JP7117533B2 - transmitter and receiver - Google Patents

Description

The present invention particularly relates to a transmitting device and a receiving device that perform communication using multiple antennas.

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

FIG. 23 shows an example of the configuration of a transmitting/receiving apparatus with two transmission antennas, two reception antennas, and two transmission modulated signals (transmission streams). The transmitter interleaves the encoded data, modulates the interleaved data, performs frequency conversion, etc., and generates a transmission signal, which is transmitted from an antenna. At this time, a spatial multiplexing MIMO system is a system in which different modulated signals are transmitted from transmission antennas at the same time and on the same frequency.

At this time, Patent Literature 1 proposes a transmission apparatus having an interleave pattern that differs for each transmission antenna. That is, in the transmitting apparatus of FIG. 23, the two interleaves (πa, πb) have mutually different interleave patterns. Then, in the receiving device, as shown in Non-Patent Document 1 and Non-Patent Document 2, the reception quality is improved by repeatedly performing the detection method using the soft value (MIMO detector in FIG. 23). will do.

By the way, as models of actual propagation environments in wireless communication, there are a NLOS (non-line of sight) environment represented by a Rayleigh fading environment and a LOS (line of sight) environment represented by a Rician fading environment. When a transmitting device transmits a single modulated signal, a receiving device performs maximum ratio combining on signals received by a plurality of antennas, and demodulates and decodes the signals after maximum ratio combining, LOS environment, In particular, in an environment where the Rice factor, which indicates the magnitude of received power of direct waves relative to received power of scattered waves, is large, good reception quality can be obtained. However, depending on the transmission system (for example, the spatial multiplexing MIMO transmission system), there is a problem that reception quality deteriorates when the Rice factor increases. (See Non-Patent Document 3)
(A) and (B) of FIG. 24 show 2×2 LDPC (low-density parity-check) encoded data in a Rayleigh fading environment and a Rician fading environment with Rician factors K = 3, 10, and 16 dB. (Two-antenna transmission, two-antenna reception) An example of simulation results of BER (Bit Error Rate) characteristics (vertical axis: BER, horizontal axis: SNR (signal-to-noise power ratio)) when spatial multiplexing MIMO transmission is shown. ing. (A) of FIG. 24 shows the BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (APP: a posterior probability) without iterative detection, and (B) of FIG. The BER characteristics of the detected Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (5 iterations) are shown. As can be seen from FIGS. 24A and 24B, regardless of whether or not iterative detection is performed, in a spatial multiplexing MIMO system, it can be confirmed that reception quality deteriorates as the Rice factor increases. From this, it can be said that the spatial multiplexing MIMO system has a problem unique to the spatial multiplexing MIMO system, which is not found in conventional systems that transmit a single modulated signal, namely, "receiving quality deteriorates when the propagation environment becomes stable in a spatial multiplexing MIMO system." Recognize.

Broadcasting and multicast communication are services that must deal with various propagation environments, and the radio wave propagation environment between a receiver owned by a user and a broadcasting station can naturally be an LOS environment. When a spatial multiplexing MIMO system with the above-mentioned problems is used for broadcasting or multicast communication, a phenomenon occurs in which the receiver cannot receive the service due to deterioration of the reception quality even though the reception field strength of the radio wave is high. there is a possibility. In other words, in order to use a spatially multiplexed MIMO system for broadcasting or multicast communication, it is desired to develop a MIMO transmission scheme that can obtain a certain level of reception quality in both NLOS and LOS environments.

Non-Patent Document 8 describes a method of selecting a codebook (precoding matrix (also referred to as a precoding weight matrix)) to be used for precoding from feedback information from the communication partner. There is no description of a method of precoding in a situation such as multicast communication in which feedback information from communication partners cannot be obtained.

On the other hand, Non-Patent Document 4 describes a method for switching precoding matrices over time, which can be applied even in the absence of feedback information. In this document, it is described that a unitary matrix is used as the matrix used for precoding, and that the unitary matrix is randomly switched. Nothing is described, only random switching is described. Naturally, there is no description of a precoding method for improving reception quality degradation in an LOS environment and a method of configuring a precoding matrix.

WO2005/050885

"Achieving near-capacity on a multiple-antenna channel" IEEE Transactions 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 2x2 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. "Guide to the Shannon limit: 'Parallel concatenated (Turbo) coding', 'Turbo (iterative) decoding' and its surroundings" The Institute of Electronics, Information and Communication Engineers, IEICE Techniques 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. 2967-2976, Aug. 2005. DVB Document A122, Framing structure, channel coding and modulation for a second generation digital terrestrial tele- vision 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, vol. 47, no. 10, pp. 146-153, Oct. 2009. T. Ohgane, T. Nishimura, and Y. Ogawa, "Application of space division multiplexing and their performance in a MIMO channel," IEICE Trans. Commun. , vol. E88-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 matrices," IEEE Trans. Inform. Theory, vol. 45, no. 2, pp399-431, 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". 1.1.2, June 2006. Y. -L. Ueng, and C.I. -C. 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. 1255-1259. S. M. Alamouti, "A simple transmit diversity technique for wireless communications," IEEE J. Am. Select. Areas Commun. , vol. 16, no. 8, pp. 1451-1458, Oct 1998. V. Tarokh, H.; Jafrkhani, andA. R. Calderbank, "Space-time block coding for wireless communications: Performance results," IEEE J. Phys. Select. Areas Commun. , vol.17, no. 3, no. 3, pp. 451-460, March 1999.

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

A transmitting apparatus according to the present invention generates a first transmission signal and a second transmission signal from a first modulation signal and a second modulation signal, which are composed of an in-phase component and a quadrature component based on a modulation scheme, and uses the same frequency band and the same frequency band. A transmission device for transmitting from one or more output ports at different timings, comprising: a phase changing unit for regularly changing the phase of an input modulated signal; a weighted combining unit that performs weighted combining using a fixed precoding matrix; and a phase of a signal based on at least one of the first modulated signal and the second modulated signal is changed by the phase changing unit, a transmitting unit configured to transmit the first transmission signal and the second transmission signal generated by subjecting both signals based on the modulated signal and the second modulated signal to weighted synthesis by the weighted synthesis unit; do.

Further, the receiving device according to the present invention receives the first transmission signal and the second transmission signal, which are transmitted in the same frequency band and at the same timing, from the transmission device. , at least one of the first transmission signal and the second transmission signal is generated by regularly changing the phase of at least one of the original first modulated signal and the second modulated signal. and a signal received by the receiving unit is demodulated by a demodulation method corresponding to the modulation method used for the first modulated signal or the second modulated signal to obtain the first modulated signal and the and a demodulator that obtains a logarithmic likelihood ratio of transmission data that is the source of the second modulated signal.

Here, the signal based on the first modulated signal refers to either the first modulated signal itself or a phase-changed or weighted (precoded) version of the first modulated signal. be. Similarly, a signal based on the second modulated signal may refer to the second modulated signal itself, or may refer to a phase-changed or weighted (precoded) version of the second modulated signal. .

As described above, according to the present invention, it is possible to provide a transmission method, a reception method, a transmission device, and a reception device that improve reception quality deterioration in an LOS environment. , can provide quality service.

Example of Configuration of Transmitting and Receiving Apparatus in Spatial Multiplexing MIMO Transmission System An example of frame configuration Example of configuration of transmitter when phase change method is applied Example of configuration of transmitter when phase change method is applied Frame configuration example Example of phase change method Configuration example of receiver Configuration example of the signal processing unit of the receiving device Configuration example of the signal processing unit of the receiving device Decryption processing method Receiving status example Example of configuration of transmitter when phase change method is applied Example of configuration of transmitter when phase change method is applied Frame configuration example Frame configuration example Frame configuration example Frame configuration example Frame configuration example An example of mapping method An example of mapping method Example of configuration of weighted synthesis unit An example of how to rearrange symbols Example of Configuration of Transmitting and Receiving Apparatus in Spatial Multiplexing MIMO Transmission System Example of BER characteristics Example of phase change method Example of phase change method Example of phase change method Example of phase change method Example of phase change method Examples of symbol arrangement for modulated signals with high reception quality Modulated signal frame configuration example for high reception quality Examples of symbol arrangement for modulated signals with high reception quality Examples of symbol arrangement for modulated signals with high reception quality Example of change in number of symbols and number of slots required for one encoded block when block code is used Example of change in number of symbols and slots required for two encoded blocks when using block code Overall configuration diagram of digital broadcasting system Block diagram showing a configuration example of a receiver Diagram showing structure of multiplexed data Diagram showing how each stream is multiplexed in multiplexed data Detailed view of how the video stream is stored in the PES packet train 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 display and audio output device An example of a communication system configuration Examples of symbol arrangement for modulated signals with high reception quality Examples of symbol arrangement for modulated signals with high reception quality Examples of symbol arrangement for modulated signals with high reception quality Examples of symbol arrangement for modulated signals with high reception quality Examples of transmitter configurations Examples of transmitter configurations Examples of transmitter configurations Examples of transmitter configurations Diagram showing a baseband signal switching unit

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
A transmission method, a transmission device, a reception method, and a reception device according to this embodiment will be described in detail.

Before proceeding to this description, an outline of a transmission method and a decoding method in a spatial multiplexing MIMO transmission system, which is a conventional system, will be described.
FIG. 1 shows the configuration of an N _{t x} N _r spatial multiplexing MIMO system. The information vector z is encoded and interleaved. Then, a vector u=(u ₁ , . . . , u _Nt ) of encoded bits is obtained as an output of interleaving. However, u _i =(u _i1 ,..., u _iM ) (M: number of transmission bits per symbol). If the _transmission ^vector _{s =} ⁽ _{s 1} , . /Nt (E _s : total energy per channel). Then, ^assuming that the received vector is _y =(y ₁ , .

At this time, H _NtNr is a channel matrix, n=(n ₁ , . . . , n _Nr ) ^T is a noise vector, ⁿ _i is i. i. d. Complex Gaussian noise. From the relationship between transmitted symbols and received symbols introduced at the receiver, the probability for the received vector can be given by a multi-dimensional Gaussian distribution as shown in equation (2).

Consider a receiver that performs iterative decoding as shown in FIG. 1, which is composed of an outer soft-in/soft-out decoder and MIMO detection. A vector (L-value) of log-likelihood ratios in FIG. 1 is represented by equations (3) to (5).

<Iterative detection method>
Here we describe iterative detection of MIMO signals in an N _t ×N _r spatially multiplexed MIMO system.
The log-likelihood ratio of u _mn is defined as Equation (6).

From Bayes' theorem, Equation (6) can be expressed as Equation (7).

However, U _mn,±1 ={u|u _mn =±1}. Then, lnΣa _j ~ max
When approximating by ln a _j , the equation (7) can be approximated as the equation (8). It should be noted that the above symbol "~" means 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 formula defined by Formula (2) is represented by Formula (12).

Therefore, from equations (7) and (13), the posterior L-value in MAP or APP (a posterior probability) is expressed as follows.

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

Hereinafter, this is called iterative Max-log APP decoding. Then, the extrinsic information required by the iterative decoding system can be obtained by subtracting the a priori input from equation (13) or (14).
<System model>
FIG. 23 shows the basic configuration of the system leading to the following description. Here, a 2×2 spatial multiplexing MIMO system is assumed, each of streams A and B has an outer encoder, and the two outer encoders are assumed to be the same LDPC code encoder (here, a configuration using an LDPC code encoder as the outer encoder will be described as an example, but the error correcting code used by the outer encoder is not limited to the LDPC code. In addition, the outer encoder is configured to be provided for each transmission antenna, but the configuration is not limited to this, and even if there are a plurality of transmission antennas, the number of outer encoders may be one. You may have more outer encoders than the number of antennas.). Streams A and B each have an interleaver (π _a , π _b ). Here, the modulation scheme is 2 ^h -QAM (one symbol transmits h bits).
It is assumed that the receiver performs iterative detection (iterative APP (or Max-log APP) decoding) of the MIMO signal described above. Then, as the decoding of the LDPC code, for example, sum-product decoding is performed.
FIG. 2 shows the frame structure and describes the order of the symbols after interleaving. At this time, ( _ia , _ja ) and ( _ib , _jb ) shall be expressed as in the following equations.

At this time, ia, ib: order of symbols after interleaving, _ja , _jb : bit positions in the modulation scheme ( _ja , _{jb =} 1, ..., h), _πa , _{πb :} stream Interleavers of ^A and ^B , Ω _aia,ja , Ω _bib,jb : order of data of streams A and B before interleaving. However, FIG. 2 shows the frame configuration when i _a =i _b .
<Iterative decoding>
Here, the algorithms for sum-product decoding and MIMO signal iterative detection used for decoding LDPC codes in the receiver will be described in detail.

Sum-Product Decoding Let the binary M×N matrix H={H _mn } be the parity check matrix of the 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 indices that are 1 in the m-th row of parity check matrix H, and B(n) is a set of row indices that are 1 in n-th row of parity check matrix H. . The sum-product decoding algorithm is as follows.
Step A·1 (initialization): Set prior value log ratio β _mn =0 for all pairs (m, n) satisfying H _mn =1. A loop variable (the number of iterations) l _sum =1 and the maximum number of loops is set as l _sum,max .
Step A 2 (row processing): For all pairs (m, n) satisfying H _mn = 1 in the order of m = 1, 2, ..., M, external value logarithm using the following update formula Update the ratio α _mn .

Then f is the Gallager function. A method for obtaining λ _n will be described later in detail.
Step A 3 (column processing): For all pairs (m, n) that satisfy H _mn = 1 in the order of n = 1, 2, ..., N, the following update formula is used to perform external value logarithm Update the ratio β _mn .

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

Step A.5 (counting the number of iterations): If l _sum <l _sum,max , increment l _sum and return to step A.2. If l _sum =l _sum,max , this round of sum-product decoding ends.

The above is the operation of one sum-product decoding. After that, iterative detection of the MIMO signal is performed. Among the variables m, n, α _mn , β _mn , λ _n , and L _n used in the above description of the operation of sum-product decoding, the variables in stream A are m _a , n _a , α ^a _mana , β ^a _mana , Let λ _na , L _na and the variables in stream ^{B be denoted by mb , n b , α b mbnb , β b} _{mbnb , λ} ^nb _{, L nb} .
<Iterative detection of MIMO signal>
Here, a method for obtaining _λn in iterative detection of MIMO signals will be described in detail.

From equation (1), the following equation holds.

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

Then, n _a , n _b ε[1, N]. Hereafter, λ _na , L _na , λ _nb , and L _nb when the iterative detection of the MIMO signal is iterative number k are represented as λ _k,na , L _k,na , λ _k,nb , and L _k,nb respectively. and

Step B·1 (initial detection; k=0): At initial detection, λ _0,na , λ _0,nb are obtained as follows.
For iterative APP decoding:

For iterative Max-log APP decoding:

However, X=a, b. Then, the number of iterations of iterative detection of the MIMO signal is set to l _mimo =0, and the maximum number of iterations is set to l _mimo,max .
Step B 2 (iterative detection; number of iterations k): λ _k,na and λ _k,nb at the number of iterations k are obtained from equations (11) (13)-(15) (16) (17) to equation ( 31)-(34). However, (X, Y)=(a, b)(b, a).
For iterative APP decoding:

For iterative Max-log APP decoding:

Step B·3 (counting the number of iterations, codeword estimation): If l _mimo <l _mimo,max , then l _mimo is incremented and the process returns to step B·2. If l _mimo =l _mimo,max , we obtain the estimated codeword as follows.

However, X=a, b.
FIG. 3 is an example of the configuration of transmitting apparatus 300 in this embodiment. The encoding unit 302A receives information (data) 301A and a frame configuration signal 313 as inputs, and uses the frame configuration signal 313 (error correction method, encoding rate, block length, etc. used by the encoding unit 302A for error correction encoding of data). information is included, and the method specified by the frame configuration signal 313 is used.Also, the error correction method may be switched.), for example, convolutional code, LDPC code, turbo code, etc. Error correction encoding is performed, and encoded data 303A is output.

The interleaver 304A receives the encoded data 303A and the frame configuration signal 313 as inputs, interleaves them, that is, rearranges their order, and outputs interleaved data 305A. (The interleaving method may be switched based on the frame configuration signal 313.)
Mapping section 306A receives interleaved data 305A and frame configuration signal 313 as inputs, performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), performs band-based modulation, etc. It outputs signal 307A. (The modulation method may be switched based on the frame configuration signal 313.)
FIG. 19 shows an example of a mapping method on the IQ plane of the in-phase component I and the quadrature component Q that constitute the baseband signal in QPSK modulation. For example, as shown in FIG. 19A, when the input data is "00", I=1.0 and Q=1.0 are output, and similarly when the input data is "01", I= −1.0, Q=1.0 are output, . . . are output. FIG. 19B is an example of a mapping method in the IQ plane of QPSK modulation different from FIG. 19A, and FIG. 19B differs from FIG. By rotating the signal point around the origin, the signal point in FIG. 19B can be obtained. Non-Patent Document 9 and Non-Patent Document 10 show such a constellation rotation method. good. As a different example from FIG. 19, FIG. 20 shows a signal point arrangement on the IQ plane for 16QAM, and an example corresponding to FIG. 19A is FIG. FIG. 20B shows an example corresponding to .

Encoding section 302B receives information (data) 301B and frame configuration signal 313 as inputs, frame configuration signal 313 (which includes information such as the error correction method to be used, coding rate, block length, etc.), and encodes frame configuration signal 313 will use the specified method.In addition, the error correction method may be switched.), for example, perform error correction coding such as convolutional code, LDPC code, turbo code, and the data after encoding 303B is output.

The interleaver 304B receives the encoded data 303B and the frame configuration signal 313, interleaves them, that is, rearranges their order, and outputs interleaved data 305B. (The interleaving method may be switched based on the frame configuration signal 313.)
Mapping section 306B receives interleaved data 305B and frame configuration signal 313 as input, performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), performs band-based modulation, etc. It outputs signal 307B. (The modulation method may be switched based on the frame configuration signal 313.)
A signal processing method information generator 314 receives the frame configuration signal 313 and outputs information 315 on the signal processing method based on the frame configuration signal 313 . The information 315 on the signal processing method includes information specifying which precoding matrix is to be fixedly used and information on the phase change pattern for changing the phase.

The weighted synthesis unit 308A receives the baseband signal 307A, the baseband signal 307B, and the information 315 regarding the signal processing method, weights and synthesizes the baseband signal 307A and the baseband signal 307B based on the information 315 regarding the signal processing method, A signal 309A after weighted synthesis is output. Details of the weighted synthesis method will be described later.

Radio section 310A receives signal 309A after weighting and combining as input, performs processing such as quadrature modulation, band limitation, frequency conversion, and amplification, and outputs transmission signal 311A. Transmission signal 511A is output as radio waves from antenna 312A. be.

The weighting synthesis unit 308B receives the baseband signal 307A, the baseband signal 307B, and the information 315 regarding the signal processing method, weights and synthesizes the baseband signal 307A and the baseband signal 307B based on the information 315 regarding the signal processing method, A signal 316B after weighted synthesis is output.

FIG. 21 shows the configuration of the weighted combining section (308A, 308B). A region surrounded by a dotted line in FIG. 21 is a weighted combining portion. Baseband signal 307A is multiplied by w11 to produce w11·s1(t) and by w21 to produce w21·s1(t). Similarly, baseband signal 307B is multiplied by w12 to produce w12·s2(t) and by w22 to produce w22·s2(t). Next, we obtain z1(t)=w11.s1(t)+w12.s2(t) and z2(t)=w21.s1(t)+w22.s2(t). At this time, s1(t) and s2(t) are BPSK (Binary
Phase Shift Keying), QPSK, 8PSK (8 Phase Shift Keying), 16QAM,
It becomes a baseband signal of a modulation system such as 32QAM (32 Quadrature Amplitude Modulation), 64QAM, 256QAM, 16APSK (16 Amplitude Phase Shift Keying).

Here, both weighted synthesis units perform weighting using a fixed precoding matrix. There is a method using (36). However, this is just an example, and the value of α is not limited to the formulas (37) and (38), and another value such as 1 may be used.

Note that the precoding matrix is

However, in the above formula (36), α is

is.
Alternatively, in the above formula (36), α is

is.
Note that the precoding matrix is not limited to formula (36), and may be the one shown in formula (39).

In this equation (39), a=Ae ^jδ11 , b=Be ^jδ12 , c=Ce ^jδ21 , and d=De ^jδ22 . Also, any one of a, b, c, and d may be "zero". For example: (1) a is zero and b, c, d are not zero; (2) b is zero and a, c, d are not zero; (3) c is zero and a, b , d is not zero, and (4) d is zero and a, b, and c are not zero.

Note that when any one of the modulation scheme, error correction code, and coding rate is changed, the precoding matrix to be used may be set and changed, and the precoding matrix may be used fixedly.

The phase changing unit 312 receives the signal 312B after weighting and combining and the information 315 regarding the signal processing method, and regularly changes the phase of the signal 312B to output. Changing regularly means changing the phase according to a predetermined phase change pattern at a predetermined cycle (for example, every n symbols (where n is an integer equal to or greater than 1) or every predetermined time). . Details of the phase change pattern will be described in Embodiment 4 below.

Radio section 310B receives phase-changed signal 309B as input, performs processing such as quadrature modulation, band limitation, frequency conversion, and amplification, and outputs transmission signal 311B, which is output as radio waves from antenna 312B. be.

FIG. 4 shows a configuration example of a transmission device 400 different from that in FIG. In FIG. 4, portions different from those in 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 encoded data 402 .

Distribution section 404 receives encoded data 403, distributes it, and outputs data 405A and data 405B. In FIG. 4, the case where there is one encoding unit is described, but the present invention is not limited to this. The present invention can be implemented in a similar manner even when the distributing unit divides the converted data into two lines of data and outputs the divided data.

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

Symbol 501_1 is a symbol for estimating channel fluctuation of modulated signal z1(t) {where t is time} transmitted by the transmitting device. Symbol 502_1 is the data symbol that modulated signal z1(t) transmits at symbol number u (on the time axis), and symbol 503_1 is the data symbol that modulated signal z1(t) transmits at symbol number u+1.

A symbol 501_2 is a symbol for estimating the channel variation of the modulated signal z2(t) {where t is time} transmitted by the transmitter. Symbol 502_2 is a data symbol transmitted by modulated signal z2(t) at symbol number u, and symbol 503_2 is a data symbol transmitted by modulated signal z2(t) at symbol number u+1.

At this time, the symbols of z1(t) and z2(t) at the same time (same time) are transmitted from the transmitting antenna using the same (common) frequency.

The relationship between the modulated signal z1(t) and the modulated signal z2(t) transmitted by the transmitter and the received signals r1(t) and r2(t) in the receiver will be described.
5, 504#1 and 504#2 denote transmitting antennas in the transmitting device, 505#1 and 505#2 denote receiving antennas in the receiving device, and the transmitting device transmits modulated signal z1(t) to the transmitting antenna 504. #1, transmit modulated signal z2(t) from transmit antenna 504#2; At this time, the modulated signal z1(t) and the modulated signal z2(t) are assumed to occupy the same (common) frequency (band). Let h11(t), h12(t), h21(t), and h22(t) be the channel fluctuations of each transmitting antenna of the transmitting device and each antenna of the receiving device, respectively, and the reception received by the receiving antenna 505#1 of the receiving device 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 holds.

FIG. 6 is a diagram related to the weighting method (precoding method) and the phase changing method in this embodiment. This is the weighted synthesis unit. As shown in FIG. 6, stream s1(t) and stream s2(t) correspond to baseband signals 307A and 307B of FIG. It becomes an in-phase I component and a quadrature Q component of the band signal. In the stream s1(t), the signal of symbol number u is represented by s1(u), the signal of symbol number u+1 is represented by s1(u+1), . Similarly, in stream s2(t), a signal with symbol number u is represented as s2(u), a signal with symbol number u+1 as s2(u+1), and so on. Then, weighted synthesis section 600 receives baseband signals 307A (s1(t)) and 307B (s2(t)) in FIG. to output signals 309A (z1(t)) and 309B (z2(t)) after weighted synthesis in FIG.

At this time, z1(t) can be expressed by the following equation (41), where W1=(w11, w12) is the first row vector in the fixed precoding matrix F.

On the other hand, z2(t) is obtained by the following formula (42 ).

Here, y(t) is an equation for changing the phase according to a predetermined method. be able to.

Similarly, the phase change formula at time u+1 can be represented by formula (44), for example.

That is, the phase change formula for time u+k can be expressed by formula (45).

Note that the regular phase change example shown in equations (43) to (45) is merely an example.
The period of regular phase change is not limited to four. If the number of cycles increases, there is a possibility that the reception performance (more precisely, the error correction performance) of the receiving device can be improved accordingly. It is likely better to avoid small values such as .)

In addition, in the phase change examples shown in the above equations (43) to (45), a configuration is shown in which the phase is sequentially rotated by a predetermined phase (in the above equation, by π/2). Instead, the phase may be changed randomly. For example, the phases to be multiplied by y(t) may be changed in the order shown in equations (46) and (47) according to a predetermined cycle. What is important in the regular phase change is that the phase of the modulated signal is regularly changed, and the degree of the phase change is as uniform as possible, for example, from -π radians to π radians. On the other hand, although it is desirable to have a uniform distribution, it may be random.

In this way, the weighted combining section 600 in FIG. 6 performs precoding using predetermined fixed precoding weights, and the phase changing section regularly adjusts the phase of the input signal and the degree of change. change while changing to

In a LOS environment, using a special precoding matrix can greatly improve reception quality, but depending on the situation of the direct wave, the special precoding matrix may be affected by the phase and amplitude components of the received direct wave. different. However, there is a certain rule in the LOS environment, and if the phase of the transmission signal is regularly changed according to this rule, the reception quality of data will be greatly improved. The present invention proposes a signal processing method that improves the LOS environment.

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

Channel fluctuation estimator 705_1 in modulated signal z1 transmitted by the transmitting device receives baseband signal 704_X as input, extracts reference symbol 501_1 for channel estimation in FIG. estimate and output a channel estimate signal 706_1.

Channel fluctuation estimator 705_2 in modulated signal z2 transmitted by the transmitter receives baseband signal 704_X, extracts reference symbol 501_2 for channel estimation in FIG. and output channel estimation signal 706_2.

Radio section 703_Y receives received signal 702_Y received by antenna 701_Y, performs processing such as frequency conversion and orthogonal demodulation, and outputs baseband signal 704_Y.
A channel fluctuation estimator 707_1 in modulated signal z1 transmitted by the transmitting device receives baseband signal 704_Y as input, extracts reference symbol 501_1 for channel estimation in FIG. estimate and output a channel estimate signal 708_1.

Channel fluctuation estimator 707_2 in modulated signal z2 transmitted by the transmitter receives baseband signal 704_Y, extracts reference symbol 501_2 for channel estimation in FIG. estimate and output a channel estimate 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 in FIG. 5, and outputs signal 710 regarding information on the transmission method notified by the transmitting apparatus.

Signal processing section 711 receives as inputs baseband signals 704_X and 704_Y, channel estimation signals 706_1, 706_2, 708_1, and 708_2, and signal 710 relating to transmission method information notified by the transmitting apparatus, performs detection and decoding, and obtains received data. Output 712_1 and 712_2.

Next, the operation of the signal processing section 711 in FIG. 7 will be described in detail. FIG. 8 shows an example of the configuration of signal processing section 711 in this embodiment. FIG. 8 mainly consists of an INNER MIMO detector, a soft-in/soft-out decoder, and a coefficient generator. The iterative decoding method in this configuration is described in detail in Non-Patent Documents 2 and 3. The MIMO transmission schemes described in Non-Patent Documents 2 and 3 are spatial multiplexing MIMO transmission method, the transmission method in the present embodiment is a MIMO transmission method in which the phase of the signal is regularly changed over time and a precoding matrix is used. This is a different point from Patent Document 3. H(t) is the (channel) matrix in equation (36), F is the precoding weight matrix in FIG. Y(t) is the matrix of the phase change formula by the phase change unit (where Y(t) changes with t), R(t)=(r1(t), r2(t)) ^T is the received vector, and the stream Vector S(t)=(s1(t), s2(t)) Assuming ^T , the following relational expression holds.

At this time, the receiving device can apply the decoding methods of Non-Patent Documents 2 and 3 to the reception vector R(t) by obtaining H(t)×Y(t)×F. .
Therefore, the coefficient generation unit 819 in FIG. 8 generates a signal 818 related to information on the transmission method notified by the transmission device (information for specifying the phase change pattern when the fixed precoding matrix used and the phase is changed). (corresponding to 710 in FIG. 7) is input, and a signal 820 relating to information on the signal processing method is output.

The INNER MIMO detection unit 803 receives as input a signal 820 relating to information on the signal processing method, and uses this signal to perform iterative detection and decoding by using the relationship of equation (48). will be explained.

In the signal processing section with the configuration shown in FIG. 8, iterative decoding (iterative detection) is performed, so the processing method shown in FIG. 10 must be performed. First, one codeword (or one frame) of the modulated signal (stream) s1 and one codeword (or one frame) of the modulated signal (stream) s2 are decoded. As a result, one codeword (or one frame) of the modulated signal (stream) s1 and one codeword (or one frame) of the modulated signal (stream) s2 are output from the soft-in/soft-out decoder. The Log-Likelihood Ratio (LLR) of the 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)). In the following, the method of creating log-likelihood ratios (LLRs) of symbols at specific times in one frame will be mainly described.

8, storage section 815 stores baseband signal 801X (corresponding to baseband signal 704_X in FIG. 7), channel estimation signal group 802X (corresponding to channel estimation signals 706_1 and 706_2 in FIG. 7), baseband Signal 801Y (corresponding to baseband signal 704_Y in FIG. 7) and channel estimation signal group 802Y (corresponding to channel estimation signals 708_1 and 708_2 in FIG. 7) are input, and iterative decoding (iterative detection) is realized. Then, H(t)×Y(t)×F in equation (48) is executed (calculated), and the calculated matrix is stored as a modified channel signal group. Storage section 815 outputs the above signals as baseband signal 816X, modified channel estimation signal group 817X, baseband signal 816Y, and modified channel estimation signal group 817Y when necessary.

Subsequent operations will be described separately for the case of initial detection and the case of iterative decoding (iterative detection).
<For initial detection>
INNER MIMO detection section 803 receives baseband signal 801X, channel estimation signal group 802X, baseband signal 801Y, and channel estimation signal group 802Y as inputs. Here, the modulation system of the modulated signal (stream) s1 and the modulated signal (stream) s2 is 16QAM.

Inner MIMO detection section 803 first executes H(t)×Y(t)×F from channel estimation signal group 802X and channel estimation signal group 802Y to obtain candidate signal points corresponding to baseband signal 801X. FIG. 11 shows the situation at that time. In FIG. 11, ● (black circles) are candidate signal points on the IQ plane, and since the modulation scheme is 16QAM, there are 256 candidate signal points. (However, since FIG. 11 shows an image diagram, not all 256 candidate signal points are shown.) Here, the 4 bits transmitted by the modulated signal s1 are b0, b1, b2, b3, and the modulated signal s2 Let b4, b5, b6, and b7 be the four bits transmitted in , there is a candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) in FIG. Then, the squared Euclidean distance between received signal point 1101 (corresponding to baseband signal 801X) and each of the candidate signal points is obtained. Each squared Euclidean distance is then divided by the noise variance σ ² . Therefore, (b0, b1,
E _X (b0, b1, b2, b3, b4, b5, b0, b1, b2, b3, b4, b5, b
6, b7) are obtained. Each baseband signal and modulated signals s1 and s2 are complex signals.

Similarly, H(t)×F×Y(t) is performed from the channel estimation signal group 802X and the channel estimation signal group 802Y to obtain candidate signal points corresponding to the baseband signal 801Y, and the received signal points (baseband signal 801Y) is obtained, and this ^squared Euclidean distance is divided by the noise variance σ2. Therefore, E _Y (b0, b1, b2) is obtained by dividing the square Euclidean distance between the candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) and the received signal point by the noise variance. , b3, b4, b5, b6, b7) are obtained.

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 section 803 outputs E(b0, b1, b2, b3, b4, b5, b6, b7) as a signal 804. FIG.
Log likelihood calculation section 805A receives signal 804 as input, calculates log likelihood of bits b0 and b1 and b2 and b3, and outputs log likelihood signal 806A. However, in calculating the logarithmic likelihood, the logarithmic likelihood at the time of "1" and the logarithmic likelihood at the time of "0" are calculated. The calculation method is as shown in Equations (28), (29), and (30), and details are shown in Non-Patent Document 2 and Non-Patent Document 3.

Similarly, log-likelihood calculation section 805B receives signal 804 as input, calculates log-likelihoods of bits b4 and b5 and b6 and b7, and outputs log-likelihood signal 806B.
A deinterleaver (807A) receives the log-likelihood signal 806A, performs deinterleaving corresponding to the interleaver (interleaver (304A) in FIG. 3), and outputs a deinterleaved log-likelihood signal 808A.

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

The log-likelihood ratio calculation unit 809A receives the deinterleaved log-likelihood signal 808A as input, and calculates the log-likelihood ratio (LLR: Log-Likelihood Ratio) of the bits encoded by the encoder 302A in FIG. and outputs log-likelihood ratio signal 810A.

Similarly, log-likelihood ratio calculation section 809B receives deinterleaved log-likelihood signal 808B as input, and the log-likelihood ratio (LLR: Log-
Likelihood Ratio) and outputs a log-likelihood ratio signal 810B.

A soft-in/soft-out decoder 811A receives the log-likelihood ratio signal 810A, decodes it, and outputs a decoded log-likelihood ratio 812A.
Similarly, the soft-in/soft-out decoder 811B receives the log-likelihood ratio signal 810B, decodes it, and outputs a 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 log-likelihood ratio after interleaving 814A. . At this time, the interleave pattern of the interleaver (813A) is the same as the interleave pattern of the interleaver (304A) in FIG.

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

INNER MIMO detection section 803 receives baseband signal 816X, modified channel estimation signal group 817X, baseband signal 816Y, modified channel estimation signal group 817Y, interleaved log-likelihood ratio 814A, and interleaved log-likelihood ratio 814B. and 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, and the modified channel estimation signal group 817Y is used because delay time occurs due to iterative decoding.

The difference between the operation of INNER MIMO detection section 803 during iterative decoding and the operation during initial detection is that the log-likelihood ratio after interleaving 814A and the log-likelihood ratio after interleaving 814B are used in signal processing. is. The INNER MIMO detection section 803 first obtains E(b0, b1, b2, b3, b4, b5, b6, b7) as in the initial detection. In addition, coefficients corresponding to equations (11) and (32) are obtained from the interleaved log-likelihood ratio 814A and the interleaved log-likelihood ratio 814B. Then, the values of E (b0, b1, b2, b3, b4, b5, b6, b7) are corrected using the obtained coefficients, and the corrected values are E'
(b0, b1, b2, b3, b4, b5, b6, b7) and output as signal 804.

Log likelihood calculation section 805A receives signal 804 as input, calculates log likelihood of bits b0 and b1 and b2 and b3, and outputs log likelihood signal 806A. However, in calculating the logarithmic likelihood, the logarithmic likelihood at the time of "1" and the logarithmic likelihood at the time of "0" are calculated. The calculation method is as shown in formulas (31), (32), (33), (34), and (35), and is shown in Non-Patent Document 2 and Non-Patent Document 3. .

Similarly, log-likelihood calculation section 805B receives signal 804 as input, calculates log-likelihoods of bits b4 and b5 and b6 and b7, and outputs log-likelihood signal 806B. The operation after the deinterleaver is the same as the initial detection.

Note that FIG. 8 shows the configuration of the signal processing unit when performing iterative detection, but iterative detection is not necessarily an essential configuration for obtaining good reception quality. , interleavers 813A and 813B may be omitted. At this time, the INNER MIMO detection section 803 does not perform iterative detection.

An important part of this embodiment is the calculation of H(t).times.Y(t).times.F. Note that initial detection and iterative detection may be performed using QR decomposition, as disclosed in Non-Patent Document 5 and the like.
Further, as shown in Non-Patent Document 11, based on H (t) × Y (t) × F, linear calculation of MMSE (Minimum Mean Square Error) and ZF (Zero Forcing) is performed, and initial detection is performed. you can go

FIG. 9 shows a configuration of a signal processing section different from that in FIG. 8, and is a signal processing section for modulated signals transmitted by the transmitting apparatus of FIG. The point different from FIG. 8 is the number of soft-in/soft-out decoders. Output the log-likelihood ratio 902 . Distribution section 903 receives as input log-likelihood ratio 902 after decoding, and performs distribution. Other than that, the operation is the same as in FIG.

As described above, as in the present embodiment, when a transmitting apparatus of a MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding matrix is multiplied, the phase is changed over time, and the phase is By regularly performing the change, it is possible to obtain the effect of improving the data reception quality in the receiving apparatus in an LOS environment where direct waves are dominant, compared to when conventional spatial multiplexing MIMO transmission is used.

In the present embodiment, especially regarding the configuration of the receiving apparatus, the operation was described with a limited number of antennas. In other words, the number of antennas in the receiving device does not affect the operation and effects of this embodiment.

In addition, in the present embodiment, the LDPC code has been described as an example, but the decoding method is not limited to this. There are other soft-in/soft-out decoding methods, such as the BCJR algorithm, the SOVA algorithm, and the Msx-log-MAP algorithm. Details are shown in Non-Patent Document 6.

Also, in the present embodiment, the single-carrier system has been described as an example, but the present invention is not limited to this, and can be carried out in the same way even when multi-carrier transmission is performed. Therefore, for example, the spread spectrum communication method, OFDM (Orthogonal Frequency-Division Multiplexing) method, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC-OFDM (Single Carrier Orthogonal Frequency Division Multiplexing) method, non-patent literature such as Frequency-Division 7 It can be implemented in the same way when using the wavelet OFDM method or the like shown in . Moreover, in the present embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc.), symbols for transmitting control information, etc., may be arranged in any frame.

In the following, an example using the OFDM system will be described as an example of the multicarrier system.
FIG. 12 shows the configuration of a transmission device using the OFDM system. In FIG. 12, the same reference numerals are assigned to the components that operate in the same manner as in FIG.

OFDM system-related processing section 1201A receives weighted signal 309A, performs OFDM system-related processing, and outputs transmission signal 1202A. Similarly, OFDM system-related processing section 1201B receives weighted signal 309B as input and outputs transmission signal 1202B.

FIG. 13 shows an example of the configuration after OFDM system-related processing units 1201A and 1201B in FIG. are 1301B to 1310B.

The serial-to-parallel converter 1302A performs serial-to-parallel conversion on the weighted signal 1301A (corresponding to the weighted signal 309A in FIG. 12) and outputs a parallel signal 1303A.

The rearrangement section 1304A receives the parallel signal 1303A, rearranges the signals, and outputs a rearranged signal 1305A. Note that rearrangement will be described later in detail.
The inverse fast Fourier transform unit 1306A receives the rearranged signal 1305A, performs inverse fast Fourier transform, and outputs a signal 1307A after the inverse Fourier transform.

Radio section 1308A receives signal 1307A after inverse Fourier transform, performs processing such as frequency conversion and amplification, and outputs modulated signal 1309A, which is output as radio waves from antenna 1310A.

The serial-parallel converter 1302B performs serial-parallel conversion on the weighted and phase-changed signal 1301B (corresponding to the phase-changed signal 309B in FIG. 12), and outputs a parallel signal 1303B.

The rearrangement section 1304B receives the parallel signal 1303B, rearranges the signals, and outputs a rearranged signal 1305B. Note that rearrangement will be described later in detail.
An inverse fast Fourier transform unit 1306B receives the rearranged signal 1305B as an input, performs an inverse fast Fourier transform, and outputs a signal 1307B after the inverse Fourier transform.

Radio section 1308B receives signal 1307B after inverse Fourier transform, performs processing such as frequency conversion and amplification, and outputs modulated signal 1309B, which is output as radio waves from antenna 1310B.

Since the transmission apparatus in FIG. 3 does not use a multi-carrier transmission system, the phase is changed so that there are four cycles as shown in FIG. 6, and the symbols after the phase change are arranged in the time axis direction. When a multi-carrier transmission system such as the OFDM system shown in FIG. 12 is used, naturally precoding is performed as shown in FIG. A method of performing each (sub)carrier may be considered, but in the case of a multicarrier transmission method, a method of arranging in the frequency axis direction or using both the frequency axis and the time axis may be considered. This point will be explained below.

FIG. 14 shows an example of a symbol rearrangement method in rearrangement sections 1301A and 1301B in FIG. 13, with frequency on the horizontal axis and time on the vertical axis. The modulated signals z1 and z2 use the same frequency band at the same time (time), FIG. indicates a method of rearranging the symbols of the modulated signal z2. #0, #1, #2, #3, . Here, since the case of period 4 is considered, #0, #1, #2, and #3 correspond to one period. In the same way, #4n, #4n+1, #4n+2, and #4n+3 (n is an integer equal to or greater than 0) correspond to one cycle.

At this time, as shown in FIG. 14A, symbols #0, #1, #2, #3, . , and thereafter symbols #10 to #19 are arranged at time $2, and so on. Note that the modulated signals z1 and z2 are complex signals.

Similarly, the symbols of the weighted and phase-changed signal 1301B input to the serial-to-parallel converter 1302B are numbered sequentially as #0, #1, #2, #3, . . Here, since the case of period 4 is considered, #0, #1, #2, and #3 are respectively performing different phase changes, and #0, #1, #2, and #3 are the same. period. In the same way, #4n, #4n+1, #4n+2, and #4n+3 (n is an integer equal to or greater than 0) are performing different phase changes, and #4n, #4n+1, #4n+2, and #4n+3 are the same. period.

At this time, as shown in FIG. 14B, symbols #0, #1, #2, #3, . , and thereafter symbols #10 to #19 are arranged at time $2, and so on.

A symbol group 1402 shown in FIG. 14B is symbols for one period when the phase changing method shown in FIG. symbol #1 is the symbol when using the phase at time u+1 in FIG. 6, symbol #2 is the symbol when using the phase at time u+2 in FIG. 6, and symbol #3 is the symbol in FIG. is a symbol when using the phase at time u+3 of . Therefore, in symbol #x, when x mod 4 is 0 (the remainder when x is divided by 4, hence mod: modulo), symbol #x is the symbol when using the phase at time u in FIG. yes, x mod
When 4 is 1, symbol #x is the symbol when using the phase at time u+1 in FIG. 6, and when x mod 4 is 2, symbol #x is the symbol when using the phase at time u+2 in FIG. When x mod 4 is 3, symbol #x is the symbol when using the phase at time u+3 in FIG.

In this embodiment, the phase of the modulated signal z1 shown in FIG. 14(A) is not changed.
In this way, when a multi-carrier transmission system such as the OFDM system is used, unlike the case of single-carrier transmission, symbols can be arranged in the direction of the frequency axis. The way of arranging the symbols is not limited to the way of arranging as shown in FIG. Another example will be described with reference to FIGS. 15 and 16. FIG.

FIG. 15 shows an example of a symbol rearrangement method in rearrangement sections 1301A and 1301B in FIG. FIG. 15B shows the symbol rearrangement method of modulated signal z2. 15A and 15B differ from FIG. 14 in that the symbol rearrangement method of modulated signal z1 and the symbol rearrangement method of modulated signal z2 are different. 0 to #5 are placed on carriers 4 to 9, symbols #6 to #9 are placed on carriers 0 to 3, and then symbols #10 to #19 are placed on each carrier in a similar manner. At this time, similarly to FIG. 14(B), the symbol group 1502 shown in FIG. 15(B) is symbols for one period when the phase change method shown in FIG. 6 is used.

FIG. 16 shows an example of a symbol rearrangement method in rearrangement sections 1301A and 1301B in FIG. Symbol Rearrangement Method FIG. 16B shows a symbol rearrangement method of modulated signal z2. 16A and 16B differ from FIG. 14 in that symbols are arranged in order on carriers in FIG. 14, whereas symbols are not arranged in order on carriers in FIG. It is a point. Of course, in FIG. 16, as in FIG. 15, the symbol rearrangement method of modulated signal z1 and the rearrangement method of modulated signal z2 may be different.

FIG. 17 shows an example of a symbol rearrangement method in rearrangement sections 1301A and 1301B in FIG. A method of rearranging the symbols of the signal z1, and FIG. 17B shows a method of rearranging the symbols of the modulated signal z2. In FIGS. 14 to 16, the symbols are arranged in the direction of the frequency axis, but in FIG. 17 the symbols are arranged using both the frequency axis and the time axis.

In FIG. 6, an example of switching the phase change in 4 slots has been described, but here, a case of switching in 8 slots will be described as an example. The symbol group 1702 shown in FIG. 17 is symbols for one cycle (thus, 8 symbols) when using the phase change method, symbol #0 is the symbol when using the phase at time u, and symbol # 1 is the symbol when using the phase at time u+1, symbol #2 is the symbol when using the phase at time u+2, symbol #3 is the symbol when using the phase at time u+3, and symbol #4 is the symbol when using the phase at time u+4, symbol #5 is the symbol when using the phase at time u+5, symbol #6 is the symbol when using the phase at time u+6, Symbol #7 is the symbol when using the phase at time u+7. Therefore, in symbol #x, when x mod 8 is 0, symbol #x is the symbol when using the phase at time u, and when x mod 8 is 1, symbol #x uses the phase at time u+1. when x mod 8 is 2, symbol #x is the symbol when using the phase at time u+2, and when x mod 8 is 3, symbol #x is the symbol when using the phase at time u+3. when x mod 8 is 4, symbol #x is the symbol when using the phase at time u+4, and when x mod 8 is 5, symbol #x is the symbol when using the phase at time u+5. when x mod 8 is 6, symbol #x is the symbol when using the phase at time u+6, and when x mod 8 is 7, symbol #x is the symbol when using the phase at time u+7. It is a symbol of when In the way of arranging symbols in FIG. 17, 4 slots in the direction of the time axis and 2 slots in the direction of the frequency axis (4×2=8 slots in total) are used to arrange the symbols for one cycle. m × n symbols (that is, there are m × n types of phases to be multiplied by the number of symbols for each cycle). It is preferable that m>n, where m is the slot used for the direction. This is because the phase of the direct wave fluctuates more moderately in the direction of the time axis than in the direction of the frequency axis. Therefore, since the regular phase change of the present embodiment is performed to reduce the influence of the steady direct wave, it is desired to reduce the fluctuation of the direct wave in the cycle of changing the phase. Therefore, it is preferable to set m>n. Considering the above points, it is better to rearrange the symbols using both the frequency axis and the time axis as shown in FIG. 17 than the direct wave is highly likely to be constant, and the effect of the present invention can be easily obtained. However, if arranged in the direction of the frequency axis, there is a possibility that diversity gain can be obtained due to steep fluctuations on the frequency axis. not necessarily the best way.

FIG. 18 shows an example of a symbol rearrangement method in rearrangement sections 1301A and 1301B in FIG. FIG. 18B shows the symbol rearrangement method of modulated signal z2. In FIG. 18, as in FIG. 17, symbols are arranged using both the frequency axis and the time axis, but the difference from FIG. 17 is that in FIG. While the symbols are arranged, FIG. 18 prioritizes the direction of the time axis and then arranges the symbols in the direction of the time axis. In FIG. 18, a symbol group 1802 is symbols for one cycle when using the phase change method.

In FIGS. 17 and 18, similar to FIG. 15, the symbol arrangement method of modulated signal z1 and the symbol arrangement method of modulated signal z2 may be arranged in a different manner, and the same implementation is possible. It is possible to obtain an effect that reception quality can be obtained. Also, in FIGS. 17 and 18, even if the symbols are not arranged in order as in FIG. 16, the same operation can be performed, and the effect of being able to obtain high reception quality can be obtained. can.

FIG. 22 shows an example of a symbol rearrangement method in the rearrangement sections 1301A and 130B of FIG. 13 with frequency on the horizontal axis and time on the vertical axis. Consider a case where four slots such as times u to u+3 in FIG. 6 are used to regularly change the phase. A characteristic point in FIG. 22 is that the symbols are arranged in order along the frequency axis, but when proceeding along the time axis, the symbols are cyclically shifted by n (n=1 in the example of FIG. 22). is. Assume that the four symbols shown in the symbol group 2210 in the frequency axis direction in FIG. 22 undergo phase changes at times u to u+3 in FIG.

At this time, the phase of #0 is changed using the phase of time u, the phase of #1 is changed using the phase of time u+1, the phase of #2 is changed using the phase of time u+2, and the phase of time u+3 is used. phase change shall be performed.

Similarly, for the symbol group 2220 in the frequency axis direction, the phase of #4 is changed using the phase of time u, the phase of #5 is changed using the phase of time u+1, and the phase of time u+2 is used for #6. It is assumed that the phase is changed using the phase at time u+3 at #7.

In the symbol at time $1, the phase is changed as described above, but since there is a cyclic shift in the direction of the time axis, the phases of the symbol groups 2201, 2202, 2203, and 2204 are changed as follows. will be performed.

In the symbol group 2201 in the time axis direction, the phase of #0 is changed using the phase of time u, the phase of #9 is changed using the phase of time u+1, and the phase of #18 is changed using the phase of time u+2. At #27, the phase is changed using the phase at time u+3.

In the symbol group 2202 along the time axis, symbol #28 is phase-changed using the phase at time u, #1 is phase-changed using the phase at time u+1, and #10 is phase-changed using the phase at time u+2. At #19, the phase is changed using the phase at time u+3.

In the symbol group 2203 in the time axis direction, the phase of #20 is changed using the phase of time u, the phase of #29 is changed using the phase of time u+1, and the phase of #21 is changed using the phase of time u+2. At #11, the phase is changed using the phase at time u+3.

In the symbol group 2204 in the time axis direction, the phase of #12 is changed using the phase of time u, the phase of #21 is changed using the phase of time u+1, and the phase of #30 is changed using the phase of time u+2. In #3, the phase is changed using the phase at time u+3.

The feature in FIG. 22 is that, for example, when focusing on the #11 symbol, both adjacent symbols (#10 and #12) in the frequency axis direction at the same time use different phases from #11 to change the phase. At the same time, the symbols (#2 and #20) on both sides of the same carrier of symbol #11 in the time axis direction are both phase-changed using phases different from #11. This is not limited to the #11 symbol, but all symbols having adjacent symbols on both sides of the frequency axis and the time axis have the same characteristics as the #11 symbol. As a result, the phase is effectively changed, and the direct wave is less likely to be affected by the steady state, so that the data reception quality is likely to be improved.

In FIG. 22, n=1 has been described, but the present invention is not limited to this, and n=3 can also be implemented in the same way. In FIG. 22, the symbols are arranged on the frequency axis, and when the time advances along the axis, the above feature is realized by cyclically shifting the order of arrangement of the symbols. There is also a method of realizing the above characteristics by arranging them (which may be regular).

(Embodiment 2)
In Embodiment 1 above, the phase of signal z(t) that is weighted and combined (precoded with a fixed precoding matrix) is changed. Here, various embodiments of the phase changing method that can obtain the same effects as those of the first embodiment will be disclosed.

In the above embodiment, as shown in FIGS. 3 and 6, the phase changer 317B is configured to change the phase of only one of the outputs from the weighted combiner 600. FIG.
However, the timing of changing the phase may be before precoding by weighted combining section 600, and instead of the configuration shown in FIG. A configuration in which the phase changing unit 317B is provided in the preceding stage of the weighted synthesis unit 600 may be employed.

In this case, the phase changer 317B performs regular phase change on the baseband signal s2(t) according to the mapping of the selected modulation scheme, so that s2′(t)=s2(t).
) y(t) (where y(t) is modified by t), weighted synthesis section 600 performs precoding on s2′(t) to produce z2(t) (= W2s2'(t)) (see equation (42)) may be output and transmitted.

Also, the phase change may be performed for both modulated signals s1(t) and s2(t), and the transmission apparatus may have the configuration shown in FIG. 26 instead of the configuration shown in FIG. , and a phase changer may be provided for both outputs of the weighted synthesis section 600 .

The phase changer 317A regularly changes the phase of the input signal similarly to the phase changer 317B, and changes the phase of the precoded signal z1′(t) from the weighted combiner, The phase-changed signal z1(t) is output to the transmitter.

However, the phase changing section 317A and the phase changing section 317B change the phase as shown in FIG. 26 at the same timing with respect to the degree of phase change. (However, the following is just one example, and the method of changing the phase is not limited to this.) At time u, the _phase changing section 317A in FIG. (t), and the phase changing unit 317B changes the phase so that z2(t)=y ₂ (t)z2′(t). For example, as shown in FIG. 26, at time u, y ₁ (u)=e ^j0 , y ₂ (u)
=e ^−j π ^/2 , at time u+1, y ₁ (u+1)=e ^j π ^/4 , y ₂ (u+1)=e ^−j3 π ^/4 , . . . , at time u+k, y ₁ (u+k) = e ^jk π ^/4 and y ₂ (u+k) = e ^j(-k π ^/4- π ^/2) to change the phase. In addition, the period of regularly changing the phase may be the same or different between the phase changing section 317A and the phase changing section 317B.

Also, as described above, the timing for changing the phase may be before precoding is performed by the weighting synthesis unit, and the transmission apparatus may have the configuration shown in FIG.27 instead of the configuration shown in FIG.26.

When the phases of both modulated signals are regularly changed, each transmission signal includes information on each phase change pattern, for example, as control information, and the receiving device obtains this control information. , the phase change method regularly switched by the transmitter, that is, the phase change pattern can be known, thereby enabling correct demodulation (detection) to be performed.

Next, modified examples of the configurations of FIGS. 6 and 25 will be described with reference to FIGS. 28 and 29. FIG. FIG. 28 differs from FIG. 6 in that there is information 2800 regarding phase change ON/OFF, and the phase is changed to either z1′(t) or z2′(t) (at the same time). , or, at the same frequency, a phase change is applied to either z1'(t) or z2'(t). Therefore, since the phase is changed to either z1'(t) or z2'(t), the phase changing section 317A and the phase changing section 317B in FIG. 28 change the phase (ON). In some cases, the phase is not changed (OFF). The control information regarding this ON/OFF becomes the information 2800 regarding phase change ON/OFF. Information 2800 regarding this phase change ON/OFF is output from the signal processing method information generating section 314 shown in FIG.

The phase changer 317A in FIG. 28 is set to z1(t)=y1(t)z1'(t), and the _phase changer 317B is set to z2(t)=y2 ₍ t)z2'(t). t), the phase is changed.

At this time, for example, z1'(t) is phase-changed at period 4. (At this time, z2′(t) does not change phase.) Therefore, at time u, y ₁ (u)=e ^j0 , y ₂ (u)=1, and at time u+1, y ₁ (u+1)= e ^j π ^/2 , y ₂ (u+1)=1, at time u+2, y ₁ (u+2)=e ^j π, y ₂ (u+2)=1, at time u+3, y ₁ (u+3)=e ^j3 π ^{/ 2} and y ₂ (u+3)=1.

Next, for example, z2'(t) is phase-changed at period 4. (At this time, z
1'(t) does not change the phase. ) Therefore, at time u+4, y ₁ (u+4)=1, y ₂ (u+4)=e ^j0 , and at time u+5, y ₁ (u+5)=1, y ₂ (u+5)=
e ^j π ^/2 , at time u+6, y ₁ (u+6)=1, y ₂ (u+6)=e ^j π, at time u+7, y ₁ (u+7)=1, y ₂ (u+7)=e ^j3 π ^{/ 2} .

So in the example above,
At time 8k, y ₁ (8k)=e ^j0 , y ₂ (8k)=1,
At time 8k+1, y ₁ (8k+1)=e ^jπ/2 , y ₂ (8k+1)=1,
At time 8k+2, y ₁ (8k+2)=e ^jπ , y ₂ (8k+2)=1,
At time 8k+3, y ₁ (8k+3)=e ^j3π/2 , y ₂ (8k+3)=1,
At time 8k+4, y ₁ (8k+4)=1, y ₂ (8k+4)=e ^j0 ,
At time 8k+5, y ₁ (8k+5)=1, y ₂ (8k+5)=e ^jπ/2 ,
At time 8k+6, y ₁ (8k+6)=1, y ₂ (8k+6)=e ^jπ ,
At time 8k+7, y ₁ (8k+7)=1, y ₂ (8k+7)=e ^j3π/2
becomes.

As described above, there is a time to change the phase of only z1'(t) and a time to change the phase of only z2'(t). Also, the period of phase change is composed of the time for changing the phase of only z1′(t) and the time of changing the phase of only z2′(t). In the above description, the period when only z1'(t) is phase-changed is the same as the period when only z2'(t) is phase-changed. The cycle when only t) is phase-changed and the cycle when only z2'(t) is phase-changed may be different. In the above example, z1'(t) is phase-changed in four cycles, and then z2'(t) is phase-changed in four cycles. , z1′(t) and z2′(t) may be phase-modified in any order (e.g., z1′(t) may be phase-modified alternately with z2′(t)). You can do it, you can follow a certain rule, or you can do it in random order.)
The phase changing unit 317A in FIG. 29 sets s1′(t)=y1(t)s1(t), and the _phase changing unit 317B sets s2′(t)=y2 ₍ t)s2(t). t), the phase is changed.

At this time, for example, the phase of s1(t) is changed every 4 cycles. (At this time, s2(t) does not undergo a phase change.) Therefore, at time u, y ₁ (u)=e ^j0 ,
y ₂ (u)=1, at time u+1, y ₁ (u+1)=e ^j π ^/2 , y ₂ (u+1)=1, at time u+2, y ₁ (u+2)=e ^j π, y ₂ (u+2 )=1, at time u+3,
Let y ₁ (u+3)=e ^j3 π ^/2 and y ₂ (u+3)=1.

Next, for example, s2(t) is assumed to undergo a phase change every four cycles. (At this time, s1(t) does not change phase.) Therefore, at time u+4, y ₁ (u+4)=1
, y ₂ (u+4)=e ^j0 , at time u+5, y ₁ (u+5)=1, y ₂ (u+5)=e ^j π ^/2 , at time u+6, y ₁ (u+6)=1, y ₂ (u+6 )=e ^j π, and at time u+7, let y ₁ (u+7)=1 and y ₂ (u+7)=e ^j3 π ^/2 .

So in the example above,
At time 8k, y ₁ (8k)=e ^j0 , y ₂ (8k)=1,
At time 8k+1, y ₁ (8k+1)=e ^jπ/2 , y ₂ (8k+1)=1,
At time 8k+2, y ₁ (8k+2)=e ^jπ , y ₂ (8k+2)=1,
At time 8k+3, y ₁ (8k+3)=e ^j3π/2 , y ₂ (8k+3)=1,
At time 8k+4, y ₁ (8k+4)=1, y ₂ (8k+4)=e ^j0 ,
At time 8k+5, y ₁ (8k+5)=1, y ₂ (8k+5)=e ^jπ/2 ,
At time 8k+6, y ₁ (8k+6)=1, y ₂ (8k+6)=e ^jπ ,
At time 8k+7, y ₁ (8k+7)=1, y ₂ (8k+7)=e ^j3π/2
becomes.

As described above, there are times when only s1(t) is phase-changed and times when only s2(t) is phase-changed. Also, the phase change cycle is composed of the time for changing the phase of only s1(t) and the time to change the phase of only s2(t). In the above description, the period when only s1(t) is phase-changed and the period when only s2(t) is phase-changed are the same. The period for changing the phase may be different from the period for changing only the phase of s2(t). In the above example, the phase of s1(t) is changed in four cycles, and then the phase of s2(t) is changed in four cycles. The order of changing the phase of (t) and changing the phase of s2(t) may be arbitrary (for example, changing the phase of s1(t) and changing the phase of s2(t) may be performed alternately, The order may be according to a certain rule, or the order may be random.
)
As a result, it is possible to equalize the reception states of the transmission signals z1(t) and z2(t) on the receiving device side, and to equalize the received signals z1(t) and z2(t). By periodically switching the phase in the symbol, it is possible to improve the error correction capability after error correction decoding, so that the reception quality in the LOS environment can be improved.

As described above, even with the configuration shown in the second embodiment, the same effect as in the first embodiment can be obtained.
In the present embodiment, an example of a single-carrier system, that is, a case where the phase is changed on the time axis has been described, but the present invention is not limited to this, and the same can be implemented even when multi-carrier transmission is performed. can be done. Therefore, for example, spread spectrum communication method, OFDM (Orthogonal Frequency-Division Multiplexing) method, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC-OFDM (Single Carrier Orthogonal Frequency Division 7 non-patent documents such as Frequency-Division 7 method It can be implemented in the same way when using the wavelet OFDM method or the like shown in . As described above, in the present embodiment, as an explanation of changing the phase, the case of changing the phase in the time t-axis direction was described. That is, in the present embodiment, in the description of the phase change in the t direction, by replacing t with f (f: frequency ((sub))carrier)), the phase change method described in the present embodiment can be applied to the phase change in the frequency direction. Also, the phase changing method of the present embodiment can be applied to phase changing in the time-frequency direction, as described in the first embodiment.

Therefore, although FIGS. 6, 25, 26 and 27 show cases where the phase is changed in the direction of the time axis, in FIGS. This corresponds to changing the phase in the frequency direction, and by replacing time t with time t and frequency f, that is, (t) with (t, f), phase change in the time-frequency block is equivalent to doing

In this embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc.), symbols for transmitting control information, etc., may be arranged in any frame.

(Embodiment 3)
In Embodiments 1 and 2, the phase is changed regularly. In the third embodiment, there is a method for each receiving device to obtain good data reception quality regardless of where the receiving device is located in the receiving devices that are scattered in various places from the viewpoint of the transmitting device. Disclose the methodology.

In the third embodiment, the symbol arrangement of signals obtained by changing the phase will be explained.
FIG. 31 shows an example of a frame configuration of some symbols of a signal on the time-frequency axis when using a multi-carrier scheme such as the OFDM scheme in a transmission scheme that regularly changes phases.

First, an example in which one baseband signal (see FIG. 6) of the two precoded baseband signals described in Embodiment 1 is phase-changed will be described.
(Note that FIG. 6 shows a case where the phase is changed in the direction of the time axis, but in FIG. 6, by replacing the time t with the carrier f, it corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, (t) with (t, f), it is equivalent to changing the phase in a time-frequency block.)
FIG. 31 shows the frame configuration of the modulated signal z2′ input to the phase changer 317B shown in FIG. , but depending on the configuration of the precoding matrix, it may contain only one of the signals s1 and s2.).

Here, attention is paid to the symbol 3100 at carrier 2 and time $2 in FIG. In addition, although described as a carrier here, it may also be referred to as a subcarrier. On carrier 2, the channel states of the symbols temporally closest to time $2, that is, the symbol 3103 at time $1 on carrier 2 and the symbol 3101 at time $3 on carrier 2 are the same as those of symbol 3100 on carrier 2 at time $2. It has a very high correlation with the channel state.

Similarly, at time $2, the channel state of the symbol of the frequency closest to carrier 2 in the frequency axis direction, that is, the symbol 3104 of carrier 1, time $2 and the symbol 3104 of time $2, carrier 3 is Both are highly correlated with the channel state of symbol 3100 at carrier 2 and time $2.

As described above, the channel conditions of symbols 3101, 3102, 3103, and 3104 are highly correlated with the channel condition of symbol 3100. FIG.
In this specification, it is assumed that in the transmission method that regularly changes the phase, N types of phases (where N is an integer of 2 or more) are prepared as phases to be multiplied. For example, the symbol shown in FIG. 31 is denoted by “e ^j0 ”, which means that the signal z2′ in FIG. 6 in this symbol is multiplied by “e ^j0 ” to change the phase. means that That is, the values described in each symbol in _FIG . 31 are y(t) in Equation (42) and y ₂ (t).

In the present embodiment, by utilizing the high correlation between the channel states of the symbols adjacent in the frequency axis direction and/or the symbols adjacent in the time axis direction, high data reception quality can be achieved on the receiving device side. We disclose a symbol constellation of phase-altered symbols that yields .

<Condition #1> and <Condition #2> are conceivable as conditions for obtaining high data reception quality on the receiving side.
<Condition #1>
As shown in FIG. 6, in the transmission method for regularly changing the phase of the baseband signal z2' after precoding, when a multicarrier transmission system such as OFDM is used, time X and carrier Y are data. Symbols for transmission (hereinafter referred to as data symbols), and symbols adjacent in the time axis direction, that is, time X−1·carrier Y and time X+1·carrier Y are both data symbols. In the baseband signal z2' after precoding corresponding to the data symbol, that is, the baseband signal z2' after precoding at time X-carrier Y, time X-1-carrier Y, and time X+1-carrier Y, Different phase changes are performed in each case.

<Condition #2>
As shown in FIG. 6, when a multi-carrier transmission method such as OFDM is used in a transmission method for regularly changing the phase of the baseband signal z2' after precoding,
Time X carrier Y is a symbol for data transmission (hereinafter referred to as a data symbol), and adjacent symbols in the frequency axis direction, that is, time X carrier Y−1 and time X carrier Y+1 are both data. symbol, then the precoded baseband signal z2′ corresponding to these three data symbols, i.e. after each precoding at time X carrier Y, time X carrier Y−1 and time X carrier Y+1. , the baseband signal z2' of , undergoes a different phase change.

Then, it is preferable that there is a data symbol that satisfies <Condition #1>. Similarly, there should be a data symbol that satisfies <Condition 2>.
The reason why <condition #1> and <condition #2> are derived is as follows.

There is a certain symbol (hereinafter referred to as symbol A) in the transmission signal, and the channel state of each symbol temporally adjacent to the symbol A has a high correlation with the channel state of symbol A, as described above.

Therefore, if different phases are used for three temporally adjacent symbols, the reception quality of symbol A is poor in the LOS environment (although high reception quality is obtained in terms of SNR, the phase relationship of the direct wave is poor). (because of the situation, the reception quality is poor), the remaining two symbols adjacent to the symbol A are very likely to be able to obtain good reception quality, and as a result, after error correction decoding can get good reception quality.

Similarly, there is a certain symbol (hereinafter referred to as symbol A) in the transmission signal, and the channel state of each symbol adjacent in frequency to this symbol A has a high correlation with the channel state of symbol A, as described above. .

Therefore, if different phases are used for three symbols adjacent in frequency, symbol A has poor reception quality in the LOS environment (although high reception quality is obtained in terms of SNR, the phase relationship of the direct wave is poor). (because of the situation, the reception quality is poor), the remaining two symbols adjacent to the symbol A are very likely to be able to obtain good reception quality, and as a result, after error correction decoding can get good reception quality.

Also, by combining <Condition #1> and <Condition #2>, there is a possibility that the reception quality of data can be further improved in the receiving device. Therefore, the following <Condition #3> can be derived.

<Condition #3>
As shown in FIG. 6, in the transmission method for regularly changing the phase of the baseband signal z2' after precoding, when a multicarrier transmission system such as OFDM is used, time X and carrier Y are data. A symbol for transmission (hereinafter referred to as a data symbol), and symbols adjacent in the time axis direction, that is, time X−1·carrier Y and time X+1·carrier Y are both data symbols, and frequency If the axially adjacent symbols, namely time X carrier Y−1 and time X carrier Y+1, are both data symbols, the precoded baseband signal z2′ corresponding to these five data symbols, namely , time X carrier Y and time X−1 carrier Y and time X+1 carrier Y and time X carrier Y−1 and time X carrier Y+1, respectively, in the baseband signal z2′ after precoding, each Different phase changes are made.

Here, a supplementary explanation will be given regarding "different phase changes". The phase change will be defined from 0 radians to 2π radians. For example, at time X and carrier ^Y , the phase change applied to the baseband signal z2' after precoding in FIG.
・In carrier Y, phase change applied to baseband signal z2′ after precoding in FIG. 6 is e ^jθX-1,Y at time X+1 0 radian≦θ _X,Y <2π, 0 radian≦θ _X−1,Y <2π, and 0 radian≦θ _X+1,Y ^< 2π. Therefore, in <Condition #1>, θ _X,Y ≠ θ _{X−1, Y} and θ _{X, Y} ≠ θ _{X+1, Y} and θ _X+
1,Y ≠θ _X−1,Y is established. Similarly, in <Condition #2>, θ _{X, Y} ≠ θ _{X, Y−1} and θ _{X, Y} ≠ θ _{X, Y+1} and θ _{X, Y−1} ≠ θ _{X−1, Y+1} . <
In condition #3>, θ _{X, Y} ≠ θ _{X−1, Y} and θ _{X, Y} ≠ θ _{X+1, Y} and θ _{X, Y} ≠ θ _{X, Y−1} and θ _{X, Y} ≠ θ _{X, Y+1} and θ _{X-1, Y} ≠ θ _{X+1, Y} and θ _{X-1, Y} ≠ θ _{X, Y-1} and θ _{X-1, Y} ≠ θ _{X, Y+1} and θ _{X+1, Y} ≠ θ _{X, Y-1} and θ _{X+1, Y} ≠ θ _{X, Y+1} and θ _{X, Y−1} ≠ θ _{X, Y+1} are established.

Then, it is preferable that there is a data symbol that satisfies <condition #3>.
FIG. 31 is an example of <Condition #3>. The phase multiplied by the precoded baseband signal z2′ in FIG. 6 corresponding to the adjacent symbol 3101 and the precoded baseband signal z2′ in FIG. 6 corresponding to 3103 and the symbols adjacent in frequency. The phases multiplied by the precoded baseband signal z2' in FIG. 6 corresponding to 3102 and the precoded baseband signal z2' corresponding to 3104 in FIG. Thus, even if the reception quality of symbol 3100 is poor on the receiving side, the reception quality of its adjacent symbols is very high, so high reception quality after error correction decoding can be ensured.

FIG. 32 shows an example of arrangement of symbols obtained by changing the phase under this condition.
As can be seen from FIG. 32, in any data symbol, the degree of phase change with respect to adjacent symbols in both the frequency axis direction and the time axis direction is a phase change amount different from each other. ing. By doing so, it is possible to further improve the error correction capability of the receiving apparatus.

That is, in FIG. 32, <condition #1> is satisfied for all Xs and all Ys when data symbols are present in adjacent symbols in the time axis direction.
Similarly, in FIG. 32, <condition #2> holds for all Xs and all Ys when data symbols are present in adjacent symbols in the frequency direction.

Similarly, in FIG. 32, if data symbols exist in adjacent symbols in the frequency direction and data symbols exist in adjacent symbols in the time axis direction, <condition #3> is all X, all It is established by Y of

Next, an example in which the two precoded baseband signals described in Embodiment 2 are phase-changed (see FIG. 26) will be described.
As shown in FIG. 26, there are several methods for changing the phase when both the precoded baseband signal z1' and the precoded baseband signal z2' are phase-changed. This point will be explained in detail.

As method 1, the phase of the precoded baseband signal z2' is changed as shown in FIG. 32 as described above. In FIG. 32, the phase change of the baseband signal z2' after precoding is 10 cycles. However, as described above, in order to satisfy <Condition #1>, <Condition #2>, and <Condition #3>, (sub)carrier 1 is applied to baseband signal z2′ after precoding. The phase change is changing with time. (In FIG. 32, such a change is applied, but the period may be 10 and another phase change method may be used.) Then, the phase change of the baseband signal z1' after precoding is as shown in FIG. Furthermore, the phase change of the baseband signal z2' after precoding is such that the phase change value for one period of the period 10 is constant. In FIG. 33, at time $1 including one cycle (of the phase change of the baseband signal z2' after precoding), the value of the phase change of the baseband signal z1' after precoding is ^ej0 , At the time $2 including the next cycle (of the phase change of the baseband signal z2' after precoding), the value of the phase change of the baseband signal z1' after precoding is ^ejπ/9 , ..., and.

For example, the symbols shown in FIG. 33 are denoted by “e ^j0 ”, which is ^obtained by multiplying the signal z1′ in FIG. is changed. That is, the values described in each symbol in FIG. 33 are the values of y ₁ (t) in z1(t)=y ₁ (t)z1′(t) described in the second embodiment.

As for the phase change of the baseband signal z1′ after precoding, as shown in FIG. The value should change with the number for one cycle. (As described above, in FIG. 33, the first cycle is e ^j0 and the second cycle is e ^jπ/9 . . . ).
As described above, although the phase change of the baseband signal z2' after precoding is a period of 10, the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are Advantageously, the period can be greater than 10 when both phase changes are taken into account. This may improve the reception quality of data in the receiving device.

As method 2, the phase of the precoded baseband signal z2' is changed as shown in FIG. 32, as described above. In FIG. 32, the phase change of the baseband signal z2' after precoding is 10 cycles. However, as described above, in order to satisfy <Condition #1>, <Condition #2>, and <Condition #3>, (sub)carrier 1 is applied to baseband signal z2′ after precoding. The phase change is changing with time. (In FIG. 32, such a change is applied, but a period of 10 may be used and another phase change method may be used.) Then, the phase change of the baseband signal z1' after precoding is shown in FIG. As shown, the phase change of the baseband signal z2' after precoding performs a phase change at period 3, which is different from period 10. FIG.

For example, the symbol shown in FIG. 30 is denoted by “e ^j0 ”, which is ^obtained by multiplying the signal z1′ in FIG. is changed. That is, the values described in each symbol in FIG. 30 are the values of y ₁ (t) in z1(t)=y ₁ (t)z1′(t) described in the second embodiment.

As described above, although the phase change of the baseband signal z2' after precoding is a period of 10, the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are The period when both phase changes are taken into consideration is 30, and the period when both the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are taken into consideration is greater than 10. You can get the effect of being able to This may improve the reception quality of data in the receiving device. As one effective method of the method 2, the period of phase change of the baseband signal z1' after precoding is set to N, and the baseband signal z2 after precoding is
' phase change period is M, especially when N and M are coprime, the phase change of the baseband signal z1' after precoding and the phase of the baseband signal z2' after precoding The period when both changes are considered has the advantage that it can be easily set to a large period of N×M, but it is possible to increase the period even if N and M are coprime.

The phase change method of the third embodiment is an example, and is not limited to this. As described in the first and second embodiments, the phase is changed in the frequency axis direction, Even if the phase is changed in the axial direction or the phase is changed in the time-frequency block, similarly, the reception quality of data in the receiving device can be improved.

In addition to the frame configuration described above, it is conceivable that a pilot symbol (SP (Scattered Pilot)), a symbol for transmitting control information, or the like is inserted between data symbols. Phase change in this case will be described in detail.

FIG. 47 shows the frame configuration on the time-frequency axis of the modulated signal (baseband signal after precoding) z1 or z1′ and the modulated signal (baseband signal after precoding) z2′. ) is the time of the modulated signal (baseband signal after precoding) z1 or z1'-frame structure on the frequency axis, FIG. 47(b) is the time of the modulated signal (baseband signal after precoding) z2'- It is a frame configuration on the frequency axis. In FIG. 47, 4701 denotes a pilot symbol, 4702 denotes a data symbol, and the data symbol 4702 is precoded or precoded and phase-changed symbol.

FIG. 47 shows a symbol arrangement when the phase of the baseband signal z2′ after precoding is changed as in FIG. 6 (the phase of the baseband signal z1 after precoding is not changed). ). (Note that FIG. 6 shows a case where the phase is changed in the direction of the time axis, but in FIG. 6, by replacing the time t with the carrier f, it corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, (t) with (t, f), it is equivalent to changing the phase in a time-frequency block.) Therefore, after precoding in FIG. The numerical values written in the symbols of the baseband signal z2' indicate the phase change values. The symbols of the baseband signal z1' (z1) after precoding in FIG. 47 are not phase-changed, so their numerical values are not shown.

The important point in FIG. 47 is that the phase change for the precoded baseband signal z2' is applied to the data symbols, that is, the precoded symbols. (Here, it is described as a symbol, but since the symbol described here is precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z2′ are not subjected to phase modification.

FIG. 48 shows the frame configuration on the time-frequency axis of the modulated signal (baseband signal after precoding) z1 or z1′ and the modulated signal (baseband signal after precoding) z2′. ) is the time of the modulated signal (baseband signal after precoding) z1 or z1'-frame structure on the frequency axis, FIG. 48(b) is the time of the modulated signal (baseband signal after precoding) z2'- It is a frame configuration on the frequency axis. In FIG. 48, 4701 indicates a pilot symbol, 4702 indicates a data symbol, and the data symbol 4702 is a symbol subjected to precoding and phase change.

FIG. 48 shows a symbol arrangement when the phases of the precoded baseband signal z1' and the precoded baseband signal z2' are changed as shown in FIG. (Note that FIG. 26 shows a case where the phase is changed in the direction of the time axis, but in FIG. 26, by replacing the time t with the carrier f, this corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, (t) with (t, f), this corresponds to phase change in the time-frequency block.) Therefore, after precoding in FIG. Numerical values written in the symbols of the baseband signal z1' and the baseband signal z2' after precoding indicate phase change values.

The important point in FIG. 48 is that the phase change for the precoded baseband signal z1′ is applied to the data symbols, that is, the precoded symbols, and the precoded baseband signal z2 ' is applied to data symbols, that is, precoded symbols. (Here, it is described as a symbol, but since the symbol described here is precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z1′ are not phase-changed, and the pilot symbols inserted at z2′ are not phase-changed.

FIG. 49 shows the frame configuration on the time-frequency axis of the modulated signal (baseband signal after precoding) z1 or z1′ and the modulated signal (baseband signal after precoding) z2′. ) is the time of the modulated signal (baseband signal after precoding) z1 or z1'-frame structure on the frequency axis, FIG. 49(b) is the time of the modulated signal (baseband signal after precoding) z2'- It is a frame configuration on the frequency axis. In FIG. 49, 4701 is a pilot symbol, 4702 is a data symbol, 4901 is a null symbol, the in-phase component I=0 and the quadrature component Q=0 of the baseband signal. At this time, the data symbol 4702 becomes a symbol subjected to precoding or precoding and phase change. The difference between FIG. 49 and FIG. 47 is the configuration method of symbols other than data symbols. Modulated signal z2′ is a null symbol at the time and carrier when a pilot symbol is inserted in modulated signal z1′, and is reversed. Another point is that the modulated signal z1' is a null symbol at the time and carrier where the pilot symbol is inserted in the modulated signal z2'.

FIG. 49 shows a symbol arrangement when the phase of the baseband signal z2′ after precoding is changed as in FIG. 6 (the phase of the baseband signal z1 after precoding is not changed). ). (Note that FIG. 6 shows a case where the phase is changed in the direction of the time axis, but in FIG. 6, by replacing the time t with the carrier f, it corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, (t) with (t, f), it is equivalent to changing the phase in a time-frequency block.) Therefore, after precoding in FIG. The numerical values written in the symbols of the baseband signal z2' indicate the phase change values. Note that the symbol of the baseband signal z1' (z1) after precoding in FIG. 49 does not change the phase, so the numerical value is not shown.

The important point in FIG. 49 is that the phase change for the precoded baseband signal z2' is applied to the data symbols, that is, the precoded symbols. (Here, it is described as a symbol, but since the symbol described here is precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z2′ are not subjected to phase modification.

FIG. 50 shows the frame configuration on the time-frequency axis of the modulated signal (baseband signal after precoding) z1 or z1′ and the modulated signal (baseband signal after precoding) z2′. ) is the time of the modulated signal (baseband signal after precoding) z1 or z1'-frame structure on the frequency axis, FIG. 50(b) is the time of the modulated signal (baseband signal after precoding) z2'- It is a frame configuration on the frequency axis. In FIG. 50, 4701 is a pilot symbol, 4702 is a data symbol, 4901 is a null symbol, the in-phase component I=0 and the quadrature component Q=0 of the baseband signal. At this time, the data symbol 4702 becomes a symbol subjected to precoding or precoding and phase change. The difference between FIG. 50 and FIG. 48 is the configuration method of symbols other than data symbols. Modulated signal z2′ is a null symbol at the time and carrier when pilot symbols are inserted in modulated signal z1′, and reverse Another point is that the modulated signal z1' is a null symbol at the time and carrier where the pilot symbol is inserted in the modulated signal z2'.

FIG. 50 shows a symbol arrangement when the phases of the precoded baseband signal z1' and the precoded baseband signal z2' are changed as shown in FIG. (Note that FIG. 26 shows a case where the phase is changed in the direction of the time axis, but in FIG. 26, by replacing the time t with the carrier f, this corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, (t) with (t, f), this corresponds to phase change in the time-frequency block.) Therefore, after precoding in FIG. Numerical values written in the symbols of the baseband signal z1' and the baseband signal z2' after precoding indicate phase change values.

The important point in FIG. 50 is that the phase change for the precoded baseband signal z1′ is applied to the data symbols, that is, the precoded symbols, and the precoded baseband signal z2 ' is applied to data symbols, that is, precoded symbols. (Here, it is described as a symbol, but since the symbol described here is precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z1′ are not phase-changed, and the pilot symbols inserted at z2′ are not phase-changed.

FIG. 51 shows an example of the configuration of a transmitting apparatus that generates and transmits modulated signals having the frame configurations of FIGS. 47 and 49, and components that operate in the same manner as in FIG. .
In FIG. 51, weighted synthesis units 308A and 308B and phase change unit 317B
It operates only when the frame configuration signal 313 indicates the timing of the data symbol.

If the frame configuration signal 313 indicates that the frame configuration signal 313 is a pilot symbol (and a null symbol), the pilot symbol (which also serves as null symbol generation) generation section 5101 in FIG. 51 generates a pilot symbol baseband signal 5102A and 5102B is output.

Although not shown in the frame configurations of FIGS. 47 to 50, precoding (and not applying phase rotation) is not performed, for example, a method of transmitting a modulated signal from one antenna (in this case, the other antenna ), or when transmitting control information symbols using a transmission method using a space-time code (especially a space-time block code), the control information symbol 5104 is the control information 5103, the frame When the configuration signal 313 is input and the frame configuration signal 313 indicates that it is a control information symbol, baseband signals 5102A and 5102B of the control information symbol are output.

Radio sections 310 and 310B in FIG. 51 select a desired baseband signal from a plurality of baseband signals based on a frame configuration signal 313 among a plurality of input baseband signals. Then, OFDM-related signal processing is performed, and modulated signals 311A and 311B according to the frame structure are respectively output.

FIG. 52 shows an example of the configuration of a transmission apparatus that generates and transmits modulated signals having the frame configurations of FIGS. is doing. The phase changer 317A added to FIG. 51 operates only when the frame configuration signal 313 indicates the timing of the data symbol. Otherwise, the operation is the same as in FIG.

FIG. 53 shows a configuration method of a transmission device different from that in FIG. Differences will be described below. The phase modulating section 317B receives a plurality of baseband signals as shown in FIG. Then, when frame configuration signal 313 indicates that it is a data symbol, phase modulating section 317B performs phase change on baseband signal 316B after precoding. Then, when frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, phase modulating section 317B stops the operation of changing the phase, and the baseband signal of each symbol is is output as is. (As an interpretation, it can be considered that the phase rotation corresponding to "e ^j0 " is forcibly performed.)
Selection section 5301 receives a plurality of baseband signals, selects and outputs baseband signals of symbols indicated by frame configuration signal 313 .

FIG. 54 shows a configuration method of a transmission device different from that in FIG. Differences will be described below. The phase modulating section 317B receives a plurality of baseband signals as shown in FIG. Then, when frame configuration signal 313 indicates that it is a data symbol, phase modulating section 317B performs phase change on baseband signal 316B after precoding. Then, when frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, phase modulating section 317B stops the operation of changing the phase, and the baseband signal of each symbol is is output as is. (As an interpretation, it can be considered that the phase rotation corresponding to "e ^j0 " is forcibly performed.)
Similarly, phase modulating section 5201 receives a plurality of baseband signals as shown in FIG. Then, when frame configuration signal 313 indicates that it is a data symbol, phase modulating section 5201 performs phase change on baseband signal 309A after precoding. Then, when frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, phase modulating section 5201 stops the operation of changing the phase, and the baseband signal of each symbol is is output as is. (As an interpretation, it can be considered that the phase rotation corresponding to "e ^j0 " is forcibly performed.)
In the above description, pilot symbols, control symbols, and data symbols have been described as an example, but the present invention is not limited to this. Similarly, if the symbol is transmitted using a method, etc., it is important not to change the phase. is important in the present invention.

Therefore, the feature of the present invention is that the phase is not changed for all symbols in the frame structure on the time-frequency axis, but only for precoded signals.

(Embodiment 4)
Embodiments 1 and 2 above disclose that the phase is regularly changed, and Embodiment 3 discloses that the degree of phase change of adjacent symbols is made different.

Embodiment 4 shows that the phase change method may differ depending on the modulation scheme used by the transmission device and the coding rate of the error correction code.
Table 1 below shows an example of a phase change method set according to various setting parameters set by the transmission device.

#1 in Table 1 is the modulated signal s1 (baseband signal s1 of the modulation scheme set by the transmitter) in the first embodiment, and #2 is the modulated signal s2 (baseband signal s2 of the modulation scheme set by the transmitter). means The coding rate column in Table 1 indicates coding rates set for the error correcting code for #1 and #2 modulation schemes. The columns of phase change patterns in Table 1 are phase change methods applied to baseband signals z1 (z1′) and z2 (z2′) after precoding, as described in Embodiments 1 to 3. , and the phase change patterns are defined as A, B, C, D, E, . For example, it is assumed that the change patterns shown in the above equations (46) and (47) are shown. In addition, although "-" is described in the example of the phase change pattern in Table 1, this means that the phase is not changed.

The combinations of modulation schemes and coding rates shown in Table 1 are examples, and modulation schemes other than the modulation schemes shown in Table 1 (eg, 128 QAM, 256 QAM, etc.) and coding rates (eg, 7/8 etc.) may be included. Also, as shown in Embodiment 1, the error correction codes may be set separately for s1 and s2 (in the case of Table 1, as shown in FIG. 4, one error correction code is encoded is applied.). Also, the same modulation scheme and coding rate may be associated with a plurality of different phase change patterns. The transmitting device transmits information indicating each phase change pattern to the receiving device, and the receiving device identifies the phase change pattern by referring to the information and Table 1, and executes demodulation and decoding. Become. When the phase change pattern is uniquely determined for the modulation scheme and error correction scheme, the transmission apparatus transmits information on the modulation scheme and error correction scheme to the reception apparatus, and the reception apparatus transmits the information. In this case, the information on the phase change pattern is not necessarily required because the phase change pattern can be known by obtaining the phase change pattern.

In Embodiments 1 to 3, the case of changing the phase of the baseband signal after precoding has been described. is also possible. Therefore, Table 1 may also correspond to an amplitude change pattern that regularly changes the amplitude of the modulated signal. In this case, the transmitter may include an amplitude changing section for changing the amplitude after the weighted combining section 308A in FIGS. 3 and 4, and an amplitude changing section for changing the amplitude after the weighted combining section 308B. Note that one of the baseband signals z1(t) and z2(t) after precoding may be subjected to amplitude modification (in this case, the amplitude modification unit may be added after either weighted synthesis unit 308A or 308B). ), and amplitude change may be applied to both.

Furthermore, although not shown in Table 1 above, instead of regularly changing the phase, the mapping unit may regularly change the mapping method.
That is, the mapping method of the modulated signal s1(t) is 16QAM, and the mapping method of the modulated signal s2(t) is 16QAM. → 16APSK (16 Amplitude Phase Shift Keying)
→ A first mapping method with a different signal point arrangement from 16QAM and 16APSK on the IQ plane → A second mapping method with a different signal point arrangement from 16QAM and 16APSK on the IQ plane → ... Then, similarly to the case where the phase is regularly changed as described above, it is possible to obtain the effect of improving the reception quality of data in the receiving apparatus.

In addition, the present invention may be any combination of the method of regularly changing the phase, the method of regularly changing the mapping method, and the method of changing the amplitude, and all of them may be taken into consideration. It may be configured to transmit a transmission signal.

This embodiment can be implemented in both single-carrier transmission and multi-carrier transmission. Therefore, for example, the spread spectrum communication method, OFDM (Orthogonal Frequency-Division Multiplexing) method, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC-OFDM (Single Carrier Orthogonal Frequency Division Multiplexing) method, non-patent literature such as Frequency-Division 7 It can also be implemented in the case of using the wavelet OFDM method or the like shown in . As described above, in this embodiment, as an explanation of phase change, amplitude change, and mapping change, the case where phase change, amplitude change, and mapping change are performed in the time t-axis direction has been described. Similarly, in the same way as when changing the phase in the direction of the frequency axis, that is, in the description of the phase change, amplitude change, and mapping change in the t direction in this embodiment, t is f (f: frequency ((sub ) carrier)), the phase change, amplitude change, and mapping change described in the present embodiment can be applied to the phase change, amplitude change, and mapping change in the frequency direction. Further, the phase change, amplitude change, and mapping change methods of the present embodiment can be applied to phase change, amplitude change, and mapping change in the time-frequency direction in the same manner as described in Embodiment 1. is.

In this embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc.), symbols for transmitting control information, etc., may be arranged in any frame.

(Embodiment A1)
In the present embodiment, as shown in Non-Patent Documents 12 to 15, QC (Quasi Cyclic) LDPC (Low-Density Prity-Check) code (not QC-LDPC code, LDPC code LDPC code and Bose-Chaudhuri-Hocquenghem code (Bose-Chaudhuri-Hocquenghem code) concatenated code, turbo code using tail biting or block code such as Duo-Binary Turbo Code regularly changing the phase I will explain in detail how to do this. Here, as an example, a case of transmitting two streams s1 and s2 will be described. However, when encoding is performed using a block code, if control information, etc., is not required, the number of bits composing the block after encoding shall be the number of bits composing the block code. It may contain control information etc. as described.). When encoding is performed using a block code, when control information (for example, CRC (cyclic redundancy check), transmission parameters, etc.) is required, the number of bits constituting a block after encoding is determined by the block code. It may be the sum of the number of bits constituting the data and the number of bits of control information or the like.

FIG. 34 is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when block codes are used. FIG. 34 shows, for example, as shown in the transmitting device in FIG. is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when using (At this time, either single-carrier transmission or multi-carrier transmission such as OFDM may be used as the transmission method.)
As shown in FIG. 34, it is assumed that the number of bits forming one encoded block in the block code is 6000 bits. In order to transmit 6000 bits, 3000 symbols are required when the modulation method is QPSK, 1500 symbols when the modulation method is 16QAM, and 1000 symbols when the modulation method is 64QAM.

Since two streams are transmitted simultaneously in the transmitting apparatus of FIG. 4, when the modulation scheme is QPSK, the aforementioned 3000 symbols are allocated to s1 with 1500 symbols and s2 with 1500 symbols. 1500 slots (referred to herein as "slots") are required to transmit the 1500 symbols transmitted in s1 and the 1500 symbols transmitted in s2.

Similarly, when the modulation scheme is 16QAM, 750 slots are required to transmit all the bits forming one coded block, and when the modulation scheme is 64QAM, all bits forming one block are 500 slots are required to transmit bits.

Next, in the method of regularly changing the phase, the relationship between the slot defined above and the phase to be multiplied will be described.
Here, the number of phase change values (or phase change sets) prepared for the method of regularly changing the phase is five. That is, it is assumed that five phase change values (or phase change sets) are prepared for the phase change unit of the transmission device in FIG. (As shown in FIG. 6, when the phase is changed only for the baseband signal z2′ after precoding, five phase change values should be prepared in order to change the phase for a period of 5. Also, FIG. , the precoded baseband signal z1'
and z2', two phase change values are required for one slot. These two phase change values are called a phase change set. Therefore, in this case, five phase change sets should be prepared in order to perform phase changes of period 5). Let us denote these five phase change values (or phase change sets) as PHASE[0], PHASE[1], PHASE[2], PHASE[3], PHASE[4].

When the modulation scheme is QPSK, the above-mentioned 1500 slots for transmitting 6000 bits constituting one encoded block include 300 slots using phase PHASE[0] and 300 slots using phase PHASE[0]. 1], 300 slots using phase PHASE[2], 300 slots using phase PHASE[3], and 300 slots using phase PHASE[4]. There is a need. This is because if there is a bias in the phases used, the phases using a large number of phases have a large effect, and the reception quality of the data in the receiving apparatus depends on this effect.

Similarly, when the modulation scheme is 16QAM, in the above-described 750 slots for transmitting 6000 bits, the number of bits constituting one encoded block, 150 slots using phase PHASE [0], 150 slots using phase PHASE[1], 150 slots using phase PHASE[2], 150 slots using phase PHASE[3], 150 slots using phase PHASE[4] Must be a slot.

Similarly, when the modulation scheme is 64QAM, in the above-described 500 slots for transmitting 6000 bits, the number of bits constituting one encoded block, 100 slots use phase PHASE [0], 100 slots using phase PHASE[1], 100 slots using phase PHASE[2], 100 slots using phase PHASE[3], 100 slots using phase PHASE[4] Must be a slot.

As described above, in the method of regularly changing the phase, N phase change values (or phase change sets) to be prepared (N different phases are PHASE[0], PHASE[1], PHASE[2 ],..., PHASE[N-2], PHASE[N-1]), when all the bits constituting one encoded block are transmitted, the phase PHASE[ 0] is K ₀ , the number of slots using phase PHASE[1] is K _{1 , the} number of slots using phase PHASE[i] is K _i (i=0, 1, 2, . . . ) , N-1), and the number of slots using phase PHASE[N-1] is K _N-1 ,

<Condition #A01>
_{K 0 = K 1 =} .・・・, N-1, a≠b)

should be

Then, when the communication system supports a plurality of modulation schemes and selects and uses one of the supported modulation schemes, <condition #A01> should be satisfied in the supported modulation schemes. .

However, when multiple modulation schemes are supported, the number of bits that can be transmitted in one symbol is generally different for each modulation scheme (in some cases, the number may be the same). In some cases, there may be a modulation scheme that cannot satisfy <Condition #A01>. In this case, instead of <Condition #A01>, the following condition should be satisfied.

<Condition #A02>
The difference between K _a and K _b is 0 or 1, i.e. |K _a −K _b | is 0 or 1
(for ∀a, ∀b, where a, b=0,1,2,...,N-1, a≠b)

FIG. 35 is a diagram showing changes in the number of symbols and the number of slots required for two encoded blocks when block codes are used. FIG. 35 shows a case where two streams of s1 and s2 are transmitted as shown in the transmitting device of FIG. 3 and the transmitting device of FIG. 12, and the transmitting device has two encoders. FIG. 10 is a "diagram showing changes in the number of symbols and the number of slots required for one encoded block when block codes are used". (At this time, either single-carrier transmission or multi-carrier transmission such as OFDM may be used as the transmission method.)
As shown in FIG. 35, it is assumed that the number of bits forming one encoded block in the block code is 6000 bits. In order to transmit 6000 bits, 3000 symbols are required when the modulation method is QPSK, 1500 symbols when the modulation method is 16QAM, and 1000 symbols when the modulation method is 64QAM.

3 and 12 transmit two streams at the same time, and since there are two encoders, the two streams transmit different code blocks. become. Therefore, when the modulation scheme is QPSK, s1 and s2 transmit two coded blocks within the same interval. Since 2 coded blocks will be transmitted, 3000 slots are required to transmit the first and second coded blocks.

Similarly, when the modulation scheme is 16QAM, 1500 slots are required to transmit all the bits that make up two coded blocks, and when the modulation scheme is 64QAM, two coded blocks 1000 slots are required to transmit all the bits that make up the .

Next, in the method of regularly changing the phase, the relationship between the slot defined above and the phase to be multiplied will be described.
Here, the number of phase change values (or phase change sets) prepared for the method of regularly changing the phase is five. That is, it is assumed that five phase change values (or phase change sets) are prepared for the phase change units of the transmission apparatuses of FIGS. ) (As shown in FIG. 6, when the phase is changed only for the baseband signal z2′ after precoding, five phase change values should be prepared in order to change the phase for a period of 5. Also, 26, two phase shift values are required for one slot when phase shift is performed on both precoded baseband signals z1′ and z2′. The value is called a phase change set, so in this case, five phase change sets should be prepared in order to perform a phase change of period 5). Let us denote these five phase change values (or phase change sets) as PHASE[0], PHASE[1], PHASE[2], PHASE[3], PHASE[4].

When the modulation scheme is QPSK, in the above-mentioned 3000 slots for transmitting 6000×2 bits, the number of bits constituting two encoded blocks, 600 slots use phase PHASE[0], and 600 slots use phase PHASE[0]. 600 slots using PHASE[1], 600 slots using phase PHASE[2], 600 slots using phase PHASE[3], 600 slots using phase PHASE[4] must be This is because if there is a bias in the phases used, the phases using a large number of phases have a large effect, and the reception quality of the data in the receiving apparatus depends on this effect.

In addition, 600 slots using phase PHASE[0], 600 slots using phase PHASE[1], and 600 slots using phase PHASE[2] are used to transmit the first encoded block. 600 slots using phase PHASE[3], 600 slots using phase PHASE[4], and to transmit the second encoded block, phase PHASE 600 slots using [0], 600 slots using phase PHASE[1], 600 slots using phase PHASE[2], 600 slots using phase PHASE[3], There may be 600 slots using phase PHASE[4].

Similarly, when the modulation scheme is 16QAM, in the above-described 1500 slots for transmitting 6000×2 bits constituting two encoded blocks, there are 300 slots using phase PHASE[0]. slots, 300 slots using phase PHASE[1], 300 slots using phase PHASE[2], 300 slots using phase PHASE[3], slots using phase PHASE[4] must be 300 slots.

In addition, 300 slots using phase PHASE[0], 300 slots using phase PHASE[1], and 300 slots using phase PHASE[2] are used to transmit the first encoded block. 300 times, 300 slots using phase PHASE[3], 300 slots using phase PHASE[4], and to transmit the second encoded block, phase PHASE 300 slots using [0], 300 slots using phase PHASE[1], 300 slots using phase PHASE[2], 300 slots using phase PHASE[3], There may be 300 slots using phase PHASE[4].

Similarly, when the modulation scheme is 64QAM, in the above-mentioned 1000 slots for transmitting 6000×2 bits constituting two encoded blocks, there are 200 slots using phase PHASE[0]. slots, 200 slots using phase PHASE[1], 200 slots using phase PHASE[2], 200 slots using phase PHASE[3], slots using phase PHASE[4] must be 200 slots.

Also, to transmit the first coded block, there are 200 slots using phase PHASE[0], 200 slots using phase PHASE[1], and 200 slots using phase PHASE[2]. 200 times, 200 slots using phase PHASE[3], 200 slots using phase PHASE[4], and to transmit the second encoded block, phase PHASE 200 slots using [0], 200 slots using phase PHASE[1], 200 slots using phase PHASE[2], 200 slots using phase PHASE[3], There may be 200 slots using phase PHASE[4].

As described above, in the method of regularly changing the phase, the prepared phase change values (or phase change sets) are PHASE[0], PHASE[1], PHASE[2], ..., PHASE[N -2] , PHASE[N-1]), the number of slots using phase PHASE[0] when transmitting all the bits constituting the two encoded blocks is K ₀ , the number of slots using phase PHASE[1] is K _{1, the} number of slots using phase PHASE[i] is K _i (i=0,1,2,...,N-1), phase PHASE[ N-1] is the number of slots using K _N-1 ,

<Condition #A03>
_{K 0 = K 1 =} .・・・, N-1, a≠b)

where K _0,1 is the number of times the phase PHASE[0] is used and K ₁ is the number of times the phase PHASE[1] is used when all the bits forming the block after the first encoding are transmitted. _1, the number of times to use phase PHASE[i] is K _i,1 (i=0,1,2,...,N-1), the number of times to use phase PHASE[N-1] is K _{N-1 , 1} ,

<Condition #A04>
K _0,1 = _{K 1,1} = . . . =K _{i,1 = .} However, a, b = 0, 1, 2, ..., N-1, a ≠ b)

where K _0,2 is the number of times the phase PHASE[0] is used and K ₁ is the number of times the phase PHASE[1] is used when all the bits forming the block after the second encoding are transmitted. _2, the number of times to use phase PHASE[i] is K _i,2 (i=0,1,2,...,N-1), the number of times to use phase PHASE[N-1] is K _{N-1 , 2} , then

<Condition #A05>
K _0,2 = _{K 1,2} = . . . =K _{i,2 = .} However, a, b = 0, 1, 2, ..., N-1, a ≠ b)

should be

Then, when the communication system supports a plurality of modulation schemes and selects and uses one of the supported modulation schemes, <condition #A03> <condition #A04> <condition #A05> is satisfied.

However, when multiple modulation schemes are supported, the number of bits that can be transmitted in one symbol is generally different for each modulation scheme (in some cases, the number may be the same). Depending on the case, there may be a modulation scheme that cannot satisfy <Condition #A03>, <Condition #A04>, and <Condition #A05>. In this case, instead of <Condition #A03>, <Condition #A04>, and <Condition #A05>, the following conditions should be satisfied.

<Condition #A06>
The difference between K _a and K _b is 0 or 1, i.e. |K _a −K _b | is 0 or 1
(for ∀a, ∀b, where a, b=0,1,2,...,N-1, a≠b)

<Condition #A07>
The difference between K _a,1 and K _b,1 is 0 or 1, i.e. |K _a,1 −K _b,1 | is 0 or 1
(for ∀a, ∀b, where a, b=0,1,2,...,N-1, a≠b)

<Condition #A08>
The difference between K _a,2 and K _b,2 is 0 or 1, i.e. |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, by associating the encoded block with the phase to be multiplied, the phase used for transmitting the encoded block is not biased, so that the receiving device improves the data reception quality. effect can be obtained.

In this embodiment, in the method of regularly changing the phase, N phase change values (or phase change sets) are required for the phase change method of period N. At this time, as N phase change values (or phase change sets), PHASE[0], PHASE[1], PHASE[2], .
PHASE[N-2] and PHASE[N-1] are prepared, but PHASE[0], PHASE[1], PHASE[2], ..., PHASE[N-2] along the frequency axis. , PHASE[N-1], but not limited to this, N phase change values (or phase change sets) PHASE[0], PHASE[1]
, PHASE[2], . , the phase can also be changed. Although the phase change method is described as a period N phase change method, the same effect can be obtained by randomly using N phase change values (or phase change sets). Although it is not necessary to use N phase change values (or phase change sets) so as to have a regular period, satisfying the conditions described above is important for obtaining high data reception quality in the receiving device. , becomes important.

In addition, a spatial multiplexing MIMO transmission method, a MIMO transmission method with a fixed precoding matrix, a space-time block coding method, a method of transmitting only one stream, and regularly changing the phase (described in Embodiments 1 to 4) transmission methods) exist, and the transmission device (broadcasting station, base station) may be able to select any transmission method from these modes.

Note that the spatial multiplexing MIMO transmission scheme is, as shown in Non-Patent Document 3, a method of transmitting signals s1 and s2 mapped by the selected modulation scheme from different antennas, and the precoding matrix is fixed. The MIMO transmission scheme is a scheme in which only precoding is performed (no phase change is performed) in Embodiments 1 to 4. FIG. Also, the space-time block coding method is a transmission method shown in Non-Patent Documents 9, 16, and 17. Transmission of only one stream is a method of performing predetermined processing on the signal s1 mapped by the selected modulation method and transmitting it from an antenna.

Also, a multi-carrier transmission system such as OFDM is used, and a first carrier group composed of a plurality of carriers, a second carrier group different from the first carrier group composed of a plurality of carriers, . . . In this way, multi-carrier transmission is realized with multiple carrier groups, and for each carrier group, the spatial multiplexing MIMO transmission method, the MIMO transmission method with a fixed precoding matrix, the space-time block coding method, the transmission of only one stream, May be set to any of the methods of regularly changing the phase,
In particular, it is preferable to implement this embodiment in (sub)carrier groups for which the method of regularly changing the phase is selected.

When the phase of one of the baseband signals after precoding is changed, for example, when the phase change value of PHASE[i] is set to "X radians", FIGS. ，
25, 29, 51, and 53, the baseband signal z2' after precoding is multiplied by ^ejX . Then, when phase change is performed on both precoded baseband signals, for example, when the phase change set of PHASE[i] is set to "X radian" and "Y radian", FIGS. 28, 52, and 54, the baseband signal z2 after precoding ^ejX is
', and ^ejY is multiplied by the precoded baseband signal z1'.

(Embodiment B1)
An application example of the transmission method and the reception method shown in the above embodiments and an example configuration of a system using the same will be described below.

FIG. 36 is a diagram showing a configuration example of a system including devices that execute the transmission method and reception method described in the above embodiments. The transmission method and reception method shown in the above embodiments are shown in FIG.
Broadcasting stations such as shown in , and various types of receivers such as television (television) 3611, DVD recorder 3612, STB (Set Top Box) 3613, computer 3620, in-vehicle television 3641 and mobile phone 3630 Digital broadcasting including system 3600 for the application. Specifically, the broadcasting station 3601 transmits multiplexed data in which video data, audio data, etc. are multiplexed to a predetermined transmission band using the transmission method shown in each of the above embodiments.

A signal transmitted from broadcasting station 3601 is received by an antenna (for example, antennas 3660 and 3640) built in each receiver or installed outside and connected to the receiver. Each receiver demodulates the signal received by the antenna using the reception method shown in each of the above embodiments to obtain multiplexed data. As a result, the digital broadcasting system 3600 can obtain the effects of the present invention described in the above embodiments.

Here, the video data included in the multiplexed data is, for example, MPEG (Moving Picture Experts Group) 2, MPEG4-AVC (Advanced
Video Coding), VC-1, etc., using a moving picture encoding method that conforms to the standard. The audio data included in the 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).
Modulation) or other audio encoding method.

FIG. 37 is a diagram showing an example of the configuration of receiver 7900 that implements the reception method described in each of the above embodiments. The receiver 3700 shown in FIG. 37 corresponds to the configuration provided in the television (television) 3611, the DVD recorder 3612, the STB (Set Top Box) 3613, the computer 3620, the in-vehicle television 3641, the mobile phone 3630, etc. shown in FIG. do. A receiver 3700 includes a tuner 3701 that converts a high-frequency signal received by an antenna 3760 into a baseband signal, and a demodulator 3702 that demodulates the frequency-converted baseband signal to obtain multiplexed data. The receiving method shown in each of the above embodiments is implemented in demodulation section 3702, whereby the effects of the present invention described in each of the above embodiments can be obtained.

The receiver 3700 also includes a stream input/output unit 3720 that separates video data and audio data from the multiplexed data obtained by the demodulation unit 3702, and a video decoding method that supports the separated video data. A signal processing unit 3704 that decodes the data into a video signal and decodes the audio data into an audio signal using an audio decoding method corresponding to the separated audio data, and an audio output unit such as a speaker that outputs the decoded audio signal. 3706 and a video display unit 3707 such as a display for displaying the decoded video signal.

For example, the user uses the remote controller (remote controller) 3750 to transmit information on the selected channel (selected (television) program, selected audio broadcast) to the operation input unit 3710 . Then, the receiver 3700 performs processing such as demodulation and error correction decoding on the signal corresponding to the selected channel in the received signal received by the antenna 3760 to obtain received data. At this time, receiver 3700 uses the transmission method (transmission method, modulation method, error correction method, etc. described in the above embodiments) included in the signal corresponding to the selected channel (see FIGS. 5 and 5). 41.) By obtaining the information of the control symbol including the information, the reception operation, the demodulation method, the error correction decoding method, etc. are set correctly, and the transmission at the broadcasting station (base station) is performed. It becomes possible to obtain the data contained in the data symbol. In the above description, the user selects a channel using the remote control 3750. However, even if the channel is selected using the channel selection key installed in the receiver 3700, the same operation as described above is performed. Become.

With the above configuration, the user can view the program received by receiver 3700 by the receiving method shown in each of the above embodiments.
In addition, receiver 3700 of this embodiment demodulates in demodulation section 3702, and multiplexed data obtained by performing error correction decoding (in some cases, for the signal obtained by demodulation in demodulation section 3702, In some cases, error correction decoding is not performed in the receiver 3700. Other signal processing may be performed after the error correction decoding in the receiver 3700. In the following description, the same expressions are also used in this respect. is the same.), or data equivalent to that data (for example, data obtained by compressing data), or data obtained by processing moving images or audio, on magnetic disks , an optical disk, a non-volatile semiconductor memory, or other recording medium (drive) 3708 for recording. 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 laser light. A magnetic disk is a recording medium that stores information by magnetizing a magnetic material using magnetic flux, such as an FD (Floppy Disk) (registered trademark) and a hard disk. A non-volatile semiconductor memory is a recording medium composed of a semiconductor element, such as a flash memory or a ferroelectric random access memory. ) and the like. Note that the types of recording media listed here are only examples, and it goes without saying that recording media other than the above recording media may be used for recording.

With the above configuration, the user can record and save the program received by the receiver 3700 by the receiving method shown in each of the above embodiments, and record the data recorded at any time after the time when the program is broadcast. can be read and viewed.

In the above description, the receiver 3700 demodulates in the demodulation unit 3702 and records the multiplexed data obtained by performing error correction decoding in the recording unit 3708. However, the data included in the multiplexed data A part of the data may be extracted and recorded. For example, when the multiplexed data obtained by demodulating and error-correcting decoding in the demodulator 3702 contains data broadcast service content other than video data and audio data, the recording unit 3708 demodulates the demodulator 3702. It is also possible to record new multiplexed data in which video data and audio data are extracted from the multiplexed data demodulated in . In addition, the recording unit 3708 demodulates in the demodulation unit 3702 and multiplexes only one of the video data and the audio data included in the multiplexed data obtained by decoding for error correction, resulting in new multiplexed data. may be recorded. Then, the recording unit 3708 may record the content of the data broadcasting service included in the multiplexed data described above.

Furthermore, if the receiver 3700 described in the present invention is installed in a television, a recording device (eg, DVD recorder, Blu-ray (registered trademark) recorder, HDD recorder, SD card, etc.), or a mobile phone, demodulation The multiplexed data obtained by demodulation and error correction decoding in the unit 3702 is added with data, personal information, and recording data for correcting defects (bugs) in software used to operate televisions and recording devices. If it contains data to correct software defects (bugs) to prevent data leakage, installing these data may correct software defects in televisions and recording devices . If the data includes data for correcting a software defect (bug) in the receiver 3700, this data can also correct the defect in the receiver 3700. FIG. As a result, the television, recording device, and mobile phone equipped with the receiver 3700 can operate more stably.

Here, the process of extracting and multiplexing part of the data included in the multiplexed data obtained by demodulating the demodulation unit 3702 and performing error correction decoding is performed by, for example, the stream input/output unit 3703. is done in Specifically, the stream input/output unit 3703 converts the multiplexed data demodulated by the demodulation unit 3702 into video data, audio data, data broadcasting service contents, etc., according to instructions from a control unit such as a CPU (not shown). The data is separated into a plurality of data, and only designated data is extracted from the separated data and multiplexed to generate new multiplexed data. The data to be extracted from the separated 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 3700 can extract and record only the data necessary for viewing the recorded program, so that the data size of the data to be recorded can be reduced.

Further, in the above description, recording section 3708 records multiplexed data obtained by demodulation by demodulation section 3702 and decoding for error correction. The video data included in the multiplexed data obtained by performing is subjected to a video code different from the video encoding method applied to the video data so that the data size or bit rate is lower than that of the video data. The video data may be converted into video data encoded by the encoding method, and new multiplexed data obtained by multiplexing the converted video data may be recorded. At this time, the moving image encoding method applied to the original video data and the moving image encoding method applied to the converted video data may conform to different standards, or may conform to the same standard. Only the parameters used during encoding may be different. Similarly, the recording unit 3708 demodulates the audio data included in the multiplexed data obtained by performing error correction decoding in the demodulation unit 3702 so that the data size or bit rate is lower than that of the audio data. Alternatively, 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 converted audio data may be recorded.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating in the demodulator 3702 and performing error correction decoding into video data and audio data with a different data size or bit rate is , for example, in the stream input/output unit 3703 and the signal processing unit 3704 . Specifically, the stream input/output unit 3703 demodulates the demodulation unit 3702 according to an instruction from a control unit such as a CPU, and performs error correction decoding. Separate into a plurality of data such as contents of data broadcasting service. The signal processing unit 3704 converts the separated video data into video data encoded by a video encoding method different from the video encoding method applied to the video data according to an instruction from the control unit. , and converting the separated audio data into audio data encoded by an audio encoding method different from the audio encoding method applied to the audio data. The stream input/output unit 3703 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 3704 may perform conversion processing on only one of the video data and audio data in accordance with 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 3700 changes the data size or bit rate of video data and audio data according to the data size recordable on the recording medium and the speed at which the recording unit 3708 records or reads data. can do. As a result, when the data size recordable on the recording medium is smaller than the data size of the multiplexed data obtained by demodulation by the demodulator 3702 and decoding for error correction, is lower than the bit rate of the multiplexed data demodulated by the demodulation unit 3702, the recording unit can record the program. It becomes possible to read out and view the data recorded in the .

Receiver 3700 also includes stream output IF (Interface) 3709 that transmits the multiplexed data demodulated by demodulator 3702 to an external device via communication medium 3730 . Examples of the stream output IF 3709 include Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Zigbee (registered trademark), etc. wireless communication apparatus that transmits multiplexed data modulated using a wireless communication method conforming to the wireless communication standard of No. 2 to an external device via a wireless medium (corresponding to the communication medium 3730). In addition, the stream output IF 3709 is Ethernet (registered trademark), USB (Universal Serial Bus), PLC (Power Line
Communication), HDMI (registered trademark) (High-Definition Multimedia Interface) and other wired transmission paths (communication media 3730 (corresponding to ) to an external device.

With the above configuration, the user can use the multiplexed data received by the receiver 3700 by the receiving method shown in each of the above embodiments in an external device. The use of the multiplexed data here means that the user views the multiplexed data in real time using an external device, records the multiplexed data with a recording unit provided in the external device, and further This includes transmitting multiplexed data to another external device.

In the above description, the receiver 3700 is demodulated by the demodulator 3702, and the stream output IF 3709 outputs multiplexed data obtained by performing error correction decoding. A part of the data may be extracted and output. For example, when the multiplexed data obtained by demodulation and error correction decoding by the demodulation unit 3702 contains data broadcast service contents other than video data and audio data, the stream output IF 3709 , and extracting video data and audio data from the multiplexed data obtained by decoding for error correction and outputting new multiplexed data. Also, the stream output IF 3709 may output new multiplexed data in which only one of the video data and audio data included in the multiplexed data demodulated by the demodulator 3702 is multiplexed.

Here, the process of extracting and multiplexing part of the data included in the multiplexed data obtained by demodulating the demodulation unit 3702 and performing error correction decoding is performed by, for example, the stream input/output unit 3703. is done in Specifically, the stream input/output unit 3703 converts the multiplexed data demodulated by the demodulation unit 3702 into video data, audio data, and data broadcasting according to instructions from a control unit such as a CPU (Central Processing Unit) (not shown). It separates into a plurality of data such as service contents, extracts only specified data from the separated data, and multiplexes them to generate new multiplexed data. The data to be extracted from the separated data may be determined by the user, or may be determined in advance for each type of stream output IF 3709 .

With the above configuration, the receiver 3700 can extract and output only the data required by the external device, so it is possible to reduce the communication band consumed by outputting the multiplexed data.

Also, in the above description, the stream output IF 3709 outputs multiplexed data obtained by demodulation by the demodulation unit 3702 and decoding for error correction. The video data included in the multiplexed data obtained by performing is subjected to a video code different from the video encoding method applied to the video data so that the data size or bit rate is lower than that of the video data. The video data may be converted into video data encoded by the encoding method, and new multiplexed data obtained by multiplexing the video data after conversion may be output. At this time, the moving image encoding method applied to the original video data and the moving image encoding method applied to the converted video data may conform to different standards, or may conform to the same standard. Only the parameters used during encoding may be different. Similarly, the stream output IF 3709 demodulates the audio data included in the multiplexed data obtained by performing error correction decoding in the demodulator 3702 so that the data size or bit rate is lower than that of the audio data. Alternatively, the converted 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 converted audio data may be output.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating in the demodulator 3702 and performing error correction decoding into video data and audio data with a different data size or bit rate is , for example, in the stream input/output unit 3703 and the signal processing unit 3704 . Specifically, the stream input/output unit 3703 demodulates with the demodulation unit 3702 according to the instruction from the control unit, and the multiplexed data obtained by performing error correction decoding is converted into video data, audio data, and data broadcasting service. separated into multiple pieces of data such as the content of The signal processing unit 3704 converts the separated video data into video data encoded by a video encoding method different from the video encoding method applied to the video data according to an instruction from the control unit. , and converting the separated audio data into audio data encoded by an audio encoding method different from the audio encoding method applied to the audio data. The stream input/output unit 3703 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 3704 may perform conversion processing on only one of the video data and audio data in accordance with 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 3709 .

With the above configuration, the receiver 3700 can change the bit rate of the video data and the audio data according to the communication speed with the external device and output them. As a result, even if the communication speed with the external device is lower than the bit rate of the multiplexed data obtained by demodulation in the demodulator 3702 and decoding for error correction, the stream output IF can be sent to the new multiplexed data from the external device. Since the multiplexed data can be output, the user can use the new multiplexed data in other communication devices.

The receiver 3700 also includes an AV (Audio and Visual) output IF (Interface) 3711 that outputs the video signal and audio signal decoded by the signal processing unit 3704 to an external device to an external communication medium. Examples of the AV output IF 3711 include wireless communication standards such as Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), and Gigbee. A wireless communication device that transmits a video signal and an audio signal modulated using a wireless communication method conforming to the above to an external device via a wireless medium. In addition, the stream output IF 3709 connects video and audio signals modulated using a communication method conforming to wired communication standards such as Ethernet (registered trademark), USB, PLC, and HDMI (registered trademark) to the stream output IF 3709. It may be a wired communication device that transmits to an external device via a wired transmission line provided. Also, the stream output IF 3709 may be a terminal for connecting a cable that outputs video and audio signals as analog signals.

With the above configuration, the user can use the video signal and audio signal decoded by the signal processing unit 3704 in the external device.
Further, the receiver 3700 includes an operation input section 3710 that receives user operation input. The receiver 3700 switches power ON/OFF, switches channels to be received, displays captions, and switches languages to be displayed, based on a control signal input to the operation input unit 3710 in accordance with a user's operation. , change various operations such as changing the volume output from the audio output unit 3706, and change settings such as setting of receivable channels.

Also, the receiver 3700 may have a function of displaying an antenna level indicating the reception quality of the signal being received by the receiver 3700 . Here, the antenna level is, for example, the RSSI (Received Signal Strength Indication, Received Signal Strength Indicator) of the signal received by the receiver 3700, the received electric field strength, and the C/N (Carrier-to-noise power ratio). , BER (Bit Error Rate), packet error rate, frame error rate, channel state information (Channel
It is an index indicating the reception quality calculated based on the State Information, etc., and is a signal indicating the signal level and the superiority or inferiority of the signal. In this case, the demodulator 3702 includes a reception quality measurement unit that measures RSSI, received field strength, C/N, BER, packet error rate, frame error rate, channel state information, etc. of the received signal. In response to the operation of , the antenna level (signal level, signal indicating the superiority or inferiority of the signal) is displayed on the video display unit 3707 in a format that can be identified by the user. The display format of the antenna level (signal level, signal indicating superiority or inferiority of the signal) is to display numerical values corresponding to RSSI, received electric field strength, C/N, BER, packet error rate, frame error rate, channel state information, etc. Alternatively, different images may be displayed according to RSSI, received electric field strength, C/N, BER, packet error rate, frame error rate, channel state information, and the like. In addition, the receiver 3700 includes a plurality of antenna levels (signal level, signal signal indicating superiority), or one antenna level (signal level, signal indicating superiority of signal) obtained from a plurality of streams s1, s2, . . . may be displayed. Further, when video data and audio data constituting a program are transmitted using a hierarchical transmission method, it is possible to indicate a signal level (a signal indicating the superiority or inferiority of a signal) for each hierarchy.

With the above configuration, the user can numerically or visually grasp the antenna level (signal level, signal indicating superiority or inferiority of the signal) when receiving using the receiving method shown in each of the above embodiments. can be done.

In the above description, the case where the receiver 3700 includes the audio output unit 3706, the video display unit 3707, the recording unit 3708, the stream output IF 3709, and the AV output IF 3711 is described as an example. It is not necessary to have all of the If the receiver 3700 has at least one of the above configurations, the user can use the multiplexed data obtained by demodulation in the demodulator 3702 and decoding for error correction. , each receiver may be provided with any combination of the above configurations according to its use.
(multiplexed data)
Next, an example of the structure of multiplexed data will be described in detail. As a data structure used for broadcasting, MPEG2-transport stream (TS) is generally used.
PEG2-TS will be described as an example. However, the data structure of the multiplexed data transmitted by the transmission method and reception method shown in each of the above embodiments is not limited to MPEG2-TS, and any other data structure will be described in each of the above embodiments. Needless to say, it is possible to obtain the desired effect.

FIG. 38 is a diagram showing an example of the structure of multiplexed data. As shown in FIG. 38, the multiplexed data is an element that constitutes a program (programme or an event that is part of it) currently provided by each service, such as a video stream, an audio stream, a presentation graphics stream (PG ), an interactive graphics stream (IG), etc., by multiplexing one or more elementary streams. If the program provided with multiplexed data is a movie, the video stream is the main video and sub-video of the movie, the audio stream is the main audio part of the movie and the sub-audio mixed with the main audio, and the presentation graphics stream. indicate movie subtitles, respectively. Here, the main image refers to the normal image displayed on the screen, and the sub-image refers to the image displayed on a small screen within the main image (for example, a text data image showing the synopsis of a movie). be. Also, the interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen.

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

FIG. 39 is a diagram schematically showing an example of how multiplexed data is multiplexed. First, a video stream 3901 consisting of a plurality of video frames and an audio stream 3904 consisting of a plurality of audio frames are converted into PES packet sequences 3902 and 3905 respectively, and converted into TS packets 3903 and 3906 . Similarly, presentation graphics stream 3911 and interactive graphics 3914 data are converted into PES packet sequences 3912 and 3915 respectively, and further converted into TS packets 3913 and 3916 . Multiplexed data 3917 is constructed by multiplexing these TS packets (3903, 3906, 3913, 3916) into one stream.

FIG. 40 shows in more detail how the video stream is stored in the PES packet train. The first row in FIG. 40 shows the video frame sequence of the video stream. The second level shows the PES packet sequence. As indicated by arrows yy1, yy2, yy3, and yy4 in FIG. 40, I pictures, B pictures, and P pictures, which are a plurality of Video Presentation Units in the video stream, are divided into individual pictures 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 the picture display time, and DTS (Decoding Time-Stamp), which is the decoding time of the picture.

FIG. 41 shows the format of the TS packet finally written to the multiplexed data. A TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as a PID that identifies a stream and a 184-byte TS payload that stores data. The PES packet is divided and stored in the TS payload. be. In the case of a BD-ROM, a 4-byte TP_Extra_Header is attached to the TS packet, forming a 192-byte source packet and written into the multiplexed data. Information such as ATS (Arrival_Time_Stamp) is described in TP_Extra_Header. ATS indicates the transfer start time of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 41, and a number incremented from the beginning of the multiplexed data is called an SPN (source packet number).

In addition to each stream such as a video stream, an audio stream, and a presentation graphics stream, the TS packets included in the multiplexed data include a PAT (Program Association Table), a PMT (Program Association Table), and the like.
Map Table), PCR (Program Clock Reference), and the like. The PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has the PID of each stream such as video, audio, subtitles, etc. included in the multiplexed data, and the stream attribute information (frame rate, aspect ratio, etc.) corresponding to each PID, and various descriptors related to the multiplexed data. have The descriptor includes copy control information and the like that instruct permission/non-permission of copying of multiplexed data. PCR corresponds to ATS in which the PCR packet is transferred to the decoder in order to synchronize ATC (Arrival Time Clock), which is the time axis of ATS, and STC (System Time Clock), which is the time axis of PTS/DTS. It has STC time information.

FIG. 42 is a diagram explaining in detail the data structure of the PMT. A PMT header describing the length of data included in the PMT is placed at the beginning of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The above copy control information and the like are described as descriptors. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information consists of a stream descriptor describing a stream type for identifying a stream compression codec, a stream PID, and stream attribute information (frame rate, aspect ratio, etc.). There are as many stream descriptors as there are streams in the multiplexed data.

When recording on a recording medium or the like, the multiplexed data is recorded together with the multiplexed data information file.
FIG. 43 shows the configuration of the multiplexed data information file. As shown in FIG. 43, the multiplexed data information file is management information for multiplexed data, corresponds to multiplexed data one-to-one, and consists of multiplexed data information, stream attribute information, and an entry map.

The multiplexed data information consists of system rate, reproduction start time, and reproduction end time, as shown in FIG. The system rate indicates the maximum transfer rate of multiplexed data to the PID filter of the system target decoder, which will be described later. The ATS interval included in the multiplexed data is set to be equal to or less than the system rate. The playback start time is the PTS of the video frame at the beginning of the multiplexed data, and the playback end time is set by adding the playback interval of one frame to the PTS of the video frame at the end of the multiplexed data.

FIG. 44 is a diagram showing the configuration of stream attribute information included in the multiplexed data information file. As for the stream attribute information, as shown in FIG. 44, attribute information for each stream included in the 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. The video stream attribute information includes what compression codec the video stream was compressed with, what the resolution of each picture data that constitutes the video stream is, what the aspect ratio is, and what the frame rate is. It has information such as how much it is. The audio stream attribute information includes what compression codec the audio stream was compressed with, how many channels the audio stream contains, what languages it supports, what the sampling frequency is, and so on. have information on These pieces of information are used, for example, to initialize the decoder before playback by the player.

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

FIG. 45 shows an example of the configuration of a video/audio output device 4500 including a receiving device 4504 that receives a modulated signal including video and audio data or data for data broadcasting transmitted from a broadcasting station (base station). is shown. The configuration of receiving device 4504 corresponds to receiving device 3700 in FIG. For example, an OS (Operating System) is installed in the video/audio output device 4500, and a communication device 4506 for connecting to the Internet (for example, for wireless LAN (Local Area Network) or Ethernet). communication device) is installed. As a result, in a portion 4501 for displaying video, video and audio data or video 4502 in data for data broadcasting, and hypertext provided on the Internet (World Wide Web: WWW) ) 4503 can be displayed simultaneously. Then, by operating a remote controller (which may be a mobile phone or a keyboard) 4507, either video 4502 in data for data broadcasting or hypertext 4503 provided on the Internet is selected to change the operation. will do. For example, when hypertext 4503 provided on the Internet is selected, the displayed WWW site is changed by operating the remote controller. In addition, when video and audio data or video 4502 in data for data broadcasting is selected, remote control 4507 is used to select the selected channel (selected (television) program, selected audio broadcast). Send information. Then, the IF 4505 acquires the information transmitted by the remote controller, and the receiving device 4504 performs processes such as demodulation and error correction decoding on the signal corresponding to the selected channel to obtain received data. At this time, receiving device 4504 obtains control symbol information including information on the transmission method (this is as described in FIG. 5) included in the signal corresponding to the selected channel. By properly setting the operation, demodulation method, error correction decoding method, etc., it is possible to obtain the data contained in the data symbol transmitted by the broadcasting station (base station). In the above description, the user selects a channel by using the remote controller 4507. However, even if the channel is selected using the channel selection key installed in the video/audio output device 4500, the same operation as described above can be performed. It works.

Alternatively, the video/audio output device 4500 may be operated using the Internet. For example, a recording (storage) reservation is made to the video/audio output device 4500 from another terminal connected to the Internet. (Therefore, the video/audio output device 4500 has a recording unit 3708 as shown in FIG. 37.) performs processing such as demodulation and error correction decoding on the signal corresponding to the selected channel to obtain received data. At this time, receiving device 4504 uses the transmission method (transmission method, modulation method, error correction method, etc. described in the above embodiments) included in the signal corresponding to the selected channel (this is described in FIG. 5). By obtaining the information of the control symbol including the information of ), it is possible to correctly set the receiving operation, demodulation method, error correction decoding method, etc., to the data symbol transmitted by the broadcasting station (base station) It becomes possible to obtain the data contained.

(Other supplements)
In this specification, it is conceivable that the transmitting device is provided with, for example, a broadcasting station, a base station, an access point, a terminal, a communication/broadcasting device such as a mobile phone, and in this case, Communication equipment such as televisions, radios, terminals, personal computers, mobile phones, access points, base stations, etc., may be equipped with receiving devices. In addition, the transmitting device and the receiving device in the present invention are devices having a communication function, and the devices have some kind of interface (or For example, it is conceivable to have a form in which connection can be made via a USB.

Also, in the present embodiment, symbols other than data symbols, for example, pilot symbols (pilot symbols may also be called preambles, unique words, postambles, reference symbols, scattered pilots, etc.), symbols for control information. etc., may be arranged in any way in the frame. Although they are named pilot symbols and symbols for control information here, they can be named in any manner, and the function itself is important.

The pilot symbols may be, for example, known symbols modulated using PSK modulation at the transmitter and receiver (or the receiver may be synchronized so that the receiver knows the symbols transmitted by the transmitter). ), and the receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation (of each modulated signal) (CSI (Channel State Information) estimation), signal detection, and the like. Become.

In addition, the symbols for control information are information that needs to be transmitted to the communication partner in order to realize communication other than data (applications, etc.) It is a symbol for transmitting the coding rate of the error correction coding system, setting information in the upper layer, etc.).

It should be noted that the present invention is not limited to all the embodiments, and can be implemented with various modifications. For example, in the above embodiment, the case of performing as a communication device has been described, but the present invention is not limited to this, and it is also possible to perform this communication method as software.

Also, in the above description, the phase change method in the method of transmitting two modulated signals from two antennas has been described, but the present invention is not limited to this. Modified to generate four modulated signals and transmit from four antennas, that is, precoding the N mapped signals to generate N modulated signals and transmit from N antennas It can also be implemented as a phase change method in which the phase is regularly changed in the same way in the method of transmitting from .

Further, in the system example shown in the above embodiment, two modulated signals are transmitted from two antennas, and a MIMO system communication system for receiving each signal with two antennas is disclosed. (Multiple Input Single Output) communication system. In the case of the MISO system, the receiving apparatus has a configuration without antenna 701_Y, radio section 703_Y, channel fluctuation estimating section 707_1 for modulated signal z1, and channel fluctuation estimating section 707_2 for modulated signal z2 in the configuration shown in FIG. Even in this case, r1 and r2 can be estimated by executing the processing described in the first embodiment. 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. is added to the conventional technology.

In addition, in the system example shown in the description of the present invention, two modulated signals are transmitted from two antennas, and a MIMO system communication system for receiving each of them with two antennas is disclosed, but the present invention naturally includes MISO (Multiple Input Single Output) communication system. In the case of the MISO scheme, precoding and phase change are applied in the transmitting apparatus as described above. On the other hand, the receiving apparatus has a configuration without antenna 701_Y, radio section 703_Y, channel fluctuation estimating section 707_1 for modulated signal z1, and channel fluctuation estimating section 707_2 for modulated signal z2 in the configuration shown in FIG. Even so, the data transmitted by the transmitting device can be estimated by executing the processing described in this specification. It is well known that multiple transmitted signals can be received and decoded by one antenna in the same frequency band and at the same time. ), and in the present invention, the signal processing unit 711 in FIG. 7 should perform demodulation (detection) in consideration of precoding and phase change used on the transmission side.

In this specification, terms such as "precoding", "precoding weight", "precoding matrix", etc. are used, but the term itself may be anything (for example, codebook). Good.) In the present invention, the signal processing itself is important.
In addition, in this specification, the reception device uses ML calculation, APP, Max-log APP, ZF, MMSE, etc., but as a result, the soft decision result of each bit of the data transmitted by the transmission device (log-likelihood, log-likelihood ratio) and a hard decision result (“0” or “1”) may be generically called detection, demodulation, detection, estimation, and separation.

Different data or the same data may be transmitted by streams s1(t) and s2(t) (s1(i) and s2(i)).
In addition, regular phase change and precoding are performed for two streams of baseband signals s1(i) and s2(i) (where i represents the order (time or frequency (carrier))). In both signal-processed baseband signals z1(i) and z2(i) generated by performing (whichever comes first), the baseband signal z1(i) after both signal processing is Let the in-phase I component be _{I 1} (i) and the quadrature component be Q _{1 (} i). i). At this time, the baseband components are exchanged,
The in-phase component of the baseband signal r1(i) after replacement is I1( _i ), the quadrature component is _Q2 (i), the in-phase component of the baseband signal r2(i) after replacement is _I2 (i), Let the quadrature component be Q ₁ (i)
Then, the modulated signal corresponding to the baseband signal r1(i) after replacement is transmitted from the transmitting antenna 1, and the modulated signal corresponding to the baseband signal r2(i) after replacement is transmitted from the transmitting antenna 2 at the same time and at the same frequency. Suppose that the modulated signal corresponding to the baseband signal r1(i) after replacement and the baseband signal r2(i) after replacement are transmitted from different antennas at the same time using the same frequency. good too. again,
・The in-phase component of the baseband signal r1(i) after exchange is I ₁ (i), and the quadrature component is I ₂ (i
), the in-phase component of the baseband signal r2(i) after exchange is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of the baseband signal r1(i) after exchange is I ₂ (i), and the quadrature component is I ₁ (i
), the in-phase component of the baseband signal r2(i) after exchange is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of the baseband signal r1(i) after exchange is I ₁ (i), and the quadrature component is I ₂ (i
), the in-phase component of the baseband signal r2(i) after exchange is Q ₂ (i), and the quadrature component is Q ₁ (i).
・The in-phase component of the baseband signal r1(i) after exchange is I ₂ (i), and the quadrature component is I ₁ (i
), the in-phase component of the baseband signal r2(i) after exchange is Q ₂ (i), and the quadrature component is Q ₁ (i).
The in-phase component of the baseband signal r1(i) after replacement is I1( _i ), the quadrature component is _Q2 (i), the in-phase component of the baseband signal r2(i) after replacement is _Q1 (i), Let the orthogonal component be I ₂ (i)
The in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), and the in-phase component of the baseband signal r2(i) after replacement is I ₂ (i), Let the quadrature component be Q ₁ (i)
The in-phase component of the baseband signal r1(i) after replacement is _Q2 (i), the quadrature component is I1(i), the in-phase component of the baseband signal r2(i) after replacement is _Q1 ( _i ), Let the orthogonal component be I ₂ (i)
・The in-phase component of the baseband signal r2(i) after exchange is I ₁ (i), and the quadrature component is I ₂ (i
), the in-phase component of the baseband signal r1(i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of the baseband signal r2(i) after exchange is I ₂ (i), and the quadrature component is I ₁ (i
), the in-phase component of the baseband signal r1(i) after replacement is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of the baseband signal r2(i) after exchange is I ₁ (i), and the quadrature component is I ₂ (i
), the in-phase component of the baseband signal r1(i) after exchange is Q ₂ (i), and the quadrature component is Q ₁ (i).
・The in-phase component of the baseband signal r2(i) after exchange is I ₂ (i), and the quadrature component is I ₁ (i
), the in-phase component of the baseband signal r1(i) after exchange is Q ₂ (i), and the quadrature component is Q ₁ (i).
The in-phase component of the baseband signal r2(i) after replacement is I1( _i ), the quadrature component is _Q2 (i), the in-phase component of the baseband signal r1(i) after replacement is _I2 (i), Let the quadrature component be Q ₁ (i)
The in-phase component of the baseband signal r2(i) after replacement is I1( _i ), the quadrature component is _Q2 (i), the in-phase component of the baseband signal r1(i) after replacement is _Q1 (i), Let the orthogonal component be I ₂ (i)
Q ₂ (i) is the in-phase component of the baseband signal r2(i) after replacement, I ₁ (i) is the quadrature component, I ₂ (i) is the in-phase component of the baseband signal r1(i) after replacement, Let the quadrature component be Q ₁ (i)
The in-phase component of the baseband signal r2(i) after replacement is _Q2 (i), the quadrature component is I1(i), the in-phase component of the baseband signal r1(i) after replacement is _Q1 ( _i ), Let the orthogonal component be I ₂ (i)
may be In the above description, both signal processing is performed on signals of two streams, and in-phase components and quadrature components of signals after both signal processing are exchanged. It is also possible to perform both signal processing on the signal and exchange the in-phase component and the quadrature component of the signal after both signal processing.

Also, in the above example, exchange of baseband signals at the same time (same frequency ((sub))carrier)) is described, but the exchange of baseband signals at the same time may not be necessary. As an example, it can be described as follows: The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i+v), the quadrature component is Q ₂ (i+w), and the baseband signal r2(i) after replacement is The in-phase component of i) is I ₂ (i+w), and the quadrature component is Q ₁ (i+v).
・The in-phase component of the baseband signal r1(i) after exchange is I ₁ (i+v), and the quadrature component is I ₂ .
(i+w), the in-phase component of the baseband signal r2(i) after replacement is Q ₁ (i+v), and the quadrature component is Q ₂ (i+w).
・The in-phase component of the baseband signal r1(i) after exchange is I ₂ (i+w), and the quadrature component is I ₁ .
(i+v), the in-phase component of the baseband signal r2(i) after replacement is Q ₁ (i+v), and the quadrature component is Q ₂ (i+w).
・The in-phase component of the baseband signal r1(i) after exchange is I ₁ (i+v), and the quadrature component is I ₂ .
(i+w), the in-phase component of the baseband signal r2(i) after replacement is Q ₂ (i+w), and the quadrature component is Q ₁ (i+v).
・The in-phase component of the baseband signal r1(i) after exchange is I ₂ (i+w), and the quadrature component is I ₁ .
(i+v), the in-phase component of the baseband signal r2(i) after replacement is Q ₂ (i+w), and the quadrature component is Q ₁ (i+v).
The in-phase component of the baseband signal r1(i) after replacement is I1( _i +v), the quadrature component is _Q2 (i+w), the in-phase component of the baseband signal r2(i) after replacement is _Q1 (i+v), Let the orthogonal component be I ₂ (i+w)
The in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i+w), the quadrature component is I ₁ (i+v), the in-phase component of the baseband signal r2(i) after replacement is I ₂ (i+w), Let the quadrature component be Q ₁ (i+v)
The in-phase component of the baseband signal r1(i) after replacement is _Q2 (i+w), the quadrature component is I1(i+v), the in-phase component of the baseband signal r2(i) after replacement is _Q1 ( _i +v), Let the orthogonal component be I ₂ (i+w)
・The in-phase component of the baseband signal r2(i) after exchange is I ₁ (i+v), and the quadrature component is I ₂ .
(i+w), the in-phase component of the baseband signal r1(i) after replacement is Q ₁ (i+v), and the quadrature component is Q ₂ (i+w).
・The in-phase component of the baseband signal r2(i) after exchange is I ₂ (i+w), and the quadrature component is I ₁ .
(i+v), the in-phase component of the baseband signal r1(i) after replacement is Q ₁ (i+v), and the quadrature component is Q ₂ (i+w).
・The in-phase component of the baseband signal r2(i) after exchange is I ₁ (i+v), and the quadrature component is I ₂ .
(i+w), the in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i+w), and the quadrature component is Q ₁ (i+v).
・The in-phase component of the baseband signal r2(i) after exchange is I ₂ (i+w), and the quadrature component is I ₁ .
(i+v), the in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i+w), and the quadrature component is Q ₁ (i+v).
The in-phase component of the baseband signal r2(i) after replacement is I1( _i +v), the quadrature component is _Q2 (i+w), the in-phase component of the baseband signal r1(i) after replacement is _I2 (i+w), Let the quadrature component be Q ₁ (i+v)
The in-phase component of the baseband signal r2(i) after replacement is I1( _i +v), the quadrature component is _Q2 (i+w), the in-phase component of the baseband signal r1(i) after replacement is _Q1 (i+v), Let the orthogonal component be I ₂ (i+w)
The in-phase component of the baseband signal r2(i) after replacement is _Q2 (i+w), the quadrature component is I1( _i +v), the in-phase component of the baseband signal r1(i) after replacement is _I2 (i+w), Let the quadrature component be Q ₁ (i+v)
The in-phase component of the baseband signal r2(i) after replacement is _Q2 (i+w), the quadrature component is I1(i+v), the in-phase component of the baseband signal r1(i) after replacement is _Q1 ( _i +v), Let the orthogonal component be I ₂ (i+w)
FIG. 55 is a diagram showing baseband signal switching section 5502 for explaining the above description. As shown in FIG. 55, in both signal-processed baseband signals z1(i) 5501_1 and z2(i) 5501_2, the in-phase I component of both signal-processed baseband signals z1(i) 5501_1 is given by I ₁ (i), the quadrature component is Q ₁ (i), the in-phase I component of the baseband signal z2(i) 5501_2 after both signal processing is I ₂ (i), and the quadrature component is Q ₂ (i). Then, the in-phase component of the baseband signal r1(i) 5503_1 after replacement is I _r1 (i), the quadrature component is Q _r1 (i), and the in-phase component of the baseband signal r2(i) 5503_2 after replacement is I _r2 ( i), the quadrature component is Q _r2 (i), the in-phase component I _r1 (i) of the baseband signal r1(i) 5503_1 after replacement, the quadrature component Q _r1 (i), the baseband signal r2 ( i) The in-phase component I _r2 (i) and the quadrature component Q _r2 (i) of 5503_2 shall be represented by any of the above. In this example, exchange of baseband signals after both signal processing at the same time (same frequency ((sub)carrier)) has been described. ))) may be replaced with baseband signals after signal processing.

A transmitting antenna of the transmitting device and a receiving antenna of the receiving device, and one antenna described in the drawings, may be composed of a plurality of antennas.
In this specification, "∀" represents a universal quantifier, and "∃" represents an existential quantifier.

Also, in this specification, the unit of phase, such as an argument, in the complex plane is 'radian'.
The complex plane can be used to represent complex numbers in polar form as polar representations. complex number
When a point (a, b) on the complex plane corresponds to z = a + jb (both a and b are real numbers and j is an imaginary unit), this point is [r, θ] in polar coordinates. 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. Then z = a + jb is expressed as re ^jθ .
In the description of the present invention, the baseband signals s1, s2, z1, and z2 are complex signals. j is an imaginary unit). At this time, I may be zero and Q may be zero.

An example of a broadcast system using the phase modification method described herein is shown in FIG. In FIG. 46, a video encoding unit 4601 receives video as input, performs video encoding, and outputs data 4602 after video encoding. A voice encoding unit 4603 receives voice as an input, performs voice encoding, and outputs voice-encoded data 4604 . A data encoding unit 4605 receives data as input, performs data encoding (for example, data compression), and outputs data 4606 after data encoding. These are collectively referred to as information source coding section 4600 .

The transmission unit 4607 receives video-encoded data 4602, audio-encoded data 4604, and data-encoded data 4606 as input, and uses any or all of these data as transmission data, Processing such as error correction coding, modulation, precoding, and phase change (for example, signal processing in the transmitting apparatus in FIG. 3) is performed, and transmission signals 4608_1 to 4608_N are output. Transmission signals 4608_1 to 4608_N are transmitted as radio waves from antennas 4609_1 to 4609_N, respectively.

Receiving section 4612 receives received signals 4611_1 to 4611_M received by antennas 4610_1 to 4610_M, and performs processing such as frequency conversion, phase change, precoding decoding, logarithmic likelihood ratio calculation, and error correction decoding (for example, in FIG. 7). processing in the receiving device), and output received data 4613, 4615, and 4617. The information source decoding unit 4619 receives the received data 4613, 4615, and 4617 as inputs, and the video decoding unit 4614 receives the received data 4613 as input, performs decoding for video, and outputs a video signal. displayed on the display. Also, audio decoding section 4616 receives received data 4615 as an input. It performs decoding for audio and outputs an audio signal, the audio flowing through the speaker. A data decoding unit 4618 receives the received data 4617, performs data decoding, and outputs data information.

Also, in the embodiments for explaining the present invention, as previously explained, in a multi-carrier transmission system such as the OFDM system, the number of encoders possessed by the transmitting apparatus is may Therefore, for example, as shown in FIG. 4, it is of course possible to apply the method in which the transmitting apparatus has one encoder and distributes the output to a multi-carrier transmission system such as the OFDM system. In this case, the radio units 310A and 310B in FIG. 4 should be replaced with the OFDM system-related processing units 1301A and 1301B in FIG. At this time, the description of the OFDM system-related processing unit is the same as in the first embodiment.

Also, in Embodiment 1, Equation (36) is given as an example of the precoding matrix, but a method using the following equation as the precoding matrix can be considered separately from this.

In addition, in precoding equations (36) and (50), it is described that equations (37) and (38) are set as the value of α. This value is also one of the effective values, since it becomes a simple precoding matrix when set.

3, 4, 6, 12, 25, 29, 51, and 53 in the embodiment A1, the phase change value for the period N (Figs. 4, Figure 6,
In FIGS. 12, 25, 29, 51, and 53, only one of the precoded baseband signals is phase-changed, so the phase change value is used. ), expressed as PHASE[i] (i=0,1,2,...,N-2,N-1). In this specification, when phase change is performed on one precoded baseband signal (that is, FIGS. 3, 4, 6, 12, 25, 29, 51, and 53 ), FIG. 3, FIG. 4, FIG. 6, FIG. 12, FIG. 25, FIG. 29, FIG. 51, and FIG. At this time, PHASE[k] is given as follows.

At this time, k=0, 1, 2, . . . , N-2, N-1. When N=5, 7, 9, 11, and 15, the receiving apparatus can obtain good data reception quality.
Also, in this specification, the phase change method in the case of transmitting two modulated signals with a plurality of antennas was described in detail, but it is not limited to this. The same can be applied to a case where precoding and phase change are performed on the band signal, and predetermined processing is performed on the baseband signal after precoding and phase change, and the signal is transmitted from a plurality of antennas.

It should be noted that, for example, a program for executing the above communication method is previously stored in a ROM (Read Only
Memory), and the program may be operated by a CPU (Central Processor Unit).

Also, a 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 computer's RAM (Random Access Memory), and the computer is operated according to the program. You can do it.

Each configuration of each of the above embodiments and the like may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be made into one chip individually, or may be made into one chip so as to include all or part of the configuration of each embodiment. Although LSI is used here, it may also be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI, depending on the degree of integration. Also, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure connections and settings of circuit cells inside the LSI may be used.

Furthermore, if an integration technology that replaces the LSI appears due to advances in semiconductor technology or another technology derived from it, it is of course possible to integrate the functional blocks using that technology. Application of biotechnology, etc. is possible.

INDUSTRIAL APPLICABILITY The present invention can be widely applied to radio systems in which different modulated signals are transmitted from a plurality of antennas, and is preferably applied to OFDM-MIMO communication systems, for example. It is also applicable to the case of performing MIMO transmission in a wired communication system having multiple transmission points (for example, a PLC (Power Line Communication) system, an optical communication system, a DSL (Digital Subscriber Line) system). can be used, in which case multiple transmission sites will be used to transmit multiple modulated signals as described in the present invention. Also, the modulated signal may be transmitted from multiple transmission locations.

302A, 302B Encoders 304A, 304B Interleavers 306A, 306B Mapping section 314 Signal processing method information generation sections 308A, 308B Weighted combining sections 310A, 310B Radio sections 312A, 312B Antennas 317A, 317B Phase changing section 402 Encoder 404 Distributing section 504#1, 504#2 Transmitting antennas 505#1, 505#2 Receiving antenna 600 Weighted combiner 701_X, 701_Y Antenna 703_X, 703_Y Radio unit 705_1 Channel fluctuation estimator 705_2 Channel fluctuation estimator 707_1 Channel fluctuation estimator 707_2 Channel fluctuation estimation Section 709 Control information decoding section 711 Signal processing section 803 INNER MIMO detection section 805A, 805B Log likelihood calculation section 807A, 807B Deinterleaver 809A, 809B Log likelihood ratio calculation section 811A, 811B Soft-in/soft-out decoder 813A, 813B interleaver 815 storage unit 819 coefficient generation unit 901 soft-in/soft-out decoder 903 distributors 1201A, 1201B OFDM system-related processing units 1302A, 1302A serial-to-parallel conversion units 1304A, 1304B rearrangement units 1306A, 1306B inverse fast Fourier transform unit 1308A, 1308B radio section

Claims (4)

A method of transmission,
For a first modulated signal sequence s1(j) containing a plurality of first modulated signals s1 and a second modulated signal sequence s2(j) containing a plurality of second modulated signals s2, where j is are index numbers of the first modulated signal and the second modulated signal, and for each set of the first modulated signal s1 and the second modulated signal s2 having the same index number,
precoding processing for precoding the first modulated signal s1 and the second modulated signal s2;
phase change processing for changing the phase of at least one of the precoded signals;
to generate a first transmission signal sequence z1(j) containing a plurality of first transmission signals z1 and a second transmission signal sequence z2(j) containing a plurality of second transmission signals z2,
transmitting the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) using a plurality of antennas;
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching the N phase change amounts according to the index number at a cycle N, and the phase change amounts of the N different phase change amounts have a minimum difference of 2π/ N, and among the N phase change amounts, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. the difference between the first phase change amount and the second phase change amount is not 2π/N, but the difference between the third phase change amount and the fourth phase change amount is 2π/N. is
Send method. a transmitting device,
For a first modulated signal sequence s1(j) containing a plurality of first modulated signals s1 and a second modulated signal sequence s2(j) containing a plurality of second modulated signals s2, where j is are index numbers of the first modulated signal and the second modulated signal, and for each set of the first modulated signal s1 and the second modulated signal s2 having the same index number,
precoding processing for precoding the first modulated signal s1 and the second modulated signal s2;
phase change processing for changing the phase of at least one of the precoded signals;
to generate a first transmission signal sequence z1(j) containing a plurality of first transmission signals z1 and a second transmission signal sequence z2(j) containing a plurality of second transmission signals z2 Department and
a transmitter that transmits the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) using a plurality of antennas;
with
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching the N phase change amounts according to the index number at a cycle N, and the phase change amounts of the N different phase change amounts have a minimum difference of 2π/ N, and among the N phase change amounts, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. the difference between the first phase change amount and the second phase change amount is not 2π/N, but the difference between the third phase change amount and the fourth phase change amount is 2π/N. is
transmitter. A receiving method comprising:
obtaining a received signal, the received signal obtained by receiving a first transmission signal sequence z1(j) and a second transmission signal sequence z2(j) transmitted using a plurality of antennas; One transmitted signal sequence z1(j) includes a plurality of first transmitted signals z1, and said second transmitted signal sequence z2(j) includes a plurality of second transmitted signals z2, where j is said second 1 and the index number of the second transmission signal, and the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) are a plurality of first modulated signals. generated by subjecting a first modulated signal sequence s1(j) including s1 and a second modulated signal sequence s2(j) including a plurality of second modulated signals s2 to predetermined signal processing,
including processing for generating received data by performing demodulation processing according to the predetermined signal processing on the acquired received signal;
The predetermined generation process includes:
a set of the first modulated signal s1 and the second modulated signal s2 having the same index number for the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j); for each
precoding processing for precoding the first modulated signal s1 and the second modulated signal s2;
phase change processing for changing the phase of at least one of the precoded signals;
including
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching the N phase change amounts according to the index number at a cycle N, and the phase change amounts of the N different phase change amounts have a minimum difference of 2π/ N, and among the N phase change amounts, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. the difference between the first phase change amount and the second phase change amount is not 2π/N, but the difference between the third phase change amount and the fourth phase change amount is 2π/N. is
receiving method. a receiving device,
obtaining a received signal, the received signal obtained by receiving a first transmission signal sequence z1(j) and a second transmission signal sequence z2(j) transmitted using a plurality of antennas; One transmitted signal sequence z1(j) includes a plurality of first transmitted signals z1, and said second transmitted signal sequence z2(j) includes a plurality of second transmitted signals z2, where j is said second 1 and the index number of the second transmission signal, and the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) are a plurality of first modulated signals. generated by subjecting a first modulated signal sequence s1(j) including s1 and a second modulated signal sequence s2(j) including a plurality of second modulated signals s2 to predetermined signal processing, a receiver;
a demodulation unit that performs demodulation processing according to the predetermined signal processing on the acquired received signal to generate received data;
with
The predetermined generation process includes:
a set of the first modulated signal s1 and the second modulated signal s2 having the same index number for the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j); for each
precoding processing for precoding the first modulated signal s1 and the second modulated signal s2;
phase change processing for changing the phase of at least one of the precoded signals;
including
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching the N phase change amounts according to the index number at a cycle N, and the phase change amounts of the N different phase change amounts have a minimum difference of 2π/ N, and among the N phase change amounts, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. the difference between the first phase change amount and the second phase change amount is not 2π/N, but the difference between the third phase change amount and the fourth phase change amount is 2π/N. is
receiving device.

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