JP7002022B2 - Transmission method, transmitter, receiver and receiver - Google Patents

Description

The present invention particularly relates to a precoding method, a precoding device, a transmitting method, a transmitting device, a receiving method, and a receiving device for communicating using a multi-antenna.

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

FIG. 28 shows an example of the configuration of the transmission / reception device when the number of transmission antennas is 2, the number of reception antennas is 2, and the number of transmission modulation signals (transmission streams) is 2. In the transmitting device, the encoded data is interleaved, the interleaved data is modulated, frequency conversion or the like is performed to generate a transmission signal, and the transmission signal is transmitted from the antenna. At this time, the spatial multiplex MIMO method is a method in which different modulated signals are transmitted from the transmitting antenna to the same frequency at the same time.

At this time, Patent Document 1 proposes a transmitting device having a different interleaving pattern for each transmitting antenna. That is, in the transmission device of FIG. 28, the two interleaves (πa, πb) have 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 soft values (MIMO detector in FIG. 28). Will be done.

By the way, as a model of the actual propagation environment in wireless communication, there are an NLOS (non-line of light) environment represented by a Rayleigh fading environment and a LOS (line of light) environment represented by a rice fading environment. When transmitting a single modulated signal in the transmitting device, performing maximum ratio synthesis on the signal received by multiple antennas in the receiving device, and demodulating and decoding the signal after maximum ratio synthesis, the LOS environment, In particular, in an environment where the rice factor indicating the magnitude of the received power of the direct wave with respect to the received power of the scattered wave is large, good reception quality can be obtained. However, depending on the transmission method (for example, spatial multiplex MIMO transmission method), there arises a problem that the reception quality deteriorates as the rice factor increases. (See Non-Patent Document 3)
In FIGS. 29A and 29B, LDPC (low-density patiity-check) -encoded data is 2 × 2 in a ray-fading environment and a rice-fading environment with rice factors K = 3, 10, and 16 dB. (2 antenna transmission, 2 antenna reception) An example of the simulation result of BER (Bit Error Rate) characteristics (vertical axis: BER, horizontal axis: SNR (signal-to-noise power ratio)) in the case of spatial multiplex MIMO transmission is shown. ing. (A) of FIG. 29 is a BER characteristic of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) without repeated detection (APP: a posterior probability), and FIG. 29 (B) is a repeat. It shows the BER characteristics of the detected Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (number of repetitions 5 times). As can be seen from FIGS. 29 (A) and 29 (B), it can be confirmed that the reception quality deteriorates as the rice factor increases in the spatial multiplex MIMO system regardless of whether or not the repeated detection is performed. From this, it is possible to have a problem peculiar to the spatial multiplex MIMO system, which is not found in the conventional single modulated signal transmission system, that "in the spatial multiplex MIMO system, the reception quality deteriorates when the propagation environment becomes stable". Recognize.

Broadcasting and multicast communication are services for users within the line of sight, and the radio wave propagation environment between the receiver and the broadcasting station possessed by the user is often the LOS environment. When a spatial multiplex MIMO system having the above-mentioned problems is used for broadcasting or multicast communication, a phenomenon occurs in the receiver that the received electric wave strength of radio waves is high, but the service cannot be received due to deterioration of reception quality. there is a possibility. That is, in order to use the spatial multiplex MIMO system in broadcasting and multicast communication, it is desired to develop a MIMO transmission method that can obtain a certain level of reception quality in both the NLOS environment and the LOS environment.
Non-Patent Document 8 describes a method of selecting a codebook (precoding matrix (also referred to as precoding weight matrix)) to be used for precoding from feedback information from a communication partner. There is no description about how to perform precoding in a situation where feedback information from the communication partner cannot be obtained, such as multicast communication.

On the other hand, Non-Patent Document 4 describes a method of switching the precoding matrix over time, which can be applied even when there is no feedback information. In this document, it is described that a unitary matrix is used as a matrix used for precoding and that the unitary matrix is randomly switched. However, the application method for the deterioration of reception quality in the LOS environment shown above is described. It is not mentioned at all, only the random switching is mentioned. As a matter of course, there is no description about the precoding method for improving the deterioration of the reception quality of the LOS environment and the method of constructing the precoding matrix.

International Publication No. 2005/050885

“Achieving near-capacity on a multiple-antenna channel” IEEE Transition on communications, vol. 51, no. 3, pp. 389-399, March 2003. "Performance analysis and design optimization of LDPC-coded MIMO OFDM systems" IEEE Transfers. Signal Processing. , Vol. 52, no. 2, pp. 348-361, Feb. 2004. "BER performance evolution in 2x2 MIMO partial multiplexing systems under Rician fading channels," IEICE Transfers. Fundamentals, vol. E91-A, no. 10, pp. 2798-2807, Oct. 2008. "Turbo space-time codes with time variing linear transformations," IEEE Trans. Wireless communications, vol. 6, no. 2, pp. 486-493, Feb. 2007. "Likelihood function for QR-MLD suitedable for soft-decision turbo decoding and it performance," IEICE Transfer. Commun. , Vol. E88-B, no. 1, pp. 47-57, Jan. 2004. "Signpost to the Shannon Limits:" Parallel Concatenate (Turbo) Coding "," Turbo (Iterative) Decoding "and its Surroundings" Institute of Electronics, Information and Communication Engineers, Intellectual Technology IT98-51 “Advanced signal processing for PLCs: Wavelet-OFDM,” Proc. of IEEE symposium on ISPLC 2008, pp. 187-192, 2008. D. J. Love, and R. W. heath, Jr. , “Limited feedback unitary precoding for spectral multiplexing systems,” IEEE Trans. Inf. Theory, vol. 51, no. 8, pp. 2967-1976, Aug. 2005. DVB Document A122, Framing strategy, channel coding and modulation for a second generation digital terrestrial terrestrial terrestrial television system2T, m (DVB) L. Vangelista, N.M. Benvenuto, and S. Tomasin, "Key technologies for next-generation terrestrial digital television standard DVB-T2," IEEE Commun. Magazine, vo. 47, no. 10, pp. 146-153, Oct. 2009. T. Ohgane, T.M. Nishimura, and Y. Ogawa, "Application of multiplexing multiplexing and those performance in a MIMO channel," IEICE Trans. Commun. , Vo. 88-B, no. 5, pp. 1843-1851, May 2005.

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

In order to solve such a problem, the transmission method according to one aspect of the present invention has a plurality of precoding matrices for performing precoding, and is a first modulation signal composed of an in-phase component and an orthogonal component based on a modulation method and a first modulation signal. Each of the two modulated signals and one of the plurality of precoding matrices are used to generate a precoded first transmission signal and a second transmission signal, and the first transmission signal is used as one or more first output ports. A transmission method in which the second transmission signal is transmitted from one or more second output ports different from the first output port, and the first transmission signal and the second transmission signal are generated. The precoding matrix is regularly switched from the plurality of precoding matrices, and is used for data transmission of the first symbol, which is one data symbol used for data transmission of the first modulation signal, and data transmission of the second modulation signal. Of the second symbol, which is one data symbol to be used, the first time and the first frequency to which the first symbol should be precoded and transmitted, and the second symbol to which the second symbol should be precoded and transmitted. Regarding the first symbol and the second symbol in which the time and the second frequency match, the two third symbols adjacent to each other in the frequency direction of the first symbol are both data symbols, and the time axis direction of the first symbol When the two fourth symbols adjacent to the above are both data symbols, the first symbol, the two third symbols, and the two fourth symbols total 4
In the symbols, different precoding matrices are used to perform precoding to generate the first transmission signal, the second symbol and the two fifth symbols adjacent in the frequency direction of the second symbol. Regarding the two sixth symbols adjacent to each other in the time axis direction of the second symbol, among the first symbol, the two third symbols, and the two fourth symbols, the symbols having the same time and frequency are used. Using the same precoding matrix as the precoding matrix used, precoding is executed to generate the second transmission signal, and the generated first transmission signal is transmitted from the one or more first output ports. It is characterized in that the generated second transmission signal is transmitted from the one or more second output ports.

Further, the transmission device according to one aspect of the present invention has a plurality of precoding matrices for performing precoding, and includes a first modulation signal and a second modulation signal each composed of an in-phase component and an orthogonal component based on a modulation method. , The first transmission signal and the second transmission signal after precoding are generated by using any one of the plurality of precoding matrices, and the first transmission signal is transmitted from one or more first output ports. A transmission device that transmits a second transmission signal from one or more second output ports different from the first output port, and the precoding matrix for generating the first transmission signal and the second transmission signal is The first symbol, which is one data symbol used for data transmission of the first modulated signal, and one data symbol used for data transmission of the second modulated signal, while regularly switching from the plurality of precoding matrices. Of the second symbols, the first time and first frequency at which the first symbol should be precoded and transmitted, and the second time and second frequency at which the second symbol should be precoded and transmitted. With respect to the first symbol and the second symbol that coincide with, the two third symbols adjacent to each other in the frequency direction of the first symbol are both data symbols, and the two adjacent symbols in the time axis direction of the first symbol. When the fourth symbol is both a data symbol, a different precoding matrix is assigned to the first symbol, the two third symbols, and the two fourth symbols in total, and the second symbol and the second symbol are assigned. , The first symbol and the two third symbols of the two fifth symbols adjacent to each other in the frequency direction of the second symbol and the two sixth symbols adjacent to each other in the time axis direction of the second symbol. , The precoding weight generation unit that allocates the same precoding matrix as the precoding matrix used for the symbols having the same time and frequency among the two fourth symbols, and the first precoding matrix that is assigned. A weighted synthesis unit that performs weighted synthesis on the 1-modulated signal and the 2nd-modulated signal to generate the 1st transmission signal and the 2nd transmission signal, and the generated 1st transmission signal are combined with the 1 or more first output ports. It is characterized by including a transmission unit that transmits from the above and transmits the generated second transmission signal from the one or more second output ports.

Further, the receiving method according to one aspect of the present invention is a receiving method for receiving the first transmission signal and the second transmission signal precoded and transmitted from the transmission device, the first transmission signal and the first transmission signal. The two transmission signals are generated by using each of the first modulation signal and the second modulation signal consisting of the in-phase component and the orthogonal component based on the modulation method, and one of a plurality of precoding matrices while regularly switching. Therefore, of the first symbol which is one data symbol used for data transmission of the first modulation signal and the second symbol which is one data symbol used for data transmission of the second modulation signal, the first symbol is A first symbol and a second symbol in which the first time and the first frequency to be precoded and transmitted coincide with the second time and the second frequency to be precoded and transmitted. When the two third symbols adjacent to each other in the frequency direction of the first symbol are both data symbols and the two fourth symbols adjacent to each other in the time axis direction of the first symbol are both data symbols, the first symbol is used. One transmission signal is generated by precoding using different precoding matrices for a total of four symbols, the first symbol, the two third symbols, and the two fourth symbols. , The second transmission signal is the second symbol, two fifth symbols adjacent to each other in the frequency direction of the second symbol, and two sixth symbols adjacent to each other in the time axis direction of the second symbol. Precoded using the same precoding matrix as the precoding matrix used for the first symbol, the two third symbols, and the symbols having the same time and frequency among the two fourth symbols. It is generated, and the first transmission signal and the second transmission signal are received, and the received first transmission signal and the second transmission signal are each demolished by a demodulation method according to the modulation method, resulting in an error. It is characterized in that data is obtained by performing correction / decoding.

Further, the receiving device according to one aspect of the present invention is a receiving method for receiving a first transmission signal and a second transmission signal precoded and transmitted from the transmission device, wherein the first transmission signal and the first transmission signal are received. The two transmission signals are generated by using each of the first modulation signal and the second modulation signal consisting of the in-phase component and the orthogonal component based on the modulation method, and one of a plurality of precoding matrices while regularly switching. Therefore, of the first symbol which is one data symbol used for data transmission of the first modulation signal and the second symbol which is one data symbol used for data transmission of the second modulation signal, the first symbol is A first symbol and a second symbol in which the first time and the first frequency to be precoded and transmitted coincide with the second time and the second frequency to be precoded and transmitted. When the two third symbols adjacent to each other in the frequency direction of the first symbol are both data symbols and the two fourth symbols adjacent to each other in the time axis direction of the first symbol are both data symbols, the first symbol is used. One transmission signal is generated by precoding using different precoding matrices for a total of four symbols, the first symbol, the two third symbols, and the two fourth symbols. , The second transmission signal is the second symbol, two fifth symbols adjacent to each other in the frequency direction of the second symbol, and two sixth symbols adjacent to each other in the time axis direction of the second symbol. Precoded using the same precoding matrix as the precoding matrix used for the first symbol, the two third symbols, and the symbols having the same time and frequency among the two fourth symbols. It is generated, and the first transmission signal and the second transmission signal are received and received, and the first transmission signal and the second transmission signal are each demolished by a demodulation method according to the modulation method. It is characterized by performing error correction and decoding to obtain data.

According to each aspect of the present invention described above, regarding the precoding matrix used for at least one data symbol from a plurality of precoding weight matrices, the precoding matrix and the data symbol in the frequency axis direction and the time axis direction. With respect to the precoding matrix used for adjacent data symbols in any one direction, the precoding matrix can be switched so that all the precoding matrices are different, and a modulated signal in which precoding is executed can be generated, so that a plurality of precoding matrices can be generated. The reception quality in the LOS environment can be improved according to the design of the coding weight matrix.

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 for improving the deterioration of reception quality in the LOS environment. , Can provide high quality service.

Example of configuration of transmitter / receiver in spatial multiplex MIMO transmission system An example of frame configuration Precoding weight switching method Example of transmitter configuration when applied Precoding weight switching method Example of transmitter configuration when applied Frame configuration example Example of precoding weight switching 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 Example of reception status BER characteristic example Precoding weight switching method Example of transmitter configuration when applied Precoding weight switching method Example of transmitter configuration when applied Frame configuration example Frame configuration example Frame configuration example Frame configuration example Frame configuration example Position of poor reception quality Position of poor reception quality An example of frame configuration An example of frame configuration An example of mapping method An example of mapping method Example of configuration of weighted composite unit An example of how to rearrange symbols Example of configuration of transmitter / receiver in spatial multiplex MIMO transmission system BER characteristic example Example of spatially multiplexed 2x2 MIMO system model Location of poor reception Location of poor reception Location of poor reception Location of poor reception Location of poor reception Example of minimum distance characteristics in the complex plane of poor reception Example of minimum distance characteristics in the complex plane of poor reception Location of poor reception Location of poor reception An example of the configuration of the transmission device according to the seventh embodiment. An example of the frame configuration of the modulated signal transmitted by the transmitter Location of poor reception Location of poor reception Location of poor reception Location of poor reception Location of poor reception An example of frame configuration on the time-frequency axis An example of frame configuration on the time-frequency axis Signal processing method Configuration of modulated signal when using spatiotemporal block code Example of detailed frame configuration on the time-frequency axis An example of a transmitter configuration An example of the configuration of the modulation signal generation units # 1 to # M in FIG. 52. FIG. 52 is a diagram showing a configuration of an OFDM method-related processing unit (5207_1 and 5207_2) in FIG. 52. Example of detailed frame configuration on the time-frequency axis An example of a receiver configuration FIG. 56 is a diagram showing a configuration of an OFDM method-related processing unit (5600_X, 5600_Y) in FIG. Example of detailed frame configuration on the time-frequency axis An example of a broadcasting system Location of poor reception Example of frame configuration of modulated signal that can obtain high reception quality Example of frame configuration of modulated signal that cannot obtain high reception quality Example of symbol arrangement of modulated signal that can obtain high reception quality Example of symbol arrangement of modulated signal that can obtain high reception quality An example of symbol arrangement in which the frequency axis direction and the time axis direction of the symbol arrangement example of FIG. 63 are exchanged. An example of symbol arrangement in which the frequency axis direction and the time axis direction of the symbol arrangement example of FIG. 64 are exchanged. Diagram showing an example of symbol placement order Symbol placement example when the pilot symbol is not inserted between the data symbols Diagram showing that pilot symbols are inserted between data symbols Symbol placement example showing that there are places where it is not possible to achieve symbol placement that provides high reception quality when the pilot symbol is inserted as it is. Symbol placement example when a pilot symbol is inserted between data symbols An example of a frame configuration that expands the range in which the precoding matrix of a modulated signal that can obtain high reception quality is different. An example of a frame configuration that expands the range in which the precoding matrix of a modulated signal that can obtain high reception quality is different. Symbol placement example when expanding the range of different precoding matrices An example of a frame configuration that expands the range in which the precoding matrix of a modulated signal that can obtain high reception quality is different. An example of symbol arrangement that can obtain high reception quality corresponding to FIG. 75. An example of a frame configuration that expands the range in which the precoding matrix of a modulated signal that can obtain high reception quality is different. An example of symbol arrangement that can obtain high reception quality corresponding to FIG. 75. Symbol placement example when a pilot symbol is inserted between data symbols in the symbol placement example when the range of different precoding matrices is expanded An example of symbol arrangement in which the precoding matrix is assigned differently from that in FIG. 70. An example of symbol arrangement in which the precoding matrix is assigned differently from that in FIG. 70. Overall configuration diagram of the digital broadcasting system Block diagram showing a configuration example of a receiver Diagram showing the structure of multiplexed data A diagram schematically showing how each stream is multiplexed in the multiplexed data. A detailed diagram showing how a video stream is stored in a PES packet string. The figure which shows the structure of TS packet and source packet in multiplexed data The figure which shows the data structure of PMT Diagram showing the internal structure of multiplexed data information Diagram showing the internal structure of stream attribute information Configuration diagram of video display and audio output device

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

Before giving this description, the outline of the transmission method and the decoding method in the spatial multiplex MIMO transmission system which is a conventional system will be described.
The configuration of the N _t xN _r spatial multiplex MIMO system is shown in FIG. The information vector z is coded and interleaved. Then, as the output of the interleave, the vector u = (u ₁ , ..., U _Nt ) of the coded bit is obtained. However, u _i = (ui ₁ , ..., u _iM ) (M: number of transmission bits per symbol). When the transmission vector s = (s ₁ , ..., s _Nt ) ^T , the transmission signal s _i = map ( _ui ) is expressed from the transmission antenna #i, and when the transmission energy is normalized, E {| s _i | ² } = Es. It is expressed as / Nt ( _Es : total energy per channel). Then, if the reception vector is y = (y ₁ , ..., y _Nr ) ^T , it is expressed as in Eq. (1).

At this time, H _NtNr is a channel matrix, n = (n ₁ , ..., n _Nr ) ^T is a noise vector, ni is an average value of ⁰ , and _i . i. d. Complex Gaussian noise. From the relationship between the transmission symbol and the reception symbol introduced in the receiver, the probability regarding the reception vector can be given by a multidimensional Gaussian distribution as in Eq. (2).

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

<Repeat detection method>
Here, iterative detection of MIMO signals in an N _t xN _r spatial multiplex MIMO system will be described.
The log-likelihood ratio of x _mn is defined as in Eq. (6).

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

However, U _{mn, ± 1} = {u | u _mn = ± 1}. And _lnΣaj ~ max
When approximated by ln a _j , equation (7) can be approximated as equation (8). The symbol "~" above means an approximation.

P (u | _umn ) and ln P (u | _umn ) in the formula (8) are expressed as follows.

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

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

Hereinafter, it is referred to as repeated APP decoding. Further, from the equations (8) and (12), in the log-likelihood ratio (Max-Log APP) based on the Max-Log approximation, the subsequent L-value is expressed as follows.

Hereinafter, it is referred to as repeated Max-log APP decoding. The external information required by the iterative decoding system can be obtained by subtracting the pre-input from the equation (13) or (14).
<System model>
FIG. 28 shows the basic configuration of the system leading to the following description. Here, it is a 2 × 2 spatial multiplexing MIMO system, each of the streams A and B has an outer encoder, and the two outer encoders are encoders having the same LDPC code (here, an LDPC code encoder is used as the outer encoder). However, the error correction code used by the outer encoder is not limited to the LDPC code, and other error correction codes such as a turbo code, a convolutional code, and an LDPC convolutional code may be used in the same manner. Further, the outer encoder is configured to be provided for each transmitting antenna, but the present invention is not limited to this, and a plurality of transmitting antennas may be used, or one outer encoder may be provided, and transmission may be performed. It may have more outer encoders than the number of antennas). The streams A and B each have an interleaver (π _a , π _b ). Here, the modulation method is 2 ^h -QAM (h bits are transmitted with one symbol).

In the receiver, iterative detection (repeated APP (or Max-log APP) decoding) of the above-mentioned MIMO signal shall be performed. Then, as the decoding of the LDPC code, for example, sum-product decoding shall be performed.

FIG. 2 shows the frame configuration and describes the order of the symbols after interleaving. At this time, ( _{ia, ja), (ib, j b ) shall be} expressed as shown in the following equation.

At this time, i _a , i _b : the order of symbols after interleaving, ja _a , j _b : bit position in the modulation method ( _{ja, j b =} 1, ..., H), π _a , π _b : stream. ^A , ^B interleaver, Ω _{aia, ja} , Ω _{bib, jb} : Indicates the order of data before interleaving of streams A and B. However, _FIG . 2 shows the frame configuration when _ia = ib.
<Repetitive decoding>
Here, the sum-product decoding and the iterative detection algorithm of the MIMO signal used for decoding the LDPC code in the receiver will be described in detail.

The sum-produce decoding binary MxN matrix H = {H _mn } is used as the inspection matrix of the LDPC code to be decoded. The subsets A (m) and B (n) of the set [1, N] = {1, 2, ..., N} are defined as follows.

At this time, A (m) means a set of column indexes that are 1 in the mth row of the check matrix H, and B (n) is a set of row indexes that are 1 in the nth row of the check matrix H. .. The algorithm for sum-produce decoding is as follows.
Step A ・ 1 (Initialization): The prior value logarithmic ratio β _mn = 0 is set for all sets (m, n) satisfying H _mn = 1. The loop variable (number of iterations) is set to l _sum = 1, and the maximum number of loops is set to l _{sum, max} .
Step A ・ 2 (row processing): External value logarithm using the following update formula for all sets (m, n) that satisfy H _mn = 1 in the order of m = 1, 2, ..., M. The ratio α _mn is updated.

At this time, f is a function of Gallager. Then, how to obtain λ _n will be described in detail below.
Step A ・ 3 (column processing): External value logarithm using the following update formula for all pairs (m, n) that satisfy H _mn = 1 in the order of n = 1, 2, ..., N. Update the ratio β _mn .

Step A ・ 4 (Calculation of log-likelihood ratio): For n ∈ [1, N], the log-likelihood ratio L _n is calculated 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. When l _sum = l _{sum, max} , this sum-produce decoding is completed.

The above is the operation of one sum-product decoding. After that, repeated detection of the MIMO signal is performed. In the variables m, n, α _mn , β _mn , λ _n , and L _n used in the above description of the operation of sum-produce decoding, the variables in the stream A are ^ma , n _a , α _{a mana} , β ^a _mana , Variables in λ _na , L _na , and stream ^{B are represented by mb, n b, α b mb nb, β b} _{mb nb ,} ^λ _{nb ,} and L _nb .
<Repeated detection of MIMO signal>
Here, a method of obtaining λ _n in repeated detection of a MIMO signal will be described in detail.

From equation (1), the following equation holds.

From the frame configuration of FIG. 2, the following relational expression is established from the equations (16) and (17).

At this time, n _a , n _b ∈ [1, N]. Hereinafter, λ _na , L _na , λ _nb , and L _nb are expressed as λ _{k, na} , L _{k, na} , λ _{k, nb} , L _k, and nb, respectively, when the number of iterations of the repeated detection of the MIMO signal is k. And.

Step B ・ 1 (Initial detection; k = 0): At the time of initial detection, λ _{0, na} , λ _{0, nb} are obtained as follows.
For iterative APP decoding:

For iterative Max-log APP decoding:

However, it is assumed that X = a and b. Then, the number of repetitions of the repeated detection of the MIMO signal is set to l _mimo .
= 0, and the maximum number of repetitions is set as _{lmimo, max} .
Step B ・ 2 (repeated detection; number of repetitions k): λ _{k, na} , λ _{k, nb} when the number of repetitions k is from equations (11) (13)-(15) (16) (17). It is expressed as 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, estimating the codeword): If l _mimo <l _{mimo, max} , increment l _mimo and return to step B ・ 2. In the case of l _mimo = l _{mimo, max} , the estimated codeword is determined as follows.

However, it is assumed that X = a and b.
FIG. 3 is an example of the configuration of the transmission device 300 according to the present embodiment. The coding unit 302A receives information (data) 301A and a frame configuration signal 313 as inputs, and has a frame configuration signal 313 (error correction method used by the coding unit 302A for error correction coding of data, a coding rate, a block length, etc.). The information of the above is included, and the method specified by the frame configuration signal 313 is used. Further, the error correction method may be switched.) According to, for example, a convolution code, an LDPC code, a turbo code, etc. Error correction coding is performed, and the encoded data 303A is output.

The interleaver 304A receives the encoded data 303A and the frame configuration signal 313 as inputs, performs interleaving, that is, rearranging the order, and outputs the interleaved data 305A. (The interleaving method may be switched based on the frame configuration signal 313.)
The mapping unit 306A receives the interleaved data 305A and the frame configuration signal 313 as inputs, and performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Modulation), 64QAM (64 Quadrature) band modulation, etc. Output signal 307A. (The modulation method may be switched based on the frame configuration signal 313.)
FIG. 24 is an example of a mapping method in the IQ plane of the in-phase component I and the orthogonal component Q constituting the baseband signal in QPSK modulation. For example, as shown in FIG. 24A, when the input data is "00", I = 1.0 and Q = 1.0 are output, and similarly, when the input data is "01", I =. -1.0, Q = 1.0 is output, ..., Is output. FIG. 24 (B) is an example of a mapping method in the IQ plane of QPSK modulation different from that of FIG. 24 (A), and the difference between FIG. 24 (B) and FIG. 24 (A) is in FIG. 24 (A). The signal point shown in FIG. 24 (B) can be obtained by rotating the signal point around the origin. The method of rotating such a constellation is shown in Non-Patent Document 9 and Non-Patent Document 10, and even if the Cyclic Q Delay shown in Non-Patent Document 9 and Non-Patent Document 10 is applied. good. As another example from FIG. 24, FIG. 25 shows the signal point arrangement in the IQ plane at 16QAM, and an example corresponding to FIG. 24 (A) is FIG. 25 (A), FIG. 24 (B). An example corresponding to is shown in FIG. 25 (B).

The coding unit 302B receives information (data) 301B and a frame constituent signal 313 as inputs, and includes information such as a frame constituent signal 313 (error correction method to be used, a coding rate, a block length, etc.), and the frame constituent signal 313. The method specified by is used. Further, the error correction method may be switched.) For example, error correction coding such as a convolution code, LDPC code, turbo code, etc. is performed, and the data after encoding is performed. Output 303B.

The interleaver 304B receives the encoded data 303B and the frame configuration signal 313 as inputs, performs interleaving, that is, rearranging the order, and the interleaving data 305B.
Is output. (The interleaving method may be switched based on the frame configuration signal 313.)
The mapping unit 306B receives the interleaved data 305B and the frame configuration signal 313 as inputs, and performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Modulation), 64QAM (64 Quadrature) band modulation, etc. Output signal 307B. (The modulation method may be switched based on the frame configuration signal 313.)
The weighting synthesis information generation unit 314 receives the frame configuration signal 313 as an input, and outputs information 315 regarding the weighting synthesis method based on the frame configuration signal 313. The weighted synthesis method is characterized in that the weighted synthesis method is regularly switched.

The weighted synthesis unit 308A receives the baseband signal 307A, the baseband signal 307B, and the information 315 regarding the weighted synthesis method as inputs, and weights and synthesizes the baseband signal 307A and the baseband signal 307B based on the information 315 regarding the weighted synthesis method. The signal 309A after weighted synthesis is output. note that. The details of the weighted composition method will be described in detail later.

The radio unit 310A receives the signal 309A after weighted synthesis as an input, performs processing such as quadrature modulation, band limitation, frequency conversion, and amplification, outputs a transmission signal 311A, and outputs a transmission signal 511A as a radio wave from the antenna 312A. To.

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

FIG. 26 shows the configuration of the weighted composition unit. The baseband signal 307A is multiplied by w11 (t) to generate w11 (t) s1 (t) and multiplied by w21 (t) to generate w21 (t) s1 (t). Similarly, the baseband signal 307B is multiplied by w12 (t) to generate w12 (t) s2 (t) and multiplied by w22 (t) to generate w22 (t) s2 (t). Next, z1 (t) = w11 (t) s1 (t) + w12 (t) s2 (t) and z2 (t) = w21 (t) s1 (t) + w22 (t) s2 (t) are obtained.
note that. The details of the weighted composition method will be described in detail later.

The radio unit 310B receives the signal 309B after weighted synthesis as an input, performs processing such as quadrature modulation, band limitation, frequency conversion, and amplification, outputs the transmission signal 311B, and outputs the transmission signal 511B as a radio wave from the antenna 312B. To.

FIG. 4 shows a configuration example of the transmission device 400 different from that of FIG. In FIG. 4, a part different from FIG. 3 will be described.
The coding unit 402 receives the information (data) 401 and the frame configuration signal 313 as inputs, performs error correction coding based on the frame configuration signal 313, and outputs the encoded data 402.

The distribution unit 404 takes the coded data 403 as an input, distributes the data, and outputs the data 405A and the data 405B. Note that FIG. 4 describes the case where there is only one coding unit, but the present invention is not limited to this, and the coding unit is m (m is an integer of 1 or more), and the code created by each coding unit is used. The present invention can be similarly carried out in the case where the distribution unit outputs the conversion data separately into two systems of data.

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

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

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

The relationship between the modulated signal z1 (t) and the modulated signal z2 (t) transmitted by the transmitting device and the received signals r1 (t) and r2 (t) in the receiving device will be described.
In FIG. 5, 504 # 1 and 504 # 2 indicate a transmitting antenna in the transmitting device, 505 # 1 and 505 # 2 indicate a receiving antenna in the receiving device, and the transmitting device transmits the modulated signal z1 (t) to the transmitting antenna 504. # 1, the modulation signal z2 (t) is transmitted from the transmission antenna 504 # 2. At this time, it is assumed that the modulated signal z1 (t) and the modulated signal z2 (t) occupy the same (common) frequency (band). The channel fluctuations of each transmitting antenna of the transmitting device and each antenna of the receiving device are set to h11 (t), h12 (t), h21 (t), and h22 (t), respectively, and the reception antenna 505 # 1 of the receiving device receives. Assuming that the signal is r1 (t) and the received signal received by the receiving antenna 505 # 2 of the receiving device is r2 (t), the following relational expression is established.

FIG. 6 is a diagram related to the weighting method (precoding method) in the present embodiment, and the weighting synthesis unit 600 is a weighting synthesis unit in which both the weighting synthesis units 308A and 308B of FIG. 3 are integrated. be. As shown in FIG. 6, the streams s1 (t) and streams s2 (t) correspond to the baseband signals 307A and 307B of FIG. 3, that is, the base according to the mapping of the modulation scheme such as QPSK, 16QAM, 64QAM. Band signal common phase I and quadrature Q component. Then, as in the frame configuration of FIG. 6, the stream s1 (t) represents the signal of the symbol number u as s1 (u), the signal of the symbol number u + 1 as s1 (u + 1), and so on. Similarly, the stream s2 (t) represents the signal with the symbol number u as s2 (u), the signal with the symbol number u + 1 as s2 (u + 1), and so on. Then, the weighting synthesis unit 600 inputs the baseband signals 307A (s1 (t)) and 307B (s2 (t)) in FIG. 3 and the information 315 regarding the weighting information, and uses the weighting method according to the information 315 regarding the weighting information. Then, the signals 309A (z1 (t)) and 309B (z2 (t)) after the weighted synthesis of FIG. 3 are output. At this time,
z1 (t) and z2 (t) are represented as follows.
When the symbol number is 4i (i is an integer of 0 or more):

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

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

As described above, the weighted composition unit of FIG. 6 periodically switches the precoding weight in a 4-slot cycle. (However, although the method of regularly switching the precoding weight in 4 slots is used here, the number of slots that are regularly switched is not limited to 4 slots.)
By the way, Non-Patent Document 4 describes that the precoding weight is switched for each slot, and Non-Patent Document 4 is characterized by randomly switching the precoding weight. On the other hand, the present embodiment is characterized in that the precoding weights are regularly switched by providing a certain period, and in a 2-row 2-column precoding weight matrix composed of 4 precoding weights, 4 Each absolute value of one precoding weight is equal (1 / sqrt (2)), and the precoding weight matrix having this feature is regularly switched.

In the LOS environment, the use of a special precoding matrix may greatly improve the reception quality, but the special precoding matrix differs depending on the direct wave conditions. However, there is a certain rule in the LOS environment, and if a special precoding matrix is regularly switched according to this rule, the data reception quality is greatly improved. On the other hand, if the precoding matrix is switched randomly, there is a possibility that there will be precoding matrices other than the special precoding matrix mentioned above, and only the biased precoding matrix that is not suitable for the LOS environment will be used. There is also the possibility of precoding, which does not necessarily result in good reception quality in the LOS environment. Therefore, it is necessary to realize a precoding switching method suitable for the LOS environment, and the present invention proposes a precoding method related thereto.

FIG. 7 shows an example of the configuration of the receiving device 700 according to the present embodiment. The radio unit 703_X receives the received signal 702_X received by the antenna 701_X as an input, performs processing such as frequency conversion and orthogonal demodulation, and outputs the baseband signal 704_X.
The channel variation estimation unit 705_1 in the modulation signal z1 transmitted by the transmission device receives the baseband signal 704_X as an input, extracts the reference symbol 501_1 for channel estimation in FIG. 5, and obtains a value corresponding to h11 in the equation (36). Estimate and output the channel estimation signal 706_1.

The channel variation estimation unit 705_2 in the modulation signal z2 transmitted by the transmission device receives the baseband signal 704_X as an input, extracts the reference symbol 501_2 for channel estimation in FIG. 5, and obtains a value corresponding to h12 in the equation (36). Estimate and output the channel estimation signal 706_2.

The radio unit 703_Y receives the received signal 702_Y received by the antenna 701_Y as an input, performs processing such as frequency conversion and orthogonal demodulation, and outputs the baseband signal 704_Y.
The channel variation estimation unit 707_1 in the modulation signal z1 transmitted by the transmission device receives the baseband signal 704_Y as an input, extracts the reference symbol 501_1 for channel estimation in FIG. 5, and obtains a value corresponding to h21 in the equation (36). Estimate and output the channel estimation signal 708_1.

The channel variation estimation unit 707_2 in the modulation signal z2 transmitted by the transmission device takes the baseband signal 704_Y as an input, extracts the reference symbol 501_2 for channel estimation in FIG. 5, and obtains a value corresponding to h22 in the equation (36). Estimate and output the channel estimation signal 708_2.

The control information decoding unit 709 inputs the baseband signals 704_X and 704_Y, detects the symbol 500_1 for notifying the transmission method of FIG. 5, and outputs the signal 710 regarding the information of the transmission method notified by the transmission device.

The signal processing unit 711 receives the baseband signals 704_X, 704_Y, the channel estimation signals 706_1, 706_2, 708_1, 708_2, and the signal 710 related to the transmission method information notified by the transmission device as inputs, performs detection and decoding, and receives data. Outputs 712_1 and 712_2.

Next, the operation of the signal processing unit 711 of FIG. 7 will be described in detail. FIG. 8 shows an example of the configuration of the signal processing unit 711 according to the present embodiment. FIG. 8 mainly includes an INNER MIMO detection unit, a soft-in / soft-out decoder, and a weighting coefficient generation unit. The method of iterative decoding in this configuration is described in detail in Non-Patent Document 2 and Non-Patent Document 3, but the MIMO transmission method described in Non-Patent Document 2 and Non-Patent Document 3 is a spatial multiplex MIMO transmission method. However, the transmission method in the present embodiment is different from Non-Patent Document 2 and Non-Patent Document 3 in that it is a MIMO transmission method in which the precoding weight is changed with time. The (channel) matrix in the equation (36) is H (t), the precoding weight matrix in FIG. 6 is W (t) (however, the precoding weight matrix changes depending on t), and the reception vector is R (t) =. (R1 (t), r2 (t)) ^T , stream vector S (t) = (s1 (t), s2 (t)) If ^T , the following relational expression holds.

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

The INNNER MIMO detection unit 803 receives a signal 820 related to the information of the weighting coefficient as an input, and uses this signal to perform the calculation of the equation (41). Then, iterative detection / decoding will be performed, and the operation thereof will be described.

In the signal processing unit of FIG. 8, it is necessary to perform the processing method as shown in FIG. 10 in order to perform iterative decoding (repeated detection). 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, from the soft-in / soft-out decoder, one codeword (or one frame) of the modulated signal (stream) s1 and one codeword (or one frame) of the modulated signal (stream) s2 are each. The log-likelihood ratio of bits (LLR: Log-Likelihood Ratio) is obtained. Then, the detection / decoding is performed again using the LLR. This operation is performed multiple times (this operation is called iterative decoding (repeated detection)). Hereinafter, a method of creating a log-likelihood ratio (LLR) of a symbol at a specific time in one frame will be mainly described.

In FIG. 8, the storage unit 815 includes a baseband signal 801X (corresponding to the baseband signal 704_X in FIG. 7), a channel estimation signal group 802X (corresponding to the channel estimation signals 706_1 and 706_2 in FIG. 7), and a baseband. Signal 801Y (corresponding to the baseband signal 704_Y in FIG. 7), channel estimation signal group 802Y (channel estimation signal 7 in FIG. 7).
It corresponds to 08_1 and 708_2. ) Is used as an input, and H (t) W (t) in the equation (41) is executed (calculated) in order to realize iterative decoding (repeated detection), and the calculated matrix is stored as a modified channel signal group. Then, the storage unit 815 outputs the above signals as a baseband signal 816X, a modified channel estimation signal group 817X, a baseband signal 816Y, and a modified channel estimation signal group 817Y when necessary.

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

First, the INNER MIMO detection unit 803 executes H (t) W (t) from the channel estimation signal group 802X and the channel estimation signal group 802Y, and obtains a candidate signal point corresponding to the baseband signal 801X. The situation at that time is shown in FIG. In FIG. 11, ● (black circle) is a candidate signal point in the IQ plane, and since the modulation method is 16QAM, there are 256 candidate signal points. (However, since FIG. 11 shows an image diagram, 256 candidate signal points are not shown.) Here, the 4 bits transmitted by the modulated signal s1 are b0, b1, b2, b3, and the modulated signal s2. Assuming that the 4 bits to be transmitted are b4, b5, b6, and b7, there are candidate signal points corresponding to (b0, b1, b2, b3, b4, b5, b6, b7) in FIG. Then, the square Euclidean distance between the received signal point 1101 (corresponding to the baseband signal 801X) and each of the candidate signal points is obtained. Then, each square Euclidean distance is divided by the noise variance σ ² . Therefore, the value obtained by dividing the candidate signal point corresponding to (b0, b1, b2, b3, b4, b5, b6, _b7 ) and the Euclidean distance squared to the received signal point by the noise variance is EX (b0, b1, b2). , B3, b4, b5, b6, b7). The baseband signal and the modulated signals s1 and s2 are complex signals.

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

Then, EX (b0, b1, b2, b3, b4, b5, b6, b7) + _EY (b0, b1, b2, b3, b4, b5, b6, _b7 ) = E (b0, b1, b2, b3). , B4, b5, b6, b7).

The INNER MIMO detection unit 803 outputs E (b0, b1, b2, b3, b4, b5, b6, b7) as a signal 804.
The log-likelihood calculation unit 805A takes the signal 804 as an input, calculates the log-likelihood of the bits b0 and b1 and b2 and b3, and outputs the log-likelihood signal 806A. However, in the calculation of the log-likelihood, the log-likelihood when it is "1" and the log-likelihood when it is "0" are calculated. The calculation method is as shown in the formula (28), the formula (29), and the formula (30), and the details are shown in Non-Patent Document 2 and Non-Patent Document 3.

Similarly, the log-likelihood calculation unit 805B takes the signal 804 as an input, calculates the log-likelihood of the bits b4 and b5 and b6 and b7, and outputs the log-likelihood signal 806B.
The deinterleaver (807A) receives the log-likelihood signal 806A as an input, performs deinterleave corresponding to the interleaver (interleaver (304A) in FIG. 3), and outputs the log-likelihood signal 808A after deinterleave.

Similarly, the deinterleaver (807B) takes the log-likelihood signal 806B as an input, performs deinterleave corresponding to the interleaver (interleaver (304B) in FIG. 3), and outputs the log-likelihood signal 808B after deinterleave.

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

Similarly, the log-likelihood ratio calculation unit 809B takes the deinterleaved log-likelihood signal 808B as an input, and the log-likelihood ratio (LLR: Log-Likelihood Ratio) of the bits encoded by the encoder 302B of FIG. 3 is used. ) Is calculated, and the log-likelihood ratio signal 810B is output.

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

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

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

The INNER MIMO detection unit 803 inputs the baseband signal 816X, the modified channel estimation signal group 817X, the baseband signal 816Y, the modified channel estimation signal group 817Y, the log-likelihood ratio 814A after interleaving, and the log-likelihood ratio 814B after interleaving. 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 group 816Y, and the modified channel estimation signal group 817Y. Is used because there is a delay time due to repeated decoding.

The difference between the operation during repeated decoding of the INNER MIMO detection unit 803 and the operation during initial detection is that the log-likelihood ratio 814A after interleaving and the log-likelihood ratio 814B after interleaving are used for signal processing. Is. The INNNER MIMO detection unit 803 first obtains E (b0, b1, b2, b3, b4, b5, b6, b7) as in the case of initial detection. In addition, the coefficients corresponding to the equations (11) and (32) are obtained from the log-likelihood ratio 814A after interleaving and the log-likelihood ratio 914B after interleaving. And E (b0, b1, b
The values of 2, b3, b4, b5, b6, b7) are corrected using this obtained coefficient, and the value is set to E'(b0, b1, b2, b3, b4, b5, b6, b7), and the signal is signaled. Output as 804.

The log-likelihood calculation unit 805A takes the signal 804 as an input, calculates the log-likelihood of the bits b0 and b1 and b2 and b3, and outputs the log-likelihood signal 806A. However, in the calculation of the log-likelihood, the log-likelihood when it is "1" and the log-likelihood when it is "0" are calculated. The calculation method is as shown in the formula (31), the formula (number 32), the formula (33), the formula (34), and the formula (35), and is shown in Non-Patent Document 2 and Non-Patent Document 3. There is.

Similarly, the log-likelihood calculation unit 805B takes the signal 804 as an input, calculates the log-likelihood of the bits b4 and b5 and b6 and b7, and outputs the log-likelihood signal 806B. The operation after the demodulator is the same as the initial detection.

Note that FIG. 8 shows the configuration of the signal processing unit when performing repeated detection, but repeated detection is not necessarily an essential configuration for obtaining good reception quality, and is a configuration portion required only for repeated detection. , The configuration may not have interleavers 813A and 813B. At this time, the INNNER MIMO detection unit 803 does not perform repetitive detection.

Then, an important part in the present embodiment is to perform the calculation of H (t) W (t). As shown in Non-Patent Document 5 and the like, initial detection and repeated detection may be performed using QR decomposition.
Further, as shown in Non-Patent Document 11, even if the linear calculation of MMSE (Minimum Mean Square Error) and ZF (Zero Forcing) is performed based on H (t) W (t) and the initial detection is performed. good.

FIG. 9 has a signal processing unit configuration different from that of FIG. 8, and is a signal processing unit for the modulated signal transmitted by the transmission device of FIG. The difference from FIG. 8 is the number of soft-in / soft-out decoders, and the soft-in / soft-out decoder 901 receives the log-likelihood ratio signals 810A and 810B as inputs, performs decoding, and after decoding. The log-likelihood ratio 902 is output. The distribution unit 903 receives the log-likelihood ratio 902 after decoding as an input and distributes. For the other parts, the operation is the same as in FIG.

FIG. 12 shows the BER characteristics when the transmission method is the transmission method using the precoding weight of the present embodiment under the same conditions as in FIG. 29. FIG. 12 (A) shows the BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) without repeated detection (APP: a posterior productivity), and FIG. 12 (B) shows the repeat. It shows the BER characteristics of the detected Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (number of repetitions 5 times). Comparing FIGS. 12 and 29, it can be seen that when the transmission method of this embodiment is used, the BER characteristics when the rice factor is large are significantly improved compared to the BER characteristics when the spatial multiplex MIMO transmission is used. , The effectiveness of the method of this embodiment can be confirmed.

As described above, as in the present embodiment, when the transmitting device of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding weight is switched over time and the switching is performed regularly. In the LOS environment where the direct wave is dominant, the effect of improving the transmission quality can be obtained as compared with the case of using the conventional spatial multiplex MIMO transmission.

In the present embodiment, in particular, regarding the configuration of the receiving device, the operation is described by limiting the number of antennas, but the same can be performed even if the number of antennas increases. That is, the number of antennas in the receiving device does not affect the operation and effect of the present embodiment. Further, in the present embodiment, the LDPC code has been described as an example, but the present invention is not limited to this, and the decoding method is also limited to sum-produce decoding as a soft-in / soft-out decoder. There are other soft-in / soft-out decoding methods such as BCJR algorithm, SOVA algorithm, and Msx-log-MAP algorithm. Details are shown in Non-Patent Document 6.

Further, in the present embodiment, the single carrier method has been described as an example, but the present invention is not limited to this, and the same can be performed even when multi-carrier transmission is performed. Therefore, for example, a spectrum diffusion communication method, an OFDM (Orthogonal Frequency-Division Multiplexing) method, a SC-FDMA (Single Carrier Frequentity Division Accession Multiple Access), SC-OFDM (Single Circuit) patent, SC-OFDM (Single Circuit) The same can be performed when the wavelet OFDM method or the like shown in is used. Further, in the present embodiment, symbols other than the data symbols, for example, pilot symbols (preambles, unique words, etc.), symbols for transmitting control information, and the like may be arranged in the frame.

Hereinafter, as an example of the multi-carrier method, an example when the OFDM method is used will be described.
FIG. 13 shows the configuration of the transmission device when the OFDM method is used. In FIG. 13, the same reference numerals are given to those operating in the same manner as in FIG.

The OFDM system-related processing unit 1301A receives the weighted signal 309A as an input, performs OFDM system-related processing, and outputs a transmission signal 1302A. Similarly, the OFDM method-related processing unit 1301B takes the weighted signal 309B as an input and outputs a transmission signal 1302B.

FIG. 14 shows an example of the configuration of the OFDM system related processing units 1301A and 1301B and later in FIG. 13, and the parts related to 1301A to 312A in FIG. 13 are 1401A to 1410A and parts related to 1301B to 312B. Is 1401B to 1410B.

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

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

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

The rearrangement unit 1404B receives the parallel signal 1403B as an input, performs rearrangement, and outputs the rearranged signal 1405B. The rearrangement will be described in detail later.
The inverse fast Fourier transform unit 1406B takes the rearranged signal 1405B as an input, performs an inverse fast Fourier transform, and outputs the signal 1407B after the inverse Fourier transform.

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

Since the transmission device of FIG. 3 is not a transmission method using a multi-carrier, the precoding is switched so as to have four cycles as shown in FIG. 6, and the symbols after the precoding are arranged in the time axis direction. When a multi-carrier transmission method such as the OFDM method as shown in FIG. 13 is used, naturally, the precoded symbols are arranged in the time axis direction as shown in FIG. 3, and they are arranged for each (sub) carrier. In the case of the multi-carrier transmission method, a method of arranging the transmission in the frequency axis direction or using both the frequency axis and the time axis can be considered. Hereinafter, this point will be described.

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

Similarly, the symbols of the weighted signal 1401B input by the serial-parallel conversion unit 1402B are numbered in order as # 1, # 2, # 3, # 4, .... At this time, as shown in FIG. 15B, symbols # 1, # 2, # 3, # 4, ... Are arranged in order from carrier 0, and symbols # 1 to # 9 are arranged at time $ 1. After that, symbols # 10 to # 19 are arranged regularly, such as at time $ 2. The modulated signals z1 and z2 are complex signals.

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

As described above, when a multi-carrier transmission method such as an OFDM method is used, the symbols can be arranged in the frequency axis direction, unlike the case of single-carrier transmission. The arrangement of the symbols is not limited to the arrangement as shown in FIG. Other examples will be described with reference to FIGS. 16 and 17.

FIG. 16 shows an example of a symbol rearrangement method in the rearrangement portions 1401A and 1401B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which are different from those in FIG. 15, and FIG. 16A shows the modulation signal z1. 16 (B) shows a method of rearranging the symbols of the modulation signal z2. 16 (A) and 16 (B) are different from FIG. 15, in that the method of rearranging the symbols of the modulated signal z1 and the method of rearranging the symbols of the modulated signal z2 are different. In FIG. 16 (B), the symbol # 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 according to the same rules. At this time, similarly to FIG. 15, the symbol group 1601 and the symbol group 1602 shown in FIG. 16 are symbols for one cycle when the precoding weight switching method shown in FIG. 6 is used.

FIG. 17 shows an example of a symbol rearrangement method in the rearrangement units 1401A and 1401B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which are different from those in FIG. 15, and FIG. 17 (A) shows the modulation signal z1. A method of rearranging the symbols, FIG. 17B shows a method of rearranging the symbols of the modulated signal z2. The difference between FIGS. 17A and 17B is that the symbols are arranged in order on the carrier in FIG. 15, whereas the symbols are not arranged in order on the carrier in FIG. It is a point. As a matter of course, in FIG. 17, as in FIG. 16, the method of rearranging the symbols of the modulated signal z1 and the method of rearranging the modulated signal z2 may be different.

18 (A) shows an example of the symbol rearrangement method in the rearrangement part 1401A and 1401B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which are different from FIGS. 18 and 15, and FIG. 18A shows a modulation signal. A method of rearranging the symbols of z1 and FIG. 18B show a method of rearranging the symbols of the modulated signal z2. In FIGS. 15 to 17, the symbols are arranged in the frequency axis direction, but in FIG. 18, the symbols are arranged using both the frequency and the time axis.

In FIG. 6, an example of switching the precoding weight in 4 slots has been described, but here, a case of switching in 8 slots will be described as an example. The symbol group 1801 and the symbol group 1802 shown in FIG. 18 are symbols for one cycle (hence, 8 symbols) when the precoding weight switching method is used, and the symbol # 0 uses the precoding weight of the slot 8i. Symbol # 1 is a symbol when the precoding weight of slot 8i + 1 is used, symbol # 2 is a symbol when the precoding weight of slot 8i + 2 is used, and symbol # 3 is a symbol of slot 8i + 3. Symbol # 4 is a symbol when the precoding weight of slot 8i + 4 is used, and symbol # 5 is a symbol when the precoding weight of slot 8i + 5 is used. , Symbol # 6 is a symbol when the precoding weight of slot 8i + 6 is used, and symbol # 7 is a symbol when the precoding weight of slot 8i + 7 is used. Therefore, in symbol # x, when x mod 8 is 0, symbol # x is a symbol when the precoding weight of slot 8i is used, and when x mod 8 is 1, symbol # x is a pre of slot 8i + 1. The symbol when the coding weight is used, when x mod 8 is 2, the symbol # x is the symbol when the precoding weight of slot 8i + 2 is used, and when x mod 8 is 3, the symbol # x is. When x mod 8 is 4, the symbol # x is a symbol when the precoding weight of slot 8i + 3 is used, and when x mod 8 is 5, the symbol # x is a symbol when the precoding weight of slot 8i + 3 is used. Symbol # x is a symbol when the precoding weight of slot 8i + 5 is used, x mod 8 is 6, symbol # x is a symbol when the precoding weight of slot 8i + 6 is used, and x mod 8 is. At 7, symbol # x is a symbol when the precoding weight of slot 8i + 7 is used. In the arrangement of the symbols in FIG. 18, a total of 4 × 2 = 8 slots, 4 slots in the time axis direction and 2 slots in the frequency axis direction, are used to arrange symbols for one cycle. At this time, one cycle is arranged. The number of minute symbols is m × n symbols (that is, there are m × n types of precoding weights). The frequency axis slot (number of carriers) used to place symbols for one cycle is n, time. Assuming that the slot used in the axial direction is m, it is preferable that m> n. This is because the phase of the direct wave, the fluctuation in the time axis direction is gradual as compared with the fluctuation in the frequency axis direction. Therefore, since the precoding weight of the present embodiment is changed in order 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 precoding weight. Therefore, it is preferable to set m> n. In consideration of the above points, it is better to rearrange the symbols using both the frequency axis and the time axis as shown in FIG. 18 rather than rearranging the symbols only in the frequency axis direction or only in the time axis direction. Is likely to be stationary, and the effect of the present invention can be easily obtained. However, when arranging in the direction of the frequency axis, the fluctuation of the frequency axis is steep, so it may be possible to obtain diversity gain. It is not always the method.

FIG. 19 shows an example of a symbol rearrangement method in the rearrangement portions 1401A and 1401B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which are different from those in FIG. 18, and FIG. 19 (A) shows the modulation signal z1. 19 (B) shows a method of rearranging the symbols of the modulation signal z2. In FIG. 19, the symbols are arranged using both the frequency and the time axis as in FIG. 18, but the difference from FIG. 18 is that in FIG. 18, the frequency direction is prioritized and then the time axis direction. Whereas the symbols are arranged, in FIG. 19, the time axis direction is prioritized, and then the symbols are arranged in the time axis direction. In FIG. 19, the symbol group 1901 and the symbol group 1902 are symbols for one cycle when the precoding switching method is used.

It should be noted that, in FIGS. 18 and 19, similarly to FIG. 16, even if the symbol arrangement method of the modulation signal z1 and the symbol arrangement method of the modulation signal z2 are arranged differently, the same can be carried out, and it is expensive. The effect of being able to obtain reception quality can be obtained. Further, in FIGS. 18 and 19, even if the symbols are not arranged in order as in FIG. 17, the same can be performed, and the effect that high reception quality can be obtained can be obtained. can.

FIG. 27 shows an example of a symbol rearrangement method in the rearrangement portions 1401A and 140B of FIG. 14 in the horizontal axis frequency and the vertical axis time, which are different from the above. Consider a case where the precoding matrix is regularly switched using 4 slots such as those in equations (37) to (40). The characteristic point in FIG. 27 is that the symbols are arranged in order in the frequency axis direction, but when the symbols are advanced in the time axis direction, the symbols are cyclically shifted by n (n = 1 in the example of FIG. 27). Is. It is assumed that the precoding matrices of equations (37) to (40) are switched in the four symbols shown in the symbol group 2710 in the frequency axis direction in FIG. 27.

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

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

The precoding matrix was switched as described above for the symbol of time $ 1, but since it is cyclically shifted in the time axis direction, the symbols 2701, 2702, 2703, and 2704 are pre-coded as follows. The coding matrix will be switched.

In the symbol group 2701 in the time axis direction, the symbol of # 0 is precoded using the precoding matrix of Eq. (37), # 9 is precoded using the precoding matrix of Eq. (38), and # 18 is precoding using the precoding matrix of Eq. (38). Precoding using the precoding matrix of 39), and precoding using the precoding matrix of Eq. (40) in # 27 shall be performed.

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

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

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

The feature in FIG. 27 is that, for example, when focusing on the symbol of # 11, the symbols (# 10 and # 12) on both sides in the frequency axis direction at the same time are precoded using a precoding matrix different from that of # 11. And the symbols (# 2 and # 20) on both sides of the same carrier of the symbol of # 11 in the time axis direction are precoded using a precoding matrix different from that of # 11. be. And this is not limited to the symbol of # 11, and all the symbols having symbols on both sides in the frequency axis direction and the time axis direction have the same characteristics as the symbol of # 11. As a result, the precoding matrix is effectively switched, and it is less likely to be affected by the constant condition of the direct wave, so that the data reception quality is likely to be improved.

In FIG. 27, the description is made with n = 1, but the present invention is not limited to this, and the same can be performed with n = 3. Further, in FIG. 27, the above characteristics are realized by arranging the symbols on the frequency axis and cyclically shifting the order of the arrangement of the symbols when the time advances in the axial direction, but the symbols are random. There is also a method of realizing the above-mentioned characteristics by arranging them (which may be regular).

(Embodiment 2)
In the first embodiment, a case where the precoding weights as shown in FIG. 6 are regularly switched has been described, but in the present embodiment, a specific precoding weight design method different from the precoding weights in FIG. 6 has been described. Will be explained.

In FIG. 6, a method of switching the precoding weights of the equations (37) to (40) has been described. If this is generalized, the precoding weight can be changed as follows. (However, the switching cycle of the precoding weight is set to 4, and the same description as in equations (37) to (40) is used.)
When the symbol number is 4i (i is an integer of 0 or more):

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

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

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

When the symbol number is 4i + 1:

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

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

When the symbol number is 4i + 1:

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

However, in equations (50) to (53), it is assumed that A is a positive real number and q is a complex number. The values of A and q are determined according to the positional relationship between the transmitting device and the receiving device. Then, equations (50) to (53) are expressed as follows.
When the symbol number is 4i:

When the symbol number is 4i + 1:

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

Then, when q is expressed as follows, since the signal component based on either s1 or s2 is not included in r1 and r2, the signal of either s1 or s2 cannot be obtained.
When the symbol number is 4i:

When the symbol number is 4i + 1:

When the symbol number is 4i + 2:

When the symbol number is 4i + 3:

At this time, if q has the same solution in the symbol numbers 4i, 4i + 1, 4i + 2, and 4i + 3, the channel element of the direct wave does not fluctuate significantly, so that the reception has a channel element in which the value of q is equal to the above-mentioned same solution. Since the device cannot obtain good reception quality at any symbol number, it is difficult to obtain an error correction capability even if an error correction code is introduced. Therefore, in order for q not to have the same solution, focusing on the solution that does not include δ among the two solutions of q, the following conditions are required from equations (58) to (61). Will be.

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

As an example of satisfying condition # 1,
(Example # 1)
<1> θ11 (4i) = θ11 (4i + 1) = θ11 (4i + 2) = θ11 (4i + 3) = 0 radians.
<2> θ21 (4i) = 0 radians <3> θ21 (4i + 1) = π / 2 radians <4> θ21 (4i + 2) = π radians <5> θ21 (4i + 3) = 3π / 2 radians Be done. (The above is an example, and in the set of (θ21 (4i), θ21 (4i + 1), θ21 (4i + 2), θ21 (4i + 3)), 0 radian, π / 2 radian, π radian, and 3π / 2 radian are one. At this time, in particular, if the condition <1> is satisfied, it is not necessary to give signal processing (rotation processing) to the baseband signal S1 (t), so that the circuit scale can be reduced. It has the advantage of being able to be planned. As another example
(Example # 2)
<6> θ11 (4i) = 0 radians <7> θ11 (4i + 1) = π / 2 radians <8> θ11 (4i + 2) = π radians <9> θ11 (4i + 3) = 3π / 2 radians.
<10> A method of setting θ21 (4i) = θ21 (4i + 1) = θ21 (4i + 2) = θ21 (4i + 3) = 0 radians is also conceivable. (The above is an example, and in the set of (θ11 (4i), θ11 (4i + 1), θ11 (4i + 2), θ11 (4i + 3)), 0 radian, π / 2 radian, π radian, and 3π / 2 radian are one. At this time, in particular, if the condition <6> is satisfied, it is not necessary to give signal processing (rotation processing) to the baseband signal S2 (t), so that the circuit scale can be reduced. It has the advantage of being able to be planned. As yet another example, the following is given.
(Example # 3)
<11> θ11 (4i) = θ11 (4i + 1) = θ11 (4i + 2) = θ11 (4i + 3) = 0 radians.
<12> θ21 (4i) = 0 radians <13> θ21 (4i + 1) = π / 4 radians <14> θ21 (4i + 2) = π / 2 radians <15> θ21 (4i + 3) = 3π / 4 radians (the above is an example) In the set of (θ21 (4i), θ21 (4i + 1), θ21 (4i + 2), θ21 (4i + 3)), there are 0 radians, π / 4 radians, π / 2 radians, and 3π / 4 radians one by one. It should exist.)
(Example # 4)
<16> θ11 (4i) = 0 radians <17> θ11 (4i + 1) = π / 4 radians <18> θ11 (4i + 2) = π / 2 radians <19> θ11 (4i + 3) = 3π / 4 radians.
<20> θ21 (4i) = θ21 (4i + 1) = θ21 (4i + 2) = θ21 (4i + 3) = 0 radians (The above is an example, and (θ11 (4i), θ11 (4i + 1), θ11 (4i + 2), θ11 ( There may be one 0 radian, one π / 4 radian, one π / 2 radian, and one 3π / 4 radian in the set of 4i + 3)).)
Although four examples have been given, the method of satisfying condition # 1 is not limited to this.

Next, not only θ11 and θ12 but also design requirements for λ and δ will be described. It suffices to set a certain value for λ, and it is necessary to give a requirement for δ as a requirement. Therefore, a method of setting δ when λ is set to 0 radians will be described.

In this case, if π / 2 radians ≤ | δ | ≤ π radians with respect to δ, in particular, LOS
Good reception quality can be obtained in the environment.
By the way, in the symbol numbers 4i, 4i + 1, 4i + 2, and 4i + 3, there are two points of q having poor reception quality. Therefore, there are 2 × 4 = 8 points. In order to prevent the reception quality from deteriorating in a specific receiving terminal in the LOS environment, it is preferable that all eight points are different solutions. In this case, the condition of <condition # 2> is required in addition to <condition # 1>.

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

In the case of (Example # 1) and (Example # 2), by setting δ to ± 3π / 4 radians, the poor reception quality is uniformly present in phase. For example, assuming (Example # 1) and δ being 3π / 4 radians, there is a point that the reception quality deteriorates once in 4 slots as shown in FIG. 20 (A is a positive real number). In the case of (Example # 3) (Example # 4), by setting δ to ± π radian, the phase of poor reception quality can be uniformly present. For example, if (Example # 3) is set and δ is π radian, there is a point that the reception quality deteriorates once in 4 slots as shown in FIG. (If the element q in the channel matrix H exists at the points shown in FIGS. 20 and 21, the reception quality deteriorates.)
By doing the above, good reception quality can be obtained in the LOS environment. In the above, an example of changing the precoding weight in a 4-slot cycle has been described, but in the following, a case where the precoding weight is changed in an N-slot cycle will be described. Considering the same as that of the first embodiment and the above description, the processing as shown below is performed for the symbol number.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

Therefore, r1 and r2 are represented as follows.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

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

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

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

・
・
・
When the symbol number is Ni + N-1:

However, in equations (70) to (73), it is assumed that A is a real number and q is a complex number. The values of A and q are determined according to the positional relationship between the transmitting device and the receiving device. Then, equations (70) to (73) are expressed as follows.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

Then, when q is expressed as follows, since the signal component based on either s1 or s2 is not included in r1 and r2, the signal of either s1 or s2 cannot be obtained.
When the symbol number Ni (i is an integer of 0 or more):

When the symbol number is Ni + 1:

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

・
・
・
When the symbol number is Ni + N-1:

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

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

Next, not only θ11 and θ12 but also design requirements for λ and δ will be described. It suffices to set a certain value for λ, and it is necessary to give a requirement for δ as a requirement. Therefore, a method of setting δ when λ is set to 0 radians will be described.

In this case, as in the case of the method of changing the precoding weight in a 4-slot cycle, if π / 2 radians ≤ | δ | ≤ π radians for δ, good reception quality is obtained especially in the LOS environment. Obtainable.

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

In addition, it is preferable that the phases of these 2N points exist uniformly. (Because the phase of the direct wave in each receiving device is likely to be uniformly distributed)
As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding weight is switched over time and the switching is performed regularly, so that the LOS environment in which the direct wave is dominant is dominated. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional spatial multiplex MIMO transmission.

In the present embodiment, the configuration of the receiving device is as described in the first embodiment. In particular, regarding the configuration of the receiving device, the operation is described by limiting the number of antennas, but the number of antennas increases. Can be carried out in the same manner. That is, the number of antennas in the receiving device does not affect the operation and effect of the present embodiment. Further, in the present embodiment, the error correction code is not limited as in the first embodiment.

Further, in the present embodiment, the method of changing the precoding weight on the time axis has been described in comparison with the first embodiment, but as described in the first embodiment, the multi-carrier transmission method is used, and the frequency axis and frequency are used. -By arranging symbols on the time axis, the precoding weight can be changed in the same way. Further, in the present embodiment, symbols other than the data symbols, for example, pilot symbols (preambles, unique words, etc.), symbols for control information, and the like may be arranged in the frame.

(Embodiment 3)
In the first and second embodiments, the case where the amplitudes of the elements of the matrix of the precoding weights are equal in the method of regularly switching the precoding weights has been described, but in the present embodiment, this condition is satisfied. An example that does not exist will be described.

In order to compare with the second embodiment, a case where the precoding weight is changed in the N slot cycle will be described. Considering the same as that of the first embodiment and the second embodiment, the symbol number is processed as shown below. However, β is a positive real number, and β ≠ 1.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

Therefore, r1 and r2 are represented as follows.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

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

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

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

・
・
・
When the symbol number is Ni + N-1:

However, in equations (90) to (93), it is assumed that A is a real number and q is a complex number. Then, it is assumed that equations (90) to (93) are expressed as follows.
When the symbol number Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is Ni + N-1:

Then, when q is expressed as follows, either the signal of s1 or s2 cannot be obtained.
When the symbol number Ni (i is an integer of 0 or more):

When the symbol number is Ni + 1:

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

・
・
・
When the symbol number is Ni + N-1:

At this time, if q has the same solution in the symbol numbers N to Ni + N-1, the channel element of the direct wave does not have a large fluctuation, so that good reception quality cannot be obtained in any of the symbol numbers. Therefore, even if an error correction code is introduced, it is difficult to obtain an error correction capability. Therefore, in order for q not to have the same solution, focusing on the solution that does not include δ among the two solutions of q, the following conditions are required from equations (98) to (101). Will be.

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

Next, not only θ11 and θ12 but also design requirements for λ and δ will be described. It suffices to set a certain value for λ, and it is necessary to give a requirement for δ as a requirement. Therefore, a method of setting δ when λ is set to 0 radians will be described.

In this case, as in the case of the method of changing the precoding weight in a 4-slot cycle, if π / 2 radians ≤ | δ | ≤ π radians for δ, good reception quality is obtained especially in the LOS environment. Obtainable.

In the symbol numbers Ni to Ni + N-1, there are two points of q having poor reception quality, and therefore there are two points of points. In order to obtain good characteristics in the LOS environment, it is preferable that these 2N points are all different solutions. In this case, in addition to <condition # 5>, β is a positive real number, and considering that β ≠ 1, the condition of <condition # 6> is required.

As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding weight is switched over time and the switching is performed regularly, so that the LOS environment in which the direct wave is dominant is dominated. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional spatial multiplex MIMO transmission.

In the present embodiment, the configuration of the receiving device is as described in the first embodiment. In particular, regarding the configuration of the receiving device, the operation is described by limiting the number of antennas, but the number of antennas increases. Can be carried out in the same manner. That is, the number of antennas in the receiving device does not affect the operation and effect of the present embodiment. Further, in the present embodiment, the error correction code is not limited as in the first embodiment.

Further, in the present embodiment, the method of changing the precoding weight on the time axis has been described in comparison with the first embodiment, but as described in the first embodiment, the multi-carrier transmission method is used, and the frequency axis and frequency are used. -By arranging symbols on the time axis, the precoding weight can be changed in the same way. Further, in the present embodiment, symbols other than the data symbols, for example, pilot symbols (preambles, unique words, etc.), symbols for control information, and the like may be arranged in the frame.

(Embodiment 4)
In the third embodiment, in the method of regularly switching the precoding weights, the amplitude of each element of the precoding weight matrix is set to 1 and β.
The two types of cases described above have been described as an example.

In addition, here,

Is ignoring.

Next, an example of switching the β value in the slot will be described.
In order to compare with the third embodiment, a case where the precoding weight is changed in a 2 × N slot period will be described.

Considering in the same manner as in the first embodiment, the second embodiment, and the third embodiment, the symbol number is processed as shown below. However, β is a positive real number, and β ≠ 1. Also, α is a positive real number, and α ≠ β.
When the symbol number is 2Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is 2Ni + N-1:

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

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

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

・
・
・
When the symbol number is 2Ni + 2N-1:

Therefore, r1 and r2 are represented as follows.
When the symbol number is 2Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is 2Ni + N-1:

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

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

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

・
・
・
When the symbol number is 2Ni + 2N-1:

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

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

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

・
・
・
When the symbol number is 2Ni + N-1:

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

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

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

・
・
・
When the symbol number is 2Ni + 2N-1:

However, in equations (118) to (125), it is assumed that A is a real number and q is a complex number. Then, equations (118) to (125) are expressed as follows.
When the symbol number is 2Ni (i is an integer of 0 or more):

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

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

・
・
・
When the symbol number is 2Ni + N-1:

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

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

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

・
・
・
When the symbol number is 2Ni + 2N-1:

Then, when q is expressed as follows, either the signal of s1 or s2 cannot be obtained.
When the symbol number is 2Ni (i is an integer of 0 or more):

When the symbol number is 2Ni + 1:

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

・
・
・
When the symbol number is 2Ni + N-1:

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

When the symbol number is 2Ni + N + 1:

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

・
・
・
When the symbol number is 2Ni + 2N-1:

At this time, if q has the same solution in the symbol numbers 2N to 2Ni + N-1, the channel element of the direct wave does not have a large fluctuation, so that good reception quality cannot be obtained in any of the symbol numbers. Therefore, even if an error correction code is introduced, it is difficult to obtain an error correction capability. Therefore, in order for q not to have the same solution, focusing on the solution that does not include δ among the two solutions of q, from equations (134) to (141) and α ≠ β, <Condition # 7> or <Condition # 8> is required.

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

Next, not only θ11 and θ12 but also design requirements for λ and δ will be described. It suffices to set a certain value for λ, and it is necessary to give a requirement for δ as a requirement. Therefore, a method of setting δ when λ is set to 0 radians will be described.

In this case, as in the case of the method of changing the precoding weight in a 4-slot cycle, if π / 2 radians ≤ | δ | ≤ π radians for δ, good reception quality is obtained especially in the LOS environment. Obtainable.

In the symbol numbers 2Ni to 2Ni + 2N-1, there are two points of q having poor reception quality, and therefore there are points of 4N points. In order to obtain good characteristics in the LOS environment, it is preferable that these 4N points are all different solutions. At this time, focusing on the amplitude, since α ≠ β for <condition # 7> or <condition # 8>, the following conditions are required.

As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding weight is switched over time and the switching is performed regularly, so that the LOS environment in which the direct wave is dominant is dominated. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional spatial multiplex MIMO transmission.

In the present embodiment, the configuration of the receiving device is as described in the first embodiment. In particular, regarding the configuration of the receiving device, the operation is described by limiting the number of antennas, but the number of antennas increases. Can be carried out in the same manner. That is, the number of antennas in the receiving device does not affect the operation and effect of the present embodiment. Further, in the present embodiment, the error correction code is not limited as in the first embodiment.

Further, in the present embodiment, the method of changing the precoding weight on the time axis has been described in comparison with the first embodiment, but as described in the first embodiment, the multi-carrier transmission method is used, and the frequency axis and frequency are used. -By arranging symbols on the time axis, it can be implemented in the same way even if the precoding weight is changed. Further, in the present embodiment, symbols other than the data symbols, for example, pilot symbols (preambles, unique words, etc.), symbols for control information, and the like may be arranged in the frame.

(Embodiment 5)
In the first to fourth embodiments, a method of regularly switching the precoding weights has been described, but in the present embodiment, a modified example thereof will be described.

In the first to fourth embodiments, a method of regularly switching the precoding weights as shown in FIG. 6 has been described. In the present embodiment, a method of regularly switching the precoding weights, which is different from that in FIG. 6, will be described.

Similar to FIG. 6, FIG. 22 shows a diagram relating to a switching method different from that of FIG. 6 in a method of switching four different precoding weights (matrix). In FIG. 22, four different precoding weights (matrix) are represented as W ₁ , W ₂ , W ₃ , and W ₄ . ((
For example, W ₁ is the precoding weight (matrix) in the equation (37), W ₂ is the precoding weight (matrix) in the equation (38), W ₃ is the precoding weight (matrix) in the equation (39), and W ₄ is. It is a precoding weight (matrix) in the equation (40). ) And those that operate in the same manner as in FIGS. 3 and 6 are designated by the same reference numerals. In FIG. 22, the unique part is
The first cycle 2201, the second cycle 2202, the third cycle 2203, ... Are all composed of 4 slots.
-In 4 slots, a different precoding weight matrix for each slot, that is, W ₁ , W ₂ , W ₃ , and W ₄ are used once.
-In the first cycle 2201, the second cycle 2202, the third cycle 2203, ..., The order of W ₁ , W ₂ , W ₃ , and W ₄ does not necessarily have to be the same.
Is. In order to realize this, the precoding weight matrix generation unit 2200 takes a signal regarding the weighting method as an input, and outputs information 2210 regarding the precoding weight according to the order in each cycle. Then, the weighting synthesis unit 600 takes this signal and s1 (t) and s2 (t) as inputs, performs weighting synthesis, and outputs z1 (t) and z2 (t).

FIG. 23 shows a weighted synthesis method with respect to FIG. 22 as opposed to the above-mentioned precoding method. In FIG. 23, the difference in FIG. 22 is that the same method as in FIG. 22 is realized by arranging the rearrangement unit after the weighting synthesis unit and rearranging the signals.

In FIG. 23, the precoding weight generation unit 2200 inputs information 315 regarding the weighting method, and the precoding weights W ₁ , W ₂ , W ₃ , W _4, W ₁ , W ₂ , W ₃ , W _4, ... -The precoding weight information 2210 is output in the order of. Therefore, the weighting synthesis unit 600 uses the precoding weights W ₁ , W ₂ , W ₃ , W _4, W ₁ , W ₂ , W ₃ , W _4, ... In this order, and after precoding. The signals 2300A and 2300B are output.

The rearrangement unit 2300 receives the precoded signals 2300A and 2300B as inputs, and the precoded signals are in the order of the first cycle 2201, the second cycle 2202, and the third cycle 2203 in FIG. Sorting is performed for 2300A and 2300B, and z1 (t) and z2 (t) are output.

In the above, the switching cycle of the precoding weight has been described as 4 in order to compare it with FIG. 6, but it can be similarly carried out at times other than the cycle 4 as in the first to fourth embodiments. It is possible.

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

As described above, when the transmitter of the MIMO transmission system transmits a plurality of modulated signals from a plurality of antennas, the precoding weight is switched over time and the switching is performed regularly, so that the LOS environment in which the direct wave is dominant is dominated. In the above, it is possible to obtain the effect of improving the transmission quality as compared with the case of using the conventional spatial multiplex MIMO transmission.

In the present embodiment, the configuration of the receiving device is as described in the first embodiment. In particular, regarding the configuration of the receiving device, the operation is described by limiting the number of antennas, but the number of antennas increases. Can be carried out in the same manner. That is, the number of antennas in the receiving device does not affect the operation and effect of the present embodiment. Further, in the present embodiment, the error correction code is not limited as in the first embodiment.

Further, in the present embodiment, the method of changing the precoding weight on the time axis has been described in comparison with the first embodiment, but as described in the first embodiment, the multi-carrier transmission method is used, and the frequency axis and frequency are used. -By arranging symbols on the time axis, the precoding weight can be changed in the same way. Further, in the present embodiment, symbols other than the data symbols, for example, pilot symbols (preambles, unique words, etc.), symbols for control information, and the like may be arranged in the frame.

(Embodiment 6)
Although the method of regularly switching the precoding weights has been described in the first to fourth embodiments, in the present embodiment, the precoding weights are regularly switched again including the contents described in the first to fourth embodiments. The method of switching is explained.

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

FIG. 30 shows a spatially multiplexed 2x2 MIMO system model to which precoding is applied in which there is no feedback from the communication partner. The information vector z is coded and interleaved. Then, as the output of the interleave, the vector u (p) = (u ₁ (p), u ₂ (p)) of the encoded bits is obtained (p is the slot time). However, u _i (p) = (u _i1 (p)…, u _ih (p)) (h: number of transmission bits per symbol). If the signal after modulation (after mapping) is s (p) = (s ₁ (p), s ₂ (p)) ^T , and if the precoding matrix is F (p), the signal after precoding x (p) = (x ₁ (p), x ₂ (p)) ^T is expressed by the following equation.

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

At this time, H (p) is the channel matrix, n (p) = (n ₁ (p), n ₂ (p)) ^T is the noise vector, n _i (p) is the mean value 0, and the variance σ ² iid complex Gaussian noise. Then, when the rice factor is K, the above equation can be expressed as follows.

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

In equation (145), it is assumed that the environment of the direct wave is uniquely determined by the positional relationship between the communication devices, and the channel matrix H _d (p) of the direct wave component does not fluctuate in time. In addition, the channel matrix H _d (p) of the direct wave component is a regular matrix of the channel matrix of the direct wave component because there is a high possibility that the distance between the transmitter and receiver will be sufficiently longer than the transmission antenna interval. And. Therefore, the channel matrix H _d (p) is expressed as follows.

Here, it is assumed that A is a positive real number and q is a complex number. In the following, we describe how to design the precoding matrix of a spatially multiplexed 2x2 MIMO system that applies precoding that does not have feedback from the communication partner, considering the LOS environment.

From the equations (144) and (145), it is difficult to analyze the state including the scattered wave, so that it is difficult to obtain the precoding matrix without the appropriate feedback in the state containing the scattered wave. In addition, the NLOS environment has less deterioration in data reception quality than the LOS environment. Therefore, the design method of the precoding matrix without appropriate feedback in the LOS environment (precoding matrix of the precoding method of switching the precoding matrix with time) will be described.

As described above, since it is difficult to analyze the state including the scattered wave from the equations (144) and (145), an appropriate precoding matrix should be obtained in the channel matrix containing only the direct wave component. To. Therefore, in Eq. (144), consider the case where the channel matrix contains only the direct wave component. Therefore, it can be expressed as follows from the equation (146).

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

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

As can be seen from equation (149), when the receiver performs a linear operation of ZF (zero forcing) or MMSE (minimum mean squared error), the bits transmitted by s ₁ (p) and s ₂ (p) are determined. You can't. For this reason, the iterative APP (or iterative Max-log APP) or APP (or Max-log APP) as described in the first embodiment is performed (hereinafter referred to as ML (Maximum Likelihood) operation), and s. The log-likelihood ratio of each bit transmitted in ₁ (p) and s ₂ (p) is obtained, and decoding is performed with the error correction code. Therefore, a method of designing a precoding matrix without appropriate feedback in the LOS environment for a receiver performing ML operation will be described.

Consider the precoding in equation (149). Multiply the right and left sides of the first line by e ^-jΨ , and similarly multiply the right and left sides of the second line by e ^-jΨ . Then, it is expressed as the following equation.

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

Next, the equation (151) is transformed into the equation (152) so as to be easy to understand.

At this time, when the minimum value of the Euclidean distance between the received signal point and the received candidate signal point is d _min ² , it is a bad point that d _min ² takes the minimum value of zero, and it is transmitted at s ₁ (p). There are two qs that are in a bad state where all the bits or all the bits transmitted by s ₂ (p) are lost.

S ₁ (p) does not exist in equation (152):

S ₂ (p) does not exist in equation (152):

(Hereafter, q that satisfies equations (153) and (154) is "reception inferior point of s ₁ and s ₂ , respectively".
Call)
When the equation (153) is satisfied, since all the bits transmitted by s ₁ (p) are lost, the received log-likelihood ratio of all the bits transmitted by s ₁ (p) cannot be obtained, and the equation (154) cannot be obtained. ), Since all the bits transmitted by s ₂ (p) are lost, the received log-likelihood ratio of all the bits transmitted by s ₂ (p) cannot be obtained.

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

The situation of direct waves between the base station and the terminal is considered to change little with time. Then, from equations (153) and (154), a terminal in an LOS environment that is in a position that meets the conditions of equation (155) or equation (156) and has a large rice factor is said to have deteriorated data reception quality. There is a possibility of falling into a phenomenon. Therefore, in order to improve this problem, it is necessary to switch the precoding matrix in time.

Therefore, consider a method (hereinafter referred to as a precoding hopping method) in which the time period is set to N slots and the precoding matrix is regularly switched.
For the time period N slot, N kinds of precoding matrices F [i] based on the equation (148) are prepared (i = 0,1, ..., N-1). At this time, the precoding matrix F [i] is expressed as follows.

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

At this time, based on the equations (153) and (154), the following precoding matrix design conditions for precoding hopping are important.

According to <Condition # 10>, in all Γ terminals, the number of slots that take the reception poor point of s ₁ at N in the time cycle is 1 slot or less. Therefore, the log-likelihood ratio of the bits transmitted in s ₁ (p) over the N-1 slot can be obtained. Similarly, according to <Condition # 11>, in all Γ terminals, the number of slots that take the reception poor point of s ₂ at N in the time cycle is 1 slot or less. Therefore, the log-likelihood ratio of the bits transmitted in s ₂ (p) over the N-1 slot can be obtained.

In this way, by giving the design norms of the precoding matrix of <condition # 10> and <condition # 11>, the number of bits from which the logarithmic likelihood ratio of the bits transmitted in s ₁ (p) can be obtained, and s. By guaranteeing the number of bits from which the logarithmic likelihood ratio of the bits transmitted in ₂ (p) can be obtained to a certain number or more in all Γ terminals, the data in the LOS environment where the rice factor is large in all Γ terminals. Consider improving the deterioration of reception quality.

The following describes an example of the precoding matrix in the precoding hopping method.
The probability density distribution of the phase of the direct wave can be considered to be a uniform distribution of [0 2π]. Therefore, it can be considered that the probability density distribution of the phase of q in Eqs. (151) and (152) is also a uniform distribution of [0 2π]. Therefore, in the same LOS environment where only the phase of q is different, the following are given as conditions for giving as fair data reception quality as possible to Γ terminals.
<Condition # 12>
When the precoding hopping method of the time cycle N slot is used, the reception poor points of s ₁ are arranged so as to be uniformly distributed with respect to the phase at N in the time cycle, and the reception poor points of s ₂ are set. Arrange so that the distribution is uniform with respect to the phase.

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

However, j is an imaginary unit, and i = 0,1, ..., 7. Instead of Eq. (160), Eq. (161) may be given (λ, θ ₁₁ [i] shall not change over time (may change).
).

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

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

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

However, j is an imaginary unit, and i = 0,1,2,3. Equation (166) instead of Equation (165)
) May be given (λ, θ ₁₁ [i] shall not change over time (may change).
).

Therefore, the reception inferior points of s ₁ and s ₂ are as shown in FIG. (In FIG. 32, the horizontal axis is the real axis and the vertical axis is the imaginary axis.) Further, the equations (167) and (168) may be given instead of the equations (165) and (166) (i). = 0,1,2,3) (λ, θ ₁₁ [i] shall not change over time (may change)).

Next, a precoding hopping method using a non-unitary matrix will be described.
Based on Eq. (148), the precoding matrix dealt with in this study is expressed as follows.

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

At this time, there are two qs in which the minimum value d _min ² of the Euclidean distance between the received signal point and the received candidate signal point is zero.
S ₁ (p) does not exist in equation (171):

S ₂ (p) does not exist in equation (171):

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

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

(Example # 7)
Let α = 1.0 of the precoding matrix in equation (174). Then, set the time cycle N = 16
In order to satisfy <Condition # 12>, <Condition # 14>, and <Condition # 15>, a precoding matrix in the precoding hopping method having a time period N = 8 as shown in the following equation is given.

When i = 0,1,…, 7:

When i = 8,9,…,15:

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

When i = 8,9,…,15:

Therefore, the reception inferior points of s ₁ and s ₂ are as shown in FIGS. 33 (a) and 33 (b).
(In FIG. 33, the horizontal axis is the real axis and the vertical axis is the imaginary axis.) Also, instead of the equation (177), the equation (178), the equation (179), and the equation (180), the precoding is as follows. You may give a matrix.

When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

(Also, in equations (177) to (184), 7π / 8 may be -7π / 8).
Next, in the same LOS environment where only the phase of q is different, which is different from <Condition # 12>, the following are given as conditions for giving as fair data reception quality as possible to Γ terminals. ..
<Condition # 16>
When using the precoding hopping method of the time cycle N slot,

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

However, i = 0,1, ..., 7.
Further, as a precoding matrix different from the equation (186), it can be given as follows (i = 0,1, ..., 7) (λ, θ ₁₁ [i] does not change with time (i). May change).).

Therefore, the reception inferior points of s ₁ and s ₂ are as shown in FIG. 34. Further, instead of the equations (186) and (187), a precoding matrix may be given as follows (i = 0,1, ..., 7) (λ, θ ₁₁ [i] changes with time. Not (may change).

or,

(Also, in equations (186) to (189), 7π / 8 may be changed to -7π / 8.)
Next, in the precoding matrix of Eq. (174), α ≠ 1, and the precoding hopping method different from that of (Example # 7) and (Example # 8) in which the point of the distance between the reception inferior points in the complex plane is taken into consideration. think.

Here, the precoding hopping method of the time cycle N of the equation (174) is dealt with. At this time, according to <condition # 14>, s ₁ is received at N within the time cycle at all Γ terminals. The number of slots that take inferior points is 1 slot or less. Therefore, the log-likelihood ratio of the bits transmitted in s ₁ (p) over the N-1 slot can be obtained. Similarly, <condition # 15>
As a result, in all Γ terminals, the number of slots that take the reception poor point of s ₂ is 1 slot or less in N within the time cycle. Therefore, the log-likelihood ratio of the bits transmitted in s ₂ (p) over the N-1 slot can be obtained.

Therefore, it can be seen that the larger the time period N is, the larger the number of slots from which the log-likelihood ratio can be obtained.
By the way, in the actual channel model, since it is affected by the scattered wave component, when the time period N is fixed, the data reception quality is improved when the minimum distance on the complex plane of the reception inferior point is as large as possible. It seems possible. Therefore, in (Example # 7) and (Example # 8), α ≠ 1, and consider an improved precoding hopping method in (Example # 7) and (Example # 8). First, an improved precoding method (Example # 8) that is easy to understand will be described.
(Example # 9)
From equation (186), the precoding matrix in the precoding hopping method with a time period N = 8 improved from (Example # 7) is given by the following equation.

However, i = 0,1, ..., 7. Further, as a precoding matrix different from Eq. (190), it can be given as follows (i = 0,1, ..., 7) (λ, θ ₁₁ [i] does not change with time (it is assumed). May change).).

or,

or,

or,

or,

or,

or,

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

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

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

(ii) When α> 1.0 When α> 1.0, the minimum distance of the reception inferior point in the complex plane is the distance between the reception inferior points # 4 and # 5 (d _{# 4, # 5} ) and the reception inferior point # 4. Focusing on the distance between and # 6 (d _{# 4, # 6} ), min {d _{# 4,}
It is expressed as _{# 5} , d _{# 4, # 6} }. At this time, the relationship between α and d _{# 4, # 5} and d _{# 4, # 6} is shown in FIG. 37. And α that maximizes min {d _{# 4, # 5} , d _{# 4, # 6} } is

Will be. At this time, min {d _{# 4, # 5} , d _{# 4, # 6} } is

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

When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

or,
When i = 0,1,…, 7:

When i = 8,9,…,15:

However, α is suitable for obtaining good data reception quality when it becomes the formula (198) or the formula (200). At this time, the poor reception of s ₁ is shown in FIGS. 38 (a) (b) when α <1.0 and in FIGS. 39 (a) (b) when α> 1.0.

In this embodiment, a method of constructing N different precoding matrices for a precoding hopping method having a time period N has been described. At this time, F [0], F [1], F [2], ..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [N-2], F [N-1] have been described in this order, but the present invention is not limited to this, and N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [N-2], F [N-1] can also be applied to a multi-carrier transmission method such as an OFDM transmission method. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method having a time period N, the same effect can be obtained by randomly using N different precoding matrices, that is, a regular period is not always used. You don't have to use N different precoding matrices to have.

Examples # 5 to # 10 are shown based on <Condition # 10> to <Condition # 16>, but in order to lengthen the switching cycle of the precoding matrix, for example, from Example # 5 to Example # 10 to a plurality. An example may be selected and a long-period precoding matrix switching method may be realized by using the precoding matrix shown in the selected example. For example, the precoding matrix shown in Example # 7 and the precoding matrix shown in Example # 10 are used to realize a long-period precoding matrix switching method. In this case, it does not always follow <Condition # 10> to <Condition # 16>. (<Condition # 10> formula (158), <Condition # 11> formula (159), <Condition # 13> formula (164), <Condition # 14> formula (175), <Condition # 15> In the equation (176) of the above, the condition of "x of existence, y of existence" is important in order to give good reception quality, where "all x, all y" is used. From another point of view, it is good if any of the precoding matrices of Examples # 5 to # 10 is included in the precoding matrix switching method of period N (N is a large natural number). It is more likely to give good reception quality.
(Embodiment 7)
In the present embodiment, the configuration of the receiving device for receiving the modulated signal transmitted by the transmission method for regularly switching the precoding matrix described in the first to sixth embodiments will be described.

In the first embodiment, a transmitting device that transmits a modulated signal using a transmission method that periodically switches the precoding matrix transmits information about the precoding matrix, and a receiving device uses the information for a transmission frame based on the information. The method of obtaining the regular precoding matrix switching information, decoding the precoding, performing detection, obtaining the log-possibility ratio of the transmission bit, and then performing error correction decoding has been described.

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

When one encoder operates, the transmit bit (4001) is encoded to obtain the encoded transmit bit, and the encoded transmit bit is distributed and distributed to the two systems. The encoder group (4002) outputs the bits (4003A) and the distributed bits (4003B).

When two encoders operate, the transmission bit (4001) is divided into two (named division bits A and B), and the first encoder receives the division bit A as an input and encodes. Then, the encoded bits are output as distributed bits (4003A). The second encoder takes the divided bit B as an input, performs encoding, and outputs the encoded bit as a distributed bit (4003B).

When the four encoders operate, the transmission bit (4001) is divided into four (named the division bits A, B, C, and D), and the first encoder receives the division bit A as an input. , Encoding is performed, and the encoded bit A is output. The second encoder takes the divided bit B as an input, performs coding, and outputs the encoded bit B. The third encoder takes the divided bit C as an input, performs coding, and outputs the coded bit C. The fourth encoder takes the divided bit D as an input, performs coding, and outputs the coded bit D. Then, the encoded bits A, B, C, and D are divided into distributed bits (4003A) and distributed bits (4003B).

As an example, the transmission device will support the transmission methods as shown in Table 1 (Table 1A and Table 1B) below.

As shown in Table 1, as the number of transmission signals (number of transmission antennas), transmission of one stream of signals and transmission of two streams of signals are supported. The modulation scheme also supports QPSK, 16QAM, 64QAM, 256QAM and 1024QAM. In particular, when the number of transmission signals is 2, the modulation method can be set separately for stream # 1 and stream # 2.
For example, in Table 1, "# 1: 256QAM, # 2: 1024QAM" indicates that "the modulation method of stream # 1 is 256QAM, and the modulation method of stream # 2 is 1024QAM" (the other expressions are expressed in the same manner). is doing). It is assumed that three types of error correction coding methods, A, B, and C, are supported. At this time, A, B, and C may all have different codes, A, B, and C may have different coding rates, and A, B, and C may have different block size coding methods. May be.

For the transmission information in Table 1, each transmission information is assigned to each mode in which the "number of transmission signals", "modulation method", "number of encoders", and "error correction coding method" are defined. Therefore, for example, in the case of "number of transmission signals: 2", "modulation method: # 1: 1024QAM, # 2: 1024QAM", "number of encoders: 4", and "error correction coding method: C", the transmission information is set to 01001101. Set. Then, the transmission device transmits the transmission information and the transmission data in the frame. Then, when transmitting the transmission data, particularly when the "number of transmission signals" is 2, the "precoding matrix switching method" is used according to Table 1. In Table 1, five types of "precoding matrix switching method", D, E, F, G, and H, are prepared, and one of these five types is set according to Table 1. .. At this time, as five different realization methods,
・ Prepare and realize 5 types with different precoding matrices.
-It is realized by setting five different types of cycles, for example, the period of D to 4, the period of E to 8, and so on.
-It is realized by using both different precoding matrices and different periods together.
Etc. are conceivable.

FIG. 41 shows an example of a frame configuration of a modulated signal transmitted by the transmitting device of FIG. 40, and the transmitting device sets a mode for transmitting two modulated signals z1 (t) and z2 (t). It is assumed that both the mode for transmitting one modulated signal and the mode for transmitting one modulated signal can be set.

In FIG. 41, the symbol (4100) is a symbol for transmitting the “transmission information” shown in Table 1. The symbols (4101-1 and 4101_2) are reference (pilot) symbols for channel estimation. The symbol (4102_1, 4103_1) is a symbol for data transmission transmitted by the modulation signal z1 (t), and the symbol (4102_1, 4103_1) is a symbol for data transmission transmitted by the modulation signal z2 (t). 4102_1) and the symbol (4102_2) are transmitted at the same time using the same (common) frequency, and the symbol (4103_1) and the symbol (4103_1) are transmitted using the same (common) frequency at the same time. The symbols (4102_1, 4103_1) and the symbols (4102_1, 4103_1) are pre-programmed when the method of regularly switching the precoding matrix described in the first to fourth embodiments and the sixth embodiment is used. It becomes a symbol after the coding matrix operation (hence, as described in the first embodiment, the configuration of the streams s1 (t) and s2 (t) is as shown in FIG. 6).
Further, in FIG. 41, the symbol (4104) is a symbol for transmitting the "transmission information" shown in Table 1. Symbol (4105) is a reference (pilot) symbol for channel estimation. The symbol (4106, 4107) is a symbol for data transmission transmitted by the modulated signal z1 (t), and at this time, the symbol for data transmission transmitted by the modulated signal z1 (t) has one transmission signal. , Precoding is not done.

Therefore, the transmitting device of FIG. 40 generates and transmits the modulated signal according to the frame configuration of FIG. 41 and Table 1. In FIG. 40, the frame configuration signal 313 includes information regarding the “number of transmitted signals”, “modulation method”, “number of encoders”, and “error correction coding method” set based on Table 1. Then, the coding unit (4002), the mapping units 306A, B, and the weighting synthesis units 308A, B take the frame configuration signal as an input, and set the "number of transmission signals", "modulation method", and "encoder" based on Table 1. The operation is performed based on "number" and "error correction coding method". Further, the "transmission information" corresponding to the set "number of transmission signals", "modulation method", "number of encoders", and "error correction coding method" is also transmitted to the receiving device.

The configuration of the receiving device can be represented by FIG. 7 as in the first embodiment. The difference from the first embodiment is that the information in Table 1 is shared in advance by the transmission / reception device, so that the transmission device does not need to transmit the information of the precoding matrix to be regularly switched, but the “number of transmission signals”. The transmitting device transmits "transmission information" corresponding to the "modulation method", "number of encoders", and "error correction coding method", and the receiving device obtains this information to periodically switch from Table 1 to the pre. The point is that information on the coding matrix can be obtained. Therefore, in the receiving device of FIG. 7, the control information decoding unit 709 obtains the "transmission information" transmitted by the transmitting device of FIG. 40, and the information of the precoding matrix that is regularly switched from the information corresponding to Table 1 is obtained. It is possible to obtain a signal 710 regarding the information of the transmission method notified by the transmission device including. Therefore, when the number of transmission signals is 2, the signal processing unit 711 can perform detection based on the switching pattern of the precoding matrix, and can obtain the received log-likelihood ratio.

In the above, as shown in Table 1, "transmission information" is set for "number of transmission signals", "modulation method", "number of encoders", and "error correction coding method", and precoding is performed for this. Although the matrix switching method is set, it is not always necessary to set "transmission information" for "number of transmission signals", "modulation method", "number of encoders", and "error correction coding method", for example. , As shown in Table 2, "transmission information" may be set for "number of transmission signals" and "modulation method", and a precoding matrix switching method may be set for this.

Here, the setting method of the "transmission information" and the precoding matrix switching method is not limited to Table 1 and Table 2, and the precoding matrix switching method includes "number of transmission signals", "modulation method", and "code". If the rules are predetermined to switch based on the transmission parameters such as "number of converters" and "error correction coding method" (if the transmitters and receivers share the predetermined rules), (That is, if the precoding matrix switching method is switched by one of the transmission parameters (or one consisting of multiple transmission parameters)), the transmitter provides information about the precoding matrix switching method. Since it is not necessary to transmit and the receiving device can determine the precoding matrix switching method used by the transmitting device by discriminating the information of the transmission parameter, accurate decoding and detection can be performed. In Tables 1 and 2, when the number of transmission modulation signals is 2, the transmission method of regularly switching the precoding matrix is used. However, if the number of transmission modulation signals is 2 or more, the precoding matrix is regularly switched. A transmission method for switching the coding matrix can be applied.

Therefore, if the transmitter / receiver shares a table of transmit parameters that include information about the precoding switching method, the transmitter does not transmit information about the precoding switching method and does not include information about the precoding switching method. By transmitting the information and obtaining this control information, the receiving device can estimate the precoding switching method.

As described above, in the present embodiment, the transmitting device does not transmit direct information on how to regularly switch the precoding matrix, and the receiving device uses the “regularly precoding matrix” used by the transmitting device. I explained how to estimate the information about precoding in "How to switch between". As a result, the transmitting device does not transmit direct information regarding the method of regularly switching the precoding matrix, so that the effect of improving the data transmission efficiency can be obtained.

In the present embodiment, the embodiment when the precoding weight is changed on the time axis has been described, but as described in the first embodiment, even when a multi-carrier transmission method such as OFDM transmission is used. The embodiment can be implemented in the same manner.

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

In the present specification, it is considered that a transmission device is provided in, for example, a communication / broadcasting device such as a broadcasting station, a base station, an access point, a terminal, or a mobile phone (mobile phone). It is conceivable that the receiver is equipped with a communication device such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, and a base station. Further, the transmitting device and the receiving device in the present invention are devices having a communication function, and the device provides some kind of interface to a device for executing an application such as a television, a radio, a personal computer, and a mobile phone. It is also conceivable that the form can be solved and connected.
Further, in the present embodiment, no matter how symbols other than the data symbols, such as pilot symbols (preamble, unique word, postamble, reference symbol, etc.), symbols for control information, etc., are arranged in the frame. good. Here, the names are pilot symbols and symbols for control information, but any naming method may be used, and the function itself is important.

The pilot symbol may be, for example, a known symbol modulated using PSK modulation in the transmitter / receiver (or by synchronizing the receiver, the receiver may be able to know the symbol transmitted by the transmitter. ), And the receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation (estimation of CSI (Channel State Information)) (estimation of CSI (Channel State Information)), signal detection, and the like. Become.

In addition, the symbol for control information is information that needs to be transmitted to the communication partner (for example, the modulation method / error correction coding method used for communication) in order to realize communication other than data (such as an application). It is a symbol for transmitting error correction coding method coding rate, setting information in the upper layer, etc.).

The present invention is not limited to the above embodiments 1 to 5, and can be modified in various ways. For example, in the above embodiment, the case of performing as a communication device is described, but the present invention is not limited to this, and this communication method can also be performed as software.

Further, in the above, the precoding switching method in the method of transmitting two modulated signals from two antennas has been described, but the present invention is not limited to this, and precoding is performed on the four mapped signals, and 4 In the method of generating one modulated signal and transmitting it from four antennas, that is, the method of precoding the N mapped signals, generating N modulated signals, and transmitting them from N antennas. Similarly, the precoding weight (matrix) can be changed as well as the precoding switching method.

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

Different data may be transmitted or the same data may be transmitted depending on the streams s1 (t) and s2 (t).
Both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, one antenna described in the drawings may be composed of a plurality of antennas.

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

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

Then, each configuration such as each of the above-described embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip so as to include all or a part of the configurations of each embodiment. Although it is referred to as an LSI here, it may be referred to as an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. Further, the method of making an integrated circuit is not limited to the 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 the connection and settings of the circuit cells inside the LSI may be used.

Further, if an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology or another technology derived from it, it is naturally possible to integrate functional blocks using that technology. There is a possibility of adaptation of biotechnology.

(Embodiment 8)
In the present embodiment, an application example of the method of regularly switching the precoding weights described in the first to fourth embodiments and the sixth embodiment will be described here.

FIG. 6 is a diagram related to the weighting method (precoding method) in the present embodiment, and the weighting synthesis unit 600 is the weighting synthesis unit 308A of FIG.
It is a weighting synthesis unit that integrates both 308B and 308B. As shown in FIG. 6, the streams s1 (t) and streams s2 (t) correspond to the baseband signals 307A and 307B of FIG. 3, that is, the base according to the mapping of the modulation scheme such as QPSK, 16QAM, 64QAM. Band signal common phase I and quadrature Q component. Then, as in the frame configuration of FIG. 6, the stream s1 (t) represents the signal of the symbol number u as s1 (u), the signal of the symbol number u + 1 as s1 (u + 1), and so on. Similarly, the stream s2 (t) represents the signal with the symbol number u as s2 (u), the signal with the symbol number u + 1 as s2 (u + 1), and so on. Then, the weighting synthesis unit 600 inputs the baseband signals 307A (s1 (t)) and 307B (s2 (t)) in FIG. 3 and the information 315 regarding the weighting information, and uses the weighting method according to the information 315 regarding the weighting information. Then, the signals 309A (z1 (t)) and 309B (z2 (t)) after the weighted synthesis of FIG. 3 are output.

At this time, for example, when the precoding matrix switching method of the period N = 8 of Example 8 in the sixth embodiment is used, z1 (t) and z2 (t) are represented as follows.
When the symbol number is 8i (i is an integer of 0 or more):

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

However, k = 1.
When the symbol number is 8i + 2:

However, k = 2.
When the symbol number is 8i + 3:

However, k = 3.
When the symbol number is 8i + 4:

However, k = 4.
When the symbol number is 8i + 5:

However, k = 5.
When the symbol number is 8i + 6:

However, k = 6.
When the symbol number is 8i + 7:

However, k = 7.
Here, although it is described as a symbol number, the symbol number may be considered as a time (time). As described in other embodiments, for example, in equation (225), z1 (8i + 7) and z2 (8i + 7) at time 8i + 7 are signals at the same time, and z1 (8i + 7) and z2 (8i + 7). Will be transmitted by the transmitter using the same (common) frequency. That is, if the signal at time T is s1 (T), s2 (T), z1 (T), z2 (T), then from some precoding matrix and s1 (T) and s2 (T), z1 (T) and The z2 (T) is obtained, and the z1 (T) and the z2 (T) are transmitted by the transmitting device (at the same time (time)) using the same (common) frequency. When a multi-carrier transmission method such as OFDM is used, the signals corresponding to s1, s2, z1, and z2 at the (sub) carrier L and time T are s1 (T, L), s2 (T, L), and z1. Assuming (T, L), z2 (T, L), from some precoding matrix and s1 (T, L) and s2 (T, L), z1 (T, L) and z
2 (T, L) is obtained, and z1 (T, L) and z2 (T, L) are transmitted by the transmitting device (at the same time (time)) using the same (common) frequency.

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

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

At this time, i = 0,1,2,3,4,5,6,7, k = 0,1, ..., M-2, M-1.
For example, when M = 2, and α <1, the reception poor point (◯) of s1 and the reception poor point (□) of s2 when k = 0 are as shown in FIG. 42 (a). Represented. Similarly, the reception poor point (◯) of s1 and the reception poor point (□) of s2 when k = 1 are represented as shown in FIG. 42 (b). In this way, based on the precoding matrix of equation (190), the poor reception points are as shown in FIG. 42 (a), and e ^jX is added to each element of the second row of the matrix on the right side of this equation (190). By making the matrix obtained by multiplying by (see Equation (226)), the reception inferior point has a rotated reception inferior point with respect to FIG. 42 (a) (see FIG. 42 (b)). .. (However, the reception inferior points in FIGS. 42 (a) and 42 (b) do not overlap. In this way, even if e ^jX is multiplied, the reception inferior points may not overlap. Instead of multiplying each element of the second row of the matrix on the right side of 190) by e ^jX , the matrix obtained by multiplying each element of the first row of the matrix on the right side of equation (190) by e ^jX is used as the precoding matrix. At this time, the precoding matrices F [0] to F [15] are expressed by the following equations.

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

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

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

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

In equations (229) and (230), when 0 radian ≤ δ <2π radian, a unitary matrix is obtained when δ = π radian, and a non-unitary matrix is obtained when δ ≠ π radian. In this method, one characteristic configuration is the case of a non-unitary matrix of π / 2 radians ≤ | δ | <π radians (the condition of δ is the same for other embodiments). , Good data reception quality will be obtained. As another configuration, there is a case of a unitary matrix, which will be described in detail in the tenth embodiment and the sixteenth embodiment. In the equations (229) and (230), when N is an odd number, good data reception is performed. The chances of getting quality are high.

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

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

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

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

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

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

Although the distance between the reception inferior points has been described in the description in the sixth embodiment, it is important that the period N is an odd number of 3 or more in order to increase the distance between the reception inferior points. This point will be described below.

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

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


Then, on the complex plane of the reception inferior point of s1 and the reception inferior point of s2 when the period N = 3 when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α <1. Arrangement in FIG. 43 (a)
In addition, the arrangement of the reception inferior point of s1 and the reception inferior point of s2 on the complex plane when the period N = 4 is shown in FIG. 43 (
Shown in b). Further, when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, the reception inferior point of s1 and the reception inferior point of s2 are on the complex plane when the period N = 3. Arrangement in Fig. 4
In FIG. 4 (a), the arrangement of the reception inferior point of s1 and the reception inferior point of s2 in the period N = 4 on the complex plane is shown in FIG. 44 (b).

At this time, when considering the phase formed by the line segment formed by the reception inferior point and the origin and the half-line formed by Real ≧ 0 on the Real axis (see FIG. 43 (a)), α> 1, In any case of α <1, when N = 4, the above-mentioned phase at the reception inferior point regarding s1 and the above-mentioned phase at the reception inferior point regarding s2 always have the same value. (See 4301, 4302 in FIG. 43 and 4401, 4402 in FIG. 44) At this time, the distance between the reception poor points becomes smaller in the complex plane. On the other hand, when N = 3, it does not occur when the above-mentioned phase at the reception poor point regarding s1 and the above-mentioned phase at the reception poor point regarding s2 have the same value.

From the above, considering that when the period N is an even number, the above-mentioned phase at the reception poor point regarding s1 and the above-mentioned phase at the reception poor point regarding s2 always have the same value, the period N is odd. It is more likely that the distance between the reception poor points will be larger in the complex plane than when the period N is even. However, when the period N is a small value, for example, N ≦ 16 or less, the minimum distance of the reception inferior points in the complex plane can be secured to some extent because the number of reception inferior points is small. Therefore, when N ≦ 16, there may be a case where the data reception quality can be ensured even if the number is even.

Therefore, in the method of regularly switching the precoding matrix based on the equation (232), if the period N is an odd number, it is highly possible that the data reception quality can be improved. The precoding matrix of F [0] to F [N-1] is generated based on the equation (232) (the precoding matrix of F [0] to F [N-1] has a period N. You can use them in any order.) Then, for example, when the symbol number is Ni, precoding is performed using F [0], and when the symbol number is Ni + 1, precoding is performed using F [1].
When the symbol number is N × i + h, precoding is performed using F [h] (h = 0, 1, 2, ..., N-2, N-1). (Here, as described in the previous embodiment, it is not always necessary to switch the precoding matrix regularly.) Further, when the modulation methods of s1 and s2 are both 16QAM, α is set.

Then, it may be possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.
In this embodiment, a method of constructing N different precoding matrices for a precoding hopping method having a time period N has been described. At this time, F [0], F [1], F [2], ..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [N-2], F [N-1] have been described in this order, but the present invention is not limited to this, and N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [N-2], F [N-1] can also be applied to a multi-carrier transmission method such as an OFDM transmission method. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method having a time period N, the same effect can be obtained by randomly using N different precoding matrices, that is, a regular period is not always used. You don't have to use N different precoding matrices to have.

Further, in the precoding matrix switching method of period H (where H is a method in which the precoding matrix is regularly switched and the period N is a larger natural number), N different precoding matrices in the present embodiment are included. If so, it is more likely to give good reception quality. At this time, <condition # 17> and <condition # 18> can be replaced with the following conditions. (Think of the cycle as N.)

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

(X is 0,1,2, ..., N-2, N-1, y is 0,1,2, ..., N-2, N-1, and x ≠ y. .)
(Embodiment 10)
In this embodiment, an example different from that of the ninth embodiment will be described with respect to a method of regularly switching the precoding matrix using the unitary matrix.

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

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

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

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

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

Then, consider adding the following conditions.

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

That is, in <condition 24>, it means that the phase difference is 2π / N radians. Further, in <Condition 25>, it means that the phase difference is -2π / N radians.

Then, when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, the reception inferior point of s1 and the reception inferior point of s2 at N = 4 are on the complex plane. Arrangement is shown in FIGS. 45 (a) and 45 (b).
Shown in. As can be seen from FIGS. 45 (a) and 45 (b), in the complex plane, the minimum distance of the reception inferior point of s1 is kept large, and similarly, the minimum distance of the reception inferior point of s2 is also kept large. There is. Then, the same state is obtained when α <1. Further, when considered in the same manner as in the ninth embodiment, there is a high possibility that the distance between the reception inferior points becomes larger in the complex plane when N is an odd number than when N is an even number. However, when N is a small value, for example, N ≦ 16 or less, the minimum distance of the reception inferior points in the complex plane can be secured to some extent because the number of reception inferior points is small. Therefore, when N ≦ 16, there may be a case where the data reception quality can be ensured even if the number is even.

Therefore, in the method of regularly switching the precoding matrix based on the equations (234) and (235), if N is an odd number, it is highly possible that the data reception quality can be improved. The precoding matrix of F [0] to F [2N-1] is generated based on the equations (234) and (235) (precoding matrix of F [0] to F [2N-1]). Can be used in any order for a period of 2N). Then, for example, precoding is performed using F [0] when the symbol number is 2Ni, precoding is performed using F [1] when the symbol number is 2Ni + 1, and ..., F when the symbol number is 2N × i + h. Precoding is performed using [h] (h = 0, 1, 2, ..., 2N-2, 2N-1). (Here, as described in the previous embodiment, the precoding matrix does not necessarily have to be switched regularly.) Further, when the modulation methods of s1 and s2 are both 16QAM, α is set to the equation (233). ), It may be possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.

Further, the following conditions are considered as conditions different from <Condition # 23>.

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

(X is N, N + 1, N + 2, ..., 2N-2,2N-1 and y is N, N + 1, N + 2, ..., 2N-2,2N-1 And x ≠ y.)
At this time, by satisfying <Condition # 21>, <Condition # 22>, <Condition # 26>, and <Condition # 27>, the distance between the reception inferior points between s1s in the complex plane is increased, and the distance between s2s is increased. Since the distance of the reception inferior point can be increased, good data reception quality can be obtained.

In this embodiment, a method of constructing 2N different precoding matrices for a precoding hopping method having a time period of 2N has been described. At this time, F [0], F [1], F [2], ..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [2N-2], F [2N-1] have been described in this order, but the present invention is not limited to this, and 2N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [2N-2], F [2N-1] can also be applied to multi-carrier transmission methods such as OFDM transmission methods. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method with a time period of 2N, the same effect can be obtained by randomly using 2N different precoding matrices, that is, a regular period is not always used. You don't have to use 2N different precoding matrices to have.

Further, in the precoding matrix switching method of the period H (H is a larger natural number in the method of regularly switching the precoding matrix), 2N different precoding matrices in the present embodiment are included. If so, it is more likely to give good reception quality.
(Embodiment 11)
In this embodiment, a method of regularly switching the precoding matrix using a non-unitary matrix will be described.

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

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

It is assumed that α> 0 and that it is a fixed value (regardless of i). (It is assumed that α in equation (236) and α in equation (237) have the same value.)
At this time, from the condition 5 of (Equation 106) and the condition 6 of (Equation 107) of the third embodiment, the following conditions are satisfied with respect to the equation (236) in order to obtain good data reception quality. It will be important.

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

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

Then, consider adding the following conditions.

In addition, instead of the equation (237), the precoding matrix of the following equation may be given.

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

That is, in <condition 31>, it means that the phase difference is 2π / N radians. Further, in <Condition 32>, it means that the phase difference is -2π / N radians.
Then, when θ ₁₁ (0) −θ ₂₁ (0) = 0 radians, α> 1, and δ = (3π) / 4 radians, the reception inferior point of s1 and s2 at N = 4 46 (a) and 46 (b) show the arrangement of the poor reception points on the complex plane. By doing so, the period for switching the pull coding matrix can be increased, and the minimum distance of the reception poor point of s1 is kept large in the complex plane, and similarly, the reception poor of s2 is kept large. Since the minimum distance of points can be kept large, good reception quality can be obtained. Here, the case where α> 1, δ = (3π) / 4 radians, and N = 4 is described as an example, but the description is not limited to this, and π / 2 radians ≦ | δ | <π radians and α. If> 0 and α ≠ 1, the same effect can be obtained.

Further, the following conditions are considered as conditions different from <Condition # 30>.

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

(X is N, N + 1, N + 2, ..., 2N-2,2N-1 and y is N, N + 1, N + 2, ..., 2N-2,2N-1 And x ≠ y.)
At this time, by satisfying <Condition # 28>, <Condition # 29>, <Condition # 33>, and <Condition # 34>, the distance between the reception inferior points between s1s in the complex plane is large, and the distance between s2s is large. Since the distance of the reception inferior point can be increased, good data reception quality can be obtained.

In this embodiment, a method of constructing 2N different precoding matrices for a precoding hopping method having a time period of 2N has been described. At this time, F [0], F [1], F [2], ..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [2N-2], F [2N-1] have been described in this order, but the present invention is not limited to this, and 2N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [2N-2], F [2N-1] can also be applied to multi-carrier transmission methods such as OFDM transmission methods. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method with a time period of 2N, the same effect can be obtained by randomly using 2N different precoding matrices, that is, a regular period is not always used. You don't have to use 2N different precoding matrices to have.

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

It is assumed that α> 0 and that it is a fixed value (regardless of i). Further, δ ≠ π radian (fixed value regardless of i), i = 0,1,2, ..., N-2, N-1.
At this time, from the condition 5 of (Equation 106) and the condition 6 of (Equation 107) of the third embodiment, the following conditions are satisfied with respect to the equation (239) in order to obtain good data reception quality. It will be important.

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

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

That is, in <condition 37>, it means that the phase difference is 2π / N radians. Further, in <Condition 38>, it means that the phase difference is -2π / N radians.
At this time, if π / 2 radian ≦ | δ | <π radian, α> 0, and α ≠ 1, the distance between the reception inferior points between s1s in the complex plane is large, and reception between s2s is large. Since the distance between the inferior points can be increased, good data reception quality can be obtained. It should be noted that <condition # 37> and <condition # 38> are not necessarily necessary conditions.

In this embodiment, a method of constructing N different precoding matrices for a precoding hopping method having a time period N has been described. At this time, F [0], F [1], F [2], ..., F [N-2], F [N-1] are prepared as N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [N-2], F [N-1] have been described in this order, but the present invention is not limited to this, and 2N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [N-2], F [N-1] can also be applied to a multi-carrier transmission method such as an OFDM transmission method. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method having a time period N, the same effect can be obtained by randomly using N different precoding matrices, that is, a regular period is not always used. You don't have to use N different precoding matrices to have.

Further, in the precoding matrix switching method of period H (where H is a method in which the precoding matrix is regularly switched and the period N is a larger natural number), N different precoding matrices in the present embodiment are included. If so, it is more likely to give good reception quality. At this time, <condition # 35> and <condition # 36> can be replaced with the following conditions. (Think of the cycle as N.)

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

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

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

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

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

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

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

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

The equation (242) of the precoding matrix having a period of 2 × N × M may be changed to the following equation.

At this time, k = 0,1, ..., M-2, M-1.
Further, the equation (243) of the precoding matrix having a period of 2 × N × M is changed from the equation (245) to the equation (24).
It may be any of 7).

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

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

At this time, k = 0,1, ..., M-2, M-1.
Focusing on the poor reception points, in equations (242) to (247),

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

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

Good data reception quality can be obtained if all of the above are satisfied. In the eighth embodiment, <condition # 39> and <condition # 40> may be satisfied.
Further, focusing on Xk and Yk of equations (242) to (247),

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

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

Good data reception quality can be obtained if the above two conditions are satisfied. In the eighth embodiment, <condition 42> may be satisfied.
In equations (242) and (247), when 0 radian ≤ δ <2π radian, a unitary matrix is obtained when δ = π radian, and a non-unitary matrix is obtained when δ ≠ π radian. In this method, a non-unitary matrix of π / 2 radians ≦ | δ | <π radians is one characteristic configuration, and good data reception quality can be obtained. As another configuration, there is a case of a unitary matrix, which will be described in detail in the tenth embodiment and the sixteenth embodiment, but when N is an odd number in the equations (242) to (247), good data reception is received. The chances of getting quality are high.

(Embodiment 14)
In the present embodiment, an example of properly using a unitary matrix and a non-unitary matrix as the precoding matrix in the method of regularly switching the precoding matrix will be described.

For example, when using a 2-by-2 precoding matrix (each element is assumed to be composed of complex numbers), that is, two modulation signals based on a certain modulation scheme (s1 (t) and s2 (t). A case where precoding is applied to)) and two signals after precoding are transmitted from two antennas will be described.
When data is transmitted using the method of regularly switching the precoding matrix, the transmission device of FIG. 13 in FIG. 3 uses the frame configuration signal 313, and the mapping units 306A and 306B switch the modulation method. At this time, the relationship between the number of modulation multi-values of the modulation method (number of modulation multi-values: the number of signal points of the modulation method in the IQ plane) and the precoding matrix will be described.

The advantage of the method of regularly switching the precoding matrix is that good data reception quality can be obtained in the LOS environment as described in the sixth embodiment, and in particular, the receiving device can perform ML operation or ML. When APP (or Max-log APP) based on calculation is applied, the effect is great. By the way, the ML calculation has a great influence on the circuit scale (calculation scale) with the number of modulation multi-values of the modulation method. For example, when two signals after precoding are transmitted from two antennas and two modulation signals (signals based on the modulation method before precoding) both use the same modulation method, the modulation method When is QPSK, the number of candidate signal points (received signal points 1101 in FIG. 11) in the IQ plane is 4 × 4 = 16, 16 × 16 = 256 for 16QAM, 64 × 64 = 4096 for 64QAM, In the case of 256QAM, it is 256 × 256 = 65536, and in the case of 1024QAM, it is 1024 × 1024 = 1048576. In the device, ML operation ((Max-log) APP based on ML operation) is used, and in the case of 256QAM and 1024QAM, detection using linear operation such as MMSE and ZF is used. (In some cases, in the case of 256QAM, ML operation may be used.)
Assuming such a receiver, when considering the SNR (signal-to-noise power ratio) after multiplex signal separation, precoding when the receiver uses linear operations such as MMSE and ZF. When a unitary matrix is suitable as a matrix and ML operation is used, either a unitary matrix or a non-unitary matrix may be used as the precoding matrix. Considering the description of any of the above embodiments, the two signals after precoding are transmitted from the two antennas, and the two modulation signals (signals based on the modulation method before precoding) are both the same modulation. When the method is used, when the number of modulation multi-values of the modulation method is 64 values or less (or 256 values or less), it is not a precoding matrix when the method of regularly switching the precoding matrix is used. If a unitary matrix is used and is greater than 64 values (or 256 values), then a unitary matrix can be used for all modulation schemes supported by the communication system and for any modulation scheme of the receiver. There is a high possibility that the effect of being able to obtain good data reception quality can be obtained while reducing the value.

In addition, it may be better to use a unitary matrix even when the number of modulation multi-values of the modulation method is 64 values or less (or 256 values or less). Considering this, if the modulation method supports multiple modulation methods with 64 values or less (or 256 values or less), the supported multiple modulation methods with 64 values or less. It is important that there is a case where a non-unitary matrix is used as the precoding matrix when the precoding matrix is regularly switched by any of the modulation methods.

In the above, as an example, the case where two precoded signals are transmitted from two antennas has been described, but the present invention is not limited to this, and N precoded signals are transmitted from N antennas. , When it is assumed that the N modulation signals (signals based on the modulation method before precoding) all use the same modulation method, a threshold value of β _N is set for the number of modulation multi-values of the modulation method, and the modulation method is used. If multiple modulation methods with a multi-valued number of β _N or less are supported, the method of regularly switching the precoding matrix with one of the supported modulation methods of β _N or less is used. In some cases, a non-unitary matrix is used as the precoding matrix when used, and in the case of a modulation method in which the modulation multi-value number of the modulation method is larger than β _N , the unitary matrix is used for all the support of the communication system. In any modulation method, there is a high possibility that the effect of being able to obtain good data reception quality while reducing the circuit scale of the receiving device can be obtained. (When the modulation multi-value number of the modulation method is β _N or less, a non-unitary matrix may always be used as the precoding matrix when the method of regularly switching the precoding matrix is used.)
In the above, the case where the same modulation method is used for the modulation methods of the N modulation signals transmitted at the same time has been described, but in the following, two or more types of modulation methods are used for the N modulation signals transmitted at the same time. The case where it exists will be described.

As an example, a case where two signals after precoding are transmitted from two antennas will be described. Assuming that the two modulation signals (signals based on the modulation method before precoding) are both the same modulation method or different modulation methods, the modulation method having a modulation multi-value number of ^2a1 and the modulation multi-value It is assumed that a modulation method in which the number is ^2a2 is used. At this time, when the ML operation ((Max-log) APP based on the ML operation) is used in the receiving device, the number of candidate signal points (received signal points 1101 in FIG. 11) in the IQ plane is 2 ^a1 × 2 ^a2 . = 2 There will be candidate signal points for ^{a1 + a2} . At this time, as described above, in order to obtain good data reception quality while reducing the circuit scale of the receiving device, a threshold value of 2 ^β is set for 2 a1 + ^a2 , and 2 ^{a1 + a2} ≤ 2 ^β . At this time, it is preferable to use a non-unitary matrix as the precoding matrix when the method of regularly switching the precoding matrix is used, and when 2 ^{a1 + a2} > 2 ^β , the unitary matrix should be used.

Further, even in the case of 2 ^{a1 + a2} ≤ 2 ^β , it may be better to use the unitary matrix. Considering this, when a combination of a plurality of modulation methods of 2 ^{a1 + a2} ≤ 2 ^β is supported, one of the supported modulation methods of a combination of a plurality of modulation methods of 2 ^{a1 + a2} ≤ 2 ^β is supported. It is important that there is a case where a non-unitary matrix is used as the precoding matrix when the method of regularly switching the precoding matrix by the combination is used.

In the above, as an example, the case where the two signals after precoding are transmitted from the two antennas has been described, but the present invention is not limited to this. For example, when the N modulation signals (signals based on the modulation method before precoding) all have the same modulation method or different modulation methods, the modulation multi-value of the modulation method of the i-th modulation signal Let the number be 2 ^ai (i = 1, 2, ..., N-1, N).

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

When a combination of a plurality of modulation methods satisfying <Condition # 44> is supported, a combination of a plurality of modulation methods satisfying the supported <Condition # 44> is regularly preliminarily used. There are cases where a non-unitary matrix is used as the precoding matrix when the method of switching the coding matrix is used.

In the case of all the modulation method combinations that satisfy <Condition # 45>, if a unitary matrix is used, the circuit scale of the receiver device is used regardless of the modulation method combination in all the modulation methods supported by the communication system. There is a high possibility that the effect of being able to obtain good data reception quality can be obtained while reducing the size. (A non-unitary matrix may be used as the precoding matrix when the method of regularly switching the precoding matrix is used in all combinations of a plurality of modulation methods that satisfy the supported <condition # 44>.)
(Embodiment 15)
In this embodiment, a system example of a method of regularly switching precoding matrices using a multi-carrier transmission method such as OFDM will be described.

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

In FIGS. 47 (A) and 47 (B), the (sub) carriers used when OFDM is used are carrier group # A and (sub) carrier b composed of (sub) carriers a to (sub) carriers a + Na. ~ (Sub) carrier group #B composed of (sub) carrier b + Nb, (sub) carrier c ~ (sub) carrier group #C composed of (sub) carrier c + Nc, (sub) carrier d ~ (sub) carrier d + Nd. It shall be divided by carrier group # D, .... Then, each subcarrier group shall support a plurality of transmission methods. Here, by supporting a plurality of transmission methods, it is possible to effectively utilize the advantages of each transmission method. For example, in FIGS. 47 (A) and 47 (B), the carrier group #A uses a spatial multiplex MIMO transmission method or a MIMO transmission method in which the precoding matrix is fixed, and the carrier group #B is regularly precoded. It is assumed that the MIMO transmission method for switching the matrix is used, the carrier group #C transmits only the stream s1, and the carrier group #D transmits using the spatiotemporal block code.

FIG. 48 shows the time-frequency of a transmission signal transmitted by a broadcasting station (base station) in a system of a method of regularly switching precoding matrices using a multi-carrier transmission method such as OFDM in the present embodiment. An example of the frame configuration on the axis is shown, and the frame configuration from the time $ X to the time $ X + T'different from that in FIG. 47 is shown. In FIG. 48, similarly to FIG. 47, the (sub) carriers used when OFDM is used are carrier group #A and (sub) carrier b composed of (sub) carriers a to (sub) carriers a + Na. ~ (Sub) carrier group #B composed of (sub) carrier b + Nb, (sub) carrier c ~ (sub) carrier group #C composed of (sub) carrier c + Nc, (sub) carrier d ~ (sub) carrier d + Nd. It shall be divided by carrier group # D, .... The difference between FIG. 48 and FIG. 47 is that there is a carrier group in which the communication method used in FIG. 47 and the communication method used in FIG. 48 are different. In FIGS. 48 (A) and (B), the carrier group #A shall be transmitted using a spatiotemporal block code, and the carrier group #B shall use a MIMO transmission method in which the precoding matrix is regularly switched. , Carrier group #C shall use a MIMO transmission method that regularly switches the precoding matrix, and carrier group #D shall transmit only the stream s1.

Next, the supported transmission methods will be described.
FIG. 49 shows a signal processing method when a spatial multiplex MIMO transmission method or a MIMO transmission method having a fixed precoding matrix is used, and is numbered in the same manner as in FIG. The weighted synthesizer 600, which is a baseband signal according to a certain modulation method, inputs the streams s1 (t) (307A) and the streams s2 (t) (307B) and the information 315 regarding the weighting method, and after weighting. The modulation signal z1 (t) (309A) and the weighted modulation signal z2 (t) (309B) are output. Here, when the information 315 regarding the weighting method indicates the spatial multiplex MIMO transmission method, the signal processing of the method # 1 of FIG. 49 is performed. That is, the following processing is performed.

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

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

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

Although only the symbols for transmitting data are shown in FIGS. 47 and 48, it is actually necessary to transmit information such as a transmission method, a modulation method, and an error correction method. For example, as shown in FIG. 51, if these information are periodically transmitted by only one modulation signal z1, these information can be transmitted to the communication partner. In addition, it is necessary to transmit the fluctuation of the transmission line, that is, the symbol for estimating the channel fluctuation of the receiving device (for example, a pilot symbol, a reference symbol, a preamble, and a known phase shift keying (PSK) symbol). .. Although these symbols are omitted in FIGS. 47 and 48, in reality, symbols for estimating channel fluctuations are included in the frame configuration of the time-frequency axis. Therefore, each carrier group is not composed only of symbols for transmitting data. (This point is the same in the first embodiment.)
FIG. 52 shows an example of the configuration of the transmission device of the broadcasting station (base station) in the present embodiment. The transmission method determination unit (5205) determines the number of carriers in each carrier group, the modulation method, the error correction method, the coding rate of the error correction code, the transmission method, and the like, and outputs the control signal (5205).

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

Similarly, the modulation signal generation unit # 2 (5201_2) takes the information (5200_2) and the control signal (5202) as inputs, and based on the information of the communication method of the control signal (5205), the carrier group # of FIGS. 47 and 48. B modulation signal z1 (5202_1) and modulation signal z2 (5203)
_2) is output.

Similarly, the modulation signal generation unit # 3 (5201_3) takes the information (5200_3) and the control signal (5205) as inputs, and based on the information of the communication method of the control signal (5205), the carrier group # of FIGS. 47 and 48. The modulation signal z1 (5202_3) and the modulation signal z2 (5203_3) of C are output.

Similarly, the modulation signal generation unit # 4 (5201_4) takes the information (5200_4) and the control signal (5205) as inputs, and based on the information of the communication method of the control signal (5205), the carrier group # of FIGS. 47 and 48. The modulation signal z1 (5202_4) and the modulation signal z2 (5203_4) of D are output.

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

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

Similarly, the OFDM method related processing unit (5207_2) includes the modulation signal z1 (5203_1) of the carrier group #A, the modulation signal z2 (5203_1) of the carrier group #B, the modulation signal z2 (5203_1) of the carrier group #C, and the carrier. Modulation signal z2 (5203_4) of group # D, ..., Modulation signal z2 (5203_M) of a certain carrier group, and control signal (5206) are used as inputs, and rearrangement, inverse Fourier conversion, frequency conversion, amplification, etc. are performed. Processing is performed, the transmission signal (5208_2) is output, and the transmission signal (5208_2) is output as a radio wave from the antenna (5209_2).

FIG. 53 shows an example of the configuration of the modulation signal generation units # 1 to # M of FIG. 52. The error correction coding unit (5302) receives information (5300) and a control signal (5301) as inputs, and sets an error correction coding method and an error correction coding coding rate according to the control signal (5301). , Error correction coding is performed, and data (5303) after error correction coding is output. (By setting the error correction coding method and the code rate of the error correction coding, for example, when an LDPC code, a turbo code, a convolution code, etc. are used, puncture is performed depending on the code rate to realize the code rate. May be done.)
The interleaving unit (5304) takes data after error correction coding (5303) and a control signal (5301) as inputs, and follows the information of the interleaving method included in the control signal (5301), and the data after error correction coding (5303). ) Is rearranged, and the interleaved data (5305) is output.

The mapping unit (5306_1) receives the interleaved data (5305) and the control signal (5301) as inputs, performs mapping processing according to the information of the modulation method included in the control signal (5301), and outputs the baseband signal (5307_1). Output.

Similarly, the mapping unit (5306_2) takes the interleaved data (5305) and the control signal (5301) as inputs, performs mapping processing according to the information of the modulation method included in the control signal (5301), and performs the mapping process to the baseband signal (5301). 5307_2) is output.

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

FIG. 54 shows an example of the configuration of the OFDM system-related processing units (5207_1 and 5207_1) in FIG. 52, and the same reference numerals are given to those operating in the same manner as in FIG. The rearrangement unit (5402A) is a modulation signal z1 (5400_1) of the carrier group #A, a modulation signal z1 (5400_1) of the carrier group #B, a modulation signal z1 (5400_3) of the carrier group #C, and a modulation of the carrier group #D. Signal z1 (5400_4), ..., Modulation signal z1 (5400_M) of a certain carrier group, and control signal (5403) are input, rearrangement is performed, and the rearranged signals 1405A and 1405B are output. In addition, in FIG. 47, FIG. 48, and FIG. A carrier group may be formed. Further, in FIGS. 47, 48, and 51, the number of carriers in the carrier group is described by an example in which the number of carriers does not change with time, but the present invention is not limited to this. This point will be described later separately.

FIG. 55 shows an example of the details of the frame configuration on the time-frequency axis of the method of setting the transmission method for each carrier group as shown in FIGS. 47, 48, and 51. In FIG. 55, the control information symbol is 5500, the individual control information symbol is 5501, the data symbol is 5502, and the pilot symbol is 5503. Further, FIG. 55 (A) shows the frame configuration of the stream s1 on the time-frequency axis, and FIG. 55 (B) shows the frame configuration of the stream s2 on the time-frequency axis.

The control information symbol is a symbol for transmitting control information common to the carrier group, and is composed of a symbol for the transceiver to perform frequency and time synchronization, information on (sub) carrier allocation, and the like. Then, it is assumed that the control control symbol is transmitted only from the stream s1 at the time $ 1.

The individual control information symbol is a symbol for transmitting control information of each subcarrier group, and is a transmission method, a modulation method, an error correction coding method, an error correction coding coding rate, and an error correction code of the data symbol. It is composed of information such as the block size of the above, information on how to insert the pilot symbol, and information on the transmission power of the pilot symbol. It is assumed that the individual control information symbol is transmitted only from the stream s1 at time $ 1.

A data symbol is a symbol for transmitting data (information), and as described with reference to FIGS. 47 to 50, for example, a spatial multiplex MIMO transmission method, a MIMO method using a fixed precoding matrix, and a rule. It is a symbol of any of the MIMO method for switching the precoding matrix, the spatiotemporal block coding, and the transmission method for transmitting only the stream s1. In the carrier group #A, the carrier group #B, the carrier group #C, and the carrier group #D, it is described that the data symbol exists in the stream s2, but the transmission method of transmitting only the stream s1 is used. In that case, the data symbol may not exist in the stream s2.

The pilot symbol is a symbol for the receiving device to estimate the channel, that is, the variation corresponding to h11 (t), h12 (t), h21 (t), h22 (t) of the equation (36). (Here, since a multi-carrier transmission method such as the OFDM method is used, fluctuations corresponding to h11 (t), h12 (t), h21 (t), and h22 (t) are estimated for each subcarrier. Therefore, the pilot symbol uses, for example, a PSK transmission method, and is configured to have a pattern known to the transceiver. The pilot symbol may also be used by the receiver for frequency offset estimation, phase distortion estimation, and time synchronization.

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

The control information decoding unit 709 of FIG. 56 takes the signal 704_X after signal processing and the signal 704_Y after signal processing as inputs, extracts the control information symbol and the individual control information symbol in FIG. 55, and controls information transmitted by these symbols. Is obtained, and a control signal 710 including this information is output.

The channel variation estimation unit 705_1 of the modulated signal z1 takes the signal 704_X after signal processing and the control signal 710 as inputs, performs channel estimation in the carrier group (desired carrier group) required by this receiving device, and performs channel estimation. The signal 706_1 is output.

Similarly, the channel variation estimation unit 705_2 of the modulated signal z2 takes the signal 704_X after signal processing and the control signal 710 as inputs, and performs channel estimation in the carrier group (desired carrier group) required by this receiving device. , Outputs the channel estimation signal 706_2.

Similarly, the channel variation estimation unit 705_1 of the modulated signal z1 takes the signal 704_Y after signal processing and the control signal 710 as inputs, and performs channel estimation in the carrier group (desired carrier group) required by this receiving device. , Outputs the channel estimation signal 708_1.

Similarly, the channel variation estimation unit 705_2 of the modulated signal z2 takes the signal 704_Y after signal processing and the control signal 710 as inputs, and performs channel estimation in the carrier group (desired carrier group) required by this receiving device. , Outputs the channel estimation signal 708_2.

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

FIG. 57 shows the configuration of the OFDM method-related processing unit (5600_X, 5600_Y) in FIG. 56, and the frequency conversion unit (5701) receives the received signal (5700) as an input, performs frequency conversion, and after frequency conversion. The signal (5702) is output.

The Fourier transform unit (5703) takes the signal (5702) after the frequency conversion as an input, performs the Fourier transform, and outputs the signal (5704) after the Fourier transform.
As described above, when a multi-carrier transmission method such as the OFDM method is used, by dividing into a plurality of carrier groups and setting the transmission method for each carrier group, the reception quality and transmission are achieved for each carrier group. Since the speed can be set, the effect of being able to build a flexible system can be obtained. At this time, by making it possible to select a method of regularly switching the precoding matrix as described in another embodiment, high reception quality can be obtained and a high transmission speed can be obtained for the LOS environment. Can be obtained, which is an advantage. In this embodiment, as the transmission method in which the carrier group can be set, "spatial multiplex MIMO transmission method, MIMO method using a fixed precoding matrix, MIMO method for regularly switching the precoding matrix, spatiotemporal block". "Transmission method for encoding and transmitting only stream s1" was mentioned, but it is not limited to this. At this time, the method of FIG. 50 was described as a spatiotemporal code, but it is not limited to this, and is fixed. The MIMO method using a typical precoding matrix is not limited to the method # 2 of FIG. 49, and may be composed of a fixed precoding matrix. Further, in the present embodiment, the case where the number of antennas of the transmitting device is 2 has been described, but the present invention is not limited to this, and even when the number of antennas is larger than 2, "spatial multiplex MIMO transmission method, fixed" is used for each carrier group. The same effect can be achieved by making it possible to select one of the transmission methods: MIMO method using precoding matrix, MIMO method that switches precoding matrix regularly, spatiotemporal block coding, and transmission method that transmits only stream s1. Obtainable.

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

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

(Embodiment 16)
In the present embodiment, as in the case of the tenth embodiment, a method of regularly switching the precoding matrix using the unitary matrix will be described when N is an odd number.

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

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

It is assumed that α> 0 and that it is a fixed value (regardless of i). (It is assumed that α in equation (253) and α in equation (254) have the same value.)
At this time, from the condition 5 of (Equation 106) and the condition 6 of (Equation 107) of the third embodiment, the following conditions are satisfied with respect to the equation (253) in order to obtain good data reception quality. It will be important.

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

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

Then, consider adding the following conditions.

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

That is, in <condition 49>, it means that the phase difference is 2π / N radians. Further, in <condition 50>, it means that the phase difference is -2π / N radians.
Then, when θ ₁₁ (0) −θ ₂₁ (0) = 0 radian and α> 1, the reception inferior point of s1 and the reception inferior point of s2 at N = 3 are on the complex plane. Arrangement is shown in FIGS. 60 (a) and 60 (b).
Shown in. As can be seen from FIGS. 60 (a) and 60 (b), in the complex plane, the minimum distance of the reception inferior point of s1 is kept large, and similarly, the minimum distance of the reception inferior point of s2 is also kept large. There is. Then, the same state is obtained when α <1. Further, as compared with FIG. 45 of the tenth embodiment, when considered in the same manner as the ninth embodiment, the distance between the reception inferior points in the complex plane is higher when N is an odd number than when N is an even number. Is likely to increase. However, when N is a small value, for example, N ≦ 16 or less, the minimum distance of the reception inferior points in the complex plane can be secured to some extent because the number of reception inferior points is small. Therefore, when N ≦ 16, there may be a case where the data reception quality can be ensured even if the number is even.

Therefore, in the method of regularly switching the precoding matrix based on the equations (253) and (254), if N is an odd number, it is highly possible that the data reception quality can be improved. The precoding matrix of F [0] to F [2N-1] is generated based on the equations (253) and (254) (precoding matrix of F [0] to F [2N-1]). Can be used in any order for a period of 2N). Then, for example, precoding is performed using F [0] when the symbol number is 2Ni, precoding is performed using F [1] when the symbol number is 2Ni + 1, and ..., F when the symbol number is 2N × i + h. Precoding is performed using [h] (h = 0, 1, 2, ..., 2N-2, 2N-1). (Here, as described in the previous embodiment, the precoding matrix does not necessarily have to be switched regularly.) Further, when the modulation methods of s1 and s2 are both 16QAM, α is set to the equation (233). ), It may be possible to obtain the effect that the minimum distance between 16 × 16 = 256 signal points in the IQ plane can be increased in a specific LOS environment.

Further, the following conditions are considered as conditions different from <Condition # 48>.

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

(X is N, N + 1, N + 2, ..., 2N-2,2N-1 and y is N, N + 1, N + 2, ..., 2N-2,2N-1 And x ≠ y.)
At this time, by satisfying <condition # 46>, <condition # 47>, <condition # 51>, and <condition # 52>, the distance between the reception inferior points between s1s in the complex plane is increased, and the distance between s2s is increased. Since the distance of the reception inferior point can be increased, good data reception quality can be obtained.

In this embodiment, a method of constructing 2N different precoding matrices for a precoding hopping method having a time period of 2N has been described. At this time, F [0], F [1], F [2], ..., F [2N-2], F [2N-1] are prepared as 2N different precoding matrices. However, since this embodiment is described by taking the case of a single carrier transmission method as an example, F [0], F [1], F [2], ... , F [2N-2], F [2N-1] have been described in this order, but the present invention is not limited to this, and 2N different precoding matrices F [0] generated in the present embodiment have been described. , F [1], F [2], ..., F [2N-2], F [2N-1] can also be applied to multi-carrier transmission methods such as OFDM transmission methods. As for the application method in this case, the precoding weight can be changed by arranging the symbols on the frequency axis and the frequency-time axis as in the first embodiment. Although it is described as a precoding hopping method with a time period of 2N, the same effect can be obtained by randomly using 2N different precoding matrices, that is, a regular period is not always used. You don't have to use 2N different precoding matrices to have.

Further, in the precoding matrix switching method of the period H (H is a larger natural number in the method of regularly switching the precoding matrix), 2N different precoding matrices in the present embodiment are included. If so, it is more likely to give good reception quality.
(Embodiment 17)
In the 17th embodiment, the precoded symbol arrangement that can obtain high reception quality in the MIMO transmission method in which the precoding matrix is regularly switched will be described.

FIG. 61 shows an example of a frame configuration of some symbols of a signal on the time-frequency axis when a multicarrier method such as an OFDM method is used in a transmission method for regularly switching precoding matrices. .. FIG. 61A shows the frame configuration of the modulation signal z1 and FIG. 61B shows the frame configuration of the modulation signal z2, in which one square represents one symbol.

In the modulated signal z1 and the modulated signal z2 shown in FIGS. 61 (a) and 61 (b), the symbols arranged at the same carrier number are both a plurality of transmitters using the same frequency at the same time. It will be transmitted from the antenna of.

Here, attention is paid to the carrier f2 in FIG. 61A and the symbol 610a at time t2. Although it is described as a carrier here, it may also be referred to as a subcarrier.
In the carrier f2, the symbols closest in time to the time t2, that is, the channel states of the symbol 613a at the time t1 of the carrier f2 and the symbol 611 at the time t3 are the channel states of the carrier f2 and the symbol 610a at the time t2. Very high correlation.

Similarly, at time t2, the symbol of the frequency closest to the carrier f2 in the frequency axis direction, that is, the channel states of the carrier f1, the symbol 612a of time t2 and the symbol 614a of time t2, carrier f3 are both carriers. It has a very high correlation with the channel state of the symbol 610a at f2 and time t2.

As described above, the channel states of the symbols 611a, 612a, 613a, and 614a have a very high correlation with the channel states of the symbol 610a.
Of course, the symbols 610b to 614b of the modulated signal z2 have the same correlation.

In the present specification, in the transmission method for regularly switching the precoding matrix, it is assumed that N kinds of matrices (where N is an integer of 5 or more) are prepared as the precoding matrix. The symbol shown in FIG. 1 is, for example, attached with the symbol "# 1", which means that this symbol is a symbol precoded using the precoding matrix # 1. That is, the precoding matrices # 1 to #N are prepared as the precoding matrix. Therefore, the symbol with the symbol "#N" means that the symbol is precoded using the precoding matrix #N.

In the present embodiment, high reception quality can be obtained on the receiving device side by utilizing the high correlation between the channel states of the symbols adjacent to each other in the frequency axis direction and the symbols adjacent to each other in the time axis direction. Disclose the symbol arrangement of the coded symbols.

The conditions (referred to as condition # 53) for obtaining high reception quality on the receiving side are as follows.

<Condition # 53>
When a multi-carrier transmission method such as OFDM is used in a transmission method for regularly switching precoding matrices, time X and carrier Y are symbols for data transmission (hereinafter referred to as data symbols), and time. Symbols adjacent in the axial direction, that is, time X-1 carrier Y and time X + 1 carrier Y are both data symbols, and adjacent symbols in the frequency axis direction, that is, time X-1 carrier Y-1 and When the time X and the carrier Y + 1 are all data symbols, all of these five data symbols are precoded by different precoding matrices.

The reason why the <condition # 53> is 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 of the symbol temporally adjacent to the symbol A and the symbol frequency adjacent to the symbol A is as described above. High correlation with channel state.

When different precoding matrices are used for these five symbols, the symbol A has poor reception quality (high reception quality as SNR, but the phase relationship of the direct wave is poor in the LOS environment. Therefore, even if the reception quality is poor), it is very likely that good reception quality can be obtained with the remaining 4 symbols adjacent to the symbol A, and as a result, it is good after error correction and decoding. Good reception quality can be obtained.

On the other hand, if the same precoding matrix as the symbol A is used for the symbol temporally adjacent to the symbol A or the symbol temporally adjacent to the symbol A, the adjacent symbol using the same precoding matrix is the symbol A. Similarly, there is a very high possibility that the reception quality will be poor, and as a result, the reception quality of the data will deteriorate after error correction and decoding.

FIG. 61 shows an example of symbol arrangement in which the high reception quality can be obtained, and FIG. 62 shows an example of symbol arrangement in which the reception quality deteriorates.
As can be seen from FIG. 61 (a), the precoding matrix used for the symbol 610a corresponding to the symbol A and the precoding matrices used for the symbols 611a and 613a temporally adjacent to the symbol 610a. And, the precoding matrices used for the symbols 612a and 614a that are adjacent in frequency are arranged so as to be different from each other, so that even if the reception quality of the symbol 610a is poor on the receiving side, they are adjacent to each other. Since the reception quality of the symbol is very high, high reception quality after error correction and decoding can be ensured. The same can be said for the modulated signal z2 shown in FIG. 61 (b).

On the other hand, as can be seen from FIG. 62 (a), the precoding matrix used for the symbol 620a corresponding to the symbol A and the precoding matrix used for the symbol 300 adjacent in frequency thereof are , The same precoding matrix. At this time, if the reception quality of the symbol 620a is poor on the receiving side, it is highly possible that the reception quality of the symbol 624a using the same precoding matrix is also poor. Reception quality deteriorates. The same can be said for the modulated signal z2 shown in FIG. 62 (b).

Therefore, it is important for the receiving device to have a symbol that satisfies <Condition # 53> in order for good data to obtain reception quality. Then, in order to improve the data reception quality, it is better to have many data symbols that satisfy <condition # 53>.

From here, a method of assigning a precoding matrix to a symbol satisfying the above <condition # 53> will be described.
From the above consideration, a method for realizing a symbol arrangement in which all the data symbols satisfy the symbol arrangement shown in FIG. 61 is shown below. One important condition (configuration method) is the following <condition # 54>.

<Condition # 54>
The required precoding matrix is 5 or more. As shown in FIG. 1, a precoding matrix to be multiplied by five symbols arranged in a cross is required at a minimum. That is, it is a necessary condition that the number N of different precoding matrices for satisfying <condition # 53> is 5 or more. In other words, it can be said that the period of the precoding matrix needs to be 5 or more.

When the condition is satisfied, if the precoding matrix is assigned based on the following method and the precoding of each symbol is executed, the symbol arrangement satisfying the above <condition # 53> becomes possible.

First, a certain precoding matrix among N precoding matrices is assigned to the smallest time (the time when the timing to be transmitted is the earliest) of the smallest carrier number in the frequency band to be used. As an example, in FIG. 63, the carrier f1 and the time t1 are assigned the precoding matrix # 1. Then, the index of the precoding matrix used for precoding is changed (incremented (increased)) one by one in the frequency axis direction. The index referred to here is used to distinguish different precoding matrices from each other. However, since the method of regularly switching the precoding matrix has a period, the precoding matrix to be used is arranged periodically and. That is, when focusing on the time t1 in FIG. 63, since the carrier f1 uses the precoding matrix of the index # 1, the carrier f2 uses the precoding matrix of the index # 2, and the carrier f3 uses the precoding matrix of the index # 3. , The carrier f4 has the precoding matrix of index # 4, the carrier f5 has the precoding matrix of index # 5, the carrier f6 has the precoding matrix of index # 1, and the carrier f7 has the precoding matrix of index # 2. The precoding matrix of index # 3 is used for f8, the precoding matrix of index # 4 is used for carrier f9, the precoding matrix of index # 5 is used for carrier f10, the precoding matrix of index # 1 is used for carrier f11, and so on. The precoding matrix of, shall be used.

Next, when considering the smallest carrier number as a reference, the index (that is, #X) of the precoding matrix assigned to the smallest carrier number is described as a predetermined number in the time axis direction (hereinafter, the predetermined number is Sc). ) Shift above. Shift is, in other words, synonymous with increasing the index by Sc. Then, in the time other than the smallest time, the index of the precoding matrix used for precoding is changed (incremented) in the frequency axis direction according to the same rule as the smallest time. Here, shifting means that when numbers 1 to N are assigned to the prepared precoding matrix, the precoding matrix assigned to the previous time in the time axis direction by the number to be shifted. It means to allocate the precoding matrix of the number added to the number of.

For example, in FIG. 63, when focusing on the time t2, the carrier f1 has the precoding matrix of index # 4, the carrier f2 has the precoding matrix of index # 5, and the carrier f3 has the precoding matrix of index # 1. The precoding matrix of index # 2 in f4, the precoding matrix of index # 3 in carrier f5, the precoding matrix of index # 4 in carrier f6, the precoding matrix of index # 5 in carrier f7, and the precoding matrix of index # 5 in carrier f8. The precoding matrix of index # 1, the precoding matrix of index # 2 in carrier f9, the precoding matrix of index # 3 in carrier f10, the precoding matrix of index # 4 in carrier f11, and so on. Allocate the precoding matrix like this. Therefore, different precoding matrices will be used for the same carrier at time t1 and time t2.

Here, the <condition # 55> of the Sc that shifts the precoding matrix by Sc in the time axis direction in order to satisfy the above <condition # 53> is as follows.

<Condition # 55>
Sc is 2 or more and N-2 or less.

That is, when the precoding matrix # 1 is assigned to the symbols of the carrier f1 and the time t1, the precoding matrix shifted by the number of Sc is assigned in the time axis direction. That is, the symbol of the carrier f1 and the time t2 has a precoding matrix of the number represented by 1 + Sc, and the symbol of the carrier f1 and the time t3 has the precoding matrix of the number represented by 1 + Sc + Sc. , The precoding matrix number + Sc, ... Assigned to the symbol of time tun-1 is assigned to the symbol of time tun. If the value obtained by addition exceeds the number N of the prepared different precoding matrices, a precoding matrix having a value obtained by subtracting N from the value obtained by addition is used. Specifically, when N is 5 and Sc is 2, and the precoding matrix # 1 is assigned to the smallest carrier f1 and time t1, the precoding matrix # 3 (1 + 2 (Sc)) is assigned to carrier f1 and time t2. Precoding matrix # 5 (3 + 2 (Sc)) at carrier f1 and time t3, precoding matrix # 2 (5 + 2 (Sc) -5 (N)) at carrier f1 and time t4, and so on. I will assign it to.

Then, once the precoding matrix assigned to each time tx of the smallest carrier number is determined, the precoding matrix assigned to each time of the smallest carrier number is incremented by 1 in the frequency axis direction. Allocate a matrix. For example, in FIG. 63, assuming that the precoding matrix used for the symbol of carrier f1 and time t1 is the precoding matrix # 1, the precoding matrix used for the symbol of carrier f2 and time t1 is the precoding matrix # 1. 2. The precoding matrix used for the symbol of carrier f3 and time t1 is assigned a precoding matrix to be multiplied by the symbol so as to be precoding matrix # 3, .... Even in the frequency axis direction, the number assigned to the precoding matrix returns to 1 when it reaches N, that is, it loops.

FIG. 63 shows an example of symbol arrangement of the data symbol to which the precoding matrix is assigned and the precoding is executed in this way. In the modulation signal z1 shown in FIG. 63A and the modulation signal z2 shown in FIG. 3B, the number of prepared precoding matrices is 5, and the value to be added as the above Sc is 3. The symbol arrangement example of is shown.

As can be seen from FIG. 63, the precoded data symbols obtained by performing the precoding using the precoding matrix in which the numbers of the precoding matrix have been shifted are arranged according to the above method. As can be seen from FIG. 63, regardless of the focus on the data symbol at any position, the precoding matrix used for the focused data symbol and the data symbol of interest are adjacent to each other in the frequency axis direction and the time axis direction. It can be seen that the precoding matrices used for all the data symbols used are all different, and the arrangement satisfies the above <condition # 53>. However, in the case of data symbol A in which the number of adjacent data symbols in the time axis and frequency direction is 3 or less, when the number of adjacent data symbols is X (X is 3 or less), X adjacent data symbols And data symbol A will use different precoding matrices. For example, f1 in FIG.
The data symbol of t1 has only 2 adjacent data symbols, the data symbol of f1 and t2 has only 3 adjacent data symbols, and the data symbol of f2 and t1 has only 3 adjacent data symbols. Even in these data symbols, the precoding matrix assigned to the data symbol adjacent to the data symbol is different.

The index difference between the precoding matrix used for the symbol 631a in FIG. 63A and the precoding matrix used for the symbol 630a is 4-1 = 3, and the precoding matrix used for the data symbol 632a. It can be seen that the difference between the precoding matrix used for the data symbol 631a and the precoding matrix used for the data symbol 631a is 2 + 5-4 = 3, and the precoding matrix having the value obtained by adding 3 as Sc is used, and the Sc is 2 ≦. Sc ≦ 3 (5 (N) -2), which satisfies <condition # 55>.

Further, FIG. 64 shows an example of symbol arrangement when the number of precoding matrices is 5 and the value to be added as the above-mentioned Sc is 2.
As a method for realizing this symbol arrangement in the transmission device, for example, when precoding is performed on a data symbol, a precoding matrix used for the symbol from the smallest carrier (for example, carrier f1 in FIG. 63) is used. The precoding matrix to which the numbers are assigned is configured to allocate the precoding matrix having the smallest number (precoding matrix # 1 in FIG. 63). Then, the precoding matrix in which the number of the precoding matrix # 1 assigned to the smallest carrier is shifted in the time axis direction by the number determined by Sc is assigned. This may include a register for designating the Sc value in advance, and may add to the precoding matrix number assigned only the value set in the register.

Then, when the precoding matrix is assigned to the smallest carrier for the required time, the precoding matrix assigned by 1 in the frequency axis direction at each time may be incremented to the largest carrier of the carrier to be used.

That is, the number of the precoding matrix used may be incremented by 1 in the frequency axis direction, and the number of the precoding matrix used may be shifted by Sc in the time axis direction.

In the modulation signal z1 shown in FIGS. 63 (a) and 64 (a), and the modulation signal z2 shown in FIG. 63 (b) and FIG. 64 (b), the numbers of the precoding matrix are shifted according to the above-mentioned method. Pre-coded symbols are arranged, and it can be seen that the above <condition # 53> is satisfied regardless of which symbol is focused.

By transmitting the signal generated in this way, even if the reception quality of a certain symbol is poor in the receiving device, the reception quality of the symbol adjacent to the symbol in the frequency axis direction and the time axis direction is high. Therefore, good quality reception quality can be ensured after error correction and decoding.

In the precoding matrix allocation method described above, the method of determining the smallest carrier and shifting by Sc in the time axis direction is shown, but this may be shifted by Sc in the frequency axis direction. .. That is, after the precoding matrix to be assigned to the earliest time t1 and the carrier f1 is determined, the precoding matrix shifted by Sc is assigned every time one carrier is moved in the frequency axis direction. Then, the index of the precoding matrix allocated by 1 in the time axis direction in the same carrier may be incremented. In this case, the symbol arrangements shown in FIGS. 63 and 64 are the symbol arrangements shown in FIGS. 65 and 66, respectively.

Further, there are various methods for incrementing the index of the precoding matrix as shown in FIGS. 67A to 67D, and any procedure may be taken. In FIG. 67, the index of the precoding matrix used in the order of the numbers 1, 2, 3, 4, ... Attached to the arrow is incremented.

FIG. 67A increments the index of the precoding matrix used in the frequency axis direction at time A, as shown in FIGS. 63 and 64, and when completed, at time A + 1 in the frequency axis direction. It means that the index of the precoding matrix to be used is incremented, and so on.

In FIG. 67 (c), as described with reference to FIGS. 63 and 64, the index of the precoding matrix to be used is incremented in the frequency axis direction at the frequency A, and when completed, the index of the precoding matrix to be used is incremented in the time axis direction at the frequency A + 1. So, the method of incrementing the index of the precoding matrix used in the time axis direction is shown.

67 (b) and 67 (d) are variants of FIGS. 67 (a) and 67 (c), first, in the symbol associated with the arrow 1 the index of the precoding matrix used in the direction of the arrow. Increment. After completion, in the symbol related to the arrow 2, the index of the precoding matrix to be used is incremented in the direction of the arrow, and so on, and the index of the precoding matrix to be used is incremented.

Further, even if the procedure is unexpected to that shown in FIG. 67, as a result, it is possible to execute the precoding method as shown in FIGS. 63 to 66 in which the number of data symbols satisfying <condition # 53> increases. desirable.

The precoding matrix may be incremented according to a procedure other than the procedure for incrementing the index of the precoding matrix shown in FIG. 67. At this time, the number of data symbols satisfying <Condition # 53> increases. A method is desired.

The modulated signal thus generated will be transmitted from the plurality of antennas of the transmitting device.
The above is an example of arrangement of precoded symbols that can suppress deterioration of reception quality on the receiving side according to the 17th embodiment. In the 17th embodiment, the number of data symbols that satisfy <Condition # 53> is increased by using the precoding matrix having a number obtained by shifting the precoding matrix used for the symbol by a predetermined number to the adjacent symbols. Although the method is shown, if a data symbol satisfying <Condition # 53> exists, data reception is performed without the regular precoding matrix allocation method as shown in the 17th embodiment. The effect of quality improvement can be obtained.

Further, in the present embodiment, the precoding matrix # 1 is assigned to the symbol assigned to the smallest carrier as the reference symbol to which the precoding matrix is initially assigned, and 1 or 1 in the frequency axis direction and the time axis direction. The method of shifting by Sc is adopted, but this may be the method of allocating from the largest carrier side. Further, the precoding matrix #N may be assigned to the smallest carrier and shifted in the direction of subtraction from the precoding matrix #N. That is, the method of assigning index numbers of different precoding matrices in the 17th embodiment is an example, and if the number of data symbols satisfying <Condition # 53> increases, how should the index numbers be assigned? May be good.

The information indicating how to allocate the precoding matrix shown in the 17th embodiment is generated by the weighting information generation unit 314 shown in the 1st embodiment, and the weighting synthesis units 308A, 308B, etc. are generated according to the generated information. Performs precoding.

Also, in the method of regularly switching the precoding matrix, the number of precoding matrices used does not change (that is, different precoding matrices 1F [0], F [1], ..., F [N-1]. ] Is prepared, and F [0], F [1], ... F [N-1] is switched and used), but in frame units, symbol block units composed of complex symbols, etc. It is also possible to switch the precoding matrix allocation method described in the embodiment or other than the present embodiment. At this time, the transmitting device transmits information on the precoding matrix allocation method, and the receiving device knows the precoding allocation method by receiving the information, and decodes the precoding based on the precoding allocation method. Become. As for the allocation method of the precoding matrix, there are predetermined allocation methods, for example, allocation method A, allocation method B, allocation method C, and allocation method D, and the transmitting device has an allocation method from among A to D. Is selected, and information indicating which method A to D is used is transmitted to the receiving device. Then, the receiving device can decode the precoding by obtaining this information.

In the present embodiment, the case where the modulated signals s1, s2 and z1 and z2 are transmitted, that is, the case where the number of streams is 2 and the number of transmitted signals is 2 has been described as an example, but the number of streams and the number of transmitted signals are included in this. The same precoding matrix allocation can be executed even if the number of streams and the number of transmitted signals are not limited to 2 or more. That is, even if there is a stream of modulated signals s3, s4, ..., And the number of transmitted signals of the modulated signals z3, z4, ... The index of the precoding matrix may be switched in the same manner as in z1 and z2.
(Embodiment 18)
In the 17th embodiment, the state in which only the data symbols are arranged has been described. However, in practice, a pilot symbol (described here as a pilot symbol, but which does not transmit data, for example, a known PSK modulation symbol is one suitable example and may be named as a reference symbol or the like). Is used for estimating the channel state, estimating the amount of frequency offset, acquiring time synchronization, detecting signals, estimating phase distortion, etc.), and it is conceivable that there are symbols for transmitting control information. Therefore, in the 18th embodiment, a method of allocating the precoding matrix to the data symbol when the pilot symbol is inserted into the data symbol will be described.

In the 17th embodiment, in FIGS. 63, 64, 65, and 66, an example is shown in which a pilot symbol or a symbol for transmitting control information does not exist at the time when the data symbol exists. .. In such a case, assuming that the start time at which the data symbol is arranged is t1, it is preferable that a pilot symbol or a symbol for transmitting control information exists before t1 (in this case, it may be called a preamble). be.). Further, in order to further improve the reception quality of the data in the receiving device, the pilot symbol may be present at a time after the last time when the data symbol is arranged (see FIG. 68 (a)). Note that FIG. 68 (a) shows the case where the pilot symbol (P) is present, but as described above, this may be replaced with the symbol (C) for transmitting control information.

Further, a specific carrier may have a pilot symbol or a symbol for transmitting control information, which is not a data symbol. As an example, FIG. 68 (b) shows an example in which pilot symbols are arranged on carriers at both ends on the frequency axis. Even in this way, as in the case of the 17th embodiment, there is a feature that many data symbols satisfying <condition # 53> can be present. Further, as shown in FIG. 68 (b), it is not always necessary to arrange pilot symbols at both ends of the frequency axis at the frequency used for the data symbol. For example, the pilot symbol (P) may be arranged on a specific carrier as shown in FIG. 68 (c), or the control information (C) instead of the pilot symbol may be arranged on the specific carrier as shown in FIG. 68 (d). ) May be arranged. Even as shown in FIGS. 68 (c) and 68 (d), many data symbols satisfying <condition # 53> can be present as in the case of the 17th embodiment. In the drawing shown in FIG. 68, the modulated signal is not distinguished, but this is an explanation common to both the modulated signals z1 and z2.

That is, even if a symbol that is not a data symbol such as a pilot symbol or a symbol that transmits control information is placed on a specific subcarrier, it has a feature that many data symbols that satisfy <condition # 53> can exist. Become. Further, as described above, in FIG. 68, a symbol that is not a data symbol, such as a pilot symbol or a symbol for transmitting control information, is placed before the time when the data symbol is first placed, that is, before the time t1. Even so, it has the characteristic that many data symbols that satisfy <condition # 53> can exist.

In addition, there is a feature that many data symbols that satisfy <Condition # 53> can be present even if there is time for only symbols other than the data symbols to exist without arranging the data symbols at a specific time. Will have.

In addition, in FIG. 68, the case where the pilot symbol exists for both the modulation signals z1 and z2 in the same time and the same carrier is described, but the present invention is not limited to this, and for example, the pilot symbol is arranged in the modulation signal z1. , A symbol having zero in-phase I and zero orthogonal Q may be arranged in the modulated signal z2, and conversely, a symbol having zero in-phase I and zero orthogonal Q in the modulated signal z1. May be arranged, and the pilot symbol may be arranged on the modulation signal z2.

Next, in the frame on the time-frequency axis described so far, a frame configuration in which symbols other than the data symbol exist only at a specific time or a specific carrier has been described, but as an example different from these examples. , As shown in FIG. 69, the case where the pilot symbol P changes the subcarrier in which the pilot symbol is present with time will be described. In particular, in the state shown in FIG. 69, the arrangement of the data symbols precoded at the arrangement position of the data symbols (square not described as P) maintains the <condition # 53> shown in the above embodiment 17. The method of allocating the coding matrix will be described. However, as described above, the case where the pilot symbol exists in both the modulation signals z1 and z2 at the same time and the same carrier is described. For example, a pilot symbol is arranged in the modulation signal z1 and the modulation signal is generated. A symbol having zero in-phase I and zero in orthogonal Q may be arranged in z2, and conversely, a symbol having zero in-phase I and zero in orthogonal Q may be arranged in the modulation signal z1. , The configuration may be such that the pilot symbol is arranged in the modulation signal z2.

First, as simply shown in the 17th embodiment, it is conceivable that the index of the precoding matrix to be used is incremented, that is, the index of the precoding matrix is not incremented for symbols other than the data symbols. FIG. 70 shows an example of symbol arrangement in this case. In FIG. 70, as shown in FIG. 67 (a), the index of the precoding matrix is incremented in the frequency axis direction, and the Sc is shifted as the time axis progresses. At this time, when incrementing the index of the precoding matrix in the frequency axis direction, the index of the precoding matrix is not incremented for symbols other than the data symbols. With such a configuration, there is an advantage that the period can be kept constant in the method of regularly switching the precoding matrix, and at the same time, it is possible to have a data symbol satisfying <Condition # 53>. There is an advantage that it can be done.

In particular, if the following conditions are satisfied, the number of data symbols satisfying <Condition # 53> can be increased.

<a> At time i-1, i, i + 1 where data symbols exist, the number of pilot symbols existing at time i-1 is A, the number of pilot symbols existing at time i is B, and the number of pilot symbols existing at time i + 1 exists. Assuming that the number of symbols is C, the difference between A and B is 0 or 1, the difference between B and C is 0 or 1, and the difference between A and C is 0 or 1.

Expressing this condition <a> in another expression,

<a'> In time i-1, i, i + 1 where data symbols exist, the number of data symbols existing in time i-1 exists in α, the number of data symbols existing in time i exists in β, and time i + 1. Assuming that the number of data symbols is γ, the difference between α and β is 0 or 1, the difference between β and γ is 0 or 1, and the difference between α and γ is 0 or 1.

Will be. If the condition <a><a'> is further relaxed,

<B> At time i-1, i, i + 1 where data symbols exist, the number of pilot symbols existing at time i-1 is A, the number of pilot symbols existing at time i is B, and the number of pilot symbols existing at time i + 1 exists. Assuming that the number of symbols is C, the difference between A and B is 0 or 1 or 2, the difference between B and C is 0 or 1 or 2, and the difference between A and C is 0 or 1 or 2.

<B'> In time i-1, i, i + 1 where data symbols exist, the number of data symbols existing in time i-1 exists in α, the number of data symbols existing in time i exists in β, and time i + 1. Assuming that the number of data symbols is γ, the difference between α and β is 0 or 1 or 2, the difference between β and γ is 0 or 1 or 2, and the difference between α and γ is 0 or 1 or 2.

Will be.

In addition, it is better to increase the cycle of the method of regularly switching the precoding matrix, and it is better to set the Sc value to "when X or more and N-X or less, X is a large value". ..

In this way, either the number of times the index of the precoding matrix is incremented at time i-1, the number of times the index of the precoding matrix is incremented at time i, or the number of times the index of the precoding matrix is incremented at time i + 1 is two. This is because it is highly possible that the situation described in the 17th embodiment is maintained because the difference is at most 1 when the above is selected and the difference is calculated.

However, focusing on the symbol 700a in FIG. 70, the precoding matrix used for the symbol 700a and the precoding matrix used for all the adjacent symbols in the frequency axis direction and the time axis direction of the symbol 700a are all different. It is a data symbol that does not satisfy the <condition # 53>, and there is a small number of such data symbols. (However, in FIG. 70, many data symbols satisfy <condition # 53> because the above conditions are satisfied. Also, depending on the allocation method, adjacent data symbols are adjacent to each other. It is possible to satisfy <Condition # 53> with all existing data symbols. This point will be shown by an example in the 20th embodiment.)
Therefore, as another method, there is a configuration method in which the index number of the precoding matrix is incremented even at the position where the pilot symbol is inserted.

FIG. 71 shows an example of the method of allocating the precoding matrix of the data symbol shown in FIG. 63, showing the method of allocating the precoding matrix when the pilot symbol shown in the present embodiment is inserted.

As shown in FIG. 71, the precoding matrix is assigned on the assumption that the data symbol exists even at the position to which the pilot symbol is assigned, that is, the precoding matrix is assigned as in the 17th embodiment. For the positions where the pilot symbols are assigned and the pilot symbols are placed, the precoding matrix numbers used there will be deleted.

By doing so, it is possible to obtain the effect that <condition # 53> is satisfied in all the data symbols in which the data symbols exist in the time axis direction and the frequency axis direction. However, since the pilot symbol is inserted, the cycle of the method of regularly switching the precoding matrix is not fixed.

The information indicating how to allocate the precoding matrix shown in the 18th embodiment is generated by the weighting information generation unit 314 shown in the first embodiment, and the weighting synthesis units 308A, 308B, etc. are generated according to the generated information. May perform precoding and at the same time send information equivalent to this information to the communication partner. (If the rules are predetermined, that is, if the method of allocating the precoding matrix is predetermined between the transmitting side and the receiving side, this information may not be transmitted.) The communication partner does not need to transmit this information. The precoding matrix used by the transmitter is assigned, and the precoding is decoded based on the allocation.

In the present embodiment, the case where the modulated signals s1 and s2 and the modulated signals z1 and z2 are transmitted, that is, the case where the number of streams is 2 and the number of transmitted signals is 2 has been described as an example, but the present invention is not limited to this. , The number of streams and the number of transmitted signals may be larger than 2, or the same precoding matrix may be assigned. That is, even if the streams of s3, s4, ... Are present and the transmission signals of z3, z4, ... Are present, the pres for the symbols in the frequency-time axis frame at z3, z4, ... The index of the coding matrix may be assigned in the same manner as the modulation signals z1 and z2.
(Embodiment 19)
In the 17th embodiment and the 18th embodiment, attention is paid to a data symbol and a total of five data symbols, which are the symbols most adjacent in time and frequency to the data symbol.
An example in which the precoding matrices assigned to these five data symbols are all different has been described. In the 19th embodiment, a method of allocating a precoding matrix that extends the range in which the precoding matrices used differ from each other will be described for adjacent data symbols. In the present embodiment, a range in which all the precoding matrices assigned to all the symbols are different is referred to as a different range for convenience.

In the 17th embodiment and the 18th embodiment, the precoding matrices are assigned so that the precoding matrices used for the data symbols are different from each other for the five data symbols arranged in a cross shape. Here, the range in which the precoding matrices different from each other are assigned to the data symbols is expanded to 9 data symbols of 3 × 3, for example, 3 symbols in the frequency direction and 3 symbols in the time axis direction. For individual data symbols, it is suggested to assign the precoding matrix so that the precoding matrices are all different. By doing so, the reception quality of the data on the receiving side is improved as compared with the case where the precoding matrices obtained by multiplying each other by only five symbols have different symbol arrangements as shown in the above embodiment 17. May be possible. (In the present embodiment, as described above, a case of expanding to N × M data symbols for M symbols in the time axis direction and N symbols in the frequency axis method will be described.)
In the following, such an extension example will be described, then the conditions for realizing this extension example will be described, and the precoding matrix allocation method will be described.

72 to 78 show an example of an extended arrangement of symbols multiplied by a frame configuration and different precoding matrices, respectively.
72 and 73 show an example of the frame configuration of the modulated signal when the difference range is set to the range of 3 × 3, and FIG. 75 shows FIG. 77 when the difference range is extended to the range of 3 × 5. Shows an example when the range is made into a rhombus shape as shown in the figure.

First, in the square difference range as shown in FIGS. 72, 73, and 75, the number of precoding matrices required is different from the number of symbols included in the difference range. It is the number of coding matrices. That is, a minimum number of precoding matrices having different numbers obtained by multiplying the number of symbols in the frequency axis direction included in the difference range by the number of symbols in the time axis direction is required. (As shown in FIG. 73, different precoding matrices may be prepared in a larger number than the above-mentioned minimum number.) That is, when the switching cycle in the method of regularly switching the precoding matrices is Z. The period Z must be N × M or more.

Next, an example of a specific precoding matrix allocation method that realizes the symbol arrangement in which the precoding matrix allocation method shown in FIGS. 72 and 73 is performed will be described.
First, as a method of allocating the precoding matrix in the frequency axis direction, as shown in the 17th embodiment, the precoding matrix of the index number obtained by incrementing the index number of the precoding matrix by 1 is allocated and prepared. When the index number of the precoding matrix is exceeded, the process returns to the precoding matrix # 1 and the precoding matrix is assigned.

Then, even when the precoded symbols are arranged in the time axis direction, Sc is added and assigned in the same manner as in the case described in the above-described 17th embodiment, but at this time, the condition of Sc is implemented. It is different from that shown in the form 17.

The Sc condition described in the 17th embodiment in the present embodiment is N and M when the difference range is extended to N × M data symbols for M symbols in the time axis direction and N symbols in the frequency axis method. If the larger value is L, it must be greater than or equal to the L symbol and less than or equal to Z-L. (The switching cycle in the method of regularly switching the precoding matrix is Z.) However, when N ≠ M, the above may not be satisfied.

In addition, when setting Sc to a number larger than L, a different coding matrix having a larger number than N × M is required as Z, that is, it is preferable to set a large switching cycle.

In the case of a 3 × 3 aspect range as shown in FIGS. 72 and 73, since L is 3, Sc must be an integer of 3 or more and Z-3 or less.
That is, the precoding matrix used for the symbols of carrier f1 and time t1 is the precoding matrix # 1, and when the difference range is 3 × 3, the precoding matrix used for the symbols of carrier f1 and time t2. Is 1 + 3, which is the precoding matrix # 4.

FIG. 74 shows the symbol arrangement of the modulated signal when the precoding matrix is assigned in the different range shown in FIG. 72 and the precoding is executed. As can be seen from FIG. 74, the precoding matrix used for the symbols in the different range is different regardless of the difference range at any point.

In FIG. 74, a precoding matrix having an index number obtained by incrementing the index number of the precoding matrix by 1 is assigned to the frequency axis, and when the index number of the prepared precoding matrix is exceeded, the index number of the precoding matrix is incremented by 1. When returning to the precoding matrix # 1, assigning the precoding matrix, and arranging the precoded symbols in the time axis direction, Sc is added as in the case described in the above embodiment 17. I explained the configuration to be assigned. However, as in the case of the 17th embodiment, in FIG. 74, the vertical axis is considered as frequency and the horizontal axis is considered as time, and the index number of the precoding matrix is incremented by 1 on the time axis. If the index number of the prepared precoding matrix is exceeded, the precoding matrix is assigned again by returning to the precoding matrix # 1, and the precoded symbols are arranged in the frequency axis direction. At the same time, it is possible to carry out the configuration in which Sc is added and allocated in the same manner as in the case described in the above-described 17th embodiment, and also in this case, the above-mentioned Sc condition is an important condition. It becomes.

FIG. 75 shows an example of a frame configuration when the difference range is a range of 3 × 5, and FIG. 76 shows the symbol arrangement of the precoded modulated signal in that case.
As can be seen from FIG. 76, in the time axis direction, the assigned precoding matrix is a precoding matrix shifted by 3 of the number of symbols in the frequency axis direction in the different range. Further, in FIG. 76, it can be seen that no matter where the different range is seen, the precoding matrices assigned to the symbols in the different range all have different configurations.

From the example of FIG. 76, when the difference range is extended to N × M data symbols for M symbols in the time axis direction and N symbols in the frequency axis method, when N ≠ M, Sc described in the 17th embodiment. The condition of can be considered as follows.

A precoding matrix with an index number obtained by incrementing the index number of the precoding matrix by 1 is assigned to the frequency axis, and when the index number of the prepared precoding matrix is exceeded, the precoding matrix # 1 is again assigned. Going back, when allocating the precoding matrix and arranging the precoded symbols in the time axis direction, if Sc is added and assigned as in the case described in the above embodiment 17, Sc is assigned. , Must be greater than or equal to N symbol and less than or equal to Z-N. (The switching cycle in the method of regularly switching the precoding matrix is Z.)
However, even if Sc is set according to the above conditions, the precoding matrices assigned to the symbols within the different range may not all have different configurations. In order to make all the precoding matrices assigned to the symbols in the difference range have different configurations, it is advisable to set a large switching cycle.

Then, a precoding matrix with an index number obtained by incrementing the index number of the precoding matrix by 1 is assigned to the time axis, and when the index number of the prepared precoding matrix is exceeded, the precoding matrix # is also assigned. Returning to 1, when allocating the precoding matrix and arranging the precoded symbols in the frequency axis direction, it is assumed that Sc is added and assigned as in the case described in the above embodiment 17. Sc must be greater than or equal to the M symbol and less than or equal to Z-M.

However, even if Sc is set according to the above conditions, the precoding matrices assigned to the symbols within the different range may not all have different configurations. In order to make all the precoding matrices assigned to the symbols in the difference range have different configurations, it is advisable to set a large switching cycle.

As a matter of course, FIG. 76 satisfies the above condition. In FIG. 76, a precoding matrix having an index number obtained by incrementing the index number of the precoding matrix by 1 is assigned to the frequency axis, and when the index number of the prepared precoding matrix is exceeded, the index number of the precoding matrix is incremented by 1. When returning to the precoding matrix # 1, assigning the precoding matrix, and arranging the precoded symbols in the time axis direction, Sc is added as in the case described in the above embodiment 17. I explained the case of allocating. However, as in the case of the 17th embodiment, in FIG. 76, the vertical axis is considered as frequency and the horizontal axis is considered as time, and the index number of the precoding matrix is incremented by 1 on the time axis. If the index number of the prepared precoding matrix is exceeded, the precoding matrix is assigned again by returning to the precoding matrix # 1, and the precoded symbols are arranged in the frequency axis direction. At the same time, it is possible to carry out the configuration in which Sc is added and allocated in the same manner as in the case described in the above-described 17th embodiment, and also in this case, the above-mentioned Sc condition is an important condition. It becomes.

Further, although the configuration has been described here in which the precoding matrix is shifted by Sc in the time axis direction and the precoding matrix is shifted by 1 in the frequency axis direction, FIGS. 65 and 66 are also used in the above embodiment 17. As described above, a precoding matrix that shifts the precoding matrix by 1 in the time axis direction and shifts the precoding matrix by Sc in the frequency axis direction may be assigned.

Furthermore, even in the diamond-shaped difference range as shown in FIG. 77, the precoding matrices used for all the symbols can be made different from each other in any difference range.

However, in this case, in order to satisfy the above conditions, a precoding matrix of the number obtained by multiplying the maximum number of symbols in the frequency axis direction of this rhombus by the maximum number of symbols in the time axis direction is required. It becomes. That is, in order to realize an arrangement in which the precoding matrices used for all the symbols are different from each other in the rhombic difference range as shown in FIG. 77, 25 (5 (maximum within the difference range in the frequency axis direction) is required. The number of symbols) x 5 (maximum number of symbols within the difference range in the time axis direction)) is required, and when such a rhombus is set as the difference range, the rhombus is substantially changed. It is equivalent to the symbol arrangement with the smallest square to enclose as the different range.

FIG. 78 shows the symbol arrangement when the precoding matrix is assigned when the range of the rhombus shown in FIG. 77 is set as the different range. In FIG. 78, it can be seen that the coding matrices assigned to the symbols included in the different range of each rhombus are all different.

In this way, even when the range in which all the precoding matrices assigned to the symbols are different from each other is extended from the five symbols shown in the seventeenth embodiment, the index of the precoding matrix assigned in the frequency axis direction and the time axis direction is extended. Can be realized by a method of incrementing one by one and allocating while shifting by Sc.

Further, up to this point, the state in which only the data symbols are arranged as in the 17th embodiment has been described, but further, as shown in the 18th embodiment, the arrangement of the data symbols when the pilot symbol is inserted is described. Will be explained.

One of the symbol arrangements when the pilot symbol is inserted is common to the concept shown in the eighteenth embodiment. That is, since the position where the pilot symbol is inserted is predetermined, the number of the precoding matrix that should be assigned to the symbol assigned when the pilot symbol is not placed at the position where the pilot symbol is inserted is skipped. The specification is to multiply the precoding matrix of the next symbol. That is, at the position where the pilot symbol is inserted, a precoding matrix having a number obtained by adding a larger number of the precoding matrix numbers to be assigned to the next data symbol is assigned. That is, in the direction of incrementing the index by 1, the precoding matrix of the number obtained by adding 2 to the number of the precoding matrix assigned to the previous symbol is added, and in the direction of shifting by Sc, the number of adding 2 × Sc is added. Assign a precoding matrix.

FIG. 79 shows an example in which a pilot symbol is inserted in the symbol arrangement shown in FIG. 74. As shown in FIG. 79, at the position where the pilot symbol is inserted, the precoding matrix to be assigned when the data symbol is arranged is skipped, and the precoding matrix is assigned. I understand.

In this way, it is possible to cope with the case where the pilot symbol is inserted even in the difference range in which the range to which the different precoding matrix is assigned is expanded.
The information indicating how to allocate the precoding matrix shown in the 17th embodiment is generated by the weighting information generation unit 314 shown in the 1st embodiment, and the weighting synthesis units 308A, 308B, etc. are generated according to the generated information. May perform precoding and at the same time send information equivalent to this information to the communication partner. (If the rules are predetermined, that is, if the method of allocating the precoding matrix is predetermined between the transmitting side and the receiving side, this information may not be transmitted.) The communication partner does not need to transmit this information. The precoding matrix used by the transmitter is assigned, and the precoding is decoded based on the allocation.

In the present embodiment, the case where the modulated signals s1 and s2 and the modulated signals z1 and z2 are transmitted, that is, the case where the number of streams is 2 and the number of transmitted signals is 2 has been described as an example, but the present invention is not limited to this. , The number of streams and the number of transmitted signals may be larger than 2, or the same precoding matrix may be assigned. That is, even if the streams of s3, s4, ... Are present and the transmission signals of z3, z4, ... Are present, the pres for the symbols in the frequency-time axis frame at z3, z4, ... The index of the coding matrix may be assigned in the same manner as the modulation signals z1 and z2.
(Embodiment 20)
In the above embodiment 18, the case where the index of the precoding matrix to be used is incremented, that is, the case where the index of the precoding matrix is not incremented for symbols other than the data symbols has been described. In this embodiment, an example of precoding matrix allocation in a frame different from that shown in FIG. 70 described in the 18th embodiment, FIGS. 80 and 81 are shown. 80 and 81 show the frame configuration of the modulated signals z1 and z2 on the time-frequency axis, and the index numbers of the pilot symbol, the data symbol, and the precoding matrix used in the data symbol, as in the case of the eighteenth embodiment. , "P" indicates the pilot, the others indicate the data symbol, and # X in the data symbol indicates the index number of the precoding matrix to be used.

FIG. 80 shows an example in which the period of the method of regularly switching the precoding matrix is increased and the Sc value is also increased as compared with FIG. 70. Further, the conditions <a><a'><b><b'> described in the eighteenth embodiment are satisfied. In this way, the number of times the precoding matrix is not incremented does not change significantly even if the time is changed, and therefore the influence of not being incremented on the relationship between the index numbers of the data symbols is small. Therefore, all the data symbols having adjacent data symbols satisfy <Condition # 53>.

As another example, FIG. 81 shows a case where the conditions <a><a'><b><b'> are not satisfied. As can be seen from FIG. 81, for example, 8100, it can be seen that <condition # 53> is not satisfied. This is because the condition described in the eighteenth embodiment is not satisfied, which has a great influence.

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

FIG. 82 is a diagram showing a configuration example of a system including a device for executing the transmission method and the reception method shown in the above embodiment. The transmission method and the reception method shown in each of the above embodiments include a broadcasting station as shown in FIG. 82, a television (television) 8211, a DVD recorder 8212, an STB (Set Top Box) 8213, a computer 8220, and an in-vehicle television. It is implemented in a digital broadcasting system 8200 including various types of receivers such as 8241 and mobile phone 8230. Specifically, the broadcasting station 8201 transmits the multiplexed data in which video data, audio data, and the like are multiplexed to a predetermined transmission band by using the transmission method shown in each of the above embodiments.

The signal transmitted from the broadcasting station 8201 is received by an antenna (for example, antennas 8260, 8240) built in or externally installed in each receiver and connected to the receiver. Each receiver demodulates the signal received at the antenna by using the receiving method shown in each of the above embodiments, and acquires the multiplexed data. Thereby, the digital broadcasting system 8200 can obtain the effect of the present invention described in each of the above embodiments.

Here, the video data included in the multiplexed data is, for example, MPEG (Moving Picture Experts Group) 2 or MPEG4-AVC (Advanced).
It is encoded using a moving image coding method compliant with standards such as Video Coding) and VC-1. 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 The).
atter Systems), DTS-HD, Linear PCM (Pulse Coding)
It is coded by a voice coding method such as Modulation).

FIG. 83 is a diagram showing an example of the configuration of the receiver 7900 that implements the receiving method described in each of the above embodiments. The receiver 8300 shown in FIG. 83 corresponds to the configuration provided in the television (television) 8211 shown in FIG. 82, the DVD recorder 8212, the STB (Set Top Box) 8213, the computer 8220, the in-vehicle television 8241, the mobile phone 8230, and the like. do. The receiver 8300 includes a tuner 8301 that converts a high-frequency signal received by the antenna 8360 into a baseband signal, and a demodulation unit 8302 that demodulates the frequency-converted baseband signal and acquires multiplexed data. The receiving method shown in each of the above embodiments is carried out in the demodulation unit 8302, whereby the effect of the present invention described in each of the above embodiments can be obtained.

Further, the receiver 8300 uses a stream input / output unit 8320 that separates video data and audio data from the multiplexed data obtained by the demodulation unit 8302, and a video decoding method corresponding to the separated video data. A signal processing unit 8304 that decodes 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. It has an 8306 and an image display unit 8307 such as a display for displaying the decoded image signal.

For example, the user uses the remote controller (remote controller) 8350 to transmit information on the selected channel (selected (television) program, selected audio broadcast) to the operation input unit 8310. Then, the receiver 8300 demodulates the signal corresponding to the selected channel in the received signal received by the antenna 8360, performs processing such as error correction and decoding, and obtains the received data. At this time, the receiver 8300 is a transmission method (transmission method, modulation method, error correction method, etc. described in the above embodiment) included in the signal corresponding to the selected channel (for this, FIGS. 5 and 5 and FIG. By obtaining the information of the control symbol including the information of (41), the reception operation, the demodulation method, the error correction / decoding, and the like are correctly set, and the transmission is performed by the broadcasting station (base station). It is possible to obtain the data contained in the data symbol. In the above, the user has described an example of selecting a channel by using the remote controller 8350, but even if the channel is selected by using the channel selection key mounted on the receiver 8300, the same operation as described above can be obtained. Become.

With the above configuration, the user can watch the program received by the receiver 8300 by the receiving method shown in each of the above embodiments.
Further, the receiver 8300 of the present embodiment demodulates with the demodulation unit 8302, and the multiplexed data obtained by decoding the error correction (in some cases, with respect to the signal obtained by demodulation by the demodulation unit 8302). In addition, the receiver 8300 may be subjected to other signal processing after the error correction / decoding. In the following, the same expression may be applied to this point. Is the same.), Data corresponding to the data (for example, data obtained by compressing the data), video, and data obtained by processing audio can be used as a magnetic disk. The recording unit (drive) 8308 for recording on a recording medium such as an optical disk or a non-volatile semiconductor memory is provided. Here, the optical disk is a recording medium such as a DVD (Digital Versaille Disc) or a BD (Blu-ray (registered trademark) Disc) in which information is stored and read out using a laser beam. A magnetic disk is a recording medium such as an FD (Floppy (registered trademark) Disk) or a hard disk (Hard Disk) that stores information by magnetizing a magnetic material using magnetic flux. The non-volatile semiconductor memory is a recording medium composed of semiconductor elements such as a flash memory and a ferroelectric memory (Feroelectric Random Access Memory), and is an S using a flash memory.
Examples include a D card and a Flash SSD (Solid State Drive). It should be noted that the types of recording media listed here are just examples, and it goes without saying that recording may be performed using recording media other than the above-mentioned recording media.

According to the above configuration, the user records and stores the program received by the receiver 8300 by the receiving method shown in each of the above embodiments, and the data recorded at an arbitrary time after the time when the program is broadcast. Can be read and viewed.

In the above description, the receiver 8300 demodulates with the demodulation unit 8302 and records the multiplexed data obtained by decoding the error correction with the recording unit 8308, but the data included in the multiplexed data. Some of the data may be extracted and recorded. For example, when the multiplexed data obtained by demodulating with the demodulating unit 8302 and decoding the error correction includes the contents of the data broadcasting service other than the video data and the audio data, the recording unit 8308 may use the demodulating unit 8302. Video data and audio data may be extracted from the multiplexed data demolished in step 1 and new multiplexed data may be recorded. Further, the recording unit 8308 demodulates with the demodulation unit 8302, and the new multiplexed data in which only one of the video data and the audio data included in the multiplexed data obtained by decoding the error correction is multiplexed. May be recorded. Then, the recording unit 8308 may record the content of the data broadcasting service included in the multiplexed data described above.

Furthermore, if the receiver 8300 described in the present invention is mounted on a television, a recording device (for example, a DVD recorder, a Blu-ray (registered trademark) recorder, an HDD recorder, an SD card, etc.), or a mobile phone, demodulation is performed. Data, personal information, and records for correcting defects (bugs) in the software used to operate televisions and recording devices in the multiplexed data obtained by demodulating in section 8302 and decoding error corrections. If there is data to fix a software defect (bug) to prevent the leakage of the data, you may fix the software defect of the TV or recording device by installing this data. .. Then, if the data includes data for correcting a defect (bug) in the software of the receiver 8300, this data can also be used to correct a defect in the receiver 8300. As a result, the television, recording device, and mobile phone on which the receiver 8300 is mounted can be operated more stably.

Here, the process of extracting a part of the data from the plurality of data included in the multiplexed data obtained by demodulating with the demodulation unit 8302 and decoding the error correction and multiplexing the data is, for example, the stream input / output unit 8303. It is done in. Specifically, the stream input / output unit 8303 converts the multiplexed data demoded by the demodulation unit 8302 into video data, audio data, data broadcasting service content, etc. in response to an instruction from a control unit such as a CPU (not shown). It separates into multiple data, extracts only the specified data from the separated data and multiplexes it, and generates new multiplexed data. The user may decide, for example, which data should be extracted from the separated data, or may be predetermined for each type of recording medium.

With the above configuration, the receiver 8300 can extract and record only the data necessary for viewing the recorded program, so that the data size of the recorded data can be reduced.

Further, in the above description, the recording unit 8308 is supposed to record the multiplexed data obtained by demodulating the data in the demodulatoring unit 8302 and decoding the error correction. The video data included in the multiplexed data obtained by performing the above is different from the video coding method applied to the video data so that the data size or bit rate is lower than that of the video data. It may be converted into video data encoded by the conversion method, and new multiplexed data in which the converted video data is multiplexed may be recorded. At this time, the moving image coding method applied to the original video data and the moving image coding method applied to the converted video data may comply with different standards or conform to the same standard. And only the parameters used at the time of encoding may be different. Similarly, the recording unit 8308 demodulates the voice data included in the multiplexed data obtained by demodulating with the demodulating unit 8302 and decoding the error correction so that the data size or bit rate of the voice data is lower than that of the voice data. , The voice data may be converted into voice data encoded by a voice coding method different from the voice coding method applied to the voice data, and new multiplexed data in which the converted voice data is multiplexed may be recorded.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating with the demodulator 8302 and decoding the error correction into video data and audio data having different data sizes or bit rates is performed. For example, it is performed by the stream input / output unit 8303 and the signal processing unit 8304. Specifically, the stream input / output unit 8303 demodulates with the demodulation unit 8302 according to an instruction from a control unit such as a CPU, and the multiplexed data obtained by decoding the error correction is used as video data, audio data, and the like. Separate into multiple data such as data broadcasting service contents. The signal processing unit 8304 is a process of converting the separated video data into video data encoded by a video coding method different from the video coding method applied to the video data according to an instruction from the control unit. , And the process of converting the separated voice data into voice data encoded by a voice coding method different from the voice coding method applied to the voice data. The stream input / output unit 8303 multiplexes the converted video data and the converted audio data according to an instruction from the control unit, and generates new multiplexed data. Note that the signal processing unit 8304 may perform conversion processing on only one of the video data and the audio data in response to an instruction from the control unit, or may perform conversion processing on both of them. Is also good. Further, the data size or bit rate of the converted video data and audio data may be determined by the user or may be predetermined for each type of recording medium.

With the above configuration, the receiver 8300 changes the data size or bit rate of video data and audio data according to the data size that can be recorded on the recording medium and the speed at which the recording unit 8308 records or reads the data. can do. As a result, when the data size that can be recorded on the recording medium is smaller than the data size of the multiplexed data obtained by demodulating the data in the demodulator 8302 and decoding the error correction, or when the recording unit records or reads the data. Even if the speed at which the data is performed is lower than the bit rate of the multiplexed data demolished by the demodulator 8302, the recording unit can record the program, so that the user can record the program at any time after the broadcast time of the program. It becomes possible to read out and view the data recorded in.

Further, the receiver 8300 includes a stream output IF (Interface) 8309 that transmits the multiplexed data demodulated by the demodulation unit 8302 to the external device via the communication medium 8330. As an example of the stream output IF8309, Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Zigbee (registered trademark), etc. A wireless communication device that transmits multiplexed data modulated using a wireless communication method compliant with the wireless communication standard of the above to an external device via a wireless medium (corresponding to a communication medium 8330). Further, the stream output IF8309 includes Ethernet (registered trademark), USB (Universal Serial Bus), and PLC (Power Line).
A wired transmission line (communication medium 8330) in which multiplexed data modulated using a communication method compliant with a wired communication standard such as Communication) or HDMI (registered trademark) (High-Definition Multimedia Interface) is connected to the stream output IF8309. It may be a wired communication device that transmits to an external device via (corresponding to).

With the above configuration, the user can use the multiplexed data received by the receiver 8300 by the receiving method shown in each of the above embodiments in the external device. The use of multiplexed data here means that the user can view the multiplexed data in real time using an external device, record the multiplexed data in the recording unit provided in the external device, and further from the external device. Includes sending multiplexed data to another external device, etc.

In the above description, the receiver 8300 demodulates with the demodulation unit 8302, and the stream output IF8309 outputs the multiplexed data obtained by decoding the error correction. However, the data included in the multiplexed data. Some of the data may be extracted and output. For example, when the multiplexed data obtained by demodulating with the demodulating unit 8302 and decoding the error correction includes the contents of the data broadcasting service other than the video data and the audio data, the stream output IF 8309 uses the demodulating unit 8302. You may output the new multiplexed data by extracting the video data and the audio data from the multiplexed data obtained by demodulating with and decoding the error correction. Further, the stream output IF 8309 may output new multiplexed data in which only one of the video data and the audio data included in the multiplexed data demodulated by the demodulation unit 8302 is multiplexed.

Here, the process of extracting a part of the data from the plurality of data included in the multiplexed data obtained by demodulating with the demodulation unit 8302 and decoding the error correction and multiplexing the data is, for example, the stream input / output unit 8303. It is done in. Specifically, the stream input / output unit 8303 broadcasts the multiplexed data demoded by the demodulation unit 8302 as video data, audio data, and data broadcasting according to an instruction from a control unit such as a CPU (Central Processing Unit) (not shown). It separates into multiple data such as service contents, extracts only the specified data from the separated data and multiplexes it, and generates new multiplexed data. The user may determine, for example, which data should be extracted from the separated data, or may be predetermined for each type of stream output IF8309.

With the above configuration, the receiver 8300 can extract and output only the data required by the external device, so that the communication band consumed by the output of the multiplexed data can be reduced.

Further, in the above description, the stream output IF 8309 is demodrated by the demodulator 8302 and records the multiplexed data obtained by decoding the error correction. The video data included in the multiplexed data obtained by performing the above is different from the video coding method applied to the video data so that the data size or bit rate is lower than that of the video data. It may be converted into video data encoded by the conversion method, and new multiplexed data in which the converted video data is multiplexed may be output. At this time, the moving image coding method applied to the original video data and the moving image coding method applied to the converted video data may comply with different standards or conform to the same standard. And only the parameters used at the time of encoding may be different. Similarly, the stream output IF 8309 has the audio data included in the multiplexed data obtained by demodulating with the demodulator 8302 and decoding the error correction so that the data size or bit rate is lower than that of the audio data. , The voice data may be converted into voice data encoded by a voice coding method different from the voice coding method applied to the voice data, and new multiplexed data in which the converted voice data is multiplexed may be output.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating with the demodulator 8302 and decoding the error correction into video data and audio data having different data sizes or bit rates is performed. For example, it is performed by the stream input / output unit 8303 and the signal processing unit 8304. Specifically, the stream input / output unit 8303 demodulates with the demodulation unit 8302 according to an instruction from the control unit, and the multiplexed data obtained by decoding the error correction is video data, audio data, and a data broadcasting service. Separate into multiple data such as the contents of. The signal processing unit 8304 is a process of converting the separated video data into video data encoded by a video coding method different from the video coding method applied to the video data according to an instruction from the control unit. , And the process of converting the separated voice data into voice data encoded by a voice coding method different from the voice coding method applied to the voice data. The stream input / output unit 8303 multiplexes the converted video data and the converted audio data according to an instruction from the control unit, and generates new multiplexed data. Note that the signal processing unit 8304 may perform conversion processing on only one of the video data and the audio data in response to an instruction from the control unit, or may perform conversion processing on both of them. Is also good. Further, the data size or bit rate of the converted video data and audio data may be determined by the user or may be predetermined for each type of stream output IF8309.

With the above configuration, the receiver 8300 can change the bit rate of the video data and the audio data according to the communication speed with the external device and output the data. As a result, even if the communication speed with the external device is lower than the bit rate of the multiplexed data obtained by demodulating with the demodulation unit 8302 and performing error correction decoding, the external device new multiplexing from the stream output IF. Since the demodulated data can be output, the user can use the new multiplexed data in other communication devices.

Further, the receiver 8300 includes an AV (Audio and Visual) output IF (Interface) 8311 that outputs a video signal and an audio signal decoded by the signal processing unit 8304 to an external device to an external communication medium. As an example of AV output IF8311, wireless communication standards such as Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WiressHD, Bluetooth (registered trademark), Gigibee, etc. Examples thereof include a wireless communication device that transmits a video signal and an audio signal modulated by using a wireless communication method compliant with the above to an external device via a wireless medium. Further, the stream output IF8309 connects a video signal and an audio signal modulated by using a communication method compliant with a wired communication standard such as Ethernet (registered trademark), USB, PLC, and HDMI (registered trademark) to the stream output IF8309. It may be a wired communication device that transmits to an external device via the wired transmission line. Further, the stream output IF8309 may be a terminal for connecting a cable that outputs a video signal and an audio signal as analog signals.

With the above configuration, the user can use the video signal and the audio signal decoded by the signal processing unit 8304 in an external device.
Further, the receiver 8300 includes an operation input unit 8310 that receives an input of a user operation. The receiver 8300 switches the power ON / OFF, the receiving channel, the presence / absence of subtitle display, and the language to be displayed based on the control signal input to the operation input unit 8310 according to the user's operation. , Switching various operations such as changing the volume output from the audio output unit 8306, and changing the settings such as the setting of the receivable channel.

Further, the receiver 8300 may have a function of displaying an antenna level indicating the reception quality of the signal being received by the receiver 8300. Here, the antenna level is, for example, RSSI (Received Signal Strength Indicator, Received Signal Strength), received electric field strength, C / N (Carrier-to-noise power) of the signal received by the receiver 8300. , 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) and the like, and is a signal indicating the signal level and the superiority or inferiority of the signal. In this case, the demodulation unit 8302 includes a reception quality measurement unit that measures RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, etc. of the received signal, and the receiver 8300 is a user. The antenna level (signal level, signal indicating superiority or inferiority of the signal) is displayed on the video display unit 8307 in a user-identifiable format according to the operation of. The display format of the antenna level (signal level, signal indicating superiority or inferiority of the signal) displays numerical values according to RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, etc. It may be such that different images are displayed according to RSSI, received electric field strength, C / N, BER, packet error rate, frame error rate, channel state information, and the like. Further, the receiver 8300 has a plurality of antenna levels (signal level, signal) obtained for each of a plurality of streams s1, s2, ... Received and separated by using the receiving method shown in each of the above embodiments. A signal indicating superiority or inferiority) may be displayed, or one antenna level (signal level, signal indicating superiority or inferiority of the signal) obtained from a plurality of streams s1, s2, ... May be displayed. Further, when the video data and the audio data constituting the program are transmitted by the hierarchical transmission method, it is also possible to indicate the signal level (signal indicating superiority or inferiority of the signal) for each layer.

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 8300 includes an audio output unit 8306, a video display unit 8307, a recording unit 8308, a stream output IF8309, and an AV output IF8311 has been described as an example, but these configurations have been described. You don't have to have all of them. If the receiver 8300 has at least one of the above configurations, the user can demodulate with the demodulation unit 8302 and use the multiplexed data obtained by decoding the error correction. , Each receiver may be provided with any combination of the above configurations according to the intended use.
(Multiplexed data)
Next, an example of the structure of the multiplexed data will be described in detail. MPEG2-Transport Stream (TS) is generally used as a data structure used for broadcasting, and MPEG2-TS will be described here as an example. However, the data structure of the multiplexed data transmitted by the transmission method and the 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, you can get the same effect.

FIG. 84 is a diagram showing an example of the configuration of multiplexed data. As shown in FIG. 84, the multiplexed data is an element that constitutes a program (program or an event that is a part thereof) currently provided by each service, for example, a video stream, an audio stream, or a presentation graphics stream (PG). ), Interactive Grafix Stream (IG), etc., obtained by multiplexing one or more of the elemental streams. If the program provided by the multiplexed data is a movie, the video stream is the main video and sub video of the movie, and the audio stream is the main audio part of the movie and the sub audio that mixes with the main audio, as the presentation graphics stream. Shows the subtitles of each movie. Here, the main image is a normal image displayed on the screen, and the sub image is an image displayed on a small screen in the main image (for example, a text data image showing the outline of a movie). be. Further, the interactive graphics stream shows an interactive screen created by arranging GUI components on the screen.

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

FIG. 85 is a diagram schematically showing an example of how the multiplexed data is multiplexed. First, a video stream 8501 composed of a plurality of video frames and an audio stream 8504 composed of a plurality of audio frames are converted into PES packet strings 8502 and 8505, respectively, and converted into TS packets 8503 and 8506, respectively. Similarly, the data of the presentation graphics stream 8511 and the interactive graphics 8514 are converted into PES packet sequences 8512 and 8515, respectively, and further converted into TS packets 8513 and 8516. The multiplexing data 8517 is configured by multiplexing these TS packets (8503, 8506, 8513, 8516) into one stream.

FIG. 86 shows in more detail how the video stream is stored in the PES packet sequence. The first stage in FIG. 86 shows a video frame sequence of a video stream. The second stage shows the PES packet sequence. As shown by arrows yy1, yy2, yy3, yy4 in FIG. 86, I-pictures, B-pictures, and P-pictures, which are a plurality of Video Presentation Units in the video stream, are divided into pictures and stored in the payload of the PES packet. .. Each PES packet has a PES header, and the PTS header stores PTS (Presentation Time-Stamp), which is the display time of the picture, and DTS (Decoding Time-Stamp), which is the decoding time of the picture.

FIG. 87 shows the format of the TS packet that is finally written to the multiplexed data. The 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, and the PES packet is divided and stored in the TS payload. Ru. In the case of a BD-ROM, a 4 BYte TP_Extra_Header is added to the TS packet to form a 192 BYte source packet, which is written to 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. As shown in the lower part of FIG. 87, source packets are arranged in the multiplexed data, and the number incremented from the beginning of the multiplexed data is called SPN (source packet number).

In addition to each stream such as a video stream, an audio stream, and a presentation graphics stream, the TS packet included in the multiplexed data includes PAT (Program Association Table) and PMT (Program).
Map Table), PCR (Program Lock 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, and subtitles contained in the multiplexed data and the attribute information (frame rate, aspect ratio, etc.) of the stream corresponding to each PID, and also contains various descriptors related to the multiplexed data. Have. Descriptors include copy control information that instructs whether to allow or disallow 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. Has information on STC time.

FIG. 88 is a diagram illustrating the data structure of the PMT in detail. At the beginning of the PMT, a PMT header describing the length of the data included in the PMT is arranged. Behind it, a plurality of descriptors related to the multiplexed data are arranged. The copy control information and the like are described as descriptors. After the descriptor, a plurality of stream information about each stream included in the multiplexed data is arranged. The stream information is composed of a stream descriptor for describing a stream type for identifying a stream compression codec and the like, 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. 89 is a diagram showing the structure of the multiplexed data file information. As shown in FIG. 89, the multiplexed data information file is management information of the multiplexed data, has a one-to-one correspondence with the multiplexed data, and is composed of the multiplexed data information, the stream attribute information, and the entry map.

As shown in FIG. 89, the multiplexed data information is composed of a system rate, a reproduction start time, and a reproduction end time. The system rate indicates the maximum transfer rate of the multiplexed data to the PID filter of the system target decoder described later. The ATS interval included in the multiplexed data is set to be less than or equal to the system rate. The reproduction start time is set to the PTS of the video frame at the beginning of the multiplexed data, and the reproduction end time is set to the PTS of the video frame at the end of the multiplexed data plus the reproduction interval for one frame.

FIG. 90 is a diagram showing a configuration of stream attribute information included in the multiplexed data file information. As the stream attribute information, as shown in FIG. 90, the attribute information for each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each of the 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 the individual picture data that makes up the video stream is, what the aspect ratio is, and the frame rate. It has information such as how much it is. The audio stream attribute information includes what compression codec the audio stream was compressed with, what number of channels the audio stream contains, what language it supports, what sampling frequency it is, and so on. Have information on. This information is used for initializing the decoder before the player plays it.

In the present embodiment, among the above-mentioned multiplexed data, the stream type included in the PMT is used. When the multiplexed data is recorded on the recording medium, the video stream attribute information included in the multiplexed data information is used. Specifically, in the moving image coding method or apparatus shown in each of the above embodiments, the moving image coding shown in each of the above embodiments is applied to the stream type or video stream attribute information included in the PMT. Provide steps or means to set unique information indicating that the video data is generated by the method or device. With this configuration, it becomes possible to distinguish between the video data generated by the moving image coding method or the apparatus shown in each of the above embodiments and the video data conforming to other standards.

FIG. 91 is an example of the configuration of a video / audio output device 9100 including a receiving device 9104 that receives video and audio data transmitted from a broadcasting station (base station) or a modulated signal including data for data broadcasting. Is shown. The configuration of the receiving device 9104 corresponds to the receiving device 8300 in FIG. The video / audio output device 9100 is equipped with, for example, an OS (Operating System), and is for a communication device 9106 (for example, a wireless LAN (Local Area Network) or an Ethernet) for connecting to the Internet. Communication device) is installed. As a result, in the part 9101 for displaying the video, the video 9102 in the video and audio data or the data for data broadcasting, and the hypertext provided on the Internet (World Wide Web (WWW)). ) 9103 can be displayed at the same time. Then, by operating the remote controller (which may be a mobile phone or keyboard) 9107, either the video 9102 in the data for data broadcasting or the hypertext 9103 provided on the Internet is selected and the operation is changed. Will be done. For example, when the hypertext 9103 provided on the Internet is selected, the displayed WWW site can be changed by operating the remote controller. Further, when the video 9102 in the video and audio data or the data for data broadcasting is selected, the channel selected by the remote controller 9107 (selected (television) program, selected audio broadcast). Send information. Then, the IF 9105 acquires the information transmitted by the remote controller, and the receiving device 9104 demodulates the signal corresponding to the selected channel, performs processing such as error correction and decoding, and obtains the received data. At this time, the receiving device 9104 obtains the information of the control symbol including the information of the transmission method (this is as described in FIGS. 5 and 41) included in the signal corresponding to the selected channel. By correctly setting the reception operation, demodulation method, error correction / decoding method, etc., it is possible to obtain the data included in the data symbol transmitted by the broadcasting station (base station). In the above, the user has described an example of selecting a channel by using the remote controller 9107, but the same as above can be obtained even if the channel is selected by using the channel selection key mounted on the video / audio output device 9100. It becomes an operation.

Further, the video / audio output device 9100 may be operated using the Internet. For example, a recording (memory) reservation is made to the video / audio output device 9100 from another terminal connected to the Internet. (Therefore, the video / audio output device 9100 has a recording unit 8308 as shown in FIG. 83.) Then, before starting recording, the channel is selected and the receiving device 9104 is selected. Will demodulate the signal corresponding to the selected channel, perform processing such as error correction and decoding, and obtain received data. At this time, the receiving device 9104 is a transmission method (transmission method, modulation method, error correction method, etc. described in the above embodiment) included in the signal corresponding to the selected channel (for this, FIGS. 5, FIG. By obtaining the information of the control symbol including the information of (41), the reception operation, the demodulation method, the error correction / decoding, and the like are correctly set, and the transmission is performed by the broadcasting station (base station). It is possible to obtain the data contained in the data symbol.

(Other supplements)
In the present specification, it is considered that a transmission device is provided in, for example, a communication / broadcasting device such as a broadcasting station, a base station, an access point, a terminal, or a mobile phone (mobile phone). It is conceivable that the receiver is equipped with a communication device such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, and a base station. Further, the transmitting device and the receiving device in the present invention are devices having a communication function, and the device has some kind of interface to a device for executing an application such as a television, a radio, a personal computer, and a mobile phone. For example, it may be possible to connect via USB).

Further, in the present embodiment, no matter how symbols other than the data symbols, such as pilot symbols (preamble, unique word, postamble, reference symbol, etc.), symbols for control information, etc., are arranged in the frame. good. Here, the names are pilot symbols and symbols for control information, but any naming method may be used, and the function itself is important.

The pilot symbol may be, for example, a known symbol modulated using PSK modulation in the transmitter / receiver (or by synchronizing the receiver, the receiver may be able to know the symbol transmitted by the transmitter. ), And the receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation (estimation of CSI (Channel State Information)) (estimation of CSI (Channel State Information)), signal detection, and the like. Become.

In addition, the symbol for control information is information that needs to be transmitted to the communication partner (for example, the modulation method / error correction coding method used for communication) in order to realize communication other than data (such as an application). It is a symbol for transmitting error correction coding method coding rate, setting information in the upper layer, etc.).

The present invention is not limited to all the above-described embodiments, and various modifications can be made. For example, in the above embodiment, the case of performing as a communication device is described, but the present invention is not limited to this, and this communication method can also be performed as software.

Further, in the above, the precoding switching method in the method of transmitting two modulated signals from two antennas has been described, but the present invention is not limited to this, and precoding is performed on the four mapped signals, and 4 In the method of generating one modulated signal and transmitting it from four antennas, that is, the method of precoding the N mapped signals, generating N modulated signals, and transmitting them from N antennas. Similarly, the precoding weight (matrix) can be changed as well as the precoding switching method.

In this specification, terms such as "precoding", "precoding matrix", and "precoding weight matrix" are used, but the name itself may be anything (for example, it is referred to as a codebook). In the present invention, the signal processing itself is important.

Further, in this specification, the receiving device is described by using the ML operation, APP, Max-logAPP, ZF, MMSE, etc., but as a result, the soft determination result of each bit of the data transmitted by the transmitting device ( A log-likelihood, a log-likelihood ratio) and a rigid determination result (“0” or “1”) will be obtained, which may be collectively referred to as detection, demodulation, detection, estimation, and separation.

Different data may be transmitted or the same data may be transmitted depending on the streams s1 (t) and s2 (t).
A precoding matrix that regularly switches the precoding matrix for two streams of baseband signals s ₁ (i) and s ₂ (i) (where i represents the order (of time or frequency (carrier))). In the precoded baseband signals z ₁ (i) and z ₂ (i) generated by coding, the in-phase I component of the precoded baseband signal z ₁ (i) is referred to as I ₁ (i), z 2 (i). Let Q ₁ (i) be the orthogonal component, I ₂ (i) be the in-phase I component of the baseband signal z ₂ (i) after precoding, and Q ₂ (i) be the orthogonal component. At this time, replace the baseband components and replace them.

The in-phase component of the replaced baseband signal r ₁ (i) is I ₁ (i), the orthogonal component is Q ₂ (i), and the in-phase component of the replaced base band signal r ₂ (i) is I ₂ (i). ), Q for the orthogonal component
₁ (i)
The modulated signal corresponding to the replaced baseband signal r1 (i) is transmitted from the transmitting antenna ₁ , and the modulated signal corresponding to the replaced baseband signal r2 (i) is transmitted from the transmitting antenna ₂ at the same time and frequency. The modulated signal corresponding to the replaced baseband signal r ₁ (i) and the replaced baseband signal r ₂ (i) are transmitted from different antennas at the same time and at the same frequency. May be sent. again,

-The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (
i) The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i), and the orthogonal component is Q ₂ (i).
-The in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (
i) The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₁ (i), and the orthogonal component is Q ₂ (i).
-The in-phase component of the baseband signal r ₁ (i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (
i) The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i), and the orthogonal component is Q ₁ (i).
-The in-phase component of the baseband signal r ₁ (i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (
i) The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i), and the orthogonal component is Q ₁ (i).
The in-phase component of the replaced baseband signal r ₁ (i) is I ₁ (i), the orthogonal component is Q ₂ (i), and the in-phase component of the replaced base band signal r ₂ (i) is Q ₁ (i). ), Orthogonal component I ₂ (i)
The in-phase component of the replaced baseband signal r ₁ (i) is Q ₂ (i), the orthogonal component is I ₁ (i), and the in-phase component of the replaced base band signal r ₂ (i) is I ₂ (i). ), The orthogonal component is Q ₁ (i)
The in-phase component of the replaced baseband signal r ₁ (i) is Q ₂ (i), the orthogonal component is I ₁ (i), and the in-phase component of the replaced base band signal r ₂ (i) is Q ₁ (i). ), Orthogonal component I ₂ (i)
-The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (
i) The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i), and the orthogonal component is Q ₂ (i).
-The in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (
i) The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i), and the orthogonal component is Q ₂ (i).
-The in-phase component of the baseband signal r ₂ (i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (
i) The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), and the orthogonal component is Q ₁ (i).
-The in-phase component of the baseband signal r ₂ (i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (
i) The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₂ (i), and the orthogonal component is Q ₁ (i).
The in-phase component of the replaced baseband signal r ₂ (i) is I ₁ (i), the orthogonal component is Q ₂ (i), and the in-phase component of the replaced base band signal r ₁ (i) is I ₂ (i). ), The orthogonal component is Q ₁ (i)
The in-phase component of the replaced baseband signal r ₂ (i) is I ₁ (i), the orthogonal component is Q ₂ (i), and the in-phase component of the replaced base band signal r ₁ (i) is Q ₁ (i). ), Orthogonal component I ₂ (i)
The in-phase component of the replaced baseband signal r ₂ (i) is Q ₂ (i), the orthogonal component is I ₁ (i), and the in-phase component of the replaced base band signal r ₁ (i) is I ₂ (i). ), Orthogonal component Q ₁ (i)
-The in-phase component of the baseband signal r ₂ (i) after replacement is Q ₂ (i), and the orthogonal component is I ₁ (
i) The in-phase component of the baseband signal r ₁ (i) after replacement is Q ₁ (i), and the orthogonal component is I ₂ (i).

May be. Further, in the above, precoding is performed on the signals of two streams, and the replacement of the in-phase component and the orthogonal component of the signal after precoding has been described. It is also possible to perform coding and replace the in-phase component and the orthogonal component of the signal after precoding.

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

Further, in the present specification, the unit of phase in the complex plane, for example, the argument angle, is referred to as "radian".
By using the complex plane, it can be displayed in polar format as a display in polar coordinates of complex numbers. Complex number
When a point (a, b) on the complex plane is associated with z = a + jb (both a and b are real numbers and j is an imaginary unit), this point is in polar coordinates [r, θ]. If it is expressed,
a = r × cos θ,
b = r × sinθ

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

Further, in the method of assigning different precoding matrices described in the present specification to frames (time axis and / or frequency axis) (for example, Embodiment 1, Embodiment 17 to Embodiment 20), the present specification. The same can be performed by using a precoding matrix different from the different precoding matrix described above. Similarly, when the method of regularly switching the precoding matrix and another transmission method coexist or are switched, the precoding is different from the method of regularly switching using the different precoding matrix described in the present specification. It can also be implemented as a method of switching regularly using a coding matrix.

FIG. 59 shows an example of a broadcasting system using the method of regularly switching the precoding matrix described in the present specification. In FIG. 59, the video coding unit 5901 receives video as an input, performs video coding, and outputs data 5902 after video coding. The voice coding unit 5903 receives voice as an input, performs voice coding, and outputs data 5904 after voice coding. The data coding unit 5905 takes data as an input, encodes the data (for example, data compression), and outputs the data 5906 after the data coding. Collectively, these are referred to as an information source coding unit 5900.

The transmission unit 5907 inputs data 5902 after video coding, data 5904 after audio coding, and data 5906 after data coding, and any one of these data or all of these data is used as transmission data. It performs processing such as error correction coding, modulation, and precoding (for example, signal processing in the transmission device of FIG. 3), and outputs transmission signals 5908_1 to 5908_N. Then, the transmission signals 5908_1 to 5908_N are transmitted as radio waves by the antennas 5909_1 to 5909_N, respectively.

The receiving unit 5912 receives the received signals 5911_1 to 5911_M received by the antennas 5910_1 to 5910_M as inputs, and performs processing such as frequency conversion, precoding decoding, log-likelihood ratio calculation, error correction decoding (for example, in the receiving device of FIG. 7). Processing) is performed, and the received data 5913, 5915, 5917 are output. The information source decoding unit 5919 inputs received data 5913, 5915, 5917, and the video decoding unit 5914 inputs received data 5913, decodes for video, outputs a video signal, and outputs the video signal to the television. Displayed on the display. Further, the voice decoding unit 5916 receives the received data 5915 as an input. Decoding for audio is performed, an audio signal is output, and audio flows from a speaker. Further, the data decoding unit 5918 receives the received data 5917 as an input, decodes the data, and outputs the data information.

Further, in the embodiment in which the present invention is described, in the multi-carrier transmission system such as the OFDM system as described above, the number of encoders possessed by the transmitter is any number. You may. Therefore, for example, as shown in FIG. 4, it is naturally possible to apply the method in which the transmitting device includes one encoder and distributes the output to a multi-carrier transmission system such as an OFDM system. At this time, the wireless units 310A and 310B in FIG. 4 may be replaced with the OFDM method related processing units 1301A and 1301B in FIG. At this time, the description of the OFDM method-related processing unit is as in the first embodiment.

Further, although it is described in the present specification as "a method of switching between different precoding matrices", the "method of switching between different precoding matrices" specifically described in the present specification is an example and is described in the present specification. In all the embodiments described, the "method of switching different precoding matrices" may be replaced with "method of regularly switching precoding matrices using a plurality of different precoding matrices". Can be carried out.

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

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

Then, each configuration such as each of the above-described embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip so as to include all or a part of the configurations of each embodiment. Although it is referred to as an LSI here, it may be referred to as an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. Further, the method of making an integrated circuit is not limited to the 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 the connection and settings of the circuit cells inside the LSI may be used.

Further, if an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology or another technology derived from it, it is naturally possible to integrate functional blocks using that technology. There is a possibility of adaptation of biotechnology.
The precoding method according to the embodiment of the present invention has a plurality of precoding matrices for performing precoding, and is a first modulation signal and a second modulation signal composed of in-phase components and orthogonal components based on the modulation method. It is a precoding method for generating a first transmission signal and a second transmission signal after precoding by using each of them and one of the plurality of precoding matrices, wherein the first transmission signal and the second transmission are transmitted. The precoding matrix for generating the signal is regularly switched from the plurality of precoding matrices, and the first symbol, which is one data symbol used for data transmission of the first modulated signal, and the second symbol. Of the second symbol, which is one data symbol used for data transmission of the modulated signal, the first time and the first frequency to be transmitted with the first symbol precoded and the second symbol are precoded. Regarding the first symbol and the second symbol that coincide with the second time and the second frequency to be transmitted, the two third symbols adjacent to each other in the frequency direction of the first symbol are both data symbols, and the first symbol. When two fourth symbols adjacent to each other in the time axis direction of one symbol are both data symbols, the first symbol, the two third symbols, and the two fourth symbols, a total of four symbols, are different from each other. Using the precoding matrix, precoding is performed to generate the first transmission signal, and the second symbol, the two fifth symbols adjacent in the frequency direction of the second symbol, and the second symbol Precoding matrix used for the first symbol, the two third symbols, and the two fourth symbols whose time and frequency match with respect to the two sixth symbols adjacent to each other in the time axis direction. It is characterized in that the precoding is executed using the same precoding matrix as the above to generate the second transmission signal.

Further, the signal processing device that executes the precoding method according to the embodiment of the present invention has a plurality of precoding matrices for performing precoding, and is the first modulation composed of in-phase components and orthogonal components based on the modulation method. A signal processing device that generates a precoded first transmission signal and a second transmission signal by using each of a signal and a second modulation signal and one of the plurality of precoding matrices, and is the first transmission. The precoding matrix for generating the signal and the second transmission signal is regularly switched from the plurality of precoding matrices, and is a first data symbol used for data transmission of the first modulated signal. Of the symbol and the second symbol which is one data symbol used for data transmission of the second modulated signal, the first time and the first frequency to which the first symbol is precoded and transmitted, and the second. For the first symbol and the second symbol whose symbols are precoded and coincide with the second time and the second frequency to be transmitted, the two third symbols adjacent to each other in the frequency direction of the first symbol are both data. When the two fourth symbols that are symbols and are adjacent to each other in the time axis direction of the first symbol are both data symbols, the sum of the first symbol, the two third symbols, and the two fourth symbols. In the four symbols, different precoding matrices are used to perform precoding to generate the first transmission signal, the second symbol and the two fifth symbols adjacent in the frequency direction of the second symbol. With respect to the two sixth symbols adjacent to each other in the time axis direction of the second symbol, the symbol having the same time and frequency among the first symbol, the two third symbols, and the two fourth symbols. Using the same precoding matrix as the precoding matrix used in the above, precoding is executed to generate the second transmission signal.

The present invention can be widely applied to a wireless system that transmits different modulated signals from a plurality of antennas, and is suitable for application to, for example, an OFDM-MIMO communication system. It also applies to the case of performing MIMO transmission in a wired communication system having a plurality of transmission points (for example, a PLC (Power Line Communication) system, an optical communication system, or a DSL (Digital Subscriber Line) system). At this time, a plurality of modulated signals as described in the present invention will be transmitted by using the plurality of transmission points. Further, the modulated signal may be transmitted from a plurality of transmission points.

302A, 302B Encoders 304A, 304B Interleaver 306A, 306B Mapping unit 314 Weighted synthesis information generator 308A, 308B Weighted synthesizer 310A, 310B Radio unit 312A, 312B Antenna 402 Indicator 404 Distributor 504 # 1,504 # 2 Transmit antenna 505 # 1,505 # 2 Receive antenna 600 Weighted synthesis unit 703_X Radio unit 701_X Antenna 705_1 Channel fluctuation estimation unit 705_2 Channel fluctuation estimation unit 707_1 Channel fluctuation estimation unit 707_2 Channel fluctuation estimation unit 709 Control information decoding unit 711 Signal processing unit 803 INNER MIMO detection unit 805A, 805B Log likelihood calculation unit 807A, 807B Deinterriver 809A, 809B Log likelihood ratio calculation unit 811A, 811B Soft-in / soft-out decoder 813A, 813B Interleaver 815 Storage unit 819 Weighting coefficient generation unit 901 Soft-in / soft-out decoder 903 Distributor 1301A, 1301B MIMO related processing unit 1402A, 1402A Serial parallel conversion unit 1404A, 1404B Sorting unit 1406A, 1406B Inverse high-speed Fourier conversion unit 1408A, 1408B Wireless unit 2200 Precoding weight matrix Generation unit 2300 Sorting unit 4002 Encoder group

Claims (2)

It ’s a transmission method.
Interleave the transmit bit string and
The first modulation signal and the second modulation signal are generated from the transmitted bit string after interleaving, and the first modulation signal and the second modulation signal are generated.
The first transmission signal and the second transmission signal are generated from the first modulation signal and the second modulation signal, and the relationship between the first modulation signal and the second modulation signal and the first transmission signal and the second transmission signal is , Represented by one of several precoding matrices,
The first transmission signal and the second transmission signal are transmitted by using a plurality of antennas.
Eight peripheral symbols other than the first symbol position, which are arranged at the same frequency as or adjacent to the first symbol position and at the same time or adjacent time to the first symbol position, and at the same time or adjacent time to the first symbol position. When the symbol of the first transmission signal and the symbol of the second transmission signal are transmitted at each of the positions,
The precoding matrix used to generate the symbol of the first transmission signal and the symbol of the second transmission signal transmitted at the first symbol position is the first transmission signal transmitted at the eight peripheral symbol positions. Unlike either the symbol or the precoding matrix used to generate the symbol for the second transmit signal,
A transmission method in which a pilot signal is arranged at a second symbol position having the same time as the first symbol position and a frequency not adjacent to the first symbol position. It ’s a transmitter,
An interleaving part that interleaves the transmission bit string,
A modulation unit that generates a first modulation signal and a second modulation signal from the transmitted bit string after interleaving, and a modulation unit.
The first transmission signal and the second transmission signal are generated from the first modulation signal and the second modulation signal, and the relationship between the first modulation signal and the second modulation signal and the first transmission signal and the second transmission signal is , A signal processing unit, represented by one of multiple precoding matrices,
A transmission unit that transmits the first transmission signal and the second transmission signal using a plurality of antennas is provided.
Eight peripheral symbols other than the first symbol position, which are arranged at the same frequency as or adjacent to the first symbol position and at the same time or adjacent time to the first symbol position, and at the same time or adjacent time to the first symbol position. When the symbol of the first transmission signal and the symbol of the second transmission signal are transmitted at each of the positions,
The precoding matrix used to generate the symbol of the first transmission signal and the symbol of the second transmission signal transmitted at the first symbol position is the first transmission signal transmitted at the eight peripheral symbol positions. Unlike either the symbol or the precoding matrix used to generate the symbol for the second transmit signal,
A transmission device in which a pilot signal is arranged at a second symbol position having the same time as the first symbol position and a frequency not adjacent to the first symbol position.

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