symbol numbers 2Ni to 2Ni + 2N-1, there are 2 points q which are bad reception quality, and therefore 4N points will be present. In the LOS environment, in order to obtain good characteristics, all these 4N points should be different solutions. At this time, focusing on the amplitude, since α 条件 β for <condition # 7> or <condition # 8>, the following conditions are required.

  As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the LOS environment in which direct waves are dominant by switching precoding weights regularly and performing switching regularly. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional space multiplex MIMO transmission.

  In the present embodiment, the configuration of the receiving apparatus is as described in the first embodiment. In particular, with regard to the configuration of the receiving apparatus, the operation has been described by limiting the number of antennas, but the number of antennas increases. Can be implemented similarly. That is, the number of antennas in the receiving apparatus does not affect the operation and effects of the present embodiment. Further, in the present embodiment, as in the first embodiment, the error correction code is not limited.

  Further, in the present embodiment, the precoding weight changing method on the time axis has been described in contrast to the first embodiment, but as described in the first embodiment, using the multicarrier transmission method, the frequency axis, frequency By arranging symbols on the time axis, the same can be implemented even if precoding weights are changed. In the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, etc.), symbols for control information, etc. may be arranged in a frame.

Fifth Embodiment
In the first to fourth embodiments, the method for regularly switching the precoding weights has been described, but in the present embodiment, a modification thereof will be described.

  In Embodiments 1 to 4, the method of regularly switching precoding weights as shown in FIG. 6 has been described. In this embodiment, a method of switching precoding weights regularly different from that in FIG. 6 will be described.

Similar to FIG. 6, FIG. 22 shows a diagram relating to a switching method different from that of FIG. 6 in the method of switching four different precoding weights (matrices). In FIG. 22, four different precoding weights (matrices) are represented as W ₁ , W ₂ , W ₃ and W ₄ . (For example, W ₁ is the precoding weight (matrix) in equation (37), W ₂ is the precoding weight (matrix) in equation (38), W ₃ is the precoding weight (matrix) in equation (39), W ₄ (40) as the precoding weights (matrices) in the equation (40)) and those that operate in the same manner as in FIG. 3 and FIG. In FIG. 22, the unique part is
The first period 2201, the second period 2202, the third period 2203,... Are all configured by four slots.
・ In 4 slots, different precoding weight matrix for each slot, that is, W ₁ ,
W ₂ , W ₃ and W ₄ are used once each. In the first period 2201, the second period 2202, the third period 2203, and so on, the order of W ₁ , W ₂ , W ₃ and W ₄ does not necessarily have to be the same.

  It is. In order to realize this, the precoding weight matrix generation unit 2200 receives a signal related to the weighting method as an input, and outputs information 2210 related to the precoding weight according to the order in each period. Then, the weighting and combining unit 600 receives this signal and s1 (t) and s2 (t), performs weighting and combining, and outputs z1 (t) and z2 (t).

  FIG. 23 shows a weighting and combining method as compared with the above-described precoding method. In FIG. 23, a different point in FIG. 22 is that rearranging units are arranged after the weighting combining unit and the signal rearrangement is performed to realize the same method as in FIG.

In FIG. 23, the precoding weight generation unit 2200 receives information 315 on the weighting method as input, and the precoding weights W ₁ , W ₂ , W ₃ , W _4, W ₁ , W ₂ , W ₃ , W ₄ ,. Output precoding weight information 2210 in the order of Therefore, the weight combining unit 600 uses precoding weights in the order of precoding weights W ₁ , W ₂ , W ₃ , W _4, W ₁ , W ₂ , W ₃ , W ₄ ,. It outputs signals 2300A and 2300B.

  Rearranger 2300 receives signals 2300A and 2300B after precoding as input, and the signals after precoding so as to be in the order of first period 2201, second period 2202 and third period 2203 in FIG. Reorders 2300A and 2300B, and outputs z1 (t) and z2 (t).

  In addition, although the switching cycle of the precoding weight has been described as 4 in order to compare with FIG. 6 in the above description, it may be implemented similarly even when other than cycle 4 as in the first to fourth embodiments. It is possible.

  Further, in the first to fourth embodiments and the above-described precoding method, the values of δ and β are described as being identical for each slot within the period, but the values of δ and β are for each slot May be switched.

  As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the LOS environment in which direct waves are dominant by switching precoding weights regularly and performing switching regularly. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional space multiplex MIMO transmission.

  In the present embodiment, the configuration of the receiving apparatus is as described in the first embodiment. In particular, with regard to the configuration of the receiving apparatus, the operation has been described by limiting the number of antennas, but the number of antennas increases. Can be implemented similarly. That is, the number of antennas in the receiving apparatus does not affect the operation and effects of the present embodiment. Further, in the present embodiment, as in the first embodiment, the error correction code is not limited.

Further, in the present embodiment, the precoding weight changing method on the time axis has been described in contrast to the first embodiment, but as described in the first embodiment, using the multicarrier transmission method, the frequency axis, frequency By arranging symbols on the time axis, the precoding weight changing method can be implemented similarly. In the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, etc.), symbols for control information, etc. may be arranged in a frame.

Sixth Embodiment
In the first to fourth embodiments, the method of regularly switching the precoding weights has been described, but in the present embodiment, the precoding weights are regularly reiterated, including the contents described in the first to fourth embodiments. The method of switching will be described.

Here, first, a method of designing a precoding matrix of a spatial multiplexing type 2x2 MIMO system to which precoding without feedback from a communication counterpart is applied in consideration of the LOS environment will be described.

FIG. 30 shows a spatially multiplexed 2 × 2 MIMO system model to which precoding has been applied without feedback from a communication counterpart. The information vector z is encoded and interleaved. Then, a vector u (p) = (u ₁ (p), u ₂ (p)) of encoded bits is obtained as an output of interleaving (p is a slot time). Here, u _i (p) = (u _i1 (p)..., U _ih (p)) (h: the number of transmission bits per symbol). Assuming that the signal after modulation (mapping) is s (p) = (s ₁ (p), s ₂ (p)) ^T , and the precoding matrix is F (p), the signal x (p) after precoding = (x ₁ (p), x ₂ (p)) ^T is represented by the following equation.

Therefore, assuming that the reception vector is y (p) = (y ₁ (p), y ₂ (p)) ^T , it is expressed by the following equation.

At this time, H (p) is a channel matrix, n (p) = (n ₁ (p), n ₂ (p)) ^T is a noise vector, n _i (p) has an average value of 0 and variance σ ² iid complex Gaussian noise. And when Rice factor is set to K, the above-mentioned formula can be expressed as follows.

At this time, H _d (p) is a channel matrix of the direct wave component, and H _s (p) is a channel matrix of the scattered wave component. Therefore, the channel matrix H (p) is expressed as follows.

In equation (145), it is assumed that the environment of the direct wave is uniquely determined by the positional relationship between the communication devices, and the channel matrix H _d (p) of the direct wave component is assumed to have no temporal change. In addition, the channel matrix H _d (p) of the direct wave component is likely to be an environment where the distance between the transmitter and the receiver is sufficiently long as compared with the transmission antenna distance. I assume. Therefore, the channel matrix H _d (p) is expressed as follows.

Here, A is a positive real number, and q is a complex number. In the following, a method of designing a precoding matrix of a spatial multiplexing type 2x2 MIMO system to which precoding without feedback from a communication partner is applied in consideration of the LOS environment will be described.

From equations (144) and (145), it is difficult to analyze in the state including the scattered wave, and it becomes difficult to obtain a suitable precoding matrix without feedback in the state including the scattered wave. In addition, in the NLOS environment, there is less degradation in data reception quality compared to the LOS environment. Therefore, a suitable feedback-free precoding matrix design method in a LOS environment (precoding matrix of precoding method of switching precoding matrix with time) will be described.

  As described above, from equations (144) and (145), it is difficult to analyze in the state including scattered waves, so in the channel matrix including the components of only direct waves, an appropriate precoding matrix should be determined Make it Therefore, in equation (144), consider the case where the channel matrix includes components of only direct waves. Therefore, from equation (146), it can be expressed as follows.

  Here, a unitary matrix is used as a precoding matrix. Therefore, the precoding matrix is expressed as follows.

  At this time, λ is a fixed value. Therefore, equation (147) can be expressed as follows.

As understood from the equation (149), when the receiver performs a linear operation of ZF (zero forcing) or MMSE (minimum mean squared error), the transmitted bit is determined by s ₁ (p), s ₂ (p) You can not do it. From this, repeated APP (or repeated Max-log APP) or APP (or Max-log APP) as described in Embodiment 1 is performed (hereinafter referred to as ML (Maximum Likelihood) operation), s The log likelihood ratio of each bit transmitted in ₁ (p), s ₂ (p) is determined, and decoding in the error correction code is performed. Therefore, a suitable feedback-less precoding matrix design method in LOS environment for a receiver performing ML operation is described.

Consider precoding in equation (149). The right side of the first line and the left side are multiplied by e ^{−j 同 様} , and similarly, the right side of the second line and the left side are multiplied by e ^{−j 同 様} . Then, it is expressed as the following equation.

^Redefine e- ^jΨ y ₁ (p), e- ^jΨ y ₂ (p), and e- ^jΨ q as y ₁ (p), y ₂ (p), q, respectively, and e- ^jΨ n (p e = ^{j Ψ} n ₁ (p), e- ^{j Ψ} n ₂ (p) ^T , and e- ^{j Ψ} n ₁ (p), e- ^{j Ψ} n ₂ (p) have an average value of 0 and variance σ ² Since iid (independently uniquely distributed) complex Gaussian noise, e ^−j- n (p) is ^{redefined as} n (p). Then, the generality is not lost even if the equation (150) is changed to the equation (151).

  Next, equation (152) is transformed to facilitate understanding of equation (151).

At this time, assuming that the minimum value of the Euclidean distance between the reception signal point and the reception candidate signal point is d _min ² , d _min ² is a bad point taking a minimum value of zero and is transmitted by s ₁ (p) There are two q that are in a bad state in which all bits or all bits transmitted in s ₂ (p) are lost.
There is no s ₁ (p) in equation (152):

There is no s ₂ (p) in equation (152):

(Hereinafter, q that satisfies the equations (153) and (154) respectively is “a poor reception point of s ₁ , s ₂ ”)
Call it)
When equation (153) is satisfied, since all bits transmitted by s ₁ (p) are lost, the reception log likelihood ratio of all bits transmitted by s ₁ (p) can not be determined, and equation (154) When all the bits transmitted by s ₂ (p) are lost, the reception log likelihood ratio of all the bits transmitted by s ₂ (p) can not be determined.

  Here, consider a broadcast / multicast communication system where the precoding matrix is not switched. At this time, consider a system model in which there is a base station that transmits a modulation signal using a precoding scheme that does not switch the precoding matrix, and a plurality of (Γ) terminals receive the modulation signal transmitted by the base station.

The situation of the direct wave between the base station and the terminal is considered to change little with time. Then, from the equations (153) and (154), the terminal in the LOS environment where the rice factor is large, which is at a position satisfying the condition of the equation (155) or the equation (156), degrades the reception quality of data. There is a possibility of falling into the phenomenon. Therefore, in order to improve this problem, it is necessary to switch precoding matrices temporally.

Therefore, let us consider a method of switching the precoding matrix regularly with N slots as the time period (hereinafter referred to as a precoding hopping method).
For the time period N slots, N types of precoding matrices F [i] based on equation (148) are prepared (i = 0, 1,..., N−1). At this time, the precoding matrix F [i] is expressed as follows.

Here, it is assumed that α does not change with time and λ does not change with time (it may be changed).
Then, as in the first embodiment, the signal after precoding in equation (142) at time (time) N × k + i (k is an integer of 0 or more, i = 0, 1,..., N−1). The precoding matrix used to obtain x (p = N × k + i) is F [i]. The same applies to the following.

At this time, based on Equations (153) and (154), design conditions for precoding matrix for precoding hopping as follows become important.

According to <condition # 10>, in all of the Γ terminals, the slot that has a poor reception score of s ₁ is 1 slot or less at N in the time period. Therefore, log likelihood ratios of bits transmitted in s ₁ (p) for N−1 slots or more can be obtained. Similarly, due to <condition # 11>, at N terminals in a time period, the number of slots that receive s ₂ reception inferior points is 1 slot or less at all Γ terminals. Therefore, log likelihood ratios of bits transmitted in s ₂ (p) for N−1 slots or more can be obtained.

Thus, by giving the design criteria of the precoding matrix of <condition # 10> and <condition # 11>, the number of bits for which the log likelihood ratio of bits transmitted in s ₁ (p) can be obtained, and Data in a LOS environment with a large Rice factor in all Γ terminals by guaranteeing the number of bits for which the log likelihood ratio of bits transmitted in ₂ (p) can be obtained to be a fixed number or more in all す べ て terminals Consider improving the degradation of reception quality.

In the following, examples of precoding matrices in the precoding hopping method will be described.
The probability density distribution of the phase of the direct wave can be considered to be a uniform distribution of [0 2π]. Therefore, the probability density distribution of the phase of q in the equations (151) and (152) can also be considered to be a uniform distribution of [0 2π]. Therefore, in the same LOS environment in which only the phase of q differs, the following is given as a condition for giving as fair reception quality of data as possible to 端末 terminals.
<Condition # 12>
When the precoding hopping method with N periods of time period is used, the reception inferior points of s ₁ are arranged to have a uniform distribution with respect to the phase at N in the time period, and the reception inferior points of s ₂ are Arrange in a uniform distribution with respect to the phase.

Therefore, an example of a precoding matrix in a precoding hopping method based on <condition # 10> to <condition # 12> will be described. Let α = 1.0 of the precoding matrix in equation (157).
(Example # 5)
Assuming that the time period N = 8 and in order to satisfy <conditions # 10> to <condition # 12>, a precoding matrix in a precoding hopping method with a time period N = 8 as given by the following equation is given.

Here, j is an imaginary unit and i = 0, 1,. The equation (161) may be given instead of the equation (160) (λ, θ ₁₁ [i] does not change with time (it may change).
).

Therefore, the receiving inferiority points of s ₁ and s ₂ are as shown in FIGS. 31 (a) and (b). (In FIG. 31, the horizontal axis is the real axis, and the vertical axis is the imaginary axis.) Further, instead of the equations (160) and (161), the equations (162) and (163) may be given (i = 0, 1,..., 7) (λ, θ ₁₁ [i] does not change with time (may change).

Next, in the same LOS environment which differs only in the q phase, which is different from the condition 12, the following is given as a condition for giving the reception quality of data as fair as possible to Γ terminals. <Condition # 13>
When using a precoding hopping method with N periods of time period,

In addition, at N in the time period, the reception inferior points of s ₁ are arranged so that the reception inferior points of the phase and s _{2 have} a uniform distribution with respect to the phase.
Therefore, an example of a precoding matrix in a precoding hopping method based on <condition # 10>, <condition # 11>, and <condition # 13> will be described. Let α = 1.0 of the precoding matrix in equation (157).
(Example # 6)
With a time period N = 4, a precoding matrix in a time period N = 4 precoding hopping method as given by the following equation is given.

However, j is an imaginary unit and i is 0, 1, 2, 3. Expression (166) instead of expression (165)
) And may be given (λ, θ ₁₁ [i] shall not change temporally (may vary).
).

Therefore, the receiving inferiority points of s ₁ and s ₂ are as shown in FIG. (In FIG. 32, the horizontal axis is a real axis, and the vertical axis is an imaginary axis.) Further, in place of formulas (165) and (166), formulas (167) and (168) may be given (i = 0, 1, 2, 3) (λ, θ ₁₁ [i] does not change with time (may change).

Next, a precoding hopping method using a non-unitary matrix will be described.
Based on equation (148), the precoding matrix handled in this examination is expressed as follows.

  Then, the equations corresponding to the equations (151) and (152) are expressed as the following equations.

At this time, there are two q where the minimum value d _min ² of the Euclidean distance between the reception signal point and the reception candidate signal point is zero.
In equation (171) s ₁ (p) does not exist:

There is no s ₂ (p) in equation (171):

  In the time period N precoding hopping method, N types of precoding matrices F [i] are expressed as follows with reference to equation (169).

  Here, it is assumed that α and δ do not change with time. At this time, based on Equations (34) and (35), design conditions for precoding matrix for precoding hopping as follows are given.

(Example # 7)
Let α = 1.0 of the precoding matrix in equation (174). And let the time period N = 16,
In order to satisfy <condition # 12>, <condition # 14>, and <condition # 15>, a precoding matrix in a precoding hopping method with a time period N = 8 as given by the following equation is given.

  When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Also, it can be given as follows as a precoding matrix different from equations (177) and (178).
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Therefore, the receiving inferiority points of s ₁ and s ₂ are as shown in FIGS. 33 (a) and (b).
(In FIG. 33, the horizontal axis is the real axis, and the vertical axis is the imaginary axis.) Also, in place of equations (177), (178) and (179), (180), precoding is performed as follows: You may give a matrix.

  When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

(Also, in the formulas (177) to (184), 7π / 8 may be −7π / 8.)
Next, in the same LOS environment different from <condition # 12> and different only in the phase of q, the following is given as a condition for giving the reception quality of data as fair as possible to 端末 terminals. .
<Condition # 16>
When using a precoding hopping method with N periods of time period,

In addition, at N in the time period, the reception inferior points of s ₁ are arranged so that the reception inferior points of the phase and s _{2 have} a uniform distribution with respect to the phase.
Therefore, an example of a precoding matrix in a precoding hopping method based on <condition # 14>, <condition # 15>, and <condition # 16> will be described. Let α = 1.0 of the precoding matrix in equation (174).
(Example # 8)
With a time period N = 8, a precoding matrix in a time period N = 8 precoding hopping method as given by the following equation is given.

Where i = 0, 1,...
Further, (i = 0, 1,..., 7) (λ, θ ₁₁ [i] can be not temporally changed as the precoding matrix different from equation (186) can be given as follows (i = 0, 1,.. May change)).

Therefore, the receiving inferiority points of s ₁ and s ₂ are as shown in FIG. Also, instead of equation (186) and equation (187), a precoding matrix may be given as follows (i = 0, 1,..., 7) (λ, θ ₁₁ [i] changes with time Not (it may change)).

  Or

(Also, in the formulas (186) to (189), 7π / 8 may be −7π / 8.)
Next, regarding a precoding hopping method different from (Example # 7) and (Example # 8) where α ≠ 1 in the precoding matrix of equation (174) and points of distance in the complex plane of reception inferior points are considered Think.

Here, the precoding hopping method of time period N in equation (174) is dealt with, but at this time, reception of s ₁ in N within the time period is performed in all the に よ り terminals by <condition # 14>. The inferiority slot is 1 slot or less. Therefore, log likelihood ratios of bits transmitted in s ₁ (p) for N−1 slots or more can be obtained. Similarly, <condition # 15>
Thus, at all N terminals in Γ, the number of slots that receive s ₂ reception inferiority points is 1 or less at N in the time period. Therefore, log likelihood ratios of bits transmitted in s ₂ (p) for N−1 slots or more can be obtained.

Therefore, it can be understood that the larger the value of the time period N, the larger the number of slots that can obtain the log likelihood ratio.
By the way, in an actual channel model, since it is affected by scattered wave components, when the time period N is fixed, data reception quality is improved if the minimum distance on the complex plane of the reception inferior point is as large as possible. It is thought that there is a possibility. Therefore, in (example # 7) and (example # 8), let α be 1, and consider a precoding hopping method in which (example # 7) and (example # 8) are improved. First, we will describe a precoding method that improves (Example # 8) to facilitate understanding.
(Example # 9)
From equation (186), the precoding matrix in the precoding hopping method with a time period N = 8, which is a modification of (example # 7), is given by the following equation.

Where i = 0, 1,... Further, (i = 0, 1,..., 7) (λ, θ ₁₁ [i] can be not temporally changed as the precoding matrix different from equation (190) can be given as follows (i = 0, 1,.. May change)).

  Or

  Or

  Or

  Or

  Or

  Or

Therefore, the reception inferior points of s ₁ and s ₂ are represented as shown in FIG. 35 (a) when α <1.0 and as shown in FIG. 35 (b) when α> 1.0.
(i) When α <1.0 When α <1.0, the minimum distance in the complex plane of reception inferiority points is the distance between reception inferiority points # 1 and # 2 (d _{# 1, # 2} ) and reception inferiority point # 1 Focusing on the distance between d and # 3 (d _{# 1, # 3} ), min {d _{# 1, # 3
It} is expressed as _{# 2} , d _{# 1, # 3} }. At this time, the relationship between α and d _{# 1, # 2} and d _{# 1, # 3} is shown in FIG. And α that maximizes min {d _{# 1, # 2} , d _{# 1, # 3} } is

It will be ¥. At this time, min {d _{# 1, # 2} , d _{# 1, # 3} } is

  It becomes. Therefore, the precoding method in which α is given by equation (198) in equations (190) to (197) is effective. However, setting the value of α as expression (198) is one appropriate method for obtaining good data reception quality. However, if α is set to take a value close to that of equation (198), there is also a possibility that good data reception quality can be obtained. Therefore, the set value of α is not limited to equation (198).

(ii) When α> 1.0 When α> 1.0, the minimum distance in the complex plane of reception inferiority points is the distance between reception inferiority points # 4 and # 5 (d _{# 4, # 5} ) and reception inferiority point # 4 Focusing on the distance between d and # 6 (d _{# 4, # 6} ), min {d _{# 4,
It} is expressed as _{# 5} , d _{# 4, # 6} }. At this time, the relationship between α and d _{# 4, # 5} and d _{# 4, # 6} is shown in FIG. And α which maximizes min {d _{# 4, # 5} , d _{# 4, # 6} } is

It becomes. At this time, min {d _{# 4, # 5} , d _{# 4, # 6} } is

It becomes. Therefore, the precoding method in which α is given by equation (200) in equations (190) to (197) is effective. However, setting the value of α to equation (200) is one appropriate method for obtaining good data reception quality. However, even if α is set to take a value close to the equation (200), there is also a possibility that good data reception quality can be obtained. Therefore, the set value of α is not limited to the equation (200).
(Example # 10)
The precoding matrix in the precoding hopping method with a time period N = 16 that improves (example # 7) from the examination of (example # 9) can be given by the following equation (λ, θ ₁₁ [i] is temporally Not change (may change)).

  When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

Or
When i = 0, 1, ..., 7:

  When i = 8, 9, ..., 15:

However, α is suitable for obtaining good reception quality of data when it becomes equation (198) or equation (200). At this time, the reception inferior point of s ₁ is expressed as shown in FIGS. 38A and 38B when α <1.0 and as shown in FIGS. 39A and 39B when α> 1.0.

In the present embodiment, the method of configuring N different precoding matrices for the time period N precoding hopping method has been described. At this time, F [0], F [1], F [2],..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. , F [N-2], and F [N-1] are described in this order, but the present invention is not necessarily limited thereto, and N different precoding matrices F [0] generated in the present embodiment are described. , F [1], F [2],..., F [N-2], F [N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with time period N is described, the same effect can be obtained by using N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use N different precoding matrices to have.

Although example # 5 to example # 10 are shown based on <condition # 10> to <condition # 16>, in order to lengthen the switching cycle of the precoding matrix, for example, a plurality of example # 5 to example # 10 to several An example may be chosen and the long period precoding matrix switching method may be implemented using the precoding matrix shown in the selected example. For example, using the precoding matrix shown in Example # 7 and the precoding matrix shown in Example # 10, a long period precoding matrix switching method is realized. In this case, it is not always necessary to follow <Condition # 10> to <Condition # 16>. (Expression (158) of <Condition # 10>, Expression (159) of <Condition # 11>, Expression (164) of <Condition # 13>, Expression (175) of <Condition # 14>, <Condition # 15> In the equation (176), the condition that "all x, all y" is "X in existing, y in existing" is important in providing good reception quality. When considering from another point of view, it is good if the precoding matrix switching method of period N (N is a large natural number) includes any of the precoding matrices of example # 5 to example # 10. There is a high possibility of giving good reception quality. Seventh Embodiment
In this embodiment, the configuration of a receiving apparatus that receives a modulated signal transmitted by the transmission method of regularly switching precoding matrices described in the first to sixth embodiments will be described.

  In the first embodiment, a transmitting apparatus that transmits a modulated signal using a transmission method that regularly switches the precoding matrix transmits information on the precoding matrix, and the receiving apparatus uses it for a transmission frame based on the information. Described is a method for obtaining regular precoding matrix switching information, performing precoding decoding and detection, obtaining log likelihood ratios of transmission bits, and then performing error correction decoding.

In this embodiment, a configuration of a receiving apparatus different from the above and a method of switching a precoding matrix will be described.
FIG. 40 shows an example of the configuration of a transmission apparatus according to this embodiment, and the same components as those in FIG. 3 are given the same reference numerals. The encoder group (4002) receives the transmission bit (4001) as an input. At this time, as described in the first embodiment, the encoder group (4002) holds a plurality of encoding units of the error correction code, and, for example, one encoding is performed based on the frame configuration signal 313. Two encoders, and any number of encoders of four encoders will operate.

  When one encoder operates, transmission bits (4001) are encoded to obtain transmission bits after encoding, and the transmission bits after encoding are distributed to two systems and distributed. The encoder group (4002) outputs a bit (4003A) and a distributed bit (4003B).

  When two encoders operate, the transmit bit (4001) is split into two (named as split bits A, B) and the first encoder takes split bit A as input and encodes And output the encoded bit as the distributed bit (4003A). The second encoder takes divided bits B as input, performs encoding, and outputs the encoded bits as distributed bits (4003B).

  When four encoders operate, the transmit bit (4001) is divided into four (named as divided bits A, B, C, D) and the first encoder takes divided bit A as input , And output the bit A after encoding. The second encoder receives divided bit B as input, performs encoding, and outputs encoded bit B. The third encoder takes divided bits C as input, performs encoding, and outputs encoded bits C. The fourth encoder takes divided bits D as input, performs encoding, and outputs encoded bits D. Then, the encoded bits A, B, C, D are divided into the distributed bits (4003A) and the distributed bits (4003B).

  A transmitter will support the transmission method as Table 1 (Table 1A and Table 1B) below as an example.

As shown in Table 1, the number of transmission signals (the number of transmission antennas) supports transmission of one stream of signals and transmission of two streams of signals. Also, modulation schemes support QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM. In particular, when the number of transmission signals is 2, stream # 1 and stream # 2 can be set modulation schemes separately.
For example, in Table 1, "# 1: 256 QAM, # 2: 1024 QAM" indicates that "the modulation scheme of stream # 1 is 256 QAM, the modulation scheme of stream # 2 is 1024 QAM" (the same applies to the others) doing). It is assumed that three error correction coding methods, A, B, and C, are supported. At this time, A, B and C may all be different codes, A, B and C may be different coding rates, and A, B and C are coding methods of different block sizes It may be

In the transmission information of Table 1, each transmission information is assigned to each mode in which "the number of transmission signals", "modulation scheme", "number of encoders", and "error correction coding method" are defined. Therefore, for example, in the case of “number of transmission signals: 2” “modulation scheme: # 1: 1024 QAM, # 2: 1024 QAM” “number of encoders: 4” “error correction coding method: C”, the transmission information is set to 0101101. Set Then, the transmitting device transmits transmission information and transmission data in the frame. Then, when transmitting transmission data, particularly when the “number of transmission signals” is 2, according to Table 1, the “precoding matrix switching method” will be used. In Table 1, five types of D, E, F, G, and H are prepared as the “precoding matrix switching method”, and one of the five types is set according to Table 1. . At this time, there are five different realization methods:
Prepare and realize five different precoding matrices.
Implemented by setting five different types of cycles, for example, the cycle of D to 4 and the cycle of E to 8.
-It realizes by using both different precoding matrices and different periods.
Etc. can be considered.

  FIG. 41 shows an example of a frame configuration of a modulated signal transmitted by the transmitting apparatus of FIG. 40, and the transmitting apparatus sets a mode in which two modulated signals z1 (t) and z2 (t) are transmitted; Also, it is possible to set both of the modes for transmitting one modulation signal.

In FIG. 41, a symbol (4100) is a symbol for transmitting the "transmission information" shown in Table 1. The symbols (4101_1 and 4101_2) are reference (pilot) symbols for channel estimation. The symbols (4102_1 and 4103_1) are symbols for data transmission to be transmitted by the modulation signal z1 (t), and the symbols (4102_2 and 4103_2) are symbols for data transmission to be transmitted by the modulation signal z2 (t). 4102_1) and the symbol (4102_2) are transmitted at the same time using the same (common) frequency, and the symbol (4103_1) and the symbol (4103_2) are transmitted using the same (common) frequency at the same time. Then, the symbols (4102_1, 4103_1) and the symbols (4102_2, 4103_2) are used when the scheme of switching the precoding matrix regularly described in the first to fourth embodiments and the sixth embodiment is used. It becomes a symbol after coding matrix operation (therefore, as described in Embodiment 1, the configuration of streams s1 (t) and s2 (t) is as shown in FIG. 6).
Furthermore, in FIG. 41, a symbol (4104) is a symbol for transmitting the "transmission information" shown in Table 1. Symbol (4105) is a reference (pilot) symbol for channel estimation. The symbols (4106, 4107) are symbols for data transmission to be transmitted by the modulation signal z1 (t), and at this time, since the symbols for data transmission to be transmitted by the modulation signal z1 (t) are one for the number of transmission signals. , Precoding has not been performed.

Therefore, the transmitting apparatus of FIG. 40 generates and transmits a modulated signal according to the frame configuration of FIG. 41 and Table 1. In FIG. 40, the frame configuration signal 313 includes information on “the number of transmission signals”, “modulation scheme”, “number of encoders”, and “error correction coding method” set based on Table 1. Then, the encoding unit (4002), the mapping units 306A and B, and the weighting and combining units 308A and B receive the frame configuration signal as an input, and set "the number of transmission signals""modulationmethod""coder" set based on Table 1. The operation based on the number “error correction coding method” will be performed. In addition, “transmission information” corresponding to the “number of transmission signals”, “modulation scheme”, “number of encoders”, and “error correction coding method” is also transmitted to the reception apparatus.

  The configuration of the receiving apparatus can be represented in FIG. 7 as in the first embodiment. The difference from the first embodiment is that since the transmitting and receiving apparatus share the information in Table 1 in advance, the "number of transmission signals" even if the transmitting apparatus does not transmit information on the precoding matrix to be switched regularly. The transmission apparatus transmits “transmission information” corresponding to “modulation method”, “number of encoders”, and “error correction coding method”, and the reception apparatus obtains this information, thereby regularly switching from Table 1 The point is that the information of the coding matrix can be obtained. Therefore, in the receiving apparatus of FIG. 7, information on the precoding matrix regularly switched from the information corresponding to Table 1 by obtaining “transmission information” transmitted by the transmitting apparatus of FIG. 40 by the control information decoding unit 709. And a signal 710 relating to the transmission method information notified by the transmission apparatus. Therefore, when the number of transmission signals is 2, the signal processing unit 711 can perform detection based on the switching pattern of the precoding matrix, and can obtain the reception log likelihood ratio.

  In the above, as shown in Table 1, “transmission information” is set for “number of transmission signals”, “modulation method”, “number of encoders”, and “error correction coding method”, while precoding Although the matrix switching method is set, “transmission information” may not necessarily be set for “number of transmission signals”, “modulation method”, “number of encoders”, and “error correction coding method”, for example. As shown in Table 2, “transmission information” may be set for “the number of transmission signals” and “modulation method”, and a precoding matrix switching method may be set for the “transmission information”.

Here, the “transmission information” and the setting method of the precoding matrix switching method are not limited to those shown in Table 1 and Table 2. The precoding matrix switching method includes “the number of transmission signals”, “modulation method”, and “code If a rule is determined in advance to switch based on transmission parameters such as the number of encoders “error correction coding method” (if the rule determined in advance is shared by the transmitting device and the receiving device), (In other words, if the precoding matrix switching method is switched by any of transmission parameters (or any of a plurality of transmission parameters)), the transmitting apparatus provides information on the precoding matrix switching method. There is no need to transmit, and the receiving apparatus switches the precoding matrix used by the transmitting apparatus by determining information on transmission parameters. Since the method can be determined, it is possible to perform accurate decoding, the detection. In Tables 1 and 2, when the number of transmission modulation signals is 2, it is assumed that a transmission method in which the precoding matrix is switched regularly is used, but if the number of transmission modulation signals is 2 or more, the transmission method is regularly performed. A transmission method of switching coding matrices can be applied.
Therefore, if the transmitting and receiving apparatus share a table on transmission parameters including information on a precoding switching method, control is performed in which the transmitting apparatus does not transmit information on the precoding switching method and does not include information on the precoding switching method. By transmitting information and obtaining this control information, the receiving apparatus can estimate the precoding switching method.

  As described above, in the present embodiment, the transmitting device uses the “precoding matrix regularly used by the transmitting device without transmitting the direct information on the method of switching the precoding matrix regularly. The method of estimating the information regarding precoding of "the method of switching" was demonstrated. As a result, the transmitting apparatus does not transmit direct information on the method of regularly switching the precoding matrix, so that an effect of improving the data transmission efficiency can be obtained.

  In the present embodiment, although an embodiment for changing precoding weights on the time axis has been described, as described in the first embodiment, even when a multicarrier transmission method such as OFDM transmission is used, the present embodiment is described. Embodiments can be implemented as well.

  Also, in particular, when the precoding switching method is changed only by the number of transmission signals, the receiving apparatus can perform the precoding switching method by obtaining information on the number of transmission signals transmitted by the transmitting apparatus. .

  In this specification, it is considered that the transmitting apparatus is equipped with, for example, communication / broadcasting equipment such as a broadcasting station, a base station, an access point, a terminal, a mobile phone, etc. It is conceivable that communication devices such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, a base station and the like are provided with the receiving device. In the present invention, the transmitting device and the receiving device are devices having a communication function, and the devices are connected to a device for executing an application such as a television, a radio, a personal computer, a mobile phone, etc. It is also conceivable that it is in a form that can be understood and connected.

  Also, in the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, postamble, reference symbol, etc.), symbols for control information, etc. are arranged in the frame no matter how. Good. And although it is naming as a pilot symbol and a symbol for control information here, what kind of naming may be performed and the function itself is important.

  The pilot symbols may for example be known symbols modulated at the transceiver using PSK modulation (or the receiver may be able to know the symbols transmitted by the transmitter by synchronizing the receiver The receiver should use this symbol to perform frequency synchronization, time synchronization, channel estimation (for each modulated signal) (estimate of CSI (Channel State Information)), signal detection, etc. Become.

  In addition, symbols for control information are information that needs to be transmitted to a communication partner (eg, modulation scheme, error correction coding scheme used for communication, etc.) to realize communication other than data (such as application) It is a symbol for transmitting the coding rate of the error correction coding method, setting information in the upper layer, and the like.

The present invention is not limited to Embodiments 1 to 5 above, and can be implemented with various modifications. For example, although the above embodiment describes the case of performing as a communication device, the present invention is not limited to this, and it is also possible to perform this communication method as software.

  Also, although the precoding switching method in the method of transmitting two modulated signals from two antennas has been described above, the present invention is not limited to this, and precoding is performed on four mapped signals. In a method of generating one modulated signal and transmitting from four antennas, that is, performing precoding on N mapped signals, generating N modulated signals, and transmitting from N antennas Can also be implemented similarly as a precoding switching method in which precoding weights (matrices) are similarly changed.

  In this specification, terms such as “precoding” and “precoding weight” are used, but the term itself may be anything, and in the present invention, the signal processing itself is important.

The streams s1 (t) and s2 (t) may transmit different data or the same data.
Both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, one of the antennas described in the drawing may be constituted by a plurality of antennas.

Note that, for example, a program for executing the above communication method is pre-stored in the ROM (Read Only).
The program may be stored in a memory) and operated by a CPU (central processor unit).

  Further, the program for executing the communication method is stored in a computer readable storage medium, the program stored in the storage medium is recorded in a RAM (Random Access Memory) of the computer, and the computer is operated according to the program You may do so.

  And each composition of each above-mentioned embodiment etc. may be realized as LSI (Large Scale Integration) which is an integrated circuit typically. These may be individually made into one chip, or may be made into one chip so as to include all or some of the configurations of the respective embodiments. Although an LSI is used here, it may be called an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After the LSI is manufactured, a field programmable gate array (FPGA) that can be programmed or a reconfigurable processor that can reconfigure connection and setting of circuit cells in the LSI may be used.

Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Adaptation of biotechnology etc. may be possible.

Eighth Embodiment
In this embodiment, an application example of the method of regularly switching the precoding weights described in Embodiments 1 to 4 and 6 will be described here.

FIG. 6 is a diagram related to the weighting method (precoding method) according to the present embodiment, and weighting combining section 600 is a weighting combining section combining weighting combining sections 308A and 308B of FIG. 3. is there. As shown in FIG. 6, stream s1
(T) and stream s2 (t) correspond to the baseband signals 307A and 307B in FIG. 3, that is, baseband signal in-phase I, quadrature Q component according to the mapping of modulation schemes such as QPSK, 16 QAM, 64 QAM, etc. Become. Then, as in the frame configuration of FIG. 6, the stream s1 (t) represents a signal of symbol number u as s1 (u), a signal of symbol number u + 1 as s1 (u + 1),. Similarly, the stream s2 (t) represents a signal of symbol number u as s2 (u), a signal of symbol number u + 1 as s2 (u + 1),. Then, weighting combining section 600 receives as input baseband signals 307A (s1 (t)) and 307B (s2 (t)) in FIG. 3 and information 315 related to weighting information, and uses a weighting method according to information 315 related to weighting information. , And outputs the signals 309A (z1 (t)) and 309B (z2 (t)) after the weighting and combining of FIG.

At this time, for example, in the case of using the precoding matrix switching method with period N = 8 in Example 8 in the sixth embodiment, z1 (t) and z2 (t) are expressed as follows.
At symbol number 8i (i is an integer greater than 0):

However, j is an imaginary unit, k = 0.
At symbol number 8i + 1:

However, k = 1.
For symbol number 8i + 2:

However, k = 2.
At symbol number 8i + 3:

However, k = 3.
In the case of symbol number 8i + 4:

However, k = 4.
In the case of symbol number 8i + 5:

However, k = 5.
In the case of symbol number 8i + 6:

However, k = 6.
At symbol number 8i + 7:

However, k = 7.
Here, although described as a symbol number, the symbol number may be considered as time (time). As described in the other embodiments, for example, in equation (225), z1 (8i + 7) and z2 (8i + 7) at time 8i + 7 are signals at the same time, and z1 (8i + 7) and z2 (8i + 7) Is transmitted by the transmitter using the same (common) frequency. That is, assuming that the signal at time T is s1 (T), s2 (T), z1 (T), z2 (T), from some precoding matrix and s1 (T) and s2 (T), z1 (T) and z2 (T) is determined, and z1 (T) and z2 (T) are transmitted by the transmitter using the same (common) frequency (at the same time (time)). When a multicarrier transmission scheme such as OFDM is used, signals corresponding to (sub) carrier L and s1, s2, z1 and z2 at time T are s1 (T, L), s2 (T, L) and z1. Given (T, L), z2 (T, L), from some precoding matrix and s1 (T, L) and s2 (T, L), z1 (T, L) and z
2 (T, L) is determined, and z1 (T, L) and z2 (T, L) are transmitted by the transmitter using the same (common) frequency (at the same time (time)).

At this time, there are Formula (198) or Formula (200) as appropriate values of α.
In this embodiment, based on the precoding matrix of equation (190) described above, a precoding switching method for increasing the period will be described.

  Assuming that the period of the precoding switching matrix is 8M, 8M different precoding matrices are represented as follows.

At this time, i = 0, 1, 2, 3, 4, 5, 6, 7 and k = 0, 1,..., M-2, M-1.
For example, when M = 2, if α <1, then the reception inferior point (s) of s1 at k = 0 and the reception inferior point (s) of s2 are as shown in FIG. 42 (a). Is represented. Similarly, the reception inferior point (○) of s1 when k = 1 and the reception inferior point (□) of s2 are represented as shown in FIG. 42 (b). Thus, based on the precoding matrix of equation (190), the reception inferiority point is as shown in FIG. 42 (a), and each element of the second row of the matrix on the right side of equation (190) is e ^jX The reception inferiority point has a rotated reception inferiority point with respect to FIG. 42 (a) by setting the matrix multiplied by A as the precoding matrix (see equation (226)) (see FIG. 42 (b)) . (However, the reception inferior points in FIG. 42 (a) and FIG. 42 (b) do not overlap. In this way, it is preferable that the reception inferior points do not overlap even when multiplying by e ^jX . instead of multiplying e ^jX to each element of the second row of the right side of the matrix 190), a matrix obtained by multiplying the e ^jX to each element of the first row of the matrix of the right side of the equation (190) as a pre-coding matrix At this time, the precoding matrices F [0] to F [15] are expressed by the following equations.

However, i = 0, 1, 2, 3, 4, 5, 6, 7 and k = 0, 1.
Then, when M = 2, precoding matrices of F [0] to F [15] are generated (precoding matrices of F [0] to F [15] are arranged in any order. Also, the matrices of F [0] to F [15] may be different from each other). Then, for example, precoding is performed using F [0] at symbol number 16i, precoding using F [1] at symbol number 16i + 1,..., F [h] at symbol number 16i + h. To perform precoding (h = 0, 1, 2,..., 14, 15). (Here, as described in the previous embodiment, it is not always necessary to switch precoding matrices regularly.)
Summarizing the above, referring to Equations (82) to (85), the precoding matrix of period N is expressed by the following equation.

At this time, since the period is N, i = 0, 1, 2,..., N-2, N-1. And the equation (228
The precoding matrix of period N × M based on) is expressed by the following equation.

At this time, i = 0, 1, 2,..., N-2, N-1, k = 0, 1,..., M-2, M-1.
Then, precoding matrices of F [0] to F [N × M−1] are generated (F [0] to F [N × M−1] have a period N × M. It may be used in any order). Then, for example, when symbol number N × M × i, precoding is performed using F [0], and when symbol number N × M × i + 1, precoding is performed using F [1],. Precoding is performed using F [h] when the symbol number is N × M × i + h (h = 0, 1, 2,
.., N × M−2, N × M−1). (Here, as described in the previous embodiment, it is not always necessary to switch precoding matrices regularly.)
By generating the precoding matrix in this way, it is possible to realize a method of switching the precoding matrix with a large period, and it is possible to easily change the position of poor reception points, which improves the reception quality of data. May lead to Although the precoding matrix of period N × M is expressed by equation (229), as described above, the precoding matrix of period N × M may be expressed by the following equation.

At this time, i = 0, 1, 2,..., N-2, N-1, k = 0, 1,..., M-2, M-1.

In Equation (229) and Equation (230), when 0 radian ≦ δ <2π radian, it becomes a unitary matrix when δ = π radian and becomes a non-unitary matrix when δ ≠ π radian. In this method, the case of a non-unitary matrix of π / 2 radians ≦ | δ | <π radians is one characteristic configuration (the condition of δ is the same as in the other embodiments). , Good reception quality of data will be obtained. There is also a unitary matrix as another configuration, and although detailed description will be made in the tenth and sixteenth embodiments, good data reception will be made if N is an odd number in the equations (229) and (230). There is a high probability of getting quality.

Embodiment 9 In this embodiment, a method of regularly switching precoding matrices using a unitary matrix will be described.

In the method of regularly switching the precoding matrix of period N as described in the eighth embodiment, the following equation is applied to the precoding matrix to be prepared for period N with reference to equations (82) to (85): It expresses with.

  At this time, i = 0, 1, 2,..., N-2, N-1. (It is assumed that α> 0.) Since the present embodiment deals with a unitary matrix, the precoding matrix of equation (231) can be expressed by the following equation.

  At this time, i = 0, 1, 2,..., N-2, N-1. (It is assumed that α> 0.) At this time, from the condition 5 of (Equation 106) of the third embodiment and the condition 6 of (Equation 107), the following conditions indicate good reception quality of data. It is important to earn.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Although the distance between the reception inferior points is described in the sixth embodiment, it is important that the period N is an odd number of 3 or more in order to increase the distance between the reception inferior points. Below, this point is explained.

As described in the sixth embodiment, <Condition 19> or <Condition 20> is provided in order to arrange reception inferior points in a uniform distribution with respect to the phase on the complex plane.

That is, <Condition 19> means that the phase difference is 2π / N radians. Further, <Condition 20> means that the phase difference is −2π / N radians.


Then, assuming that θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α <1, it is on the complex plane of the reception inferior point of s1 and the reception inferior point of s2 when the period N = 3. Figure 43 (a) shows the arrangement of
The arrangement of the reception inferiority points of s1 and the reception inferiority points of s2 on the complex plane when the period N = 4 is shown in FIG.
shown in b). Also, assuming that θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, it is on the complex plane of poor reception of s1 and poor reception of s2 when period N = 3. Placement in Figure 4
FIG. 44 (b) shows the arrangement of the reception inferior point of s1 and the reception inferior point of s2 on the complex plane when the period N = 4 in 4 (a).

At this time, when considering a phase (see FIG. 43A) formed by a line segment formed by the reception inferior point and the origin and a half line of Real ≧ 0 on the axis of Real, α>1; In any of the cases where α <1 also, when N = 4, the above-mentioned phase at the reception inferior point for s1 and the above-mentioned phase at the reception inferior point for s2 always have the same value. (Refer to 4301 and 4302 in FIG. 43 and 4401 and 4402 in FIG. 44) At this time, in the complex plane, the distance between the reception inferior points decreases. On the other hand, when N = 3, the above-described phase at the reception inferior point for s1 and the above-described phase at the reception inferior point for s2 do not have the same value.

From the above, considering that when the period N is an even number, the above phase at the reception inferior point for s1 and the above phase at the reception inferior point for s2 always have the same value, the period N is an odd number. When the period N is even, it is more likely that the distance between the reception inferior points is larger in the complex plane than when the period N is even. However, when the cycle N is a small value, for example, N ≦ 16 or less, the minimum distance of reception inferior points in the complex plane can secure a certain length because the number of reception inferior points is small. Therefore, in the case of N ≦ 16, there is a possibility that data reception quality can be ensured even if it is even.

Therefore, in the scheme of regularly switching the precoding matrix based on Equation (232), if the period N is an odd number, there is a high possibility that the reception quality of data can be improved. It is to be noted that the precoding matrices of F [0] to F [N-1] are generated based on equation (232) (the precoding matrix of F [0] to F [N-1] has a period N May be used in any order). Then, for example, precoding is performed using F [0] for symbol number Ni, and precoding using F [1] for symbol number Ni + 1,
Precoding is performed using F [h] when the symbol number is N × i + h (h = 0, 1, 2,..., N−2, N−1). (Here, as described in the previous embodiment, the precoding matrix does not necessarily have to be switched regularly.) Also, when the modulation schemes of s1 and s2 are both 16 QAM, α is

Then, it is possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.
In the present embodiment, the method of configuring N different precoding matrices for the time period N precoding hopping method has been described. At this time, F [0], F [1], F [2],..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. , F [N-2], and F [N-1] are described in this order, but the present invention is not necessarily limited thereto, and N different precoding matrices F [0] generated in the present embodiment are described. , F [1], F [2],..., F [N-2], F [N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with time period N is described, the same effect can be obtained by using N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use N different precoding matrices to have.

In addition, in the precoding matrix switching method of period H (H is a natural number where the period N of the above scheme regularly switching the precoding matrix is a natural number), N different precoding matrices in the present embodiment are included. Is likely to give good reception quality. At this time, <condition # 17><condition#18> can be replaced with the following conditions. (Period is considered as N.)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)
Tenth Embodiment
In this embodiment, an example different from that in Embodiment 9 will be described as to a method of regularly switching precoding matrices using a unitary matrix.

  In the method of regularly switching the precoding matrix of period 2N, the precoding matrix prepared for period 2N is expressed by the following equation.

  It is assumed that α> 0 and it is a fixed value (regardless of i).

It is assumed that α> 0 and it is a fixed value (regardless of i). (It is assumed that α in equation (234) and α in equation (235) have the same value.)
At this time, under the condition 5 of (Equation 106) of the third embodiment and the condition 6 of (Equation 107), the condition of the following applies to the equation (234) in order to obtain good reception quality of data It becomes important.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Then, consider adding the following conditions.

  Next, as described in the sixth embodiment, <condition # 24> or <condition # 25> is set to arrange reception poor points on the complex plane so as to have uniform distribution with respect to the phase. give.

That is, <condition 24> means that the phase difference is 2π / N radians. Also, <Condition 25> means that the phase difference is −2π / N radians.

Then, assuming that θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, it is assumed that the reception inferiority of s1 and the reception inferiority of s2 when N = 4 on the complex plane The arrangement is shown in FIG. 45 (a) (b)
Shown in. As can be seen from FIGS. 45 (a) and 45 (b), in the complex plane, the minimum distance of poor reception of s1 is kept large, and, similarly, the minimum distance of poor reception of s2 is also large. There is. Then, the same state is obtained when α <1. Also, considering as in the ninth embodiment, when N is an odd number, the distance between poor reception points is more likely to be larger in the complex plane than when N is an even number. However, when N is a small value, for example, N ≦ 16 or less, the minimum distance of poor reception points in the complex plane can secure a certain length since the number of poor reception points is small. Therefore, in the case of N ≦ 16, there is a possibility that data reception quality can be ensured even if it is even.

Therefore, in the scheme of regularly switching the precoding matrix based on Equations (234) and (235), if N is an odd number, there is a high possibility that the reception quality of data can be improved. In addition, the precoding matrix of F [0] to F [2N-1] is generated based on the equations (234) and (235) (the precoding matrix of F [0] to F [2N-1] is generated. May be used in any order with respect to the cycle 2N). Then, for example, precoding is performed using F [0] when symbol number 2Ni, precoding using F [1] when symbol number 2Ni + 1,..., F when symbol number 2N × i + h Precoding is performed using [h] (h = 0, 1, 2, ..., 2N-2, 2N-1). (Here, as described in the previous embodiment, the precoding matrix does not necessarily have to be switched regularly.) Also, when the modulation schemes of s1 and s2 are both 16 QAM, α is In this case, it is possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.

  Also, the following conditions are considered as conditions different from <condition # 23>.

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)
At this time, by satisfying <condition # 21>, <condition # 22>, and <condition # 26> and <condition # 27>, the distance between inferior reception points of s1 in the complex plane is large, and s2 is Since the distance of poor reception points can be increased, good data reception quality can be obtained.

  In this embodiment, the method of constructing 2N different precoding matrices for the precoding hopping method with time period 2N has been described. At this time, F [0], F [1], F [2],..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. , F [2N-2], and F [2N-1] are described in this order, but the present invention is not necessarily limited thereto, and 2N different precoding matrices F [0] generated in this embodiment are used. , F [1], F [2],..., F [2N-2], F [2N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with a time period of 2N is described, the same effect can be obtained by using 2N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use 2N different precoding matrices to have.

In addition, in the precoding matrix switching method of period H (H is a scheme in which the precoding matrix is switched regularly as described above, period 2N is a larger natural number), 2N different precoding matrices in the present embodiment are included. Is likely to give good reception quality.
(Embodiment 11)
In this embodiment, a method of regularly switching precoding matrices using non-unitary matrices will be described.

  In the method of regularly switching the precoding matrix of period 2N, the precoding matrix prepared for period 2N is expressed by the following equation.

It is assumed that α> 0 and it is a fixed value (regardless of i). Also, let δ ≠ π radians.

It is assumed that α> 0 and it is a fixed value (regardless of i). (It is assumed that α in equation (236) and α in equation (237) have the same value).
At this time, based on condition 5 of (Equation 106) of the third embodiment and condition 6 of (Equation 107), the following condition applies to equation (236) to obtain good reception quality of data: It becomes important.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Then, consider adding the following conditions.

Here, instead of equation (237), a precoding matrix of the following equation may be provided.

It is assumed that α> 0 and it is a fixed value (regardless of i). (It is assumed that α in equation (236) and α in equation (238) have the same value).
As an example, as described in the sixth embodiment, <condition # 31> or <condition # 32> is set to arrange reception inferiority points so as to have uniform distribution with respect to the phase on the complex plane. give.

That is, <condition 31> means that the phase difference is 2π / N radians. Also, <Condition 32> means that the phase difference is −2π / N radians.
Then, when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian, and α> 1 and δ = (3π) / 4 radian, the reception inferior point of s 1 and s 2 when N = 4 The arrangement of the reception inferiority points on the complex plane is shown in (a) and (b) of FIG. By doing this, it is possible to increase the cycle of switching the pull coding matrix, and in the complex plane, keep the minimum distance of the reception inferiority points of s1 large, and similarly, the reception inferiority of s2 Since the minimum distance of points can also be kept large, good reception quality can be obtained. Here, the case of α> 1, δ = (3π) / 4 radian, and N = 4 has been described as an example, but it is not limited to this, π / 2 radian ≦ | δ | <π radian, and α If> 0 and α 得 る 1, similar effects can be obtained.

  Also, the following conditions are considered as conditions different from <condition # 30>.

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)
At this time, by satisfying <Condition # 28>, <Condition # 29>, and <Condition # 33> and <Condition # 34>, the distance between poor reception points of s1 in the complex plane is large, and s2 is large. Since the distance of poor reception points can be increased, good data reception quality can be obtained.

  In this embodiment, the method of constructing 2N different precoding matrices for the precoding hopping method with time period 2N has been described. At this time, F [0], F [1], F [2],..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. , F [2N-2], and F [2N-1] are described in this order, but the present invention is not necessarily limited thereto, and 2N different precoding matrices F [0] generated in this embodiment are used. , F [1], F [2],..., F [2N-2], F [2N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with a time period of 2N is described, the same effect can be obtained by using 2N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use 2N different precoding matrices to have.

In addition, in the precoding matrix switching method of period H (H is a scheme in which the precoding matrix is switched regularly as described above, period 2N is a larger natural number), 2N different precoding matrices in the present embodiment are included. Is likely to give good reception quality.
(Embodiment 12)
In this embodiment, a method of regularly switching precoding matrices using non-unitary matrices will be described. In the method of regularly switching the precoding matrix of period N, the precoding matrix prepared for period N is expressed by the following equation.

It is assumed that α> 0 and it is a fixed value (regardless of i). Further, it is assumed that δ ≠ π radian (fixed value regardless of i), i = 0, 1, 2,..., N−2, N−1.
At this time, under the condition 5 of (Equation 106) of the third embodiment and the condition 6 of (Equation 107), the following conditions for equation (239) are to obtain good data reception quality: It becomes important.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)
As an example, as described in the sixth embodiment, <condition # 37> or <condition # 38> is set in order to arrange reception inferiority points so as to have uniform distribution with respect to the phase on the complex plane. give.

That is, <Condition 37> means that the phase difference is 2π / N radians. Further, <Condition 38> means that the phase difference is −2π / N radians.
At this time, if π / 2 radians ≦ | δ | <π radians, and α> 0 and α ≠ 1, then the distance between poor reception points of s1s in the complex plane is large, and the reception of s2s is also received Since the distance of the bad points can be increased, good data reception quality can be obtained. Note that <Condition # 37> and <Condition # 38> are not necessarily required.

In the present embodiment, the method of configuring N different precoding matrices for the time period N precoding hopping method has been described. At this time, F [0], F [1], F [2],..., F [N-2], F [N-1] are prepared as N different precoding matrices. Since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. Although the case where they are arranged in the order of F [N-2] and F [N-1] has been described, the present invention is not necessarily limited thereto, and 2N different precoding matrices F [0] generated in the present embodiment, F [1], F [2],..., F [N-2], F [N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with time period N is described, the same effect can be obtained by using N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use N different precoding matrices to have.

In addition, in the precoding matrix switching method of period H (H is a natural number where the period N of the above scheme regularly switching the precoding matrix is a natural number), N different precoding matrices in the present embodiment are included. Is likely to give good reception quality. At this time, <condition # 35><condition#36> can be replaced with the following conditions. (Period is considered as N.)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(Embodiment 13)
In this embodiment, another example of the eighth embodiment will be described.

  In the method of regularly switching the precoding matrix of period 2N, the precoding matrix prepared for period 2N is expressed by the following equation.

It is assumed that α> 0 and it is a fixed value (regardless of i). Also, let δ ≠ π radians.

It is assumed that α> 0 and it is a fixed value (regardless of i). (It is assumed that α of Formula (240) and α of Formula (241) have the same value).
Then, a precoding matrix with a period of 2 × N × M based on equations (240) and (241) is expressed by the following equation.

  At this time, k = 0, 1,..., M−2, M−1.

At this time, k = 0, 1,..., M−2, M−1. Further, Xk may be Yk or may be Xk ≠ Yk.
Then, a precoding matrix of F [0] to F [2 × N × M−1] is generated (F [0] to F [2 × N × M−1] precoding matrix is Period 2 × N × M may be used in any order). Then, for example, precoding is performed using F [0] when the symbol number is 2 × N × M × i, and precoding is performed using F [1] when the symbol number is 2 × N × M × i + 1, .... Precoding is performed using F [h] when symbol number is 2 × N × M × i + h (h = 0, 1, 2,..., 2 × N × M−2, 2 × N X M-1). (Here, as described in the previous embodiment, it is not always necessary to switch precoding matrices regularly.)
By generating the precoding matrix in this way, it is possible to realize a method of switching the precoding matrix with a large period, and it is possible to easily change the position of poor reception points, which improves the reception quality of data. May lead to

The equation (242) of the precoding matrix of period 2 × N × M may be expressed by the following equation.

At this time, k = 0, 1,..., M−2, M−1.
Also, equation (243) of the 2 × N × M period precoding matrix can be expressed by equations (245) to (24).
It may be any of 7).

At this time, k = 0, 1,..., M−2, M−1.

  At this time, k = 0, 1,..., M−2, M−1.

At this time, k = 0, 1,..., M−2, M−1.
In addition, focusing on reception inferiority points, in equations (242) to (247),

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

If all of the above are satisfied, good data reception quality can be obtained. In the eighth embodiment, it is preferable to satisfy <condition # 39> and <condition # 40>.
Also, focusing on Xk and Yk in Equation (242) to Equation (247),

(A is 0, 1, 2, ..., M-2, M-1 and b is 0, 1, 2, ..., M-2, M-1, and a ≠ b .)
However, s is an integer.

(A is 0, 1, 2, ..., M-2, M-1 and b is 0, 1, 2, ..., M-2, M-1, and a ≠ b .)
However, u is an integer.

It is possible to obtain good data reception quality if the two conditions of In the eighth embodiment, it is preferable to satisfy <Condition 42>.
In equation (242) and equation (247), when 0 radian ≦ δ <2π radian, it becomes a unitary matrix when δ = π radian and becomes a non-unitary matrix when δ ≠ π radian. In this method, the case of non unitary matrix of π / 2 radians ≦ | δ | <π radians is one characteristic configuration, and good data reception quality can be obtained. There is also the case of unitary matrix as another configuration, but although detailed description will be made in Embodiment 10 and Embodiment 16, good data reception is possible when N is an odd number in Equations (242) to (247). There is a high probability of getting quality.

Fourteenth Embodiment
In this embodiment, in the scheme of regularly switching the precoding matrix, an example of selective use in the case of using a unitary matrix and the case of using a non-unitary matrix as the precoding matrix will be described.

  For example, in the case of using a 2 × 2 precoding matrix (each element is assumed to be composed of complex numbers), that is, two modulated signals (s 1 (t) and s 2 (t The case where the precoding is applied and two signals after precoding are transmitted from two antennas will be described.

When transmitting data using a method of regularly switching the precoding matrix, the transmitting apparatus of FIG. 13 of FIG.
6B will switch the modulation scheme. At this time, the relationship between the modulation multi-level number (the modulation multi-level number: the number of signal points of the modulation system on the IQ plane) of the modulation system and the precoding matrix will be described.

The advantage of the method of regularly switching the precoding matrix is that good reception quality of data can be obtained in the LOS environment as described in the sixth embodiment, and in particular, the receiving apparatus can perform ML operation or ML operation. The effect is large when APP (or Max-log APP) based on operation is applied. By the way, the ML operation greatly affects the circuit scale (calculation scale) according to the modulation multi-level number of the modulation scheme. For example, in the case where two signals after precoding are transmitted from two antennas and two modulation signals (signals based on the modulation scheme before precoding) both use the same modulation scheme, the modulation scheme When the QPSK is QPSK, the number of candidate signal points (received signal points 1101 in FIG. 11) in the IQ plane is 4 × 4 = 16, 16 × 16 = 256 for 16 QAM, 64 × 64 = 4096 for 64 QAM, In the case of 256 QAM, 256 × 256 = 65536, and in the case of 1024 QAM, 1024 × 1024 = 1048576, and in order to suppress the operation scale of the receiving apparatus with a certain circuit scale, reception is performed when the modulation scheme is QPSK, 16 QAM, 64 QAM The apparatus uses ML operation (Max-log APP based on ML operation), and in the case of 256 QAM and 1024 QAM, uses detection using linear operation such as MMSE and ZF. (In some cases, in the case of 256 QAM, ML operation may be used.)
Assuming such a receiver, pre-coding in the case where linear operations such as MMSE and ZF are used in the receiver when SNR (signal-to-noise power ratio) after multiplex signal separation is considered. A unitary matrix is suitable as a matrix, and in the case of using an ML operation, either a unitary matrix or a non-unitary matrix may be used as a precoding matrix. In consideration of the description of any of the above embodiments, two signals after precoding are transmitted from two antennas, and the two modulation signals (signals based on the modulation scheme before precoding) are the same modulation. When it is assumed that the modulation scheme is used, if the modulation multi-level number of the modulation scheme is 64 values or less (or 256 values or less), it is not used as a precoding matrix when the scheme of regularly switching the precoding matrix is used. When using a unitary matrix and using more than 64 values (or more than 256 values), using a unitary matrix, the circuit size of the receiver for any modulation scheme supported by the communication system, for any modulation scheme The possibility of obtaining the effect of being able to obtain good data reception quality while reducing the

Further, there is a possibility that it may be better to use a unitary matrix even when the modulation multi-level number of the modulation scheme is 64 values or less (or 256 values or less). When such things are considered, when the modulation multi-level number of the modulation system supports a plurality of modulation systems having 64 values or less (or 256 values or less), the plurality of 64 value modulation systems or less supported. It is important that there is a case where a non-unitary matrix is used as a precoding matrix when using a scheme of regularly switching the precoding matrix in any one of the modulation schemes.

In the above, as an example, the case where two signals after precoding are transmitted from two antennas has been described, but the invention is not limited thereto, and N signals after precoding are transmitted from N antennas If the N modulation signals (signals based on the modulation scheme before precoding) all use the same modulation scheme, a threshold value of β _N is provided for the modulation multi-value number of the modulation scheme, and the modulation scheme If multiple modulation schemes with a modulation level of β _N or less are supported, a scheme that regularly switches the precoding matrix in any modulation scheme of a plurality of modulation schemes below β _N supported When there is a case where a non-unitary matrix is used as a precoding matrix when it is used, and in the case of a modulation scheme in which the modulation multi-level number of modulation scheme is larger than β _N , using a unitary matrix results in communication In all modulation schemes supported by the stem, in any modulation scheme, it is possible to obtain the effect that good data reception quality can be obtained while reducing the circuit scale of the receiver. Get higher. (A non-unitary matrix may always be used as the precoding matrix when the precoding matrix is switched regularly when the modulation multilevel number of the modulation system is β _N or less.
In the above description, the modulation scheme of N modulation signals to be transmitted simultaneously has been described as using the same modulation scheme, but in the following, two or more modulation schemes are used for N modulation signals to be simultaneously transmitted. The case of existence will be described.

As an example, the case where two signals after precoding are transmitted from two antennas will be described. Assuming that two modulation signals (signals based on the modulation scheme before precoding) are all the same modulation scheme or different modulation schemes, the modulation scheme of modulation value number 2 ^a1 and modulation multiple It is assumed that the number 2 a ² modulation scheme is used. At this time, when the ML operation ((Max-log) APP based on ML operation) is used in the receiving apparatus, the number of candidate signal points (received signal points 1101 in FIG. 11) in the IQ plane is 2 ^a1 × 2 ^a2 There are 2 = 2 ^{a1 + a2} candidate signal points. At this time, as described above, in order to be able to obtain reception quality of good data while reducing the circuit scale of the receiving apparatus, the threshold of relative ^{2 a1 + a2} 2 β provided, ^{2 a1 + a2} ≦ 2 β In this case, a non-unitary matrix may be used as a precoding matrix when a scheme of switching precoding matrices regularly, and a unitary matrix may be used when 2 ^{a1 + a2} > 2 ^β .

Also in the case of 2 ^{a1 + a 2} ≦ 2 ^β , it may be better to use a unitary matrix. In view of such fact, 2 ^{a1 + a2} ≦ 2 if it supports a combination of a plurality of modulation schemes ^beta, a combination of a plurality of modulation schemes 2 ^{a1 + a2} ≦ 2 ^β supporting either modulation method It is important that there is a case where a non-unitary matrix is used as a precoding matrix when using a scheme of regularly switching the precoding matrix in combination.

Although the case where two signals after precoding were transmitted from two antennas was described above as an example, it is not limited to this. For example, when N modulation signals (signals based on the modulation scheme before precoding) all have the same modulation scheme or different modulation schemes, modulation multi-values of the modulation scheme of the i-th modulation signal Let the number be 2 ^ai (i = 1, 2, ..., N-1, N).

At this time, when the ML operation ((Max-log) APP based on ML operation) is used in the receiving apparatus, the number of candidate signal points (received signal points 1101 in FIG. 11) in the IQ plane is 2 ^a1 × 2 ^a2 × · · · × 2 ^ai × · · · × 2 ^aN = 2 ^{a1 + a 2 + · · · + ai + · · · + aN} candidate signal points will exist. At this time, as described above, in order to obtain good data reception quality while reducing the circuit scale of the receiving apparatus, a threshold value of 2 ^β with ^respect to 2 ^{a1 + a 2 +... + Ai +.} Provide

  When a combination of a plurality of modulation schemes satisfying <condition # 44> is supported, a combination of a plurality of modulation schemes satisfying <condition # 44> that support <prediction # 44> is regularly used in combination of modulation schemes. There is a case where a non-unitary matrix is used as a precoding matrix when the coding matrix switching scheme is used,

In the case of the combination of all modulation schemes that satisfy <condition # 45>, using a unitary matrix, the circuit size of the receiving apparatus in any modulation scheme combination in all the modulation schemes supported by the communication system The possibility of obtaining the effect of being able to obtain good data reception quality while reducing the (A non-unitary matrix may be used as a precoding matrix when a scheme of regularly switching the precoding matrix is used in all combinations of a plurality of modulation schemes that satisfy supported <condition # 44>.)
(Fifteenth Embodiment)
In this embodiment, a system example of a scheme of regularly switching precoding matrices using a multicarrier transmission scheme such as OFDM will be described.

  FIG. 47 shows time-frequency of a transmission signal transmitted by a broadcast station (base station) in a system of regularly switching precoding matrices using a multicarrier transmission scheme such as OFDM in this embodiment. An example of the frame configuration in the axis is shown. (A frame configuration from time $ 1 to time $ T is taken.) FIG. 47 (A) is a frame configuration on the time-frequency axis of stream s1 described in the first embodiment etc., and FIG. 47 (B) is an implementation. The frame configuration on the time-frequency axis of the stream s2 described in the first embodiment and the like is shown. The symbols for the same time on the stream s1 and the stream s2 on the same (sub) carrier will be transmitted on the same time and the same frequency using multiple antennas.

  In (A) and (B) of FIG. 47, (sub) carriers used when OFDM is used are (sub) carrier a to (sub) carrier a + Na carrier group #A, (sub) carrier b. Carrier group #B composed of (sub) carrier b + Nb, carrier group #C composed of (sub) carrier c ~ (sub) carrier c + Nc, and (sub) carrier d ~ (sub) carrier d + Nd It is assumed that carrier groups #D,. Each subcarrier group supports a plurality of transmission methods. Here, by supporting a plurality of transmission methods, it is possible to effectively utilize the advantages of each transmission method. For example, in FIGS. 47 (A) and (B), it is assumed that carrier group #A uses a spatial multiplexing MIMO transmission method or a MIMO transmission method in which the precoding matrix is fixed, and carrier group #B is regularly precoding It is assumed that the MIMO transmission scheme in which the matrix is switched is used, and the carrier group #C transmits only the stream s1, and the carrier group #D transmits using the space-time block code.

  FIG. 48 shows a time-frequency diagram of a transmission signal transmitted by a broadcast station (base station) in a system of regularly switching precoding matrices using a multicarrier transmission scheme such as OFDM in this embodiment. An example of the frame configuration in the axis is shown, and a frame configuration from time $ X to time $ X + T ′ different from FIG. 47 is shown. Similar to FIG. 47, FIG. 48 shows that (sub) carriers used when OFDM is used are (sub) carrier a to (sub) carrier a + Na carrier group #A, (sub) carrier b. Carrier group #B composed of (sub) carrier b + Nb, carrier group #C composed of (sub) carrier c ~ (sub) carrier c + Nc, and (sub) carrier d ~ (sub) carrier d + Nd It is assumed that carrier groups #D,. And, FIG. 48 differs from FIG. 47 in that carrier groups having different communication methods used in FIG. 47 and in FIG. 48 exist. In FIG. 48, in (A) and (B), it is assumed that carrier group #A is transmitted using space-time block code, and carrier group #B is using MIMO transmission scheme in which precoding matrices are switched regularly. The carrier group #C uses a MIMO transmission scheme in which the precoding matrix is switched regularly, and the carrier group #D transmits only the stream s1.

Next, supported transmission methods will be described.
FIG. 49 shows a signal processing method when using a space multiplexing MIMO transmission method or a MIMO transmission method in which the precoding matrix is fixed, and the same reference numerals as in FIG. 6 are attached. The weighting / combining unit 600, which is a baseband signal according to a certain modulation scheme, receives the streams s1 (t) (307A) and s2 (t) (307B), and the information 315 on the weighting method as input, and after weighting The modulation signal z1 (t) (309A) and the weighted modulation signal z2 (t) (309B) are output. Here, if the information 315 on the weighting method indicates a space-multiplexed MIMO transmission method, the signal processing of method # 1 in FIG. 49 is performed. That is, the following processing is performed.

  However, when a scheme of transmitting one modulated signal is supported, equation (250) may be expressed as equation (251) from the viewpoint of transmission power.

  Then, when the information 315 on the weighting method indicates a MIMO transmission method in which the precoding matrix is fixed, for example, the signal processing of method # 2 in FIG. 49 is performed. That is, the following processing is performed.

Here, θ11, θ12, λ, and δ have fixed values.
FIG. 50 shows the configuration of a modulation signal when a space-time block code is used. The space-time block coding unit (5002) in FIG. 50 receives as input a baseband signal based on a certain modulation signal. For example, the space-time block coding unit (5002) takes as input symbols s1, symbols s2,. Then, as shown in FIG. 50, space-time block coding is performed, and z1 (5003A) is "s1 as symbol # 0", "-s2 ^* as symbol # 1", "s3 as symbol # 2", "symbol # 3 As-s4 ^* "... and z2 (5003B) becomes" s2 as symbol # 0 "" s1 ^* as symbol # 1 "" s4 as symbol # 2 "" s3 ^* "as symbol # 3 and so on. Become. At this time, the symbol # in z1
The symbol #X in X, z2 will be transmitted from the antenna at the same time and at the same frequency.

In FIG. 47 and FIG. 48, only symbols for transmitting data are described, but in actuality, it is necessary to transmit information such as a transmission method, a modulation method, an error correction method and the like. For example, as shown in FIG. 51, if the information is periodically transmitted by only one modulation signal z1, the information can be transmitted to the communication partner. In addition, it is necessary to transmit channel fluctuation, that is, a symbol for a receiver to estimate channel fluctuation (for example, pilot symbol, reference symbol, preamble, known (PSK: Phase Shift Keying) symbol for transmission and reception) . Although FIG. 47 and FIG. 48 omit and describe these symbols, actually, symbols for estimating channel fluctuation are included in the frame configuration of the time-frequency axis. Therefore, each carrier group is not composed only of symbols for transmitting data. (This point is the same as in Embodiment 1.)
FIG. 52 shows an example of the configuration of a transmitter of a broadcast station (base station) according to this embodiment. The transmission method determination unit (5205) determines the number of carriers in each carrier group, the modulation method, the error correction method, the coding rate of the error correction code, the transmission method, and the like, and outputs it as a control signal (5205).

  Modulation signal generation unit # 1 (5201_1) receives information (5200_1) and control signal (5205), and modulates carrier group #A in FIGS. 47 and 48 based on the information of the communication system of the control signal (5205). The signal z1 (5202_1) and the modulation signal z2 (5203_1) are output.

  Similarly, modulation signal generation unit # 2 (5201_2) receives information (5200_2) and control signal (5205) as input, and based on information of the communication system of control signal (5205), carrier group # in FIG. 47 and FIG. The modulation signal z1 (5202_2) of B and the modulation signal z2 (5203_2) are output.

  Similarly, modulation signal generation unit # 3 (5201_3) receives information (5200_3) and control signal (5205) as input, and based on information of the communication system of the control signal (5205), carrier group # in FIG. 47 and FIG. The C modulation signal z1 (5202_3) and the modulation signal z2 (5203_3) are output.

  Similarly, modulation signal generation unit # 4 (5201_4) receives information (5200_4) and control signal (5205) as input, and based on the information of the communication system of the control signal (5205), carrier group # in FIGS. The modulation signal z1 (5202_4) of D and the modulation signal z2 (5203_4) are output.

・
・
・
Similarly, the modulation signal generation unit #M (5201_M) receives the information (5200_M) and the control signal (5205), and based on the information of the communication system of the control signal (5205), the modulation signal z1 (5202_M) of a certain carrier group And the modulation signal z2 (5203_M).

The OFDM system related processing unit (5207_1) includes modulated signal z1 (5202_1) of carrier group #A, modulated signal z1 (5202_2) of carrier group #B, modulated signal z1 (5202_3) of carrier group #C, and carrier group #D. Modulation signal z1 (5202_4), ..., modulation signal z1 (5202_M) of a certain carrier group, and control signal (5206) are input, subjected to processing such as inverse Fourier transform, frequency conversion, amplification, etc. The transmission signal (5208_1) is output, and the transmission signal (5208_1) is output as a radio wave from the antenna (5209_1).

  Similarly, the OFDM system related processor (5207_2) modulates the modulated signal z1 (5203_1) of the carrier group #A, the modulated signal z2 (5203_2) of the carrier group #B, the modulated signal z2 (5203_3) of the carrier group #C, and the carrier Modulated signal z2 (5203_4) of group #D,..., Modulated signal z2 (5203_M) of a certain carrier group and control signal (5206) are input and rearranged, inverse Fourier transform, frequency conversion, amplification, etc. Processing is performed to output a transmission signal (5208_2), and the transmission signal (5208_2) is output as a radio wave from an antenna (5209_2).

FIG. 53 shows an example of the configuration of modulation signal generation units # 1 to #M in FIG. The error correction coding unit (5302) receives the information (5300) and the control signal (5301), and sets the error correction coding scheme and the coding rate of the error correction coding according to the control signal (5301). , Error correction coding is performed, and data (5303) after error correction coding is output. (For example, when using an LDPC code, turbo code, convolutional code, etc., depending on the coding rate, puncturing may be performed to realize a coding rate by setting an error correction coding method and a coding rate for error correction coding. May)
The interleaving unit (5304) receives the error-correction-coded data (5303) and the control signal (5301), and the error-correction encoded data (5303) according to the interleaving method information included in the control signal (5301). ) And outputs interleaved data (5305).

  Mapping section (5306_1) receives interleaved data (5305) and control signal (5301), performs mapping processing according to the modulation scheme information included in control signal (5301), and generates baseband signal (5307_1). Output.

  Similarly, mapping section (5306_2) receives interleaved data (5305) and control signal (5301), performs mapping processing according to the information of modulation scheme included in control signal (5301), Output 5307_2).

  The signal processing unit (5308) receives the baseband signal (5307_1), the baseband signal (5307_2) and the control signal (5301), and transmits the transmission method (here, for example, spatial multiplexing MIMO) included in the control signal (5301). Signal processing is performed based on information on transmission scheme, MIMO scheme using fixed precoding matrix, MIMO scheme to switch precoding matrix regularly, space-time block coding, transmission scheme to transmit only stream s1, and signals The processed signal z1 (5309_1) and the processed signal z2 (5309_2) are output. When the transmission method for transmitting only the stream s1 is selected, the signal processing unit (5308) may not output z2 (5309_2) after signal processing. Further, FIG. 53 shows the configuration in the case where there is one error correction coding unit, but the present invention is not limited to this. For example, as shown in FIG. 3, a plurality of encoders may be provided. .

FIG. 54 shows an example of the configuration of the OFDM system related processing units (5207_1 and 5207_2) in FIG. 52, and components that operate in the same manner as in FIG. The rearrangement unit (5402A) modulates the modulated signal z1 (5400_1) of the carrier group #A, the modulated signal z1 (5400_2) of the carrier group #B, the modulated signal z1 (5400_3) of the carrier group #C, and the modulation of the carrier group #D. Signal z1 (5400_4),..., Modulation signal z1 (5400_M) of a certain carrier group and control signal (5403) are input, they are rearranged, and rearranged signals 1405A and 1405B are output. In FIG. 47, FIG. 48, and FIG. 51, although an example in which carrier group allocation is configured by aggregated subcarriers is described, the present invention is not limited to this, and discrete subcarriers may be used every time. Carrier groups may be configured. Further, in FIG. 47, FIG. 48, and FIG. 51, although the number of carriers in the carrier group is described as an example which does not change in time, it is not limited to this. This point will be described later separately.

  FIG. 55 shows an example of the details of the frame configuration on the time-frequency axis of the scheme in which the transmission scheme is set for each carrier group as in FIG. 47, FIG. 48 and FIG. In FIG. 55, a control information symbol is indicated by 5500, an individual control information symbol by 5501, a data symbol by 5502, and a pilot symbol by 5503. 55 (A) shows a frame configuration on the time-frequency axis of stream s1, and FIG. 55 (B) shows a frame configuration on the time-frequency axis of stream s2.

  The control information symbol is a symbol for transmitting control information common to the carrier group, and is configured of a frequency, a symbol for performing time synchronization with the transceiver, information on assignment of (sub) carriers, and the like. Then, the control symbol is transmitted from only the stream s1 at time $ 1.

  The individual control information symbol is a symbol for transmitting control information specific to the subcarrier group, and is a data symbol of transmission system, modulation system, error correction coding system, coding rate of error correction coding, error correction code The information includes the information such as the block size, the information on the pilot symbol insertion method, the information on the transmission power of the pilot symbol, and the like. The individual control information symbol is assumed to be transmitted only from the stream s1 at time $ 1.

  A data symbol is a symbol for transmitting data (information), and as described with reference to FIGS. 47 to 50, for example, a spatial multiplexing MIMO transmission scheme, a MIMO scheme using a fixed precoding matrix, a rule It is a symbol of a transmission scheme of either the MIMO scheme in which the precoding matrix is switched in advance, space-time block coding, or the transmission scheme of transmitting only the stream s1. Although in the carrier group #A, the carrier group #B, the carrier group #C, and the carrier group #D, the data symbol is present in the stream s2, a transmission scheme in which only the stream s1 is transmitted is used. In this case, there may be no data symbol in the stream s2.

  The pilot symbol is a symbol for the receiver to estimate the channel estimation, that is, the variation corresponding to h11 (t), h12 (t), h21 (t) and h22 (t) in equation (36). (Here, since a multicarrier transmission scheme such as OFDM scheme is used, in order to estimate fluctuations corresponding to h11 (t), h12 (t), h21 (t), h22 (t) for each subcarrier) Therefore, the pilot symbols, for example, use a PSK transmission scheme, and are configured to have a known pattern at the transceiver. Also, the receiver may use the pilot symbol for frequency offset estimation, phase distortion estimation, and time synchronization.

FIG. 56 shows an example of the configuration of a receiving apparatus for receiving the modulated signal transmitted by the transmitting apparatus of FIG. 52, and the same reference numerals are given to those operating in the same manner as FIG.
In FIG. 56, the OFDM system related processor (5600 X) receives the received signal 702 X, performs predetermined processing, and outputs a signal 704 X after signal processing. Similarly, the OFDM system related processing unit (5600_Y) receives the received signal 702_Y, performs predetermined processing, and outputs a signal 704_Y after signal processing.

  Control information decoding section 709 in FIG. 56 receives signal 704 _X after signal processing and signal 704 _Y after signal processing as input, extracts control information symbols and individual control information symbols in FIG. 55, and transmits control information by these symbols And outputs a control signal 710 containing this information.

  The channel fluctuation estimation unit 705_1 of the modulated signal z1 receives the signal 704_X after signal processing and the control signal 710, and performs channel estimation in a carrier group (desired carrier group) required by the receiving apparatus to perform channel estimation. The signal 706_1 is output.

  Similarly, channel fluctuation estimation section 705_2 of modulated signal z2 receives as input signal 704_X after signal processing and control signal 710, and performs channel estimation in a carrier group (desired carrier group) required by the receiving apparatus. , Channel estimation signal 706_2 is output.

  Similarly, the channel fluctuation estimation unit 705_1 of the modulated signal z1 receives the signal 704_Y after signal processing and the control signal 710, and performs channel estimation in a carrier group (desired carrier group) required by the receiving apparatus. , Channel estimation signal 708_1 is output.

  Similarly, channel fluctuation estimation section 705_2 of modulated signal z2 receives as input signal 704_Y after signal processing and control signal 710, and performs channel estimation in a carrier group (desired carrier group) required by the receiving apparatus. , Channel estimation signal 708_2 is output.

  Then, the signal processing unit 711 receives the signals 706_1, 706_2, 708_1, 708_2, 704_X, and 704_Y and the control signal 710, and transmits the data symbol contained in the control signal 710 and transmitted on the desired carrier group. Based on the information such as the method, modulation method, error correction coding method, coding rate of error correction coding, block size of error correction code, demodulation and decoding processing is performed, and the received data 712 is output.

  FIG. 57 shows the configuration of the OFDM system related processor (5600 _X, 5600 _Y) in FIG. 56. The frequency converter (5701) receives the received signal (5700), performs frequency conversion, and performs frequency conversion. Output a signal (5702).

The Fourier transform unit (5703) receives the frequency-transformed signal (5702), performs Fourier transform, and outputs a Fourier-transformed signal (5704).
As described above, when a multicarrier transmission scheme such as OFDM scheme is used, reception quality and transmission are determined for each carrier group by dividing into a plurality of carrier groups and setting the transmission scheme for each carrier group. Since the speed can be set, an effect that a flexible system can be built can be obtained. At this time, high reception quality can be obtained for the LOS environment, and high transmission speed can be obtained by enabling selection of a method of regularly switching precoding matrices as described in the other embodiments. The advantage of being able to obtain is obtained. In this embodiment, as a transmission method that can set a carrier group, “a space multiplex MIMO transmission method, a MIMO method using a fixed precoding matrix, a MIMO method that regularly switches a precoding matrix, a space-time block "Encoding, transmission scheme for transmitting only stream s1" is mentioned, but it is not limited to this. At this time, although the scheme of FIG. 50 has been described as a space-time code, it is not limited to this. The MIMO scheme using a typical precoding matrix is not limited to scheme # 2 in FIG. 49, and may be configured by a fixed precoding matrix. Further, in the present embodiment, the number of antennas of the transmitting apparatus has been described in the case of two, but the number of antennas is not limited to this. If it is possible to select one of the MIMO scheme using precoding matrix, the MIMO scheme in which precoding matrix is switched regularly, space-time block coding, and the transmission scheme of transmitting only stream s1, the same effect can be obtained. You can get it.

  FIG. 58 shows a carrier group allocation method different from those in FIGS. 47, 48, and 51. In FIG. 47, FIG. 48, FIG. 51, and FIG. 55, allocation of carrier groups is described using an example of aggregation of subcarriers, but in FIG. 58 carriers of carrier groups are discretely arranged. It is characterized by FIG. 58 shows an example of a frame configuration on the time-frequency axis different from FIGS. 47, 48, 51 and 55. In FIG. 58, carrier 1 to carrier H, time $ 1 to time $ K The same reference numerals are given to those similar to FIG. In the data symbol of FIG. 58, the symbol described as "A" is a symbol of carrier group A, the symbol described as "B" is a symbol of carrier group B, described as "C" It indicates that the symbol being performed is a symbol of carrier group C, and the symbol described as "D" is a symbol of carrier group D. In this way, carrier groups can be implemented similarly even if they are discretely arranged in the (sub) carrier direction, and it is not necessary to always use the same carrier in the time axis direction. By such an arrangement, it is possible to obtain the effect that time and frequency diversity gains can be obtained.

In FIG. 47, FIG. 48, FIG. 51, and FIG. 58, the control information symbol and the unique control information symbol are arranged at the same time for each carrier group, but may be arranged at different times. Also, the number of (sub) carriers used by the carrier group may be changed with time.


Sixteenth Embodiment
In the present embodiment, as in the tenth embodiment, a method of regularly switching precoding matrices using a unitary matrix will be described in the case where N is an odd number.

  In the method of regularly switching the precoding matrix of period 2N, the precoding matrix prepared for period 2N is expressed by the following equation.

  It is assumed that α> 0 and it is a fixed value (regardless of i).

It is assumed that α> 0 and it is a fixed value (regardless of i). (Alpha of formula (253) and formula (2
It is assumed that α in 54) has the same value. )
At this time, under the condition 5 of (Equation 106) of the third embodiment and the condition 6 of (Equation 107), the following condition is satisfied with respect to the equation (253) in order to obtain good reception quality of data: It becomes important.

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

(X is 0, 1, 2, ..., N-2, N-1, y is 0, 1, 2, ..., N-2, N-1, x ≠ y .)

Then, consider adding the following conditions.

  Next, as described in the sixth embodiment, <condition # 49> or <condition # 50> is set to arrange reception poor points on the complex plane so as to have uniform distribution with respect to the phase. give.

That is, <condition 49> means that the phase difference is 2π / N radians. Further, <Condition 50> means that the phase difference is −2π / N radians.
And when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, it is assumed that the reception inferiority of s1 and the reception inferiority of s2 when N = 3 on the complex plane The arrangement is shown in FIG. 60 (a) (b)
Shown in. As can be seen from FIGS. 60 (a) and 60 (b), in the complex plane, the minimum distance of reception inferior points of s1 is kept large, and, similarly, the minimum distance of reception inferior points of s2 is also large. There is. Then, the same state is obtained when α <1. Also, in comparison with FIG. 45 of the tenth embodiment, considering in the same manner as the ninth embodiment, the distance between reception inferior points in the complex plane in the case where N is an odd number is compared with the case where N is an even number. Is likely to be large. However, when N is a small value, for example, N ≦ 16 or less, the minimum distance of poor reception points in the complex plane can secure a certain length since the number of poor reception points is small. Therefore, in the case of N ≦ 16, there is a possibility that data reception quality can be ensured even if it is even.

Therefore, in the scheme of regularly switching the precoding matrix based on Equations (253) and (254), if N is an odd number, there is a high possibility that the reception quality of data can be improved. In addition, the precoding matrix of F [0] to F [2N-1] is generated based on the equations (253) and (254) (the precoding matrix of F [0] to F [2N-1] is generated. May be used in any order with respect to the cycle 2N). Then, for example, precoding is performed using F [0] when symbol number 2Ni, precoding using F [1] when symbol number 2Ni + 1,..., F when symbol number 2N × i + h Precoding is performed using [h] (h = 0, 1, 2, ..., 2N-2, 2N-1). (Here, as described in the previous embodiment, the precoding matrix does not necessarily have to be switched regularly.) Also, when the modulation schemes of s1 and s2 are both 16 QAM, α is In this case, it is possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.

  Also, the following conditions are considered as conditions different from <condition # 48>.

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)

(X is N, N + 1, N + 2, ..., 2N-2, 2N-1, y is N, N + 1, N + 2, ..., 2N-2, 2N-1 And x ≠ y.)
At this time, by satisfying <condition # 46>, <condition # 47>, and <condition # 51> and <condition # 52>, the distance between poor reception points of s1 in the complex plane is large, and s2 is large. Since the distance of poor reception points can be increased, good data reception quality can be obtained.

  In this embodiment, the method of constructing 2N different precoding matrices for the precoding hopping method with time period 2N has been described. At this time, F [0], F [1], F [2],..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since the present embodiment is described with the single carrier transmission method as an example, in the time axis (or frequency axis) direction, F [0], F [1], F [2],. , F [2N-2], and F [2N-1] are described in this order, but the present invention is not necessarily limited thereto, and 2N different precoding matrices F [0] generated in this embodiment are used. , F [1], F [2],..., F [2N-2], F [2N-1] can also be applied to a multicarrier transmission scheme such as an OFDM transmission scheme. As to the application method in this case, as in the first embodiment, the precoding weights can be changed by arranging symbols on the frequency axis and the frequency-time axis. Although the precoding hopping method with a time period of 2N is described, the same effect can be obtained by using 2N different precoding matrices at random, that is, a regular period is not always required. It is not necessary to use 2N different precoding matrices to have.

In addition, in the precoding matrix switching method of period H (H is a scheme in which the precoding matrix is switched regularly as described above, period 2N is a larger natural number), 2N different precoding matrices in the present embodiment are included. Is likely to give good reception quality.

Embodiment A1
In this embodiment, hierarchical transmission is applied when transmitting data, and the transmission method when using the method of regularly switching the precoding matrix described in the first to sixteenth embodiments will be described in detail. Do.

  61 and 62 show an example of the configuration of a transmitter of a broadcast station, for example, in this embodiment. The error correction coding unit (6101_1) for the base stream (base layer) receives the information (6100_1) of the base stream (base layer), performs error correction coding, and performs coding on the base stream (base layer) Output information (6102_1).

  The error correction coding unit (6101_2) for the extension stream (extension layer) takes the information (6100_2) of the extension stream (extension layer) as input, performs error correction coding, and encodes the extension stream (extension layer) Output information (6102_2).

  The interleaving unit (6103_1) receives the information (6102_1) of the basic stream (basic layer) after encoding, performs interleaving, and outputs the data after interleave (6104_1) after encoding.

  Similarly, the interleaving unit (6103_2) receives as input the information (6102) of the extension stream (extension layer) after coding, performs interleaving, and outputs the data after coding (6104_2) after interleaving.

The mapping unit (6105_1) receives the encoded data after interleaved (6104_1) and the information signal (6111) related to the transmission method as input, and based on the transmission method specified by the information signal (6111) related to the transmission method, by modulating the predetermined modulation method, a baseband signal (6106_1) to _(s 1 in FIG. 3 (t) (307A) to the corresponding) and the baseband signal (6106_2) _(s 2 in FIG. 3 (t) (307B) Output). As the information (6111) on the transmission method, for example, a transmission method at the time of hierarchical transmission (a modulation method, a transmission method, and a transmission method for regularly switching the precoding matrix) This information is information such as the coding matrix) and the error correction code method (type of code, coding rate).

Similarly, the mapping unit (6105_2) receives the encoded data (6104_2) after interleaving and the information signal (6111) related to the transmission method as input, and the transmission method specified by the information signal (6111) related to the transmission method The base band signal (6107_1) (corresponding to s ₁ (t) (307 A) in FIG. 3) and the baseband signal (6107 _2) (s ₂ (t) in FIG. Output corresponding to 307B).

Precoding unit (6108_1) is equivalent to the baseband signal (6106_1) (corresponding to _s 1 in FIG. 3 (t) (307A)) and the baseband signal (6106_2) _(s in Fig. 3 2 (t) (307B) And an information signal (6111) relating to the transmission method, and precoding is performed based on the regular precoding matrix switching method specified by the information signal (6111) relating to the transmission method, and baseband after precoding and it outputs a signal (6109_1) (corresponding to _z 2 of FIG. 3 (t) (309B)) _(z 1 in FIG. 3 (t) (corresponding to 309A)) and a baseband signal after precoding (6109_2).

Similarly, the precoding unit (6108_2) performs baseband signal (6107_1)
(Equivalent to s ₁ (t) (307 A) in FIG. 3), baseband signal (6107_2) (equivalent to s ₂ (t) (307 B) in FIG. 3), and an information signal (6111) related to the transmission method Then, precoding is performed based on the regular precoding matrix switching method specified by the information signal (6111) related to the transmission method, and the baseband signal after precoding (6110_1) (z ₁ (t) (FIG. 3) And a baseband signal (6110_2) after precoding (corresponding to z ₂ (t) (309 B) in FIG. 3).

  In FIG. 62, the reordering unit (6200_1) takes the baseband signal (6109_1) after precoding and the baseband signal (6110_1) after precoding as input, performs reordering, and performs precoding after reordering. The latter baseband signal (6201_1) is output.

  Similarly, the reordering unit (6200_2) takes as input the baseband signal after precoding (6109_2) and the baseband signal after precoding (6110_2), performs reordering, and after reordering after precoding The baseband signal (6201_2) of

  The OFDM system related processing unit (6202_1) receives as input the baseband signal (6201_1) after precoding after rearrangement, performs the signal processing described in the first embodiment, and outputs a transmission signal (6203_1) for transmission The signal (6203_1) is output from the antenna (6204_1).

  Similarly, the OFDM system related processing unit (6202_2) receives the baseband signal (6201_2) after precoding after reordering as an input, performs the signal processing described in the first embodiment, and outputs a transmission signal (6203_2). The transmission signal (6203_2) is output from the antenna (6204_2).

FIG. 63 is a diagram for explaining the operation of the precoding unit (6108_1) in FIG. 61. The configuration and operation are the same as the configurations and operations described in FIG. 3, FIG. 6, FIG. Suppose that precoding matrices are switched regularly. FIG. 63 is a description of the precoding unit (6108_1) in FIG. 61, and thus shows the operation of weighting and combining for a base stream (base layer). As shown in FIG. 63, when the precoding unit 6108_1 performs weighted combining, that is, when performing precoding to generate a baseband signal after precoding, the precoding matrix is switched regularly. By performing precoding, z ₁ (t) and z ₂ (t) are generated. Here, in the precoding for the base stream (base layer), it is assumed that the precoding matrix is switched as period 8, and the precoding matrix for weighting and combining is F [0], F [1], F [2 ], F [3], F [4], F [5], F [6], F [7]
It shall be expressed as At this time, each symbol of the signals z ₁ (t) and z ₂ (t) after precoding is represented as 6301 and 6302. In FIG. 63, “base #X F [Y]” is shown, which is the X-th symbol of the base stream (base layer), and F [Y] is used for this X-th symbol. It is indicated that precoding is performed using a precoding matrix (here, Y is any of 0 to 7).

FIG. 64 is a diagram for explaining the operation of the precoding unit (6108_2) in FIG. 61. The configuration and operation are the same as the configurations and operations described in FIG. 3, FIG. 6, FIG. Suppose that precoding matrices are switched regularly. FIG. 64 is a description of the precoding unit (6108_2) of FIG. 61, and thus shows the operation of weighting and combining for the extension stream (extension layer). As shown in FIG. 64, when the precoding unit 6108_1 performs weighted combining, that is, when performing precoding to generate a baseband signal after precoding, the precoding matrix is switched regularly. By performing precoding, z ₁ (t) and z ₂ (t) are generated. Here, in the precoding for the extension stream (extension layer), it is assumed that the precoding matrix is switched as period 4 and the precoding matrix for weighting and combining is f [0], f [1], f [2 and f [3]. At this time, each symbol of the signals z ₁ (t) and z ₂ (t) after precoding is represented as 6403 and 6404. In FIG. 64, “expansion #X f [Y]” is shown, which is the X-th symbol of the extension stream (extension layer), and f [Y] is used for this X-th symbol. It indicates that precoding is performed using a precoding matrix (here, Y is any of 0 to 4).

  FIG. 65 is a diagram showing a symbol sorting method of the sorting unit (6200_1) and the sorting unit (6200_2) in FIG. The rearrangement unit (6200_1) and the rearrangement unit (6200_2) arrange the symbols shown in FIGS. 63 and 64 on the frequency axis and the time axis as shown in FIG. At this time, symbols of the same (sub) carrier and the same time are transmitted from the respective antennas at the same frequency and the same time. The arrangement of symbols on the frequency axis and time axis shown in FIG. 65 is an example, and the symbols may be arranged based on the arrangement method described in Embodiment 1.

When transmitting the base stream (base layer) and the extension stream (extension layer), the reception quality of the data of the base stream (base layer) is the reception quality of the data of the extension stream (extension layer) due to the nature of each stream (layer) Need to be higher. For this reason, as in the present embodiment, when using a method of regularly switching the precoding matrix, the modulation method in transmitting the base stream (base layer) and the modulation in transmitting the extension stream (extension stream) The scheme will be set differently. For example, as shown in Table 3, it is conceivable to use any of the modes # 1 to # 5.

Along with this, the method of switching the regular precoding matrix used when transmitting the base stream (base layer) differs from the method of switching the regular precoding matrix used when transmitting the extension stream (extension stream) Such setting may improve the reception quality of data in the receiving apparatus or may simplify the configuration of the transmitting apparatus and the receiving apparatus. As an example, as shown in FIG. 63 and FIG. 64, when using the modulation scheme according to the modulation multi-level number (the number of signal points on the IQ plane), the method of regularly switching the precoding matrix is different It may be good. Therefore, the period in the switching method of the regular precoding matrix used when transmitting the base stream (base layer) and the period in the switching method of the regular precoding matrix used when transmitting the extension stream (extension layer) Is an effective means in improving the reception quality of data in the receiver or simplifying the configuration of the transmitter and the receiver, and it is also possible to make the basic stream (base layer) Method of constructing precoding matrix in switching method of regular precoding matrix used in transmission and configuration of precoding matrix in switching method of regular precoding matrix used in transmission of extension stream (extension layer) The method may be different. Therefore, the precoding matrix switching method is set as shown in Table 4 for the settable modes of the modulation method of each stream (layer) in Table 3. (In Table 4, A, B, C, and D indicate that they are different precoding switching methods.)

  Therefore, in the transmitters of the broadcast stations shown in FIGS. 61 and 62, the precoding methods in the precoding units (6108_1 and 6108_2) are switched together with the switching of the modulation scheme in the mapping units (6105_1 and 6105_2). Table 4 is merely an example, and the precoding matrix switching method may be the same even if the modulation scheme is different. For example, the precoding matrix switching method for 64 QAM and the precoding matrix switching method for 256 QAM may be the same. The point is that there is more than one type of precoding matrix switching method when there are multiple supported modulation schemes. This point is not limited to the case where hierarchical transmission is used, and the relationship as described above for the method of switching between the modulation scheme and the precoding matrix is given even when hierarchical transmission is not used. The data reception quality may be improved, or the configuration of the transmission device or the reception device may be simplified.

As a system, a system that supports not only hierarchical transmission but also transmission that does not use hierarchical transmission can be considered. In this case, when performing transmission without using hierarchical transmission in FIGS. 61 and 62, the operation of the functional unit related to the extension stream (extension layer) is stopped, and only the basic stream (base layer) is transmitted. It will be. Therefore, in such a case, the correspondence table relating to the settable modes, modulation methods, and precoding matrix switching methods corresponding to Table 4 described above is as shown in Table 5.

  In Table 5, modes # 1 to # 5 are modes when hierarchical transmission is used, and modes # 6 to # 10 are modes when hierarchical transmission is not used. At this time, the precoding switching method is to set a precoding switching method suitable for each mode.

  Next, the operation of the receiving apparatus when hierarchical transmission is supported will be described. The configuration of the receiving apparatus in this embodiment can be configured as shown in FIG. 7 described in Embodiment 1. At this time, FIG. 66 shows a configuration of the signal processing unit 711 of FIG.

  In FIG. 66, reference numeral 6601X denotes a channel estimation signal, which corresponds to channel estimation signal 706_1 in FIG. 6602X is a channel estimation signal, which corresponds to the channel estimation signal 706_2 of FIG. 6603X is a baseband signal, which corresponds to the baseband signal 704 X in FIG. 6604 is a signal related to the information of the transmission method notified by the transmission apparatus, and corresponds to the signal 710 related to the information of the transmission method notified by the transmission apparatus of FIG.

  6601Y is a channel estimation signal, which corresponds to the channel estimation signal 708_1 of FIG. 6602Y is a channel estimation signal, which corresponds to the channel estimation signal 708_2 in FIG. 6603Y is a baseband signal, which corresponds to the baseband signal 704_Y in FIG.

  The signal distribution unit (6605) receives as input the channel estimation signals (6601X, 6602X, 6601Y, 6602Y), the baseband signals (6603X, 6603Y), and the signal (6604) relating to the transmission method information notified by the transmitting apparatus. Based on the signal (6604) on the transmission method information notified by the transmission apparatus, the signal is distributed to the signal on the basic stream (base layer) and the information on the extension stream (extension layer), and channel estimation signals for the basic stream (6606_1, 6607_1, 6609_1, 6610_1), baseband signals for the base stream (6608_1, 6611_1), and channel estimation signals for the extension stream (6606_2, 6607_2, 6609_2, 6610_2), the base stream for the extension stream Baseband and outputs a signal (6608_2,6611_2).

The detection and log likelihood ratio calculation unit (6612_1) is a processing unit for the base stream (base layer), and the channel estimation signals (6606_1, 6607_1, 6609_1, 6610_1) for the base stream, the baseband signal for the base stream (the base stream (base layer). 6608_1, 6611_1) and a signal (6604) relating to transmission method information notified by the transmission apparatus, and from the signal (6604) relating to transmission method information notified by the transmission apparatus, for the basic stream (base layer) The modulation scheme and precoding matrix switching method are estimated, detection based on them and precoding decoding are performed, the log likelihood ratio of each bit is calculated, and the log likelihood ratio signal (6613_1) is output. In Table 5, the detection and log likelihood ratio calculation unit (6612_1) performs detection and precoding decoding even in the modes # 6 to # 10 in which no extension stream (extension layer) is present, and the log likelihood Output ratio signal.

  The detection and log likelihood ratio calculation unit (6612_2) is a processing unit for the extension stream (extension layer), and channel estimation signals (6606_2, 6607_2, 6609_2, 6610_2) for the extension stream, and baseband signals for the extension stream ( 6608_2, 6611_2) and a signal (6604) related to transmission method information notified by the transmission apparatus, from the signal (6604) related to transmission method information notified by the transmission apparatus, for the extension stream (extension layer) The modulation scheme and precoding matrix switching method are estimated, detection based on them and precoding decoding are performed, the log likelihood ratio of each bit is calculated, and the log likelihood ratio signal (6613_2) is output. In Table 5, in the modes # 6 to # 10 in which the extension stream (extension layer) does not exist, the operation is stopped.

  In the transmitting apparatus described with reference to FIGS. 61 and 62, only the hierarchical transmission method is described, but in fact, when information on the transmission method is performed separately from the hierarchical transmission method, for example, hierarchical transmission Transmission method (modulation method, transmission method, information about precoding matrix used when transmitting method to switch precoding matrix regularly), error correction code method (type of code, coding rate), etc. The information needs to be transmitted to the receiver. Also, in the receiving apparatus, channel estimation (estimation of propagation fluctuation), frequency synchronization, frequency offset estimation, pilot symbols for signal detection, reference symbols, and preambles have a frame configuration that exists separately in the transmission signal. This is true not only for the embodiment A1 but also for the embodiment A2 and subsequent embodiments.

Deinterleaver (6614_1) receives log likelihood ratio signal (6613_1), performs reordering, and outputs deinterleaved log likelihood ratio signal (6615_1).
Similarly, the deinterleaver (6614_2) receives the log likelihood ratio signal (6613_2), performs reordering, and outputs the deinterleaved log likelihood ratio signal (6615_2).

The decoding unit (6616_1) receives the deinterleaved log likelihood ratio signal (6615_1), performs error correction decoding, and outputs reception information (6617_1).
Similarly, the decoding unit (6616_2) receives the deinterleaved log likelihood ratio signal (6615_2), performs error correction decoding, and outputs reception information (6617_2).

As shown in Table 5, if the transmission mode exists,
-As described in Embodiment 1, the transmitting apparatus transmits information on the precoding matrix used in the precoding matrix switching method, and the detection and log likelihood ratio calculation units (6612_1, 6612_2) transmit this information. As described in the seventh embodiment, the transmitting and receiving apparatus share the information in Table 5 in advance, and the transmitting apparatus transmits the information on the mode to obtain the receiving apparatus. There is a method of estimating the precoding matrix used in the precoding matrix switching method based on Table 5, and performing precoding decoding.

As described above, when hierarchical transmission is used, the above-described precoding matrix switching method can achieve the effect of improving the reception quality of data.
In this embodiment, in the method of regularly switching the precoding matrix, an example in which the periods are 4 and 8 has been described, but the period is not limited to this. Therefore, N different precoding matrices are required for the period N precoding hopping method. At this time, F [0], F [1], F [2], ... as N different precoding matrices.
· Although F [N-2] and F [N-1] are prepared, in the present embodiment, F [0], F [1], F [2],. The description has been made of the case of arranging in order of F [N-2] and F [N-1], but the present invention is not necessarily limited to this, and N different precoding matrices F [0 generated in this embodiment] ]
, F [1], F [2],..., F [N-2], F [N-1] as in the first embodiment, symbols are arranged with respect to time axis and frequency-time axis. By doing this, it is possible to change the precoding weight. Although the precoding hopping method with period N is described, the same effect can be obtained by using N different precoding matrices at random, that is, it always has a regular period. Thus, it is not necessary to use N different precoding matrices.

Also, Table 5 describes the case where there is a mode of the method of regularly switching the precoding matrix without using the hierarchical transmission method as an example when hierarchical transmission is not used, but the mode which exists is limited to this. As described in Embodiment 15, the spatial multiplexing MIMO transmission scheme, the MIMO transmission scheme in which the precoding matrix is fixed, the space-time block coding scheme, and the mode of transmission of only one stream are the same as those described in the fifteenth embodiment. In addition to the hierarchical transmission method described above, the transmission apparatus (broadcast station, base station) may be able to select any transmission method from these modes. At this time, in the case of hierarchical transmission or hierarchical transmission in the spatial multiplexing MIMO transmission scheme, the MIMO transmission scheme in which the precoding matrix is fixed, the space-time block coding scheme, and only one stream transmission mode. May also be supported. Also, a mode using another transmission method may exist. Then, the present embodiment is applied to the fifteenth embodiment, and in the fifteenth embodiment, the method of regularly switching the precoding matrix described in the present embodiment in any (sub) carrier group is used. A hierarchical transmission method may be applied.

Embodiment A2
Although Embodiment A1 describes a method of realizing hierarchical transmission by a method of regularly switching precoding matrices, this embodiment describes a method of realizing hierarchical transmission different from this.

  67 and 68 show the configuration of the transmitting apparatus when hierarchical transmission in this embodiment is used, and elements that operate in the same manner as in FIGS. 61 and 62 are assigned the same reference numerals. . The difference from FIG. 61 in FIG. 67 is that precoding unit 6108_1 is not provided, and in the present embodiment, precoding is not performed on the basic stream (layer) in the embodiment A1. It is different.

  The mapping unit (6105_1) in FIG. 67 receives as input the encoded data (6104_1) after interleaving and an information signal (6111) related to the transmission method, and performs predetermined modulation based on the information signal (6111) related to the transmission method Mapping of the scheme is performed to output a baseband signal (6700).

The reordering unit (6200_1) in FIG. 68 receives a baseband signal (6700), a baseband signal (6110_1) after precoding, and an information signal (6111) related to the transmission method as input signals related to the transmission method (6111) It rearranges based on it, and outputs the baseband signal (6201_1) after rearrangement.

  The rearrangement unit (6200_2) receives the baseband signal (6110_2) after precoding and the information signal (6111) related to the transmission method as input, and performs rearrangement based on the information signal (6111) related to the transmission method, and after rearrangement The baseband signal (6201_2) of

  FIG. 69 shows an example of the symbol configuration of the baseband signal of FIG. 67, and 6901 is its symbol group. In the symbol group (6901), “group #X” is described, which indicates “Xth symbol of basic stream (basic layer)”. The symbol configuration of the extension stream (extension layer) is as shown in FIG.

  FIG. 70 is a diagram showing a method of rearranging (6200_1) and (6200_2) in FIG. The symbols shown in FIGS. 64 and 69 are arranged on the frequency axis and the time axis as shown in FIG. In FIG. 70, "-" means that there is no symbol. At this time, symbols of the same (sub) carrier and the same time are transmitted from the respective antennas at the same frequency and the same time. Note that the arrangement of symbols on the frequency axis and the time axis in FIG. 70 is an example, and the symbols may be arranged based on the arrangement method described in Embodiment 1.

When transmitting the base stream (base layer) and the extension stream (extension layer), the reception quality of the data of the base stream (base layer) is the reception quality of the data of the extension stream (extension layer) due to the nature of each stream (layer) Need to be higher. Therefore, as in the present embodiment, when transmitting the basic stream, data reception quality is ensured by transmitting using only the modulation signal z ₁ (that is, not transmitting the modulation signal z ₂ ). . On the other hand, when transmitting the extension stream, hierarchical transmission is realized by using a method of regularly switching the precoding matrix in order to prioritize transmission speed improvement. For example, as shown in Table 6, it is conceivable to use one of the modes # 1 to # 9.

  The characteristic point in Table 6 is that the modulation scheme of the base stream (base layer) and the modulation scheme of the extension stream (extension layer) can be made the same. This means that even if the modulation method is the same, the transmission quality that can be secured by the base stream (base layer) and the transmission quality that can be secured by the extension stream (extension layer) use different transmission methods for each stream (layer) Because it is different.

  The configuration of the receiving apparatus in this embodiment is as shown in FIG. 7 and FIG. The difference in operation from the embodiment A1 is that the detection and log likelihood ratio calculation unit (6612_1) in FIG. 66 does not perform precoding decoding.

  Also, in the extension stream (extension layer), a method of regularly switching the precoding matrix is used. At this time, if the transmitting apparatus transmits information on the precoding method, the receiving apparatus By obtaining the information, it is possible to know the precoding method used. As another method, when Table 6 is shared by the transmitting and receiving apparatus, the transmitting apparatus transmits mode information and obtains mode information to know the precoding method used in the extension stream (extension layer). be able to. Therefore, by changing the signal processing method in the detection and log likelihood ratio calculation unit in the receiving apparatus of FIG. 66, it is possible to obtain the log likelihood ratio for each bit. Note that although the modes that can be set have been described using Table 6, the present invention is not limited to this, and the modes of the transmission method described in the eighth embodiment and the modes of the transmission method described in the following embodiments Can be implemented as well.

As described above, when hierarchical transmission is used, the above-described precoding matrix switching method can be advantageously used to improve the reception quality of data in the receiving apparatus according to the present embodiment. The period of precoding matrix switching in the method of regularly switching the precoding matrix is not limited to this. For the period N precoding hopping method, N different precoding matrices are required. At this time, F [0], F [1], F [2],..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, in the present embodiment, F [0], F [1], F [2],.
, F [N-2], and F [N-1] are described in this order, but the present invention is not necessarily limited thereto, and N different precoding matrices F [0] generated in the present embodiment are described. , F [1], F [2],.
· · · Precoding weight can be changed by arranging symbols for time axis and frequency-time axis in the same manner as in the first embodiment with F [N-2] and F [N-1]. it can. Note that the period N
The same effect can be obtained even if N different precoding matrices are used at random, that is, N not necessarily have a regular period. It is not necessary to use different precoding matrices of.

In addition, Table 6 describes the mode of the hierarchical transmission method according to the present embodiment, but the present mode is not limited to this, and as described in Embodiment 15, the spatial multiplexing MIMO transmission method, A mode of MIMO transmission method with fixed precoding matrix, space-time block coding method, transmission of only one stream, and method of switching precoding matrix regularly exists separately from the hierarchical transmission method described in this embodiment. The transmitting apparatus (broadcast station, base station) may be able to select one of the transmission methods from these modes. At this time, hierarchical transmission is performed in a mode of spatial multiplexing MIMO transmission scheme, MIMO transmission scheme with fixed precoding matrix, space-time block coding scheme, transmission of only one stream, and regular precoding matrix switching. Either case of hierarchical transmission may not be supported. Also, a mode using another transmission method may exist. The present embodiment may be applied to the fifteenth embodiment, and the hierarchical transmission method described in the present embodiment may be applied to any (sub) carrier group in the fifteenth embodiment.

Embodiment A3
In this embodiment, an implementation of hierarchical transmission different from those in Embodiments A1 and A2 will be described.

  FIG. 71 and FIG. 72 show the configuration of the transmitting apparatus when hierarchical transmission in this embodiment is used, and the elements operating in the same manner as FIG. 61 and FIG. . The difference from FIG. 61 in FIG. 71 is that a space-time block coding unit 7101 is provided, and in the present embodiment, a space-time block code is applied to the basic stream (layer). It is different from A2.

The space-time block coding unit (in some cases, the frequency-space block coding unit) (7101) in FIG. 71 includes the baseband signal (7100) after mapping and the information signal (6111) related to the transmission method. Space-time block coding is performed on the basis of an information signal (6111) relating to a transmission method as an input, and a baseband signal (7102) (expressed as z ₁ (t)) after space-time block coding, and space-time block The encoded baseband signal (7102_2) (denoted as z ₂ (t)) is output.

  Here, although it is called space-time block code, arranging the space-time block coded symbols in order in the time axis direction is not limited, but it is possible to arrange the space-time block coded symbols in order in the frequency axis direction Good. Alternatively, a block may be formed by a plurality of time axis symbols and a plurality of frequency axis symbols, and may be appropriately arranged in this block (that is, both time and frequency axes may be used and arranged). .

  The rearrangement unit (6200_1) in FIG. 72 receives the baseband signal (7102_1) after space-time block coding, the baseband signal (6110_1) after precoding, and the information signal (6111) related to the transmission method as input, and transmits Reordering is performed based on the information signal (6111) relating to, and the post-sorted baseband signal (6201_1) is output.

  Similarly, the rearrangement unit (6200_2) receives the baseband signal after space-time block coding (7102_2), the baseband signal after precoding (6110_2), and the information signal (6111) related to the transmission method as the transmission method. Are rearranged on the basis of the information signal (6111) relating to V.4 and the baseband signal (6201_2) after the rearrangement is output.

FIG. 73 shows an example of symbol configurations of baseband signals (7102_1, 7102_2) after space-time block coding output from the space-time block coding unit (7101) in FIG. The symbol group (7301) corresponds to the baseband signal (7102_1) (represented as z ₁ (t)) after space-time block coding, and the symbol group (7302) corresponds to the baseband signal after space-time block coding It corresponds to (7102_2) (represented as z ₂ (t)).

Symbols output by the mapping unit (6105_1) in FIG. 71 are, in order, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s10, s11, s12,. Then, the space-time block coding unit (7101) in FIG. 71 performs space-time block coding on s1 and s2 to generate s1 and s2, and s1 ^* and -s2 ^* ( ^* : conjugate complex , As shown in FIG. Similarly, space-time block coding is performed on each set of (s3, s4), (s5, s6), (s7, s8), (s9, s10), (s11, s12),. Symbols will be arranged as shown in FIG. In addition, it can implement similarly not only using the space-time block code demonstrated in this Embodiment, but using another space-time block code.

  FIG. 74 is an example of a diagram showing a method of rearranging (6200_1) and (6200_2) in FIG. 72. FIG. 74A shows an example of arrangement of symbols on the time axis of the modulation signal z1 and on the frequency axis. Further, FIG. 74 (B) shows an exemplary arrangement of symbols on the time axis of the modulation signal z2 and on the frequency axis. At this time, symbols of the same (sub) carrier and the same time are transmitted from the respective antennas at the same frequency and the same time. A characteristic point of FIG. 74 is that space-time block coded symbols are arranged in order on the frequency axis.

  FIG. 75 is an example of a diagram showing a method of rearranging the rearranging unit (6200_1) and the rearranging unit (6200_2) in FIG. FIG. 75A shows an example of arrangement of symbols on the time axis of the modulation signal z1 and on the frequency axis. Further, FIG. 75 (B) shows an exemplary arrangement of symbols on the time axis of the modulation signal z2 and on the frequency axis. At this time, symbols of the same (sub) carrier and the same time are transmitted from the respective antennas at the same frequency and the same time. A characteristic point of FIG. 75 is that space-time block coded symbols are arranged in order on the time axis.

In this way, space-time block-coded symbols can be arranged on the frequency axis, and can also be arranged on the time axis.
When transmitting the base stream (base layer) and the extension stream (extension layer), the reception quality of the data of the base stream (base layer) is the reception quality of the data of the extension stream (extension layer) due to the nature of each stream (layer) Need to be higher. Therefore, as in the present embodiment, when transmitting the basic stream, the reception quality of data is ensured by using a space-time block code and obtaining diversity gain. On the other hand, when transmitting the extension stream, hierarchical transmission is realized by using a method of regularly switching the precoding matrix in order to prioritize transmission speed improvement. For example, as shown in Table 7, it is conceivable to use one of the modes # 1 to # 9.

The characteristic point in Table 7 is that the modulation scheme of the base stream (base layer) and the modulation scheme of the extension stream (extension layer) can be made the same. This means that even if the modulation method is the same, the transmission quality that can be secured by the base stream (base layer) and the transmission quality that can be secured by the extension stream (extension layer) use different transmission methods for each stream (layer) Because it is different.

  Although modes # 1 to # 9 in Table 7 show the modes of hierarchical transmission, modes other than the mode of hierarchical transmission may be simultaneously supported. In the case of the present embodiment, there may be a mode of only space-time block code, a single mode of regularly switching the precoding matrix as a mode that is not hierarchical transmission, and the transmitting apparatus and receiving apparatus in the present embodiment. In the case of supporting the hierarchical transmission mode of Table 7, it is possible to easily set a single mode of space-time block code only mode and a single mode of regularly switching the precoding matrix.

  In the extension stream (extension layer), a method of regularly switching the precoding matrix is used. At this time, if the transmitting apparatus transmits information on the precoding method, the receiving apparatus should By obtaining, it is possible to know the precoding method used. As another method, when Table 7 is shared by the transmitting and receiving apparatus, the transmitting apparatus transmits mode information and obtains mode information to know the precoding method used in the extension stream (extension layer). be able to. Therefore, by changing the signal processing method in the detection and log likelihood ratio calculation unit in the receiving apparatus of FIG. 66, it is possible to obtain the log likelihood ratio for each bit. Note that although the modes that can be set are described using Table 7, the present invention is not limited to this, and the modes of the transmission method described in the eighth embodiment and the modes of the transmission method described in the following embodiments Can be implemented as well.

  As described above, when hierarchical transmission is used, the effect of improving the reception quality of data in the receiving apparatus can be obtained by using the above-described precoding matrix switching method.

In the present embodiment, the period of precoding matrix switching in the method of regularly switching the precoding matrix is not limited to this. For the period N precoding hopping method, N different precoding matrices are required. At this time, F [0], F [1], F [2],..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, in the present embodiment, F [0], F [1], F [2],.
, F [N-2], and F [N-1] are described in this order, but the present invention is not necessarily limited thereto, and N different precoding matrices F [0] generated in the present embodiment are described. , F [1], F [2],.
· · · Precoding weight can be changed by arranging symbols for time axis and frequency-time axis in the same manner as in the first embodiment with F [N-2] and F [N-1]. it can. Note that the period N
The same effect can be obtained even if N different precoding matrices are used at random, that is, N not necessarily have a regular period. It is not necessary to use different precoding matrices of.

Further, Table 7 describes the mode of the hierarchical transmission method in the present embodiment, but the present mode is not limited to this, and as described in Embodiment 15, the spatial multiplexing MIMO transmission system, A mode of MIMO transmission method with fixed precoding matrix, space-time block coding method, transmission of only one stream, and method of switching precoding matrix regularly exists separately from the hierarchical transmission method described in this embodiment. The transmitting apparatus (broadcast station, base station) may be able to select one of the transmission methods from these modes. At this time, hierarchical transmission is performed in a mode of spatial multiplexing MIMO transmission scheme, MIMO transmission scheme with fixed precoding matrix, space-time block coding scheme, transmission of only one stream, and regular precoding matrix switching. Either case of hierarchical transmission may not be supported. Also, a mode using another transmission method may exist. The present embodiment may be applied to the fifteenth embodiment, and the hierarchical transmission method described in the present embodiment may be applied to any (sub) carrier group in the fifteenth embodiment.

Embodiment A4
In the present embodiment, as shown in Non-Patent Documents 12 to 15, QC (Quasi Cyclic) LDPC (Low-Density Prity-Check) code (non-QC-LDPC code, LDPC code). A method of regularly switching the precoding matrix when a block code such as a concatenated code of an LDPC code and a BCH code (Bose-Chaudhuri-Hocquenghem code) is used will be described in detail. Here, as an example, the case of transmitting two streams s1 and s2 will be described as an example. However, when coding is performed using a block code, when control information and the like are not necessary, the number of bits constituting the block after coding is the number of bits constituting the block code (however, Control information etc. as described may be included. When encoding is performed using a block code, when control information or the like (for example, CRC (cyclic redundancy check), transmission parameters, etc.) is required, the number of bits constituting the block after encoding is the block code. It may be the sum of the number of bits to be configured and the number of bits such as control information.

FIG. 76 is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when a block code is used. FIG. 76, for example, transmits two streams of s1 and s2 as shown in the transmission apparatus of FIG. 4 and “block code when the transmission apparatus has one encoder” When used, it is a diagram showing changes in the number of symbols and the number of slots required for one encoded block. (At this time, any one of single carrier transmission and multicarrier transmission such as OFDM may be used as a transmission method.)
As shown in FIG. 76, it is assumed that the number of bits constituting one encoded block in the block code is 6000 bits. In order to transmit these 6000 bits, 3000 symbols are required when the modulation scheme is QPSK, 1500 symbols when 16 QAM, and 1000 symbols when 64 QAM.

  Then, since the transmitter of FIG. 4 transmits two streams simultaneously, when the modulation scheme is QPSK, the above 3000 symbols are allocated 1500 symbols to s1 and 1500 symbols to s2. In order to transmit 1500 symbols to be transmitted in s1 and 1500 symbols to be transmitted in s2, 1500 slots (named "slot" here) are required.

  Similarly, when the modulation scheme is 16 QAM, 750 slots are required to transmit all the bits that make up one encoded block, and when the modulation scheme is 64 QAM, all the blocks that make up one block 500 slots are required to transmit bits.

Next, in the method of regularly switching the precoding matrix, the relationship between the slot defined above and the precoding matrix will be described.
Here, it is assumed that the number of precoding matrices prepared for the method of regularly switching the precoding matrix is five. That is, five different precoding matrices are prepared for the weighting and combining unit of the transmission apparatus of FIG. These five different precoding matrices are represented as F [0], F [1], F [2], F [3], F [4].

When the modulation scheme is QPSK, in the above-described 1500 slots for transmitting 6000 bits of bits constituting one encoded block, 300 slots for precoding matrix F [0] are used. The slot using coding matrix F [1] is 300 slots, the slot using precoding matrix F [2] is 300 slots, the slot using precoding matrix F [3] is 300 slots, precoding matrix F [4] The slot using [] needs to be 300 slots. This is because if there is a bias in the precoding matrix to be used, the effect of the precoding matrix using many numbers will be the reception quality of data that is large.

  Similarly, when the modulation scheme is 16 QAM, in the above-described 750 slots for transmitting 6000 bits that constitute one encoded block, 150 slots using the precoding matrix F [0] are 150. Slot, 150 slots using precoding matrix F [1], 150 slots using precoding matrix F [2], 150 slots using precoding matrix F [3], precoding matrix The slot using F [4] needs to be 150 slots.

  Similarly, when the modulation scheme is 64 QAM, in the above-described 500 slots for transmitting 6000 bits that constitute one encoded block, there are 100 slots using precoding matrix F [0]. Slots, 100 slots using precoding matrix F [1], 100 slots using precoding matrix F [2], 100 slots using precoding matrix F [3], precoding matrix The slot using F [4] needs to be 100 slots.

As described above, in the scheme in which precoding matrices are switched regularly, N different precoding matrices (N different precoding matrices F [0], F [1], F [2],.
·, F [N−2] and F [N−1], when transmitting all the bits that make up one encoded block, the precoding matrix F [0] The number of slots using N is K ₀ , the number of slots using precoding matrix F [1] is K _{1, the} number of slots using precoding matrix F [i] is K _i (i = 0, 1, 2,. When the number of slots using the precoding matrix F [N-1] is K _N-1 ,.

<Condition # 53>
K ₀ = K ₁ = ... = K _i = ... = K _N-1 , that is, K _a = K _b , (for ∀a, ∀b, where a, b = 0, 1, 2, 3, ..., N-1, a ≠ b)

It is good.

  Then, if the communication system supports a plurality of modulation schemes and selects from among the supported modulation schemes, <condition # 53> should be satisfied in the supported modulation schemes. .

However, when a plurality of modulation schemes are supported, it is general that the number of bits that can be transmitted in one symbol differs depending on each modulation scheme (in some cases, they may be the same). In some cases, there may be modulation schemes that can not satisfy <condition # 53>. In this case, instead of <condition # 53>, the following condition may be satisfied.

<Condition # 54>
The difference between K _a and K _b is 0 or 1, ie, | K _a −K _b | is 0 or 1
(For ∀a, ∀b, where a, b = 0, 1, 2, ..., N-1, a ≠ b)

FIG. 77 is a diagram showing changes in the number of symbols and the number of slots required for two encoded blocks when a block code is used. 77 shows two streams of s1 and s2 as shown in the transmitter of FIG. 3 and the transmitter of FIG. 13, and the transmitter has two encoders. FIG. 16 is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when a block code is used. (At this time, any one of single carrier transmission and multicarrier transmission such as OFDM may be used as a transmission method.)
As shown in FIG. 77, it is assumed that the number of bits constituting one encoded block in the block code is 6000 bits. In order to transmit these 6000 bits, 3000 symbols are required when the modulation scheme is QPSK, 1500 symbols when 16 QAM, and 1000 symbols when 64 QAM.

  Then, in the transmitting apparatus of FIG. 3 and the transmitting apparatus of FIG. 13, two streams are to be transmitted simultaneously, and since two encoders exist, in the two streams, different code blocks are transmitted. become. Therefore, when the modulation scheme is QPSK, two encoded blocks are transmitted in the same section by s1 and s2, so that, for example, the first encoded block is transmitted by s1, and s2 Since two coded blocks are to be transmitted, 3000 slots are required to transmit the first and second coded blocks.

  Similarly, if the modulation scheme is 16 QAM, 1500 slots are required to transmit all the bits that make up the two encoded blocks, and if the modulation scheme is 64 QAM, all 22 blocks will be configured. It takes 1000 slots to transmit bits.

Next, in the method of regularly switching the precoding matrix, the relationship between the slot defined above and the precoding matrix will be described.
Here, it is assumed that the number of precoding matrices prepared for the method of regularly switching the precoding matrix is five. That is, it is assumed that five different precoding matrices are prepared for the transmitter of FIG. 3 and the weighting combiner of the transmitter of the transmitter of FIG. These five different precoding matrices are represented as F [0], F [1], F [2], F [3], F [4].

  When the modulation scheme is QPSK, the above 3000 slots for transmitting the number of bits of 6000 × 2 bits constituting two encoded blocks are 600 slots using the precoding matrix F [0]. , 600 slots using precoding matrix F [1], 600 slots using precoding matrix F [2], 600 slots using precoding matrix F [3], precoding matrix F The slot using [4] needs to be 600 slots. This is because if there is a bias in the precoding matrix to be used, the effect of the precoding matrix using many numbers will be the reception quality of data that is large.

  Also, to transmit the first coding block, the slot that uses precoding matrix F [0] is 600 times, the slot that uses precoding matrix F [1] is 600 times, and precoding matrix F [2 ], The slot using 600 slots, the slot using precoding matrix F [3] 600 times, the slot using precoding matrix F [4] 600 times, and the second code In order to transmit an encoded block, the slot using the precoding matrix F [0] is 600 times, the slot using the precoding matrix F [1] is 600 times, and the slot using the precoding matrix F [2] It may be 600 slots, 600 slots using the precoding matrix F [3], and 600 slots using the precoding matrix F [4].

Similarly, when the modulation scheme is 16 QAM, a slot using the precoding matrix F [0] in the above-mentioned 1500 slots for transmitting the number of bits of 6000 × 2 bits constituting two coded blocks Is 300 slots, the slot using precoding matrix F [1] is 300 slots, the slot using precoding matrix F [2] is 300 slots, the slot using precoding matrix F [3] is 300 slots, pre The slot using the coding matrix F [4] needs to be 300 slots.

  Also, to transmit the first coding block, 300 slots using precoding matrix F [0], 300 slots using precoding matrix F [1], and 300 precoding matrix F [2]. ], The slot using 300 slots, the slot using precoding matrix F [3] 300 times, the slot using precoding matrix F [4] 300 times, and the second code To transmit a block, the slot using precoding matrix F [0] is 300 times, the slot using precoding matrix F [1] is 300 times, the slot using precoding matrix F [2] It may be 300 slots, 300 slots using the precoding matrix F [3], and 300 slots using the precoding matrix F [4].

  Similarly, when the modulation scheme is 64 QAM, a slot using the precoding matrix F [0] in the 1000 slots mentioned above for transmitting the number of bits of 6000 × 2 bits constituting two encoded blocks 200 slots, 200 slots using precoding matrix F [1], 200 slots using precoding matrix F [2], 200 slots using precoding matrix F [3], 200 slots The slot using the coding matrix F [4] needs to be 200 slots.

  Also, to transmit the first coding block, 200 slots using precoding matrix F [0], 200 slots using precoding matrix F [1], and 200 precoding matrix F [2] ], The slot using 200 slots, the slot using precoding matrix F [3] 200 times, the slot using precoding matrix F [4] 200 times, and the second code To transmit a block, the slot using precoding matrix F [0] is 200 times, the slot using precoding matrix F [1] is 200 times, and the slot using precoding matrix F [2] is It may be 200 slots, 200 slots using the precoding matrix F [3], and 200 slots using the precoding matrix F [4].

As described above, in the scheme in which precoding matrices are switched regularly, N different precoding matrices (N different precoding matrices F [0], F [1], F [2],.
·, F [N−2] and F [N−1], when transmitting all the bits constituting the two encoded blocks, the precoding matrix F [0] The number of slots using N is K ₀ , the number of slots using precoding matrix F [1] is K _{1, the} number of slots using precoding matrix F [i] is K _i (i = 0, 1, 2,. When the number of slots using the precoding matrix F [N-1] is K _N-1 ,.

<Condition # 55>
K ₀ = K ₁ = ... = K _i = ... = K _N-1 , that is, K _a = K _b , (for ∀a, ∀b, where a, b = 0, 1, 2, 3, ..., N-1, a ≠ b)

And K _{0,1 is} the number of times the precoding matrix F [0] is used, and the number of times the precoding matrix F [1] is used, when transmitting all the bits that make up the first encoded block. , K _{1,1 and} the number of times to use the precoding matrix F [i] K _{i, 1} (i = 0,1,2,..., N−1
When the number of times to use the precoding matrix F [N-1] is K _{N -1} ,

<Condition # 56>
K _0,1 = K _1,1 =... = K _{i, 1} =... = K _{N -1} , that is, K _{a, 1} = K _{b, 1} (for ∀a, ∀b, Where a, b = 0, 1, 2, ..., N-1, a ≠ b)

And K _{0,2 is} the number of times the precoding matrix F [0] is used, and the number of times the precoding matrix F [1] is used, when transmitting all the bits that make up the second encoded block. , _{K1,2 and} the number of times to use the precoding matrix F [i] K _{i, 2} (i = 0,1,2,..., N−1
When the number of times to use the precoding matrix F [N−1] is K _N−1,2 ,

<Condition # 57>
K _0,2 = K _1,2 =... = K _{i, 2} =... = K _N -1,2 That is, K _{a, 2} = K _{b, 2} (for ∀a, ∀b, Where a, b = 0, 1, 2, ..., N-1, a ≠ b)

It is good.

  Then, when the communication system supports a plurality of modulation schemes, and selects one of the supported modulation schemes for use, in the supported modulation schemes, <condition # 55> <condition # 56> <condition It will be good if # 57> is true.

However, when a plurality of modulation schemes are supported, it is general that the number of bits that can be transmitted in one symbol differs depending on each modulation scheme (in some cases, they may be the same). In some cases, there may be modulation schemes that can not satisfy <condition # 55><condition#56><condition#57>. In this case, instead of <condition # 55><condition#56><condition#57>, the following condition may be satisfied.

<Condition # 58>
The difference between K _a and K _b is 0 or 1, ie, | K _a −K _b | is 0 or 1
(For ∀a, ∀b, where a, b = 0, 1, 2, ..., N-1, a ≠ b)

<Condition # 59> The difference between _{Ka, 1} and _{Kb, 1} is 0 or 1, that is, | Ka _{, 1} - _{Kb, 1} | is 0 or 1
(For ∀a, ∀b, where a, b = 0, 1, 2, ..., N-1, a ≠ b)

<Condition # 60>
The difference between K _{a, 2} and K _{b, 2} is 0 or 1, that is, | K _{a, 2-} K _{b, 2} | is 0 or 1
(For ∀a, ∀b, where a, b = 0, 1, 2, ..., N-1, a ≠ b)

As described above, since the precoding matrix used for transmitting the coding block is lost in the relationship between the block after coding and the precoding matrix, the reception quality of the data can be increased in the receiving apparatus. Can be obtained.

  In this case, of course, there is no bias among the precoding matrices used, but if there are N precoding matrices prepared in the transmitter, all N precoding matrices are used. It is desirable to perform precoding, where it is preferable to perform precoding using each of the N precoding matrices equally. Here, "equal" means that the difference between the largest number and the smallest number of times of using each precoding matrix is at most 1 as described above.

Also, although it is desirable to use all N precoding matrices, this does not use all N precoding matrices to be used if the reception quality at each reception point is as uniform as possible. The precoding may be performed by regularly switching the precoding matrix after thinning out several precoding matrices. However, in order to ensure the reception quality at the reception points in each place when thinning the precoding matrix, it is necessary to equally thin out the precoding matrix. Equally decimating means, for example, that the precoding matrices are F [0], F [1], F [2], F [3], F [4], F [5], F [6], F [7 The precoding matrix to be used is assumed to be F [0], F [2], F [4], F [6], or the precoding matrix is F [0]. , F [1], F [2],..., F [14], F [15], the precoding matrix to be used is assumed to be F [0], F [4] , F [8] and F [12]. Also, if 16 precoding matrices F [0], F [1], F [2],..., F [14], F [15] are prepared, the precoding matrix to be used is , F [0], F [2], F [4], F [6], F [8], F [10], F [12], and F [14] to equally reduce the precoding matrix It can be said that

In this embodiment, in the method of regularly switching the precoding matrix, the period N
The N precoding hopping methods require N different precoding matrices. At this time, F [0], F [1], F [2],.
··, F [N-2], F becomes to prepare [N-1], F [0] in the frequency axis direction, F [1], F [2], ···, F [N There is also a method of arranging in the order of -2] and F [N-1], but it is not necessarily limited thereto, and N different precoding matrices F [0] and F [1] generated in this embodiment are available. , F [2],..., F [N-2] and F [N-1] are arranged in the time axis and frequency-time axis in the same manner as in the first embodiment. The coding weight can be changed. Although the precoding hopping method with period N is described, the same effect can be obtained by using N different precoding matrices at random, that is, it always has a regular period. Thus, it is not necessary to use N different precoding matrices.

In addition, as described in Embodiment 15, the spatial multiplexing MIMO transmission method, the MIMO transmission method in which the precoding matrix is fixed, the space-time block coding method, the method of transmitting only one stream, and regularly switching the precoding matrix A mode may exist, and the transmitting apparatus (broadcast station, base station) may be able to select one of the transmission methods from these modes. At this time, in the mode of the spatial multiplexing MIMO transmission scheme, the MIMO transmission scheme in which the precoding matrix is fixed, the space-time block coding scheme, the transmission of only one stream, and the method of regularly switching the precoding matrix, In the (sub) carrier group in which the method of switching is selected, this embodiment may be implemented.

Embodiment B1
In the following, application examples of the transmission method and the reception method shown in each of the above embodiments and a configuration example of a system using the same will be described.

FIG. 78 is a diagram showing an example of a configuration of a system including an apparatus that executes the transmission method and the reception method shown in the above embodiment. The transmitting method and receiving method shown in each of the above embodiments are the broadcasting station as shown in FIG. 78, a television (television) 7811, a DVD recorder 7812, an STB (Set Top Box) 7813, a computer 7820, and a car-mounted television A digital broadcast system 7800 may be implemented that includes various types of receivers such as the 7841 and the cellular telephone 7830. Specifically, the broadcast station 7801 transmits multiplexed data in which video data, audio data, and the like are multiplexed to a predetermined transmission band using the transmission method described in each of the above embodiments.

A signal transmitted from the broadcast station 7801 is received by an antenna (for example, antennas 7960 and 7840) incorporated in each receiver or installed outside and connected to the receiver. Each receiver demodulates the signal received at the antenna using the reception method described in each of the above embodiments to obtain multiplexed data. Thus, the digital broadcasting system 7800
Thus, the effects of the present invention described in the above embodiments can be obtained.

Here, video data included in multiplexed data is, for example, MPEG (Moving Picture Experts Group) 2, MPEG 4-AVC (Advanced).
It is encoded using a video coding method conforming to standards such as Video Coding) and VC-1. Also, audio data included in multiplexed data is, for example, Dolby AC (Audio Coding) -3, Dolby Digital Plus, MLP (Meridian Lossless Packing), DTS (Digital Theater Systems), DTS-HD, Linear PCM (Pulse Coding)
It is encoded by a speech encoding method such as Modulation).

FIG. 79 is a diagram showing an example of a configuration of a receiver 7900 that implements the reception method described in each of the above embodiments. As shown in FIG. 79, as an example of one configuration of the receiver 7900, the modem portion is configured by one LSI (or chip set), and the codec portion is configured by another one LSI (or chip set). The configuration method is conceivable. The receiver 7900 shown in FIG. 79 includes the television (television) 7811, the DVD recorder 7812, the STB (Set Top Box) 7813, the computer 7820, and the in-vehicle television 784 shown in FIG.
This corresponds to the configuration provided in the mobile phone 7830 and the mobile phone 7830 and the like. The receiver 7900 includes a tuner 7901 which converts a high frequency signal received by the antenna 7960 into a baseband signal, and a demodulator 7902 which demodulates the frequency-converted baseband signal to obtain multiplexed data. The receiving method shown in each of the above embodiments is implemented in the demodulation unit 7902, whereby the effects of the present invention described in each of the above embodiments can be obtained.

  Also, the receiver 7900 uses a stream input / output unit 7920 to separate video data and audio data from multiplexed data obtained by the demodulation unit 7902 and a video decoding method corresponding to the separated video data. A signal processing unit 7904 that decodes data into a video signal and decodes audio data into an audio signal using an audio decoding method corresponding to separated audio data, and an audio output unit such as a speaker that outputs the decoded audio signal 7906 and a video display unit 7907 such as a display for displaying a decoded video signal.

  For example, the user uses the remote control (remote controller) 7950 to transmit information on the selected channel (selected (television) program, selected audio broadcast) to the operation input unit 7910. Then, in the reception signal received by the antenna 7960, the receiver 7900 demodulates the signal corresponding to the selected channel, performs processing such as error correction decoding, and obtains reception data. At this time, the receiver 7900 transmits the transmission method (the transmission method, the modulation method, the error correction method, etc. described in the above embodiment) included in the signal corresponding to the selected channel (this is described in Embodiment A1). ~ A method of reception operation, demodulation method, error correction decoding, etc. by obtaining information of control symbols including the information of the embodiment A4 and the information shown in FIG. 5 and FIG. By setting H correctly, it becomes possible to obtain data included in data symbols transmitted by the broadcast station (base station). In the above, an example in which the user selects a channel by remote control 7950 has been described. However, even if the channel is selected using the channel selection key installed in receiver 7900, the same operation as above is performed. Become.

With the above configuration, the user can view the program received by the receiver 7900 according to the receiving method described in the above embodiments.
Further, in the receiver 7900 of this embodiment, multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding (in some cases, to a signal obtained by demodulation by the demodulation unit 7902) In addition, the receiver 7900 may be subjected to other signal processing after the error correction decoding, and this may also be applied to the parts in which the same expression is performed. The same applies to the above) or data corresponding to the data (eg, data obtained by compressing the data), data obtained by processing moving And a recording unit (drive) 7908 for recording on a recording medium such as an optical disk and a nonvolatile semiconductor memory. Here, the optical disc is a recording medium, such as a DVD (Digital Versatile Disc) or a BD (Blu-ray (registered trademark) Disc), in which information is stored and read using a laser beam. The magnetic disk is, for example, a recording medium such as FD (Floppy (registered trademark) Disk) or a hard disk (Hard Disk), which stores information by magnetizing a magnetic body using magnetic flux. The nonvolatile semiconductor memory is, for example, a recording medium composed of semiconductor elements such as a flash memory and a ferroelectric random access memory (SD memory), and an SD card and a flash solid state drive (SSD) using the flash memory. And the like. The types of recording media listed here are merely examples, and it goes without saying that recording may be performed using recording media other than the above recording media.

  With the above configuration, the user records and stores the program received by the receiver 7900 according to the receiving method described in each of the above embodiments, and data recorded at an arbitrary time after the time the program is being broadcasted Can be read and viewed.

  In the above description, the receiver 7900 demodulates in the demodulation unit 7902 and records multiplexed data obtained by performing error correction decoding in the recording unit 7908. However, the data included in the multiplexed data Some of the data may be extracted and recorded. For example, in the case where multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding includes the content of a data broadcast service other than video data and audio data, the recording unit 7908 is a demodulator 7902. It is also possible to extract video data and audio data from multiplexed data demodulated in the above and record new multiplexed data multiplexed. In addition, the recording unit 7908 is new multiplexed data obtained by multiplexing only one of video data and audio data included in multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding. You may record Then, the recording unit 7908 may record the content of the data broadcast service included in the multiplexed data described above.

  Furthermore, when the receiver 7900 described in the present invention is mounted on a television, a recording device (for example, a DVD recorder, a Blu-ray (registered trademark) recorder, an HDD recorder, an SD card, etc.) or a mobile phone, demodulation is performed. Data, personal information, and recording for correcting defects (bugs) in software used to operate a television and a recording apparatus, in multiplexed data obtained by performing demodulation by the portion 7902 and decoding of error correction. If it contains data for correcting software defects (bugs) to prevent the leak of data, installing these data may correct software defects in the television or recording device. . Then, when the data includes data for correcting a defect (bug) in the software of the receiver 7900, this data can also correct the defect in the receiver 7900. Thus, the television, the recording device, and the mobile phone in which the receiver 7900 is mounted can be operated more stably.

  Here, the processing of extracting and multiplexing part of data from a plurality of data included in multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding is, for example, the stream input / output unit 7903. It takes place in Specifically, in response to an instruction from a control unit such as a CPU (not shown), the stream input / output unit 7903 demodulates the multiplexed data demodulated by the demodulation unit 7902 into video data, audio data, contents of data broadcasting service, etc. A plurality of data is separated, and only designated data is extracted from the separated data and multiplexed to generate new multiplexed data. The user may decide, for example, which data to extract from the data after separation, or may be determined in advance for each type of recording medium.

  According to the above configuration, the receiver 7900 can extract and record only data necessary for viewing a recorded program, and therefore, the data size of data to be recorded can be reduced.

  In the above description, the recording unit 7908 demodulates in the demodulation unit 7902 and records multiplexed data obtained by performing error correction decoding. However, the recording unit 7908 demodulates in the demodulation unit 7902 and decodes the error correction A moving picture code different from the moving picture coding method applied to the video data so that the data size or bit rate of the video data included in the multiplexed data obtained by performing the step is lower than that of the video data It may be converted into video data encoded by a coding method, and new multiplexed data obtained by multiplexing the converted video data may be recorded. At this time, the moving picture coding method applied to the original video data and the moving picture coding method applied to the converted video data may conform to different standards, or conform to the same standards. Only the parameters used during encoding may differ. Similarly, the recording unit 7908 demodulates in the demodulation unit 7902 and decodes the error correction so that the audio data included in the multiplexed data has a data size or bit rate lower than that of the audio data. The audio data may be converted into audio data encoded by an audio encoding method different from the audio encoding method applied to the audio data, and new multiplexed data obtained by multiplexing the audio data after conversion may be recorded.

  Here, processing for converting video data and audio data included in multiplexed data obtained by performing demodulation by error correction using the demodulation unit 7902 into video data and audio data having different data sizes or bit rates is described. For example, the stream input / output unit 7903 and the signal processing unit 7904 are performed. Specifically, the stream input / output unit 7903 demodulates in the demodulation unit 7902 in accordance with an instruction from a control unit such as a CPU, and the multiplexed data obtained by performing error correction decoding is video data, audio data, Separate into multiple data such as data broadcast service content. The signal processing unit 7904 converts the separated video data into video data encoded by a moving picture coding method different from the moving picture coding method applied to the video data according to an instruction from the control unit. And the separated voice data is converted into voice data encoded by a voice coding method different from the voice coding method applied to the voice data. The stream input / output unit 7903 multiplexes the converted video data and the converted audio data according to an instruction from the control unit to generate new multiplexed data. Note that the signal processing unit 7904 may perform conversion processing on only one of video data and audio data according to an instruction from the control unit, or may perform conversion processing on both. Also good. Also, the data size or bit rate of the converted video data and audio data may be determined by the user or may be determined in advance for each type of recording medium.

  With the above configuration, the receiver 7900 changes the data size or bit rate of the video data and audio data according to the data size recordable on the recording medium and the speed at which the recording unit 7908 records or reads data, and records can do. As a result, the data size that can be recorded on the recording medium is smaller than the data size of multiplexed data obtained by demodulating by the demodulation unit 7902 and performing error correction decoding, or the recording unit records or reads data. The recording unit can record the program even if the speed at which it performs is lower than the bit rate of the multiplexed data demodulated by the demodulation unit 7902. Therefore, the user can select any time after the time the program is being broadcasted. It is possible to read out and view the data recorded in the.

Also, the receiver 7900 includes a stream output IF (Interface: interface) 7909 that transmits the multiplexed data demodulated by the demodulator 7902 to an external device via the communication medium 7930. As an example of the stream output IF 7909, Wi-Fi (registered trademark) (IEEE 802.11a, IEEE 802.11b, IEEE 802.
11g, IEEE 802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Zigbee (registered trademark), etc. The multiplexed data modulated using the wireless communication method conforming to the wireless communication standard is transmitted to the wireless medium (communication medium 7930) Wireless communication device that transmits to an external device via Also, the stream output IF 7909 is Ethernet (registered trademark), USB (Universal Serial Bus), PLC (Power Line)
Communication) and a wired transmission path (communication medium 7930) in which multiplexed data modulated using a communication method conforming to a wired communication standard such as HDMI (registered trademark) (High-Definition Multimedia Interface) is connected to the stream output IF 7909 And a wired communication device that transmits to an external device via

  With the above configuration, the user can use multiplexed data received by the receiver 7900 according to the reception method described in each of the above-described embodiments in an external device. Here, the use of multiplexed data means that the user views the multiplexed data in real time using the external device, that the recording unit provided in the external device records the multiplexed data, further from the external device It includes transmitting multiplexed data to another external device.

  In the above description, the receiver 7900 demodulates in the demodulation unit 7902 and outputs multiplexed data obtained by performing error correction decoding, and the stream output IF 7909 outputs the data included in the multiplexed data. Some of the data may be extracted and output. For example, when the multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding includes the content of a data broadcast service other than video data and audio data, the stream output IF 7909 outputs the demodulation unit 7902. The video data and the audio data may be extracted from multiplexed data obtained by performing demodulation and error correction decoding, and new multiplexed data multiplexed may be output. Further, the stream output IF 7909 may output new multiplexed data in which only one of video data and audio data included in multiplexed data demodulated by the demodulation unit 7902 is multiplexed.

  Here, the processing of extracting and multiplexing part of data from a plurality of data included in multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding is, for example, the stream input / output unit 7903. It takes place in Specifically, the stream input / output unit 7903 receives video data, audio data, data broadcasting, and the like from the multiplexed data demodulated by the demodulation unit 7902 according to an instruction from a control unit such as a CPU (Central Processing Unit) not shown. The data is separated into a plurality of data such as service contents, and only the designated data is extracted from the separated data and multiplexed to generate new multiplexed data. The user may determine, for example, which data to extract from the separated data, or may be determined in advance for each type of stream output IF 7909.

  According to the above configuration, the receiver 7900 can extract and output only the data necessary for the external device, so that the communication bandwidth consumed by the output of the multiplexed data can be reduced.

In the above description, the stream output IF 7909 demodulates in the demodulation unit 7902 and records multiplexed data obtained by performing error correction decoding. However, the stream output IF 7909 performs demodulation in the error correction decoding by the demodulation unit 7902 A moving picture code different from the moving picture coding method applied to the video data so that the data size or bit rate of the video data included in the multiplexed data obtained by performing the step is lower than that of the video data It may be converted into video data encoded by a coding method, and new multiplexed data obtained by multiplexing the converted video data may be output. At this time, the moving picture coding method applied to the original video data and the moving picture coding method applied to the converted video data may conform to different standards, or conform to the same standards. Only the parameters used during encoding may differ. Similarly, the stream output IF 7909
The audio data included in the multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding is applied to the audio data so that the data size or bit rate is lower than that of the audio data. It may be converted into speech data encoded by a speech coding method different from the speech coding method, and new multiplexed data obtained by multiplexing the speech data after conversion may be output.

  Here, processing for converting video data and audio data included in multiplexed data obtained by performing demodulation by error correction using the demodulation unit 7902 into video data and audio data having different data sizes or bit rates is described. For example, the stream input / output unit 7903 and the signal processing unit 7904 are performed. Specifically, the stream input / output unit 7903 demodulates in the demodulation unit 7902 in accordance with an instruction from the control unit, and decodes multiplexed data obtained by error correction as video data, audio data, data broadcasting service To separate multiple data such as The signal processing unit 7904 converts the separated video data into video data encoded by a moving picture coding method different from the moving picture coding method applied to the video data according to an instruction from the control unit. And the separated voice data is converted into voice data encoded by a voice coding method different from the voice coding method applied to the voice data. The stream input / output unit 7903 multiplexes the converted video data and the converted audio data according to an instruction from the control unit to generate new multiplexed data. Note that the signal processing unit 7904 may perform conversion processing on only one of video data and audio data according to an instruction from the control unit, or may perform conversion processing on both. Also good. Also, the data size or bit rate of the converted video data and audio data may be determined by the user, or may be determined in advance for each type of stream output IF 7909.

  With the above configuration, the receiver 7911 can change and output the bit rate of video data and audio data in accordance with the communication speed with the external device. As a result, even if the communication speed with the external device is lower than the bit rate of multiplexed data obtained by performing demodulation by the demodulation unit 7902 and performing error correction decoding, the stream output IF to external device new multiplexed Since it is possible to output the raw data, the user can use the new multiplexed data in other communication devices.

  The receiver 7911 also includes an AV (Audio and Visual) output IF (Interface) 7911 that outputs the video signal and the audio signal decoded by the signal processing unit 7904 to the external device to an external communication medium. Examples of the AV output IF7911 include wireless communication standards such as Wi-Fi (registered trademark) (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Gigbee, etc. A wireless communication apparatus may be used which transmits a video signal and an audio signal modulated by using a wireless communication method compliant with the above to an external device through a wireless medium. Further, the stream output IF 7909 connects a video signal and an audio signal modulated using a communication method conforming to a wired communication standard such as Ethernet (registered trademark), USB, PLC, HDMI (registered trademark) to the stream output IF 7909 It may be a wired communication device that transmits data to an external device via the wired transmission path. In addition, the stream output IF 7909 may be a terminal to which a cable for outputting a video signal and an audio signal as an analog signal is connected.

With the above configuration, the user can use the video signal and the audio signal decoded by the signal processing unit 7904 in an external device.
Furthermore, the receiver 7900 includes an operation input unit 7910 that receives an input of a user operation. The receiver 7900 switches the power ON / OFF, switches the channel to be received, switches the presence / absence of subtitle display, and switches the language to be displayed based on the control signal input to the operation input unit 7910 according to the user's operation. , Switching of various operations such as changing the volume output from the audio output unit 7906, and changing settings such as setting of receivable channels.

In addition, the receiver 7900 may have a function of displaying an antenna level indicating the reception quality of a signal being received by the receiver 7900. Here, the antenna level means, for example, the RSSI (Received Signal Strength Indication, Received Signal Strength Indicator, received signal strength), received electric field strength, C / N (Carrier-to-noise power ratio) of the signal received by the receiver 7900. , BER (Bit Error Rate), packet error rate, frame error rate, channel state information (Channel
State Information) is an index indicating the reception quality calculated based on the information, etc., and is a signal indicating the signal level and the superiority of the signal. In this case, the demodulation unit 7901 includes a reception quality measurement unit that measures the RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, etc. of the received signal. The antenna level (signal level, signal indicating superiority or inferiority of the signal) is displayed on the video display unit 7907 in a format that can be identified by the user according to the operation of. Display format of antenna level (signal level, signal indicating superiority or inferiority of the signal) displays numerical values according to RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, etc. Different images may be displayed depending on the RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, and the like. In addition, the receiver 7900 obtains a plurality of antenna levels (signal levels, signal levels, etc.) obtained for each of a plurality of streams s1, s2,... Received and separated using the receiving method described in each of the above embodiments. A signal indicating superiority or inferiority may be displayed, or one antenna level (signal level, signal indicating superiority or inferiority of signal) obtained from a plurality of streams s1, s2,. In addition, when video data and audio data that constitute a program are transmitted using a hierarchical transmission method, it is also possible to indicate the level of the signal (signal indicating superiority or inferiority of the signal) for each hierarchy.

  With the above configuration, the user numerically or visually grasps the antenna level (signal level, signal indicating superiority or inferiority of signal) in the case of reception using the reception method described in each of the above embodiments. Can.

In the above description, the receiver 7900 includes the audio output unit 7906, the video display unit 7907, the recording unit 7908, the stream output IF 7909, and the AV output IF 7911. It is not necessary to have all of the If the receiver 7900 has at least one of the above configurations, the user can demodulate in the demodulation unit 7902 and use multiplexed data obtained by performing error correction decoding. Each receiver may be provided with any combination of the above configurations according to its application.
(Multiplexed data)
Next, an example of the structure of multiplexed data will be described in detail. As a data structure used for broadcasting, an MPEG2-transport stream (TS) is generally used, and here, an MPEG2-TS will be described as an example. However, the data structure of multiplexed data transmitted by the transmission method and reception method shown in the above embodiments is not limited to MPEG2-TS, and any other data structure will be described in the above embodiments. Needless to say, you can get the

FIG. 80 shows an example of the structure of multiplexed data. As shown in FIG. 80, multiplexed data is an element constituting a program (programme or an event that is a part thereof) currently provided in each service, for example, a video stream, an audio stream, a presentation graphics stream (PG And one or more of elementary streams such as an interactive graphics stream (IG). If the program provided as multiplexed data is a movie, the video stream is the main video and subvideo of the movie, and the audio stream is the secondary audio to be mixed with the main audio portion of the movie and the main audio, as a presentation graphics stream Show the subtitles of the movie respectively. Here, the main video refers to a normal video displayed on the screen, and the sub video refers to a video displayed on a small screen in the main video (for example, a video of text data indicating a synopsis of a movie). is there. The interactive graphics stream also shows an interactive screen created by arranging GUI parts on the screen.

  Each stream included in multiplexed data is identified by PID which is an identifier assigned to each stream. For example, 0x1011 for video streams used for movie images, 0x1100 to 0x111F for audio streams, 0x1200 to 0x121F for presentation graphics, 0x1400 to 0x141F for interactive graphics streams, movie 0x1B00 to 0x1B1F are assigned to the video stream used for the sub video, and 0x1A00 to 0x1A1F are assigned to the audio stream used for the sub audio to be mixed with the main audio.

  FIG. 81 schematically shows an example of how multiplexed data is multiplexed. First, a video stream 8101 consisting of a plurality of video frames and an audio stream 8104 consisting of a plurality of audio frames are converted into PES packet sequences 8102 and 8105, respectively, and converted into TS packets 8103 and 8106. Similarly, data of presentation graphics stream 8111 and interactive graphics 8116 are converted to PES packet sequences 8112 and 9115, respectively, and further converted to TS packets 8113 and 8116. The multiplexed data 8117 is configured by multiplexing these TS packets (8103, 8106, 8113, 8116) into one stream.

FIG. 82 shows in more detail how the video stream is stored in the PES packet sequence. The first row in FIG. 82 shows a video frame sequence of a video stream. The second row shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, yy4 in FIG. 82, a plurality of Video Presentation Units I picture, B picture, and P picture in the video stream are divided for each picture and stored in the payload of the PES packet. . Each PES packet has a PES header, and the PES header stores PTS (Presentation Time-Stamp), which is a picture display time, and DTS (Decoding Time-Stamp), which is a picture decoding time.

FIG. 83 shows the format of a TS packet that is ultimately written to multiplexed data. The TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as PID identifying a stream and a 184-byte TS payload storing data, and the PES packet is divided and stored in the TS payload. Ru. In the case of the BD-ROM, 4 Bytes of TP_Extra_Header is attached to the TS packet, and a 192 Byte source packet is configured and written to multiplexed data. TP_Extra_Header describes information such as ATS (Arrival_Time_Stamp). ATS indicates the transfer start time of the TS packet to the PID filter of the decoder. In the multiplexed data, source packets are arranged as shown in the lower part of FIG. 83, and the number incremented from the head of the multiplexed data is called SPN (source packet number).

In addition, TS packets included in multiplexed data include PAs other than streams such as video streams, audio streams, and presentation graphics streams.
T (Program Association Table), PMT (Program
Map Table), PCR (Program Clock Reference), etc. The PAT indicates what is the PID of the PMT used in multiplexed data, and the PID of the PAT itself is registered at 0. The PMT has PIDs of respective streams such as video, audio and subtitles included in multiplexed data and attribute information (frame rate, aspect ratio, etc.) of streams corresponding to each PID, and various descriptors relating to multiplexed data. Have. The descriptor includes copy control information for instructing permission or non-permission of copying of multiplexed data. The PCR corresponds to an ATS to which the PCR packet is transferred to the decoder in order to synchronize ATC (Arrival Time Clock), which is the ATS time axis, and STC (System Time Clock), which is the PTS · DTS time axis. It has STC time information.

FIG. 84 is a diagram for explaining in detail the data structure of the PMT. At the top of the PMT, a PMT header in which the length of data included in the PMT, etc. is described is placed. After that, a plurality of descriptors related to multiplexed data are arranged. The copy control information etc. is described as a descriptor. A plurality of stream information related to each stream included in the multiplexed data is disposed after the descriptor. The stream information is composed of a stream type for identifying a compression codec of the stream, a PID of the stream, and a stream descriptor in which attribute information of the stream (frame rate, aspect ratio, etc.) is described. There are as many stream descriptors as there are streams present in multiplexed data.

When recording on a recording medium or the like, the multiplexed data is recorded together with the multiplexed data information file.
FIG. 85 shows a structure of the multiplexed data file information. The multiplexed data information file is management information of multiplexed data as shown in FIG. 85, and has one-to-one correspondence with multiplexed data, and is composed of multiplexed data information, stream attribute information and an entry map.

  As shown in FIG. 85, multiplexed data information is composed of a system rate, playback start time, and playback end time. The system rate indicates the maximum transfer rate of multiplexed data to the PID filter of the system target decoder described later. The interval of ATS included in multiplexed data is set to be equal to or less than the system rate. The playback start time is the PTS of the leading video frame of multiplexed data, and the playback end time is set to the PTS of the video frame at the end of multiplexed data plus the playback interval of one frame.

  FIG. 86 shows a structure of stream attribute information included in multiplexed data file information. As shown in FIG. 86, in the stream attribute information, attribute information on each stream included in multiplexed data is registered for each PID. Attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. In the video stream attribute information, the frame rate is determined by what compression codec the video stream is compressed, the resolution of the individual picture data making up the video stream, the aspect ratio, It has information such as how much it is. The audio stream attribute information is such as what compression codec the audio stream is compressed, what number of channels is included in the audio stream, what language it corresponds to, what sampling frequency is, etc. With the information of These pieces of information are used, for example, to initialize the decoder before the player reproduces.

In the present embodiment, the stream type included in the PMT among the multiplexed data is used. Also, when multiplexed data is recorded on the recording medium, video stream attribute information included in the multiplexed data information is used. Specifically, in the moving picture coding method or apparatus shown in each of the above embodiments, the moving picture coding shown in each of the above embodiments for the stream type or video stream attribute information included in PMT. Providing a step or means for setting unique information indicating that the data is video data generated by the method or apparatus. With this configuration, it is possible to distinguish between video data generated by the moving picture coding method or apparatus described in each of the above embodiments and video data conforming to another standard.

FIG. 87 shows an example of the configuration of a video and audio output device 8700 including a receiving device 8704 that receives video and audio data transmitted from a broadcast station (base station) or a modulated signal including data for data broadcasting. Is shown. The configuration of the reception device 8704 corresponds to the reception device 7900 in FIG. For example, an OS (Operating System: operating system) is installed in the video and audio output device 8700, and a communication device 8706 for connecting to the Internet (for example, for a wireless LAN (Local Area Network) or Ethernet) Communication device) is mounted. Thus, in the portion 8701 for displaying the video, the video and audio data, or the video 8702 in the data for data broadcasting, and the hypertext (World Wide Web (WWW) provided on the Internet) ) 8703 can be displayed simultaneously. Then, by operating the remote control (which may be a mobile phone or a keyboard) 8707, either the video 8702 in the data for data broadcasting or the hypertext 8703 provided on the Internet is selected to change the operation. It will be done. For example, when the hypertext 8703 provided on the Internet is selected, the displayed WWW site is changed by operating the remote control. When video and audio data or video 8702 in data for data broadcasting is selected, the remote control 8707 selects a selected channel (selected (television) program, selected audio broadcast). Send information Then, the IF 8705 acquires the information transmitted by the remote control, and the receiving device 8704 demodulates the signal corresponding to the selected channel, performs processing such as error correction decoding, and obtains received data. At this time, the transmission method included in the signal corresponding to the selected channel by the reception device 8704 (this is described in Embodiment A1 to Embodiment A4 and described in FIGS. 5 and 41). Of the control symbol including the information of (1), to correctly set the receiving operation, demodulation method, error correction decoding, etc., to be included in the data symbol transmitted by the broadcasting station (base station). Data can be obtained. In the above, an example in which the user selects a channel by remote control 8707 has been described. However, even if the channel is selected using the channel selection key installed in video and audio output device 8700, the same as above is performed. It becomes operation.

Further, the video and audio output device 8700 may be operated using the Internet. For example, recording (storage) reservation is performed on the video and audio output device 8700 from another terminal connected to the Internet. (Thus, as shown in FIG. 79, the video and audio output device 8700 has the recording unit 7908.) Then, before starting recording, the channel will be selected, and the receiving device 8704 In this case, the signal corresponding to the selected channel is demodulated, and processing such as error correction decoding is performed to obtain received data. At this time, the receiving device 8704 is configured to transmit the transmission method (the transmission method, the modulation method, the error correction method, etc. described in the above embodiment) included in the signal corresponding to the selected channel. ~ A method of reception operation, demodulation method, error correction decoding, etc. by obtaining information of control symbols including the information of the embodiment A4 and the information shown in FIG. 5 and FIG. By setting H correctly, it becomes possible to obtain data included in data symbols transmitted by the broadcast station (base station).

(Other supplements)
In this specification, it is considered that the transmitting apparatus is equipped with, for example, communication / broadcasting equipment such as a broadcasting station, a base station, an access point, a terminal, a mobile phone, etc. It is conceivable that communication devices such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, a base station and the like are provided with the receiving device. Further, the transmitting device and the receiving device in the present invention are devices having a communication function, and the device has an interface (for example, an apparatus for executing applications such as a television, a radio, a personal computer, and a mobile phone) For example, it is also conceivable that the connection can be made via USB.

  Also, in the present embodiment, symbols other than data symbols, for example, pilot symbols (preamble, unique word, postamble, reference symbol, etc.), symbols for control information, etc. are arranged in the frame no matter how. Good. And although it is naming as a pilot symbol and a symbol for control information here, what kind of naming may be performed and the function itself becomes important.

  The pilot symbols may for example be known symbols modulated at the transceiver using PSK modulation (or the receiver may be able to know the symbols transmitted by the transmitter by synchronizing the receiver The receiver should use this symbol to perform frequency synchronization, time synchronization, channel estimation (for each modulated signal) (estimate of CSI (Channel State Information)), signal detection, etc. Become.

  In addition, symbols for control information are information that needs to be transmitted to a communication partner (eg, modulation scheme, error correction coding scheme used for communication, etc.) to realize communication other than data (such as application) It is a symbol for transmitting the coding rate of the error correction coding method, setting information in the upper layer, and the like.

  The present invention is not limited to the above embodiments, and can be implemented with various modifications. For example, although the above embodiment describes the case of performing as a communication device, the present invention is not limited to this, and it is also possible to perform this communication method as software.

  Also, although the precoding switching method in the method of transmitting two modulated signals from two antennas has been described above, the present invention is not limited to this, and precoding is performed on four mapped signals. In a method of generating one modulated signal and transmitting from four antennas, that is, performing precoding on N mapped signals, generating N modulated signals, and transmitting from N antennas Can also be implemented similarly as a precoding switching method in which precoding weights (matrices) are similarly changed.

Although the terms "precoding", "precoding weights", "precoding matrix" and the like are used in this specification, the term itself may be anything (for example, called a code book). In the present invention, the signal processing itself becomes important.

The streams s1 (t) and s2 (t) may transmit different data or the same data.
Both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, one of the antennas described in the drawing may be constituted by a plurality of antennas.

As used herein, “∀” refers to a universal quantifier, and “∃” refers to an existing quantifier.

Also, in the present specification, the unit of phase in the complex plane, for example, the argument, is "radian".
The complex plane can be displayed in polar form as a polar coordinate display of complex numbers. When a point (a, b) on the complex plane is made to correspond to the complex number z = a + jb (a and b are both real numbers and j is an imaginary unit), this point corresponds to polar coordinates [r, θ If it is expressed as],
a = r × cos θ,
b = r × sin θ

Where r is the absolute value of z (r = | z |) and θ is the argument. And z = a + jb is expressed as re ^jθ .
In the description of the present invention, although the baseband signals s1, s2, z1 and z2 are complex signals, the complex signals are I + jQ (I + jQ (I j is expressed as an imaginary unit). At this time, I may be zero or Q may be zero.

  An example of a broadcast system using the method of regularly switching precoding matrices described in this specification is shown in FIG. Referring to FIG. 59, a video coding unit 5901 receives a video, performs video coding, and outputs data 5902 after video coding. Speech coding section 5903 receives speech, performs speech coding, and outputs data 5904 after speech coding. Data encoding section 5905 receives data, performs data encoding (for example, data compression), and outputs data 5906 after data encoding. These are collectively referred to as an information source coding unit 5900.

  The transmitting unit 5907 receives the data 5902 after video coding, the data 5904 after audio coding, and the data 5906 after data coding as input, and uses any one of these data or all of these data as transmission data, Processing such as error correction coding, modulation, precoding (for example, signal processing in the transmission apparatus of FIG. 3) is performed, and transmission signals 5908 _ 1 to 5908 _N are output. Then, the transmission signals 5908_1 to 5908_N are transmitted as radio waves by the antennas 5909_1 to 5909_N, respectively.

  Receiving section 5912 receives received signals 5911_1 to 5911_M received by antennas 5910_1 to 5910_M, and performs processing such as frequency conversion, precoding decoding, log likelihood ratio calculation, error correction decoding and the like (for example, in the receiving apparatus of FIG. Process) and output received data 5913, 5915, 5917. The information source decoding unit 5919 receives the reception data 5913, 5915, and 5917, and the video decoding unit 5914 receives the reception data 5913, performs decoding for a video, and outputs a video signal. Displayed on the display. Further, the speech decoding unit 5916 receives the received data 5915 as an input. Decoding for audio, outputting an audio signal, audio flows from the speaker. Further, data decoding unit 5918 receives received data 5917 as input, decodes for data, and outputs data information.

Also, in the embodiments describing the present invention, the OFD as described earlier
In a multicarrier transmission scheme such as the M scheme, the transmitter may have any number of encoders. Therefore, for example, as shown in FIG. 4, it is of course possible to apply the method in which the transmitter has one encoder and distributes the output to a multicarrier transmission scheme such as OFDM scheme. At this time, the radio units 310A and 310B in FIG. 4 may be replaced with the OFDM system related processors 1301A and 1301B in FIG. At this time, the description of the OFDM system related processor is as in the first embodiment.

  Also, in Embodiment A1 to Embodiment A4, a method of regularly switching precoding matrices using a plurality of precoding matrices different from the “method of switching different precoding matrices” described in this specification is used. Even if realized, it can be implemented similarly.

Note that, for example, a program for executing the above communication method is pre-stored in the ROM (Read Only).
The program may be stored in a memory) and operated by a CPU (central processor unit).

  Further, the program for executing the communication method is stored in a computer readable storage medium, the program stored in the storage medium is recorded in a RAM (Random Access Memory) of the computer, and the computer is operated according to the program You may do so.

  And each composition of each above-mentioned embodiment etc. may be realized as LSI (Large Scale Integration) which is an integrated circuit typically. These may be individually made into one chip, or may be made into one chip so as to include all or some of the configurations of the respective embodiments. Although an LSI is used here, it may be called an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After the LSI is manufactured, a field programmable gate array (FPGA) that can be programmed or a reconfigurable processor that can reconfigure connection and setting of circuit cells in the LSI may be used.

  Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Adaptation of biotechnology etc. may be possible.

  In the precoding method according to one embodiment of the present invention, the first transmission signal and the second transmission signal are composed of a basic modulation signal consisting of a basic stream and an extension modulation signal consisting of an extension stream of data different from the basic stream. A precoding method executed by a transmitting apparatus that generates each of the generated transmission signals at the same frequency band and at the same timing from different one or more output ports, Select one precoding matrix from among the precoding matrices on a regular basis, perform precoding using the selected precoding matrix, and generate an enhanced modulation signal after precoding; The signal and the second transmission signal are a signal based on the basic modulation signal, and the signal after the precoding. Characterized in that it is produced from Zhang modulation signal.

Further, a signal processing apparatus executing the precoding method according to one embodiment of the present invention transmits a first transmission signal from a basic modulation signal consisting of a basic stream and an extended modulation signal consisting of an extension stream of data different from the basic stream. A signal processing apparatus mounted on a transmitting device that generates a signal and a second transmission signal, and transmits each of the generated transmission signals from one or more different output ports at the same frequency band and at the same timing, For the modulation signal, one precoding matrix is selected while switching regularly from among a plurality of precoding matrices, precoding is performed using the selected precoding matrix, and the enhanced modulation signal after precoding And the first transmission signal and the second transmission signal are signals based on the basic modulation signal, Characterized in that it is produced from the expanded modulated signal after over loading.

  In the transmission method according to one embodiment of the present invention, the first transmission signal and the second transmission signal are composed of a basic modulation signal consisting of a basic stream and an extension modulation signal consisting of an extension stream of data different from the basic stream. A transmitting method in which a transmitting device transmits each of the generated transmission signals generated from the one or more different output ports at the same frequency band and at the same timing, and a plurality of precoding matrices for the extended modulation signal. Select one of the precoding matrices regularly while switching, and perform precoding using the selected precoding matrix to generate a precoded extended modulation signal, and a signal based on the basic modulation signal Generating a first transmission signal and a second transmission signal from the precoding and the extended modulation signal after the precoding; 1 transmission signal is transmitted from one or more first output ports, and the second transmission signal is transmitted from one or more second output ports different from the first output port, and encoding based on the extended modulation signal When precoding a block, the number of slots required to transmit the coding block as the first transmission signal and the second transmission signal according to a modulation scheme is M, and the plurality of precodings are different from each other The number of matrices is N, the index for identifying each of the plurality of precoding matrices is F (F is any one of 1 to N), and the number of slots to which the precoding matrix of index F is allocated is C [F] ( When C [F] is less than M, the difference between C [a] and C [b] for any a, b (a, b is any of 1 to N, where a ≠ b) Is 0 or 1 Sea urchin and allocating to each M slots using any of a plurality of precoding matrices in the transmission of the coded block.

  Further, according to an embodiment of the present invention, there is provided a transmission apparatus comprising: a first transmission signal and a second transmission signal from a basic modulation signal consisting of a basic stream and an expansion modulation signal consisting of an extension stream of data different from the basic stream; A transmitting apparatus for generating and transmitting each generated transmission signal from one or more different output ports at the same frequency band and at the same timing, wherein a plurality of precoding matrices are used for the extended modulation signal. A weighting / combining unit that selects one precoding matrix while switching regularly and performs precoding using the selected precoding matrix to generate a precoded extended modulation signal, and based on the basic modulation signal A first transmission signal and a second transmission signal are generated from the signal and the premodulated extended modulation signal. A transmitter configured to transmit the first transmission signal from one or more first output ports, and transmit the second transmission signal from one or more second output ports different from the first output port; The weighting / combining unit, when precoding a coding block based on the extended modulation signal, needs to transmit the coding block as the first transmission signal and the second transmission signal according to a modulation scheme. Let M be the number of slots, N be the number of different precoding matrices different from one another, F be an index for identifying each of the multiple precoding matrices F (F is any of 1 to N), index F Let C [F] (C [F] is less than M) be the number of slots to which the precoding matrix is assigned, and any a, b (a, b is any of 1 to N, where a ≠ b ) Assigning one of a plurality of precoding matrices to each of M slots used for transmitting the coding block such that the difference between C [a] and C [b] is 0 or 1 It is characterized by

In the reception method according to one embodiment of the present invention, the reception device receives the first transmission signal and the second transmission signal transmitted by the transmission device from one or more different output ports at the same frequency band and the same timing. In the reception method, the first transmission signal and the second transmission signal are the extension modulation signal of the basic modulation signal of the basic stream and the extension modulation signal of the extension stream of data different from the basic stream. On the other hand, one precoding matrix is selected while switching regularly from among a plurality of precoding matrices, and precoding is performed using the selected precoding matrix to generate an enhanced modulation signal after precoding. A signal based on the basic modulation signal and an extended modulation signal after the precoding Demodulating each of the received first transmission signal and the received second transmission signal according to a demodulation scheme corresponding to the modulation scheme used for the basic modulation signal and the extended modulation signal, and performing error correction decoding to obtain data In the reception method, when the coding block based on the extended modulation signal is precoded, the coding block is transmitted as the first transmission signal and the second transmission signal according to a modulation scheme. Let M be the number of slots required for the purpose, N be the number of different precoding matrices different from one another, and F be an index for identifying each of the multiple precoding matrices (F is any of 1 to N) If the number of slots to which the precoding matrix of index F is assigned is C [F] (C [F] is less than M), any a , B (a, b is any of 1 to N, where a ≠ b), any one of a plurality of precoding matrices such that the difference between C [a] and C [b] is 0 or 1 Are assigned to each of M slots used to transmit the coding block.

Further, in the receiving device according to one embodiment of the present invention, the receiving device receives the first transmission signal and the second transmission signal transmitted by the transmitting device from one or more different output ports respectively in the same frequency band and the same timing. The first transmission signal and the second transmission signal are generated by adding the basic modulation signal of the basic stream and the extension modulation signal of the extension stream of data different from the basic stream to the extension modulation signal. On the other hand, one precoding matrix is selected while switching regularly from among a plurality of precoding matrices, and precoding is performed using the selected precoding matrix to generate an enhanced modulation signal after precoding. A signal based on the basic modulation signal and an extended modulation signal after the precoding Demodulating each of the received first transmission signal and the received second transmission signal according to a demodulation scheme corresponding to the modulation scheme used for the basic modulation signal and the extended modulation signal, and performing error correction decoding to obtain data And in the receiving apparatus, when a coding block based on the extended modulation signal is precoded, the coding block is transmitted as the first transmission signal and the second transmission signal according to a modulation scheme. Let M be the number of slots required for the purpose, N be the number of different precoding matrices different from one another, and F be an index for identifying each of the multiple precoding matrices (F is any of 1 to N) If the number of slots to which the precoding matrix of index F is assigned is C [F] (C [F] is less than M), any a , B (a, b is any of 1 to N, where a ≠ b), any one of a plurality of precoding matrices such that the difference between C [a] and C [b] is 0 or 1 Are assigned to each of M slots used to transmit the coding block.
(Other supplement 2)
2 streams of baseband signals s ₁ (i), s ₂ (i) (baseband signals after mapping of a certain modulation scheme) (where i represents the order of time or frequency (carrier)) contrast, generated performs precoding for switching regularly precoding matrix, in the baseband signal z ₁ after precoding _(i), z 2 _(i), the baseband signal z ₁ after precoding _(i The in-phase I component of I) is I ₁ (i), the quadrature component is Q ₁ (i), the in-phase I component of baseband signal z ₂ (i) after precoding is I ₂ (i), and the quadrature component is Q ₂ (I) At this time, the baseband component is replaced,
· The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), and the in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i ), Quadrature component Q ₁ (i)
And the modulated signal corresponding to the post-replacement baseband signal r ₁ (i) is the transmitting antenna 1,
The modulated signal corresponding to the post-replacement baseband signal r ₂ (i) is transmitted from the transmitting antenna 2 using the same frequency at the same time, etc., equivalent to the post-replacement baseband signal r ₁ (i) And the switched baseband signal r ₂ (i) may be transmitted from different antennas using the same frequency at the same time. Also,
· The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), and the quadrature component is I ₂ (I
i), the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i)
The in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i), and the quadrature component is I ₁ (i)
i), the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i)
· The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), and the quadrature component is I ₂ (I
i), Q ₂ (i) is the in-phase component of the baseband signal r ₂ (i) after replacement, and Q ₁ (i) is the quadrature component
The in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i), and the quadrature component is I ₁ (i)
i), Q ₂ (i) is the in-phase component of the baseband signal r ₂ (i) after replacement, and Q ₁ (i) is the quadrature component
· The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), and the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i ), Orthogonal component I ₂ (i)
· The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), and the in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i ), Quadrature component Q ₁ (i)
· The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), and the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i ), Orthogonal component I ₂ (i)
· The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), and the quadrature component is I ₂ (I
i), the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i)
The in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i), and the quadrature component is I ₁ (I
i), the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i)
· The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), and the quadrature component is I ₂ (I
i), the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), and the quadrature component is Q ₁ (i)
The in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i), and the quadrature component is I ₁ (I
i), the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), and the quadrature component is Q ₁ (i)
· The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), and the in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i ), Quadrature component Q ₁ (i)
-The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), and the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i ), Orthogonal component I ₂ (i)
· The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), and the in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i ), Quadrature component Q ₁ (i)
-The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), and the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i ), Orthogonal component I ₂ (i)

It may be In the above description, precoding is performed on two streams of signals, and switching of the in-phase component and the quadrature component of the precoded signal has been described. However, the present invention is not limited to this. It is also possible to code and replace the in-phase component and the quadrature component of the precoded signal.

In the above example, replacement of baseband signals at the same time (the same frequency ((sub) carrier)) is described, but it is not necessary to replace baseband signals at the same time. As an example, it can be described as follows: I ₁ (i + v) is the in-phase component of the baseband signal r ₁ (i) after replacement, Q ₂ (i + w) is the quadrature component, and the baseband signal r after replacement _{The in-} phase component of ₂ (i) is I ₂ (i + w), and the quadrature component is Q ₁ (i + v)
・ The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i + v), and the quadrature component is I
₂ (i + w), the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i + v), and the quadrature component is Q ₂ (i + w)
· I ₂ (i + w) is the in-phase component of the baseband signal r ₁ (i) after replacement, and I is the quadrature component
₁ (i + v), Q ₁ (i + v) is the in-phase component of the baseband signal r ₂ (i) after replacement, and Q ₂ (i + w) is the quadrature component
・ The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i + v), and the quadrature component is I
₂ (i + w), Q ₂ (i + w) is the in-phase component of the baseband signal r ₂ (i) after replacement, and Q ₁ (i + v) is the quadrature component
· I ₂ (i + w) is the in-phase component of the baseband signal r ₁ (i) after replacement, and I is the quadrature component
₁ (i + v), Q ₂ (i + w) is the in-phase component of the baseband signal r ₂ (i) after replacement, and Q ₁ (i + v) is the quadrature component
· The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i + v), the quadrature component is Q ₂ (i + w), and the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i + v) ), Orthogonal component I ₂ (i + w)
· The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i + w), the quadrature component is I ₁ (i + v), and the in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i + w) ), Quadrature component Q ₁ (i + v)
· The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i + w), the quadrature component is I ₁ (i + v), and the in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i + v) ), Orthogonal component I ₂ (i + w)
・ The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i + v), and the quadrature component is I
₂ (i + w), the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i + v), and the quadrature component is Q ₂ (i + w)
· I ₂ (i + w) is the in-phase component of the baseband signal r ₂ (i) after replacement, and I is the quadrature component
₁ (i + v), Q ₁ (i + v) is the in-phase component of the baseband signal r ₁ (i) after replacement, and Q ₂ (i + w) is the quadrature component
・ The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i + v), and the quadrature component is I
₂ (i + w), Q ₂ (i + w) is the in-phase component of the baseband signal r ₁ (i) after replacement, and Q ₁ (i + v) is the quadrature component
· I ₂ (i + w) is the in-phase component of the baseband signal r ₂ (i) after replacement, and I is the quadrature component
₁ (i + v), Q ₂ (i + w) is the in-phase component of the baseband signal r ₁ (i) after replacement, and Q ₁ (i + v) is the quadrature component
・ The in-phase component of baseband signal r ₂ (i) after replacement is I ₁ (i + v), the quadrature component is Q ₂ (i + w), and the in-phase component of baseband signal r ₁ (i) after replacement is I ₂ (i + w) ), Quadrature component Q ₁ (i + v)
· The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i + v), the quadrature component is Q ₂ (i + w), and the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i + v) ), Orthogonal component I ₂ (i + w)
· The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i + w), the quadrature component is I ₁ (i + v), and the in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i + w) ), Quadrature component Q ₁ (i + v)
· The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i + w), the quadrature component is I ₁ (i + v), and the in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i + v) ), Orthogonal component I ₂ (i + w)

FIG. 88 is a diagram showing a baseband signal rearrangement unit 8802 for describing the above description. As shown in FIG. 1, in the baseband signals z ₁ (i) 8801_1 and z ₂ (i) 8801_2 after precoding, the in-phase I component of the baseband signal z ₁ (i) 8801_1 after precoding is I ₁ (I ₁ i) Let the quadrature component be Q ₁ (i), let the in-phase I component of the pre-coded baseband signal z ₂ (i) 8801_2 be I ₂ (i), and let the quadrature component be Q ₂ (i). Then, the in-phase component of the baseband signal r ₁ (i) after replacement is Ir ₁ (i), the quadrature component is Qr ₁ (i), and the in-phase component of the baseband signal r ₂ (i) 8803_2 after replacement is Ir. ₂ (i), assuming that the quadrature component is Qr ₂ (i), the in-phase component Ir ₁ (i), the quadrature component Qr ₁ (i) of the baseband signal r ₁ (i) 8803_1 after replacement, the baseband after replacement signal _r 2 (i) 8803_2 phase component _Ir 2 (i), the orthogonal component _Qr 2 (i) shall be represented by any one described above. In this example, replacement of baseband signals after precoding at the same time (the same frequency ((sub) carrier) has been described, but as described above, different times (different frequencies ((sub) carriers)) It may be exchange of the baseband signal after precoding.

Then, the modulated signal corresponding to the post-replacement baseband signal r ₁ (i) 8803_1 is transmitted antenna 1, and the modulated signal corresponding to the post-replacement baseband signal r ₂ (i) 8803_2 is transmitted from transmission antenna 2 at the same time. The modulation signal corresponding to the post-replacement baseband signal r ₁ (i) 8803 _ ₁ and the post-replacement baseband signal r ₂ (i) 8803 _ ₂ are transmitted from different antennas at the same time. It will transmit using the same frequency.

  Further, in the symbol arrangement method described in Embodiment A1 to Embodiment A4 and Embodiment 1, a plurality of precoding matrices different from the “method of switching different precoding matrices” described in this specification are used. It can implement similarly as a precoding method which changes a precoding matrix regularly using. The same applies to the other embodiments. In the following, a plurality of different precoding matrices will be supplementarily described.

To prepare the precoding method to switch precoding matrix regularly N pieces of prepared precoding are F [0], F [1], F [2],... F [N-3], F [N -2] and F [N-1]. At this time, it is assumed that the “different plural precoding matrices” described above satisfy the following two conditions (conditions * 1 and conditions * 2).

According to this condition * 1, “(x is an integer from 0 to N−1, y is an integer from 0 to N−1 and x ≠ y) and all x, all of the above are satisfied It is assumed that F [x] ≠ F [y] holds for y.

  Note that a 2 × 2 matrix is used as an example. Let the 2 × 2 matrices R and S be represented as follows.

It is ^assumed that a = Ae ^{jδ 11} , b = Be ^{jδ 12} , c = C e ^{jδ 21} , d = D e ^{jδ 22} , and e = E e ^{jγ 11} , f = Fe ^{jγ 12} , g = Ge ^{jγ 21} , h = He ^{jγ 22} . However, A, B, C, D, E, F, G, H are real numbers of 0 or more, and units of δ11, δ12, δ21, δ22, γ11, γ12, γ21, γ22 are expressed in radians. At this time, when (1) a ≠ e, (2) b ≠ f, (3) c (g, and (4) d ≠ h are defined as R ≠ S, this (1), (2) And at least one of (3) and (4) is established.

  Also, as the precoding matrix, in the matrix R, a matrix in which any one of a, b, c, and d is “zero” may be used. That is, (1) a is zero, b, c, d are not zero, (2) b is zero, a, c, d are not zero, (3) c is zero, a, b , D may not be zero, (4) d may be zero, and a, b and c may not be zero.

And, in the example of the system shown in the description of the present invention, a MIMO communication system is disclosed in which two modulated signals are transmitted from two antennas and each received by two antennas. The present invention can also be applied to a (Multiple Input Single Output) communication system. As described above, in the case of the MISO method, the transmitting apparatus applies a precoding method in which a plurality of precoding matrices are switched regularly. On the other hand, in the configuration shown in FIG. 7, the receiving apparatus is configured without the antenna 701 _Y, the radio unit 703 _Y, the channel fluctuation estimation unit 707_1 of the modulation signal z1, and the channel fluctuation estimation unit 707_2 of the modulation signal z2. Even by performing the process described in the present specification, it is possible to estimate the data transmitted by the transmitting device. It should be noted that it is well known that a plurality of transmitted signals can be received and decoded by one antenna in the same frequency band and at the same time (processing such as ML operation (Max-log APP etc. in one antenna reception) In the present invention, the signal processing unit 711 in FIG. 7 may perform demodulation (detection) in consideration of the precoding method to be switched regularly used on the transmission side.

  The present invention is widely applicable to radio systems that transmit different modulated signals from a plurality of antennas, and is suitable for application to, for example, an OFDM-MIMO communication system. The present invention is also applicable to the case of performing MIMO transmission in a wired communication system (for example, PLC (Power Line Communication) system, optical communication system, DSL (Digital Subscriber Line) system) having a plurality of transmission points. At this time, a plurality of transmission points are used to transmit a plurality of modulated signals as described in the present invention. Also, the modulation signal may be transmitted from a plurality of transmission points.

302A, 302B encoder 304A, 304B interleaver 306A, 306B mapping unit 314 weighted combining information generating unit 308A, 308B weighting combining unit 310A, 310B radio unit 312A, 312B antenna 402 encoder 404 distributing unit 504 # 1, 504 # 2 Transmitting antenna 505 # 1, 505 # 2 Receiving antenna 600 Weighted combining unit 703 _ X Radio unit 701 _ X Antenna 705 _ 1 Channel fluctuation estimating unit 705 _ 2 Channel fluctuation estimating unit 707 _ 2 Channel fluctuation estimating unit 709 Control information decoding unit 711 Signal processing unit 803 INNER MIMO detectors 805A and 805B log likelihood calculators 807A and 807B deinterleavers 809A and 809B log likelihood ratio calculators 811A and 811B Soft- n / soft-out decoder 813A, 813B interleaver 815 storage unit 819 weighting coefficient generation unit 901 Soft-in / soft-out decoder 903 distributor 1301A, 1301B OFDM system related processing unit 1402A, 1402A serial-to-parallel converter 1404A, 1404B Reordering Sections 1406A, 1406B Inverse Fast Fourier Transform Section 1408A, 1408B Radio section 2200 Precoding weight matrix generation section 2300 Reordering section 4002 Coder group

Claims (4)

A transmission method,
A first modulation signal sequence s1 (j) including a plurality of first modulation signals s1; and a second modulation signal sequence s2 (j) including a plurality of second modulation signals s2, where j is the first Of the first modulation signal s1 and the second modulation signal s2 and is an integer greater than or equal to 0), and the first modulation signal s1 and the second modulation signal having the same index number. The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j) are subjected to precoding processing in accordance with one of a plurality of different precoding schemes for each set of modulation signals s2. And a generation process of cyclically switching among the plurality of precoding schemes according to the value of the index number, and generating the precoding scheme used for the precoding process;
The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j) are transmitted using a plurality of antennas, and the first transmission signal z1 and the second transmission having the same index number are transmitted. Transmission processing simultaneously transmitted on the same frequency as the signal z2;
Including
Each of the plurality of precoding schemes is the following N matrices F [i] (where i is an integer of 0 or more and N-1 or less, and N is the number of the plurality of precoding schemes): Represented by either
Where λ is an arbitrary angle and α is a positive real number,
θ ₁₁ (i) and θ ₂₁ (i) are
and
Meet the transmission method. A transmitting device,
A first modulation signal sequence s1 (j) including a plurality of first modulation signals s1; and a second modulation signal sequence s2 (j) including a plurality of second modulation signals s2, where j is the first Of the first modulation signal s1 and the second modulation signal s2 and is an integer greater than or equal to 0), and the first modulation signal s1 and the second modulation signal having the same index number. The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j) are subjected to precoding processing in accordance with one of a plurality of different precoding schemes for each set of modulation signals s2. And a generation unit configured to periodically switch among the plurality of precoding schemes according to the value of the index number.
The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j) are transmitted using a plurality of antennas, and the first transmission signal z1 and the second transmission having the same index number are transmitted. A transmitter that simultaneously transmits the signal z2 at the same frequency;
Including
Each of the plurality of precoding schemes is the following N matrices F [i] (where i is an integer of 0 or more and N-1 or less, and N is the number of the plurality of precoding schemes): Represented by either
Where λ is an arbitrary angle and α is a positive real number,
θ ₁₁ (i) and θ ₂₁ (i) are
and
Meet the sending device. The receiving method,
A reception signal is obtained, and the reception signal is obtained by receiving the first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j) transmitted using a plurality of antennas (where j is Is an index indicating the numbers of the first transmission signal z1 and the second transmission signal z2 and is an integer greater than or equal to 0.), the first transmission signal z1 having the same index number and the second transmission The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j), which are simultaneously transmitted at the same frequency as the signal z2, include a plurality of first modulation signals s1. It is generated by performing predetermined generation processing on one modulation signal sequence s1 (j) and a second modulation signal sequence s2 (j) including a plurality of second modulation signals s2,
Demodulation processing according to the generation processing is performed on the acquired reception signal to generate reception data;
In the generation process, the first modulation signal s1 and the second modulation signal s1 having the same index number for the first modulation signal sequence s1 (j) and the second modulation signal sequence s2 (j). The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 are subjected to precoding processing in accordance with one of a plurality of different precoding schemes for each set of modulation signals s2. (J) is generated, and the precoding scheme used for the precoding process is periodically switched among the plurality of precoding schemes according to the value of the index number,
Each of the plurality of precoding schemes is the following N matrices F [i] (where i is an integer of 0 or more and N-1 or less, and N is the number of the plurality of precoding schemes): Represented by either
Where λ is an arbitrary angle and α is a positive real number,
θ ₁₁ (i) and θ ₂₁ (i) are
and
Meet
Reception method. A receiving device,
And an acquisition unit for acquiring a reception signal,
The reception signal is obtained by receiving a first transmission signal sequence z1 (j) and a second transmission signal sequence z2 (j) transmitted using a plurality of antennas (where j is the first transmission) The index indicating the number of the signal z1 and the second transmission signal z2 and is an integer greater than or equal to 0.) The first transmission signal z1 and the second transmission signal z2 having the same index number are the same. The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 (j), which are simultaneously transmitted at a frequency, are a first modulation signal sequence s1 including a plurality of first modulation signals s1. (J) and a second modulation signal sequence s2 (j) including a plurality of second modulation signals s2 are generated by performing predetermined generation processing,
And a demodulation unit that performs demodulation processing on the acquired reception signal to generate reception data.
In the generation process, the first modulation signal s1 and the second modulation signal s1 having the same index number for the first modulation signal sequence s1 (j) and the second modulation signal sequence s2 (j). The first transmission signal sequence z1 (j) and the second transmission signal sequence z2 are subjected to precoding processing in accordance with one of a plurality of different precoding schemes for each set of modulation signals s2. (J) is generated, and the precoding scheme used for the precoding process is periodically switched among the plurality of precoding schemes according to the index number,
Each of the plurality of precoding schemes is the following N matrices F [i] (where i is an integer of 0 or more and N-1 or less, and N is the number of the plurality of precoding schemes): Represented by either
Where λ is an arbitrary angle and α is a positive real number,
θ ₁₁ (i) and θ ₂₁ (i) are
and
Meet
Receiver.