JP7417911B2 - Transmitter and receiver - Google Patents

Description

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

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

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

At this time, Patent Document 1 proposes a transmitting device having a different interleaving pattern for each transmitting antenna. In other words, in the transmitting device of FIG. 23, the two interleave patterns (πa, πb) have different interleaving 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. 23). I will do it.

By the way, as models of actual propagation environments in wireless communication, there are an NLOS (non-line of sight) environment, represented by a Rayleigh fading environment, and a LOS (line of sight) environment, represented by a Rician fading environment. When a transmitting device transmits a single modulated signal, a receiving device performs maximum ratio combining on the signals received by multiple antennas, and demodulates and decodes the signal after maximum ratio combining, the LOS environment, Particularly in an environment where the Rice factor, which indicates the magnitude of the received power of direct waves relative to the received power of scattered waves, is large, good reception quality can be obtained. However, depending on the transmission method (eg, spatial multiplexing MIMO transmission method), a problem arises in that reception quality deteriorates when the Rice factor becomes large. (See Non-Patent Document 3)
(A) and (B) of FIG. 24 show 2×2 LDPC (low-density parity-check) encoded data in a Rayleigh fading environment and a Rician fading environment with a Rician factor K of 3, 10, and 16 dB. An example of simulation results of BER (Bit Error Rate) characteristics (vertical axis: BER, horizontal axis: SNR (signal-to-noise power ratio)) when performing spatially multiplexed MIMO transmission (2 antenna transmission, 2 antenna reception) is shown. ing. (A) of FIG. 24 shows the BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (APP: a posterior probability) without iterative detection, and (B) of FIG. It shows the BER characteristics of Max-log-APP (see Non-Patent Document 1 and Non-Patent Document 2) (repetition number of times: 5) in which detection was performed. As can be seen from FIGS. 24(A) and 24(B), regardless of whether iterative detection is performed or not, in the spatially multiplexed MIMO system, it can be confirmed that as the Rice factor increases, the reception quality deteriorates. This suggests that spatially multiplexed MIMO systems have an issue unique to spatially multiplexed MIMO systems that does not exist in conventional systems that transmit single modulated signals, such as ``in spatially multiplexed MIMO systems, reception quality deteriorates when the propagation environment becomes stable.'' Recognize.

Broadcasting and multicast communications are services that must be compatible with various propagation environments, and it is naturally possible that the radio wave propagation environment between a receiver owned by a user and a broadcasting station is a LOS environment. When a spatially multiplexed MIMO system with the above-mentioned problems is used for broadcasting or multicast communication, a phenomenon occurs in which, although the receiving field strength of radio waves is high at the receiver, the reception quality deteriorates and the service cannot be received. there is a possibility. In other words, in order to use a spatially multiplexed MIMO system in broadcasting or multicast communication, it is desired to develop a MIMO transmission method that can obtain a certain degree of reception quality in both NLOS and LOS environments.

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

On the other hand, Non-Patent Document 4 describes a method of switching precoding matrices over time, which can be applied even when there is no feedback information. This document describes the use of unitary matrices as matrices used for precoding and the switching of unitary matrices at random. It is not described at all, only that it is switched randomly. Naturally, there is no description of a precoding method for improving the deterioration of reception quality in a LOS environment and a method of configuring a precoding matrix.

International Publication No. 2005/050885

"Achieving near-capacity on a multiple-antenna channel" IEEE Transaction on communications, vol. 51, no. 3, pp. 389-399, March 2003. "Performance analysis and design optimization of LDPC-coded MIMO OFDM systems" IEEE Trans. Signal Processing. , vol. 52, no. 2, pp. 348-361, Feb. 2004. "BER performance evaluation in 2x2 MIMO spatial multiplexing systems under Rician fading channels," IEICE Trans. Fundamentals, vol. E91-A, no. 10, pp. 2798-2807, Oct. 2008. "Turbo space-time codes with time varying linear transformations," IEEE Trans. Wireless communications, vol. 6, no. 2, pp. 486-493, Feb. 2007. "Likelihood function for QR-MLD suitable for soft-decision turbo decoding and its performance," IEICE Trans. Commun. , vol. E88-B, no. 1, pp. 47-57, Jan. 2004. "Signpost to the Shannon limit: 'Parallel concatenated (Turbo) coding', 'Turbo (iterative) decoding' and their surroundings" Institute of Electronics, Information and Communication Engineers, IEICE Techniques IT98-51 "Advanced signal processing for PLCs: Wavelet-OFDM," Proc. of IEEE International symposium on ISPLC 2008, pp. 187-192, 2008. D. J. Love, and R. W. heath, jr. , "Limited feedback unitary precoding for spatial multiplexing systems," IEEE Trans. Inf. Theory, vol. 51, no. 8, pp. 2967-2976, Aug. 2005. DVB Document A122, Framing structure, channel coding and modulation for a second generation digital terrestrial television broadcasting system, m (DVB-T2), June 2008. L. Vangelista, N. Benvenuto, and S. Thomasin, "Key technologies for next-generation terrestrial digital television standard DVB-T2," IEEE Commun. Magazine, vol. 47, no. 10, pp. 146-153, Oct. 2009. T. Ohgane, T. Nishimura, and Y. Ogawa, "Application of space division multiplexing and those performance in a MIMO channel," IEICE Trans. Commun. , vol. E88-B, no. 5, pp. 1843-1851, May 2005. R. G. Gallager, "Low-density parity-check codes," IRE Trans. Information. Theory, IT-8, pp-21-28, 1962. D. J. C. Mackay, "Good error-correcting codes based on very sparse matrices," IEEE Trans. Information. Theory, vol. 45, no. 2, pp399-431, March 1999. ETSI EN 302 307, "Second generation framing structure, channel coding and modulation systems for broadcasting, interactive s services, news gathering and other broadband satellite applications, "v. 1.1.2, June 2006. Y. -L. Ueng, and C. -C. Cheng, “a fast-convergence decoding method and memory-efficient VLSI decoder architecture for irregular LDPC codes in the IE EE 802.16e standards," IEEE VTC-2007 Fall, pp. 1255-1259. S. M. Alamouti, "A simple transmit diversity technique for wireless communications," IEEE J. Select. Areas Commun. , vol. 16, no. 8, pp. 1451-1458, Oct 1998. V. Tarokh, H. Jafrkhani, and A. R. Calderbank, "Space-time block coding for wireless communications: Performance results," IEEE J. Select. Areas Commun. , vol.17, no. 3, no.3, pp. 451-460, March 1999.

An object of the present invention is to provide a MIMO system that can improve reception quality in a LOS environment.

The transmitting device according to the present invention generates a first transmitting signal and a second transmitting signal from a first modulating signal and a second modulating signal consisting of an in-phase component and a quadrature component based on a modulation method, and generates a first transmitting signal and a second transmitting signal from the same frequency band and the same A transmitting device that transmits data from one or more different output ports at different timings, the transmitting device includes a phase changer that regularly changes the phase of an input modulated signal, and a phase changer that regularly changes the phase of an input modulated signal, and a phase changer that regularly changes the phase of an input modulated signal. a weighted synthesis section that performs weighted synthesis using a fixed precoding matrix; a signal based on at least one of the first modulation signal and the second modulation signal whose phase is changed by the phase change section; It is characterized by comprising a transmitting section that transmits the first transmission signal and the second transmission signal, in which both signals based on the modulated signal and the second modulated signal are generated through weighted combination by the weighted combination section. do.

Further, the receiving device according to the present invention receives from the transmitting device the first transmitting signal and the second transmitting signal, in which the first transmitting signal and the second transmitting signal are transmitted in the same frequency band and at the same timing. , at least one of the first transmission signal and the second transmission signal is generated by regularly changing the phase of at least one of the first modulation signal and the second modulation signal, respectively. a receiving section, which is a signal received by the receiving section, and demodulates the signal received by the receiving section using a demodulation method according to the modulation method used for the first modulated signal or the second modulated signal to obtain the first modulated signal and the second modulated signal. A demodulation unit that calculates a log-likelihood ratio of transmission data that is the source of the second modulated signal.

Here, the term "signal based on the first modulation signal" refers to the first modulation signal itself, or to a signal obtained by changing the phase of the first modulation signal or by weighting (precoding) it. be. Similarly, a signal based on the second modulation signal may refer to the second modulation signal itself, or may refer to a phase-changed or weighted (pre-coded) second modulation signal. .

As described above, according to the present invention, it is possible to provide a transmitting method, a receiving method, a transmitting device, and a receiving device that improve the deterioration of reception quality in a LOS environment. , can provide high quality services.

Example of configuration of transmitter/receiver in spatially multiplexed MIMO transmission system An example of frame configuration Example of configuration of transmitter when applying phase change method Example of configuration of transmitter when applying phase change method Example of frame configuration Example of phase change method Example configuration of receiving device Configuration example of the signal processing section of the receiving device Configuration example of the signal processing section of the receiving device Decryption method Example of reception status Example of configuration of transmitter when applying phase change method Example of configuration of transmitter when applying phase change method Example of frame configuration Example of frame configuration Example of frame configuration Example of frame configuration Example of frame configuration An example of mapping method An example of mapping method Example of configuration of weighted synthesis section An example of how to rearrange symbols Example of configuration of transmitter/receiver in spatially multiplexed MIMO transmission system BER characteristic example Example of phase change method Example of phase change method Example of phase change method Example of phase change method Example of phase change method Example of symbol arrangement of modulated signal to obtain high reception quality Example of frame configuration of modulated signal that provides high reception quality Example of symbol arrangement of modulated signal to obtain high reception quality Example of symbol arrangement of modulated signal to obtain high reception quality Examples of changes in the number of symbols and slots required for one encoded block when using block codes Examples of changes in the number of symbols and slots required for two encoded blocks when using block codes Overall configuration diagram of digital broadcasting system Block diagram showing an example configuration of a receiver Diagram showing the configuration of multiplexed data Diagram schematically showing how each stream is multiplexed in multiplexed data Detailed diagram showing how video streams are stored in PES packet strings Diagram showing the structure of TS packets and source packets in multiplexed data Diagram showing 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 An example of a communication system configuration Example of symbol arrangement of modulated signal to obtain high reception quality Example of symbol arrangement of modulated signal to obtain high reception quality Example of symbol arrangement of modulated signal to obtain high reception quality Example of symbol arrangement of modulated signal to obtain high reception quality Example of transmitter configuration Example of transmitter configuration Example of transmitter configuration Example of transmitter configuration Diagram showing the baseband signal switching section

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

Before proceeding with the present description, an overview of the transmission method and decoding method in a spatially multiplexed MIMO transmission system, which is a conventional system, will be explained.
The configuration of an N _t x N _r spatially multiplexed MIMO system is shown in FIG. The information vector z is encoded and interleaved. Then, as an output of interleaving, a vector of encoded bits u=(u ₁ , . . . , u _Nt ) is obtained. However, it is assumed that u _i =(u _i1 , . . . , u _iM ) (M: number of transmission bits per symbol). When the transmission vector s = (s ₁ ,...,s _Nt ) ^T , the transmission signal from the transmission antenna #i is expressed as s _i =map (u _i ), and when the transmission energy is normalized, E {|s _i | ² } = Es /Nt ( _Es : total energy per channel). Then, if the reception vector is y=(y ₁ , . . . , y _Nr ) ^T , it is expressed as in equation (1).

At this time, H _NtNr is a channel matrix, n=(n ₁ ,...,n _Nr ) ^T is a noise vector, and n _i is ⁱ . i. d. It is complex Gaussian noise. Based on the relationship between the transmitted symbols and received symbols introduced at the receiver, the probability regarding the received vector can be given by a multidimensional Gaussian distribution as shown in equation (2).

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

<Iterative detection method>
Here, iterative detection of MIMO signals in an N _t xN _r spatially multiplexed MIMO system will be described.
The log-likelihood ratio of u _mn is defined as in equation (6).

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

However, U _{mn, ±1} = {u|u _mn = ±1}. And lnΣa _j ~max
When approximated by ln a _j , equation (7) can be approximated as equation (8). Note that the symbol “~” above means approximation.

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

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

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

Hereinafter, this will be referred to as iterative APP decoding. Furthermore, from equations (8) and (12), in the log likelihood ratio (Max-Log APP) based on Max-Log approximation, the posterior L-value is expressed as follows.

Hereinafter, this will be referred to as iterative Max-log APP decoding. The external information required by the iterative decoding system can be obtained by subtracting the prior input from equation (13) or (14).
<System model>
FIG. 23 shows the basic configuration of the system, which will be explained later. Here, a 2×2 spatial multiplexing MIMO system is used, and streams A and B each have an outer encoder, and the two outer encoders are encoders of the same LDPC code (here, the configuration uses an LDPC code encoder as the outer encoder). will be explained using an example, but the error correction code used by the outer encoder is not limited to the LDPC code, and the same implementation can be performed using other error correction codes such as turbo codes, convolutional codes, and LDPC convolutional codes. In addition, although the outer encoder is configured to be provided for each transmitting antenna, it is not limited to this, and even if there are multiple transmitting antennas, there may be one outer encoder. (The number of outer encoders may be greater than the number of antennas.) Streams A and B each have interleavers (π _a , π _b ). Here, the modulation method is 2 ^h -QAM (h bits are transmitted in one symbol).
It is assumed that the receiver performs iterative detection (iterative APP (or Max-log APP) decoding) of the MIMO signal described above. As for the decoding of the LDPC code, for example, sum-product decoding is performed.
FIG. 2 shows the frame structure and describes the order of symbols after interleaving. At this time, ( _ia , _ja ) and ( _ib , _jb ) are expressed as shown in the following equation.

At this time, i _a , i _b : order of symbols after interleaving, j _a , j _b : bit position in modulation method (ja _, j _b =1,...,h), π _a , π _b : stream The interleaver for A and B, Ω ^a _{ia, ja} , Ω ^bi _{ib, jb} : indicates the order of data before interleaving of streams A and B. However, FIG. 2 shows the frame configuration when i _a =i _b .
<Iterative decoding>
Here, the algorithms for sum-product decoding and iterative detection of MIMO signals used in decoding the LDPC code in the receiver will be described in detail.

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

At this time, A(m) means a set of column indexes that are 1 in the m-th row of the parity check matrix H, and B(n) is a set of row indexes that are 1 in the n-th row of the parity check matrix H. . The algorithm for sum-product decoding is as follows.
Step A.1 (initialization): For all pairs (m, n) that satisfy H _mn =1, set the a priori value log ratio β _mn =0. The loop variable (number of iterations) l _sum is set to 1, and the maximum number of loops is set to l _sum,max .
Step A.2 (row processing): For all pairs (m, n) that satisfy H _mn = 1 in the order of m = 1, 2, ..., M, use the following update formula to calculate the external value logarithm. Update the ratio α _mn .

At this time, f is a Gallager's function. The method for determining λ _n will be explained in detail below.
Step A.3 (column processing): For all pairs (m, n) that satisfy H _mn = 1 in the order of n = 1, 2, ..., N, use the following update formula to calculate the external value logarithm. Update the ratio β _mn .

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

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

The above is the operation of one sum-product decoding. Thereafter, iterative detection of the MIMO signal is performed. In the variables m, n, α _mn , β _mn , λ _n , L _n used in the explanation of the operation of sum-product decoding above, the variables in stream A are m _a , _na , α ^a _mana , β ^a _mana , Let λ _na , L _na and variables in stream B be expressed by m _b , n _b , α ^b _mbnb , β ^b _mbnb , λ _nb , and L _nb .
<Iterative detection of MIMO signal>
Here, a method for determining λ _n in iterative detection of MIMO signals will be explained in detail.

From equation (1), the following equation holds true.

From the frame configuration of FIG. 2 and equations (16) and (17), the following relational expression holds true.

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

Step B.1 (initial detection; k=0): At the time of initial detection, λ _0,na and λ _0,nb are determined as follows.
When iterative APP decoding:

For iterative Max-log APP decoding:

However, it is assumed that X=a, b. Then, the number of repetitions of the iterative detection of the MIMO signal is set to l _mimo =0, and the maximum number of repetitions is set to l _mimo,max .
Step B・2 (iterative detection; number of repetitions k): λ _k,na , λ _k,nb when the number of repetitions is k are calculated from formulas (11), (13)-(15), (16), and (17). 31)-(34). However, (X, Y)=(a, b) (b, a).
When iterative APP decoding:

For iterative Max-log APP decoding:

Step B.3 (counting the number of iterations, estimating the code word): 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, b.
FIG. 3 is an example of the configuration of transmitting device 300 in this embodiment. The encoding unit 302A inputs information (data) 301A and a frame configuration signal 313, and inputs the frame configuration signal 313 (error correction method, coding rate, block length, etc. used by the encoding unit 302A for error correction encoding of data). The method specified by the frame configuration signal 313 is used. Also, the error correction method may be switched. For example, convolutional codes, LDPC codes, turbo codes, etc. Error correction encoding is performed and encoded data 303A is output.

The interleaver 304A inputs the encoded data 303A and the frame configuration signal 313, performs interleaving, that is, rearranges 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 inputs the interleaved data 305A and the frame configuration signal 313, and performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), and 64QAM (64 Quadrature Amplitude Modulation). modulation such as re Amplitude Modulation), and baseband Outputs signal 307A. (The modulation method may be switched based on the frame configuration signal 313.)
FIG. 19 shows an example of a method of mapping an in-phase component I and a quadrature component Q, which constitute a baseband signal in QPSK modulation, on an IQ plane. For example, as shown in FIG. 19(A), when the input data is "00", I=1.0 and Q=1.0 are output, and similarly, when the input data is "01", I= -1.0, Q=1.0 are output, and so on. FIG. 19(B) is an example of a mapping method on the IQ plane of QPSK modulation that is different from FIG. 19(A). The difference between FIG. 19(B) and FIG. 19(A) is that By rotating the signal point around the origin, the signal point shown in FIG. 19(B) can be obtained. Such a constellation rotation method 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 an example different from FIG. 19, FIG. 20 shows the signal point arrangement on the IQ plane for 16QAM, and FIG. 20(A) corresponds to FIG. 19(A), and FIG. 19(B) An example corresponding to this is shown in FIG. 20(B).

The encoding unit 302B inputs information (data) 301B and a frame configuration signal 313, and receives the frame configuration signal 313 (which includes information such as the error correction method to be used, the coding rate, and the block length). (The error correction method may be switched.) For example, error correction coding such as convolutional code, LDPC code, turbo code, etc. is performed, and the encoded data is Outputs 303B.

The interleaver 304B inputs the encoded data 303B and the frame configuration signal 313, performs interleaving, that is, rearranges the order, and outputs the interleaved data 305B. (The interleaving method may be switched based on the frame configuration signal 313.)
The mapping unit 306B inputs the interleaved data 305B and the frame configuration signal 313, and performs QPSK (Quadrature Phase Shift Keying), 16QAM (16 Quadrature Amplitude Modulation), 64QAM (64 Quadrature Amplitude Modulation), modulation such as re Amplitude Modulation), and baseband Outputs signal 307B. (The modulation method may be switched based on the frame configuration signal 313.)
The signal processing method information generation unit 314 receives the frame configuration signal 313 as input and outputs information 315 regarding the signal processing method based on the frame configuration signal 313. Note that the information 315 regarding the signal processing method includes information specifying which precoding matrix is fixedly used, and information on a phase change pattern for changing the phase.

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

The radio unit 310A inputs the weighted and combined signal 309A, performs processing such as orthogonal modulation, band limitation, frequency conversion, and amplification, and outputs a transmission signal 311A, which is output as a radio wave from an antenna 312A. Ru.

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

FIG. 21 shows the configuration of the weighted synthesis section (308A, 308B). In FIG. 21, the area surrounded by the dotted line is the weighted synthesis section. The baseband signal 307A is multiplied by w11 to generate w11·s1(t), and multiplied by w21 to generate w21·s1(t). Similarly, the baseband signal 307B is multiplied by w12 to generate w12·s2(t), and multiplied by w22 to generate w22·s2(t). Next, z1(t)=w11·s1(t)+w12·s2(t) and z2(t)=w21·s1(t)+w22·s2(t) are obtained. At this time, s1(t) and s2(t) are BPSK (Binary
Phase Shift Keying), QPSK, 8PSK (8 Phase Shift Keying), 16QAM,
This is a baseband signal of a modulation method such as 32QAM (32 Quadrature Amplitude Modulation), 64QAM, 256QAM, or 16APSK (16 Amplitude Phase Shift Keying).

Here, it is assumed that both weighting synthesis units execute weighting using a fixed precoding matrix, and the precoding matrix is, as an example, based on the following formula (37) or formula (38). There is a method using (36). However, this is just an example, and the value of α is not limited to equations (37) and (38), and may be set to another value, for example, α may be 1.

Note that the precoding matrix is

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

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

It is.
Note that the precoding matrix is not limited to Equation (36), but may be used as shown in Equation (39).

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

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

The phase change unit 312 inputs the weighted and combined signal 312B and information 315 regarding the signal processing method, regularly changes the phase of the signal 312B, and outputs the resultant signal. Changing regularly means changing the phase according to a predetermined phase change pattern at a predetermined period (for example, every n symbols (n is an integer greater than or equal to 1) or every predetermined time). . Details of the phase change pattern will be explained in Embodiment 4 below.

The radio section 310B inputs the phase-changed signal 309B, performs processing such as quadrature modulation, band limitation, frequency conversion, and amplification, and outputs a transmission signal 311B, which is output as a radio wave from an antenna 312B. Ru.

FIG. 4 shows a configuration example of a transmitting device 400 that is different from FIG. 3. In FIG. In FIG. 4, parts different from those in FIG. 3 will be explained.
The encoding unit 402 receives information (data) 401 and a frame configuration signal 313 as input, performs error correction encoding based on the frame configuration signal 313, and outputs encoded data 402.

The distribution unit 404 inputs the encoded data 403, distributes it, and outputs data 405A and data 405B. Although FIG. 4 shows the case where there is one encoding unit, the case is not limited to this, and the number of encoding units is m (m is an integer greater than or equal to 1), and the code created by each encoding unit is The present invention can be implemented in the same manner even when the distribution section outputs the divided data into two types of data.

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

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

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

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

The relationship between the modulated signal z1(t) and modulated signal z2(t) transmitted by the transmitting device and the received signals r1(t) and r2(t) in the receiving device will be explained.
In FIG. 5, 504#1 and 504#2 indicate transmitting antennas in the transmitting device, and 505#1 and 505#2 indicate receiving antennas in the receiving device. #1, the modulated signal z2(t) is transmitted from the transmitting 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). Let the channel fluctuations of each transmitting antenna of the transmitting device and each antenna of the receiving device be h11(t), h12(t), h21(t), and h22(t), respectively, and the reception received by the receiving antenna 505#1 of the receiving device Assuming that the signal is r1(t) and the received signal received by the receiving antenna 505#2 of the receiving device is r2(t), the following relational expression holds true.

FIG. 6 is a diagram related to a weighting method (precoding method) and a phase change method in this embodiment, and a weighting synthesis section 600 is a diagram that is a combination of both weighting synthesis sections 308A and 308B in FIG. This is a weighted synthesis section. As shown in FIG. 6, stream s1(t) and stream s2(t) correspond to baseband signals 307A and 307B in FIG. These become the in-phase I component and quadrature Q component of the band signal. As shown in the frame structure of FIG. 6, in the stream s1(t), the signal with symbol number u is expressed as s1(u), the signal with symbol number u+1 is expressed as s1(u+1), and so on. Similarly, in stream s2(t), the signal with symbol number u is expressed as s2(u), the signal with symbol number u+1 is expressed as s2(u+1), and so on. Then, the weighted synthesis unit 600 receives the baseband signals 307A (s1(t)) and 307B (s2(t)) in FIG. are applied, and the weighted and combined signals 309A (z1(t)) and 309B (z2(t)) of FIG. 3 are output.

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

On the other hand, z2(t) is calculated by the following equation (42 ).

Here, y(t) is an equation for changing the phase according to a predetermined method. For example, if the period is 4, the phase changing equation at time u is expressed, for example, by equation (43). be able to.

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

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

Note that the examples of regular phase changes shown in equations (43) to (45) are only examples.
The period of regular phase change is not limited to four. As the number of cycles increases, it may be possible to improve the receiving performance (more precisely, error correction performance) of the receiving device (although it is not necessarily the case that the cycle is large, 2 It is likely best to avoid small values such as ).

Furthermore, in the phase change examples shown in equations (43) to (45) above, the configuration is shown in which the phase is sequentially rotated by a predetermined phase (in the above equation, in steps of π/2), but it is not possible to rotate the phase by the same amount. Alternatively, the phase may be changed randomly. For example, the phase by which y(t) is multiplied may be changed according to a predetermined cycle in the order shown in equation (46) or equation (47). What is important in regular phase changes is that the phase of the modulation signal is changed regularly, and the degree of phase change should be as uniform as possible, for example, from -π radians to π radians. Although it is desirable that the distribution be uniform, it may be random.

In this way, the weighted synthesis unit 600 in FIG. 6 executes precoding using predetermined fixed precoding weights, and the phase change unit regularly changes the degree of change in the phase of the input signal. Change while changing to .

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

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

The channel fluctuation estimation unit 705_1 in the modulated signal z1 transmitted by the transmitter receives the baseband signal 704_X as input, extracts the reference symbol 501_1 for channel estimation in FIG. 5, and calculates the value corresponding to h11 in equation (40). and outputs a channel estimation signal 706_1.

The channel fluctuation estimator 705_2 in the modulated signal z2 transmitted by the transmitter receives the baseband signal 704_X, extracts the reference symbol 501_2 for channel estimation in FIG. 5, and calculates the value corresponding to h12 in equation (40). and outputs a channel estimation signal 706_2.

The radio unit 703_Y receives the received signal 702_Y received by the antenna 701_Y, performs processing such as frequency conversion and orthogonal demodulation, and outputs a baseband signal 704_Y.
The channel fluctuation estimator 707_1 in the modulated signal z1 transmitted by the transmitter receives the baseband signal 704_Y, extracts the reference symbol 501_1 for channel estimation in FIG. 5, and calculates the value corresponding to h21 in equation (40). and outputs a channel estimation signal 708_1.

The channel fluctuation estimator 707_2 in the modulated signal z2 transmitted by the transmitter receives the baseband signal 704_Y, extracts the reference symbol 501_2 for channel estimation in FIG. 5, and calculates the value corresponding to h22 in equation (40). and outputs a channel estimation signal 708_2.

Control information decoding section 709 receives baseband signals 704_X and 704_Y, detects symbol 500_1 for notifying the transmission method in FIG. 5, and outputs signal 710 regarding information on the transmission method notified by the transmitting device.

The signal processing unit 711 receives as input baseband signals 704_X, 704_Y, channel estimation signals 706_1, 706_2, 708_1, 708_2, and a signal 710 related to the information on the transmission method notified by the transmitting device, performs detection and decoding, and converts the received data. 712_1 and 712_2 are output.

Next, the operation of the signal processing section 711 in FIG. 7 will be explained in detail. FIG. 8 shows an example of the configuration of the signal processing section 711 in this embodiment. FIG. 8 mainly includes an INNER MIMO detection section, a soft-in/soft-out decoder, and a coefficient generation section. The iterative decoding method in this configuration is described in detail in Non-patent Document 2 and Non-patent Document 3, but the MIMO transmission method described in Non-patent Document 2 and Non-patent Document 3 is based on spatial multiplexing MIMO transmission. However, the transmission method in this embodiment is a MIMO transmission method that regularly changes the phase of the signal over time and uses a precoding matrix, as described in Non-Patent Document 2, Non-Patent Document 2, This is different from Patent Document 3. The (channel) matrix in equation (36) is H(t), the precoding weight matrix in FIG. 6 is F (here, the precoding matrix is a fixed one that does not change during one received signal), and The matrix of the phase change equation by the phase change unit is Y(t) (here, Y(t) changes depending on t), the received vector is R(t)=(r1(t), r2(t)) ^T , and the stream When vector S(t)=(s1(t), s2(t)) is ^T , the following relational expression holds true.

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

The INNER MIMO detection unit 803 receives a signal 820 regarding information on the signal processing method as input, and uses this signal to perform iterative detection and decoding by using the relationship in equation (48). I will explain about it.

In the signal processing section having the configuration shown in FIG. 8, in order to perform iterative decoding (iterative detection), it is necessary to perform a processing method as shown in FIG. First, one code word (or one frame) of the modulated signal (stream) s1 and one code word (or one frame) of the modulated signal (stream) s2 are decoded. As a result, one code word (or one frame) of the modulated signal (stream) s1 and one code word (or one frame) of the modulated signal (stream) s2 are output from the soft-in/soft-out decoder. A bit log-likelihood ratio (LLR) is obtained. Then, detection and decoding are performed again using the LLR. This operation is performed multiple times (this operation is called iterative decoding (iterative detection)). Hereinafter, a method for creating a log likelihood ratio (LLR) of a symbol at a specific time in one frame will be mainly explained.

In FIG. 8, a storage unit 815 stores 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), a baseband signal 801X (corresponding to the baseband signal 704_X in FIG. In order to realize iterative decoding (iterative detection) by inputting a signal 801Y (corresponding to the baseband signal 704_Y in FIG. 7) and a channel estimation signal group 802Y (corresponding to the channel estimation signals 708_1 and 708_2 in FIG. 7). Then, H(t)×Y(t)×F in equation (48) is executed (calculated), and the calculated matrix is stored as a modified channel signal group. Then, the storage unit 815 outputs the 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.

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

The INNER MIMO detection unit 803 first performs H(t)×Y(t)×F from the channel estimation signal group 802X and the channel estimation signal group 802Y to find candidate signal points corresponding to the baseband signal 801X. The situation at that time is shown in FIG. In FIG. 11, ● (black circles) are candidate signal points on the IQ plane, and since the modulation method is 16QAM, there are 256 candidate signal points. (However, since FIG. 11 shows an image diagram, all 256 candidate signal points are not shown.) Here, the 4 bits transmitted by the modulation signal s1 are b0, b1, b2, b3, and the modulation signal s2 If 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 squared Euclidean distance between the received signal point 1101 (corresponding to the baseband signal 801X) and each candidate signal point is determined. Then, each squared Euclidean distance is divided by the noise variance σ ² . Therefore, (b0, b1,
E _X (b0, b1, b2, b3, b4, b5, b
6, b7) can be found. Note that each baseband signal and modulated signals s1 and s2 are complex signals.

Similarly, H(t)×F×Y(t) is executed from the channel estimated signal group 802X and the channel estimated signal group 802Y to find candidate signal points corresponding to the baseband signal 801Y, and the received signal point (baseband signal 801Y) is calculated, and this squared Euclidean distance is divided by the noise variance σ ² . Therefore, E _Y (b0, b1, b2 , b3, b4, b5, b6, b7).

_{And E} , b4, b5, b6, b7).

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

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

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

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

Similarly, the log-likelihood ratio calculation unit 809B inputs the deinterleaved log-likelihood signal 808B and log-likelihood ratio (LLR: Log-
Likelihood Ratio) is calculated and a log-likelihood ratio signal 810B is output.

The soft-in/soft-out decoder 811A receives the log-likelihood ratio signal 810A, decodes it, and outputs the decoded log-likelihood ratio 812A.
Similarly, the soft-in/soft-out decoder 811B inputs the log-likelihood ratio signal 810B, decodes it, and outputs the decoded log-likelihood ratio 812B.

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

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

The INNER MIMO detection unit 803 inputs a baseband signal 816X, a group of modified channel estimation signals 817X, a baseband signal 816Y, a group of modified channel estimation signals 817Y, a log-likelihood ratio after interleaving 814A, and a log-likelihood ratio after interleaving 814B. shall be. Here, instead of the baseband signal 801X, channel estimation signal group 802X, baseband signal 801Y, and channel estimation signal group 802Y, the baseband signal 816X, modified channel estimation signal group 817X, baseband signal 816Y, and modified channel estimation signal group 817Y are used. is used because delay time occurs due to iterative decoding.

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

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

Similarly, log-likelihood calculating section 805B receives signal 804, calculates the log-likelihood of bits b4 and b5, and b6 and b7, and outputs log-likelihood signal 806B. The operations after the deinterleaver are the same as the initial detection.

Note that although FIG. 8 shows the configuration of the signal processing unit when iterative detection is performed, iterative detection is not necessarily an essential configuration to obtain good reception quality, and the configuration is only necessary for iterative detection. , a configuration that does not include interleavers 813A and 813B may also be used. At this time, the INNER MIMO detection section 803 does not perform repetitive detection.

The important part in this embodiment is to perform the calculation of H(t)×Y(t)×F. Note that, as shown in Non-Patent Document 5, etc., initial detection and iterative detection may be performed using QR decomposition.
In addition, as shown in Non-Patent Document 11, linear calculations of MMSE (Minimum Mean Square Error) and ZF (Zero Forcing) are performed based on H(t)×Y(t)×F to perform initial detection. You may go.

FIG. 9 shows a configuration of a signal processing section different from that in FIG. 8, and is a signal processing section for the modulated signal transmitted by the transmitting 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 inputs the log-likelihood ratio signals 810A and 810B, performs decoding, and decodes the A log likelihood ratio 902 is output. The distribution unit 903 receives the decoded log-likelihood ratio 902 as input and performs distribution. The other parts operate in the same manner as in FIG.

As described above, when the transmitting device of the MIMO transmission system transmits multiple modulated signals from multiple antennas as in this embodiment, it multiplies the precoding matrix and changes the phase over time. By making the changes regularly, in a LOS environment where direct waves are dominant, it is possible to obtain the effect that the reception quality of data at the receiving device is improved compared to when using conventional spatially multiplexed MIMO transmission.

In this embodiment, the operation has been described with a limited number of antennas, particularly regarding the configuration of the receiving device, but the same implementation can be performed even if the number of antennas is increased. In other words, the number of antennas in the receiving device does not affect the operation and effects of this embodiment.

Further, in this embodiment, the explanation is given using an LDPC code as an example, but the explanation is not limited to this, and the decoding method is also limited to an example of sum-product decoding as a soft-in/soft-out decoder. There are other soft-in/soft-out decoding methods, such as the BCJR algorithm, SOVA algorithm, and Msx-log-MAP algorithm. Details are shown in Non-Patent Document 6.

Furthermore, although the present embodiment has been described using a single carrier method as an example, the present invention is not limited to this, and the same implementation is possible even when multicarrier transmission is performed. Therefore, for example, spread spectrum communication system, OFDM (Orthogonal Frequency-Division Multiplexing) system, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC -OFDM (Single Carrier Orthogonal Frequency-Division Multiplexing) method, Non-Patent Document 7, etc. The same implementation is also possible when using the wavelet OFDM method shown in . Furthermore, in this embodiment, symbols other than data symbols, such as pilot symbols (preamble, unique word, etc.), symbols for transmitting control information, etc., may be arranged in any way in the frame.

In the following, an example using the OFDM method will be described as an example of the multicarrier method.
FIG. 12 shows the configuration of a transmitting device when using the OFDM method. In FIG. 12, parts that operate in the same way as in FIG. 3 are given the same reference numerals.

The OFDM system-related processing unit 1201A receives the weighted signal 309A, performs OFDM system-related processing, and outputs a transmission signal 1202A. Similarly, the OFDM system related processing unit 1201B inputs the weighted signal 309B and outputs a transmission signal 1202B.

FIG. 13 shows an example of the configuration of the OFDM system-related processing units 1201A and 1201B in FIG. 12, and the parts related to 1201A to 312A in FIG. are from 1301B to 1310B.

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

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

The radio section 1308A inputs the signal 1307A after inverse Fourier transform, performs processing such as frequency conversion and amplification, and outputs a modulated signal 1309A, which is outputted as a radio wave from the antenna 1310A.

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

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

The radio section 1308B receives the inverse Fourier transformed signal 1307B, performs processing such as frequency conversion and amplification, and outputs a modulated signal 1309B, which is output as a radio wave from the antenna 1310B.

Since the transmitter shown in FIG. 3 does not use a transmission method using multicarriers, the phase is changed so that there are four periods, and the symbols after the phase change are arranged in the time axis direction, as shown in FIG. When using a multicarrier transmission method such as the OFDM method shown in FIG. 12, it is natural to precode as shown in FIG. 3, arrange the symbols after changing the phase in the time axis direction, and A method of arranging for each (sub)carrier is conceivable, but in the case of a multicarrier transmission method, a method of arranging using the frequency axis direction or both the frequency axis and the time axis is conceivable. This point will be explained below.

FIG. 14 shows an example of how symbols are rearranged in the rearrangement units 1301A and 1301B of FIG. 13, with the horizontal axis frequency and the vertical axis time. The modulated signals z1 and z2 use the same frequency band at the same time (time), and FIG. 14(A) shows the method of rearranging the symbols of the modulated signal z1, and FIG. 14(B) shows a method of rearranging symbols of modulated signal z2. The symbols of the weighted signal 1301A input to the serial-parallel converter 1302A are numbered #0, #1, #2, #3, . . . in order. Here, we are considering the case of 4 cycles, so #0, #1, #2, and #3 correspond to one cycle. Similarly, #4n, #4n+1, #4n+2, #4n+3 (n is an integer of 0 or more) corresponds to one cycle.

At this time, as shown in FIG. 14(a), symbols #0, #1, #2, #3, ... are placed in order from carrier 0, and symbols #0 to #9 are placed at time $1. , and then symbols #10 to #19 are arranged regularly, such as at time $2. Note that the modulation signals z1 and z2 are complex signals.

Similarly, the symbols of the weighted and phase-changed signal 1301B that is input to the serial-parallel converter 1302B are sequentially numbered #0, #1, #2, #3, etc. . Here, we are considering the case of period 4, so #0, #1, #2, and #3 are each undergoing different phase changes, and #0, #1, #2, and #3 are This is the period. Considering the same way, #4n, #4n+1, #4n+2, #4n+3 (n is an integer greater than or equal to 0) are performing different phase changes, and #4n, #4n+1, #4n+2, and #4n+3 are This is the period.

At this time, as shown in FIG. 14(b), symbols #0, #1, #2, #3, ... are placed in order from carrier 0, and symbols #0 to #9 are placed at time $1. , and then symbols #10 to #19 are arranged regularly, such as at time $2.

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

Note that in this embodiment, the phase of the modulated signal z1 shown in FIG. 14(A) is not changed.
In this way, when a multi-carrier transmission system such as the OFDM system is used, unlike single-carrier transmission, it has the characteristic that symbols can be arranged in the frequency axis direction. The arrangement of the symbols is not limited to the arrangement shown in FIG. 14. Other examples will be explained using FIGS. 15 and 16.

FIG. 15 shows an example of a symbol rearrangement method in the rearrangement units 1301A and 1301B of FIG. 13, in which the horizontal axis is frequency and the vertical axis is time, which is different from that in FIG. FIG. 15B shows a method for rearranging the symbols of the modulated signal z2. 15(A) and 15(B) differ from FIG. 14 in that the method of rearranging the symbols of the modulated signal z1 and the symbol of the modulated signal z2 are different. In FIG. 15(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 using the same rules. At this time, similarly to FIG. 14(B), symbol group 1502 shown in FIG. 15(B) is symbols for one period when the phase change method shown in FIG. 6 is used.

FIG. 16 shows an example of a symbol rearrangement method in the rearrangement units 1301A and 1301B of FIG. 13 in the horizontal axis frequency and the vertical axis time, which is different from that in FIG. 14. FIG. Method of rearranging symbols: FIG. 16(B) shows a method of rearranging symbols of modulated signal z2. The difference between FIGS. 16(A) and 16(B) from FIG. 14 is that in FIG. 14, the symbols are arranged in order on the carriers, whereas in FIG. 16, the symbols are not arranged on the carriers in order. It is a point. Of course, in FIG. 16, similarly to FIG. 15, the method of rearranging the symbols of modulated signal z1 and the method of rearranging the symbols of modulated signal z2 may be different.

FIG. 17 shows an example of a symbol rearrangement method in the rearrangement units 1301A and 1301B of FIG. 13 in the horizontal axis frequency and the vertical axis time, which is different from FIGS. 14 to 16. FIG. 17B shows a method for rearranging the symbols of the signal z1. FIG. 17B shows a method for rearranging the symbols of the modulated signal z2. In FIGS. 14 to 16, the symbols are arranged along the frequency axis, but in FIG. 17, the symbols are arranged using both the frequency and time axes.

In FIG. 6, an example in which the phase is changed in 4 slots has been described, but here, a case in which the phase is changed in 8 slots will be described as an example. A symbol group 1702 shown in FIG. 17 is a symbol for one period (therefore, 8 symbols) when the phase change method is used, symbol #0 is a symbol when the phase of time u is used, and symbol #0 is a symbol when the phase of time u is used. 1 is a symbol when using the phase at time u+1, symbol #2 is a symbol when using the phase at time u+2, symbol #3 is a symbol when using the phase at time u+3, and the symbol #4 is a symbol when using the phase of time u+4, symbol #5 is a symbol when using the phase of time u+5, symbol #6 is a symbol when using the phase of time u+6, Symbol #7 is a symbol when the phase of time u+7 is used. Therefore, in symbol #x, when x mod 8 is 0, symbol #x is a symbol using the phase at time u, and when x mod 8 is 1, symbol #x is a symbol using the phase at time u+1. When x mod 8 is 2, symbol #x is the symbol when using the phase at time u+2, and when x mod 8 is 3, symbol #x is the symbol when using the phase at time u+3. When x mod 8 is 4, symbol #x is the symbol when using the phase at time u+4, and when x mod 8 is 5, symbol #x is the symbol when using the phase at time u+5. When x mod 8 is 6, symbol #x is the symbol when using the phase at time u+6, and when x mod 8 is 7, symbol #x is the symbol when using the phase at time u+7. It is a symbol of the time. In the arrangement of symbols in FIG. 17, symbols for one period are arranged using 4 slots in the time axis direction and 2 slots in the frequency axis direction, a total of 4 × 2 = 8 slots. The number of symbols for 1 period is m x n symbols (that is, there are m x n types of phases to be multiplied.) The slots (number of carriers) in the frequency axis direction used to arrange symbols for one period are n, and the time axis If the number of slots used in the direction is m, it is preferable that m>n. This is because the phase of the direct wave varies more slowly in the time axis direction than in the frequency axis direction. Therefore, in order to reduce the influence of stationary direct waves, regular phase changes are performed in this embodiment, so it is desired to reduce fluctuations in the direct waves in the period in which the phase is changed. Therefore, it is preferable that m>n. Also, considering the above points, it is better to rearrange symbols using both the frequency axis and the time axis as shown in Figure 17, rather than rearranging the symbols only in the frequency axis direction or only in the time axis direction. is likely to become stationary, and the effect of the present invention can be easily obtained. However, if you arrange them in the frequency axis direction, the variation in the frequency axis is steep, so it may be possible to obtain diversity gain, so it is not always the best to sort them using both the frequency axis and the time axis. It is not necessarily the best method.

FIG. 18 shows an example of a symbol rearrangement method in the rearrangement units 1301A and 1301B of FIG. 13 in the horizontal axis frequency and the vertical axis time, which is different from that in FIG. 17. FIG. 18B shows a method for rearranging the symbols of the modulated signal z2. 18, like FIG. 17, symbols are arranged using both the frequency and time axes, but the difference from FIG. 17 is that in FIG. 17, the frequency direction is prioritized, and then the time axis direction is In contrast to the arrangement of symbols, in FIG. 18, priority is given to the time axis direction, and then symbols are arranged in the time axis direction. In FIG. 18, a symbol group 1802 is symbols for one period when the phase change method is used.

Note that in FIGS. 17 and 18, similar to FIG. 15, the same implementation can be performed even if the symbols of the modulated signal z1 and the modulated signal z2 are arranged in different ways. It is possible to obtain the effect that reception quality can be obtained. In addition, in FIGS. 17 and 18, even if the symbols are not arranged in sequence as in FIG. 16, the same implementation can be performed, and the effect of obtaining high reception quality can be obtained. can.

FIG. 22 shows an example of a method of rearranging symbols in the rearrangement units 1301A and 130B of FIG. 13 in which the horizontal axis is frequency and the vertical axis is time, which is different from the above. Consider a case where the phase is changed regularly using four slots such as times u to u+3 in FIG. 6. The characteristic point in FIG. 22 is that the symbols are arranged in order in the frequency axis direction, but when moving forward in the time axis direction, they are cyclically shifted by n symbols (n=1 in the example of FIG. 22). It is. It is assumed that the phases of the four symbols shown in the symbol group 2210 in the frequency axis direction in FIG. 22 are changed at times u to u+3 in FIG.

At this time, symbol #0 changes the phase using the phase at time u, #1 uses the phase at time u+1, #2 uses the phase at time u+2, and symbol #2 uses the phase at time u+3. The phase change shall be made according to the

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

The phase of the symbol at time $1 was changed as described above, but since it was cyclically shifted in the time axis direction, the phase of symbol groups 2201, 2202, 2203, and 2204 was changed as follows. will be carried out.

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

In the symbol group 2202 in the time axis direction, symbol #28 has a phase change using the phase of time u, #1 has a phase change using the phase of time u+1, #10 has a phase change using the phase of time u+2, In #19, the phase is changed using the phase at time u+3.

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

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

The feature in FIG. 22 is that when focusing on symbol #11, for example, the symbols on both sides in the frequency axis direction at the same time (#10 and #12) are both changed in phase by using a phase different from that of #11. At the same time, the symbols (#2 and #20) on both sides of the same carrier of symbol #11 in the time axis direction are both changed in phase using a phase different from that of #11. This is not limited to the #11 symbol, but all symbols that have symbols on both sides in both the frequency axis direction and the time axis direction have the same characteristics as the #11 symbol. This effectively changes the phase and makes it less susceptible to the steady state of direct waves, increasing the possibility that data reception quality will be improved.

In FIG. 22, the explanation is given with n=1, but the present invention is not limited to this, and the same implementation can be made with n=3. In addition, in Fig. 22, the above feature was achieved by arranging the symbols on the frequency axis and cyclically shifting the order of symbol arrangement when time progresses in the axis direction. There is also a method of realizing the above feature by arranging the elements (which may be regular).

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

In the above embodiment, as shown in FIGS. 3 and 6, the phase change section 317B is configured to change the phase of only one output from the weighted synthesis section 600.
However, the phase change may be performed before the precoding by the weighting synthesis section 600, and the transmitting device may have the configuration shown in FIG. 25 instead of the configuration shown in FIG. The phase change section 317B may be provided before the weighted synthesis section 600.

In this case, the phase change unit 317B regularly changes the phase of the baseband signal s2(t) according to the mapping of the selected modulation method, so that s2'(t)=s2(t
)y(t) (however, y(t) is changed by t), and the weighted synthesis unit 600 performs precoding on s2'(t) to obtain z2(t)(= W2s2'(t)) (see equation (42)) may be output and transmitted.

Further, the phase change may be performed on both modulated signals s1(t) and s2(t), and the transmitting device may have the configuration shown in FIG. 26 instead of the configuration shown in FIG. , a phase change unit may be provided for both outputs of the weighted synthesis unit 600.

The phase change unit 317A, like the phase change unit 317B, regularly changes the phase of the input signal, and changes the phase of the precoded signal z1'(t) from the weighted synthesis unit, The phase-changed signal z1(t) is output to the transmitter.

However, the phase change unit 317A and the phase change unit 317B change the phases to the same degree as shown in FIG. 26 at the same timing. (However, the following is an example, and the method of changing the phase is not limited to this.) At time u, the phase changing unit 317A in FIG. 26 calculates z1(t)=y ₁ (t)z1' (t), and the phase changing unit 317B changes the phase so that z2(t)=y ₂ (t)z2'(t). For example, as shown in FIG. 26, at time u, y ₁ (u)=e ^j0 , y ₂ (u)
= e ^-j π ^/2 , at time u+1, y ₁ (u+1) = e ^j π ^/4 , y ₂ (u+1) = e ^-j3 π ^/4 , ..., at time u+k, y ₁ (u+k) The phase is changed as follows: = e ^jk π ^/4 , y ₂ (u+k) = e ^j(-k π ^/4- π ^/2) . Note that the period for regularly changing the phase may be the same or different between the phase changing section 317A and the phase changing section 317B.

Further, as described above, the timing for changing the phase may be before the weighting synthesis section performs precoding, and the transmitting device may have the configuration shown in FIG. 27 instead of the configuration shown in FIG. 26.

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

Next, a modification of the configuration shown in FIGS. 6 and 25 will be described with reference to FIGS. 28 and 29. The difference between FIG. 28 and FIG. 6 is that information 2800 regarding phase change ON/OFF exists, and the phase is changed to either z1'(t) or z2'(t) (at the same time). , or a phase change is applied to either z1'(t) or z2'(t) at the same frequency. Therefore, the phase is changed to either z1'(t) or z2'(t), so the phase changing unit 317A and phase changing unit 317B in FIG. 28 change the phase (ON). There are cases where the phase is not changed (OFF). Control information regarding this ON/OFF becomes information 2800 regarding phase change ON/OFF. Information 2800 regarding this phase change ON/OFF is output from the signal processing method information generation unit 314 shown in FIG.

The phase changing unit 317A in FIG. 28 adjusts z1(t)=y ₁ (t)z1'(t), and the phase changing unit 317B adjusts z2(t)=y ₂ (t)z2'( t).

At this time, it is assumed that, for example, z1'(t) undergoes a phase change at a cycle of 4. (At this time, z2'(t) does not change the phase.) Therefore, at time u, y ₁ (u)=e ^j0 , y ₂ (u)=1, and at time u+1, y ₁ (u+1)= e ^j π ^/2 , y ₂ (u+1)=1, at time u+2, y ₁ (u+2)=e ^j π, y ₂ (u+2)=1, at time u+3, y ₁ (u+3)=e ^j3 π ^{/ 2} , y ₂ (u+3)=1.

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

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

As described above, there is a time when the phase of only z1'(t) is changed and a time when the phase of only z2'(t) is changed. Further, the period of phase change is composed of the time for changing the phase of only z1'(t) and the time for changing the phase of only z2'(t). Note that in the above, the period when changing the phase of only z1'(t) is the same as the period when changing the phase of only z2'(t), but this is not limiting; The period when only the phase of t) is changed and the period when only the phase of z2'(t) is changed may be different. Furthermore, in the above example, the phase of z1'(t) is changed in four cycles, and then the phase of z2'(t) is changed in four cycles, but this is not limited to this. , the phase change of z1'(t) and the phase change of z2'(t) may be changed in any order (for example, the phase change of z1'(t) and the phase change of z2'(t) may be alternately changed). You can do it in any order you like, follow a certain rule, or the order can be random.)
The phase change unit 317A in FIG. 29 sets s1'(t)=y ₁ (t)s1(t), and the phase change unit 317B sets s2'(t)=y ₂ (t)s2( t).

At this time, for example, it is assumed that s1(t) undergoes a phase change at a cycle of 4. (At this time, s2(t) does not change the phase.) Therefore, at time u, y ₁ (u)=e ^j0 ,
y ₂ (u)=1, at time u+1, y ₁ (u+1)=e ^j π ^/2 , y ₂ (u+1)=1, at time u+2, y ₁ (u+2)=e ^j π, y ₂ (u+2 )=1, at time u+3,
It is assumed that y ₁ (u+3)=e ^j3 π ^/2 and y ₂ (u+3)=1.

Next, for example, it is assumed that s2(t) undergoes a phase change at a period of 4. (At this time, s1(t) does not change the phase.) Therefore, at time u+4, y ₁ (u+4)=1
, y ₂ (u+4)=e ^j0 , at time u+5, y ₁ (u+5)=1, y ₂ (u+5)=e ^j π ^/2 , at time u+6, y ₁ (u+6)=1, y ₂ (u+6 )=e ^j π, and at time u+7, y ₁ (u+7)=1 and y ₂ (u+7)=e ^j3 π ^/2 .

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

As described above, there is a time when the phase of only s1(t) is changed and a time when the phase of only s2(t) is changed. Further, the period of phase change is composed of the time for changing the phase of only s1(t) and the time for changing the phase of only s2(t). Note that in the above, the period when only s1(t) is changed is the same as the period when only s2(t) is changed; however, this is not limited to this, and only s1(t) is changed. The period when the phase is changed may be different from the period when only s2(t) is changed. Furthermore, in the above example, it is explained that the phase of s1(t) is changed in four cycles, and then the phase of s2(t) is changed in four cycles, but this is not limited to this. The phase change of (t) and the phase change of s2(t) may be performed in any order (for example, the phase change of s1(t) and the phase change of s2(t) may be performed alternately, The order may be according to a certain rule, or the order may be random.
)
As a result, it is possible to equalize the reception status of each of the transmission signals z1(t) and z2(t) on the receiving device side, and also to equalize the reception status of each of the received signals z1(t) and z2(t). By periodically switching the phase in the symbols, it is possible to improve the error correction ability after error correction decoding, and therefore it is possible to improve the reception quality in a LOS environment.

As described above, even with the configuration shown in Embodiment 2, the same effects as in Embodiment 1 can be obtained.
In this embodiment, the single carrier method is used as an example, that is, the case where the phase change is performed on the time axis. However, the present invention is not limited to this, and the same implementation can be performed even when multicarrier transmission is performed. Can be done. Therefore, for example, spread spectrum communication system, OFDM (Orthogonal Frequency-Division Multiplexing) system, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC -OFDM (Single Carrier Orthogonal Frequency-Division Multiplexing) method, Non-Patent Document 7, etc. The same implementation is also possible when using the wavelet OFDM method shown in . As mentioned above, in this embodiment, the case where the phase change is performed in the time t-axis direction has been explained as a case in which the phase change is performed in the time t-axis direction. That is, in this embodiment, in the explanation of phase change in the t direction, by replacing t with f (f: frequency ((sub)carrier)), the phase change method explained in this embodiment can be applied to change the phase in the frequency direction. Further, the phase change method of this embodiment can also be applied to phase change in the time-frequency direction, similar to the description of Embodiment 1.

Therefore, although FIGS. 6, 25, 26, and 27 show cases in which the phase is changed in the time axis direction, in FIGS. 6, 25, 26, and 27, time t is replaced with carrier f. This corresponds to changing the phase in the frequency direction, and by replacing time t with time t and frequency f, that is, (t) with (t, f), we can change the phase in a time-frequency block. This corresponds to doing the following.

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

(Embodiment 3)
In the first and second embodiments described above, the phase is changed regularly. In Embodiment 3, among the receiving devices that are scattered in various places when viewed from the transmitting device, the system is designed so that each receiving device can obtain good data reception quality regardless of where the receiving devices are placed. Disclose your methods.

In the third embodiment, a symbol arrangement of a signal obtained by changing the phase will be explained.
FIG. 31 shows an example of a frame structure of some symbols of a signal in the time-frequency axis when a multicarrier method such as the OFDM method is used in a transmission method that regularly changes the phase.

First, an example will be described in which a phase change is performed on one of the two baseband signals after precoding (see FIG. 6) described in the first embodiment.
(Although FIG. 6 shows a case where the phase is changed in the time axis direction, if we replace the time t with the carrier f in FIG. 6, this corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, replacing (t) with (t, f), this corresponds to changing the phase in a time-frequency block.)
FIG. 31 shows the frame structure of the modulated signal z2' that is the input to the phase change unit 317B shown in FIG. (However, depending on the configuration of the precoding matrix, it may include only one of the signals s1 and s2.)

Here, we will focus on symbol 3100 of carrier 2 and time $2 in FIG. Note that although it is described as a carrier here, it may also be called a subcarrier. In carrier 2, the channel state of the symbol 3103 at time $1 and symbol 3101 at time $3 of carrier 2, which is temporally closest to time $2, is the same as that of symbol 3100 of carrier 2, time $2. It is highly correlated with the channel condition.

Similarly, at time $2, the channel state of the symbol of the frequency most adjacent to carrier 2 in the frequency axis direction, that is, the symbol 3104 of carrier 1, time $2, and the symbol 3104 of carrier 3, time $2, is as follows. Both have a very high correlation with the channel state of symbol 3100 of carrier 2 and time $2.

As described above, the channel states of symbols 3101, 3102, 3103, and 3104 have a very high correlation with the channel state of symbol 3100.
In this specification, in a transmission method that regularly changes phases, it is assumed that N types of phases (N is an integer of 2 or more) are prepared as phases to be multiplied. For example, the symbol shown in FIG. 31 is labeled with "e ^j0 ", which means that the signal z2' in FIG. 6 in this symbol is multiplied by "e ^j0 " to change the phase. means that it has been done. In other words, _the values described in each symbol in FIG. It becomes the value of y ₂ (t).

In this embodiment, by utilizing the high correlation between the channel states of symbols adjacent to each other in the frequency axis direction and/or symbols adjacent to each other in the time axis direction, the receiving device side achieves high data reception quality. A symbol constellation of phase-altered symbols that yields is disclosed.

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

<Condition #2>
As shown in FIG. 6, when a multicarrier transmission method such as OFDM is used in a transmission method that regularly changes the phase of the baseband signal z2' after precoding,
Time X and carrier Y are symbols for data transmission (hereinafter referred to as data symbols), and adjacent symbols in the frequency axis direction, that is, time X and carrier Y-1 and time X and carrier Y+1 are both data symbols. If it is a symbol, the baseband signal z2' after precoding corresponding to these three data symbols, that is, after each precoding at time X and carrier Y, time X and carrier Y-1, and time X and carrier Y+1 Different phase changes are performed on the baseband signal z2'.

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

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

Therefore, if different phases are used for three temporally adjacent symbols, in a LOS environment, symbol A will have poor reception quality (although the reception quality is high in terms of SNR, the phase relationship of the direct waves will be poor). Even if the reception quality is poor due to the situation where the reception quality is poor (because of the situation where can obtain good reception quality.

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

Therefore, if different phases are used for three symbols adjacent to each other in terms of frequency, symbol A will have poor reception quality in the LOS environment (although the reception quality is high in terms of SNR, the phase relationship of the direct waves will be poor). Even if the reception quality is poor due to the situation where the reception quality is poor (because of the situation where can obtain good reception quality.

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

<Condition #3>
As shown in FIG. 6, when a multicarrier transmission method such as OFDM is used in a transmission method that regularly changes the phase of the baseband signal z2' after precoding, time X and carrier Y are It is a symbol for transmission (hereinafter referred to as a data symbol), and adjacent symbols in the time axis direction, that is, time X-1 and carrier Y, and time X+1 and carrier Y are both data symbols, and the frequency When symbols adjacent in the axial direction, that is, time X/carrier Y-1 and time , the baseband signal z2' after precoding at time X, carrier Y and time X-1, carrier Y and time X+1, carrier Y and time Different phase changes are made.

Here, we will provide some additional information regarding "different phase changes." The phase change will be defined from 0 radians to 2π radians. For example, at time X and carrier Y, the phase change applied to the baseband signal z2' after precoding in ^FIG .
- At carrier Y, the phase change to be applied to baseband signal z2' after precoding in FIG. 6 is e ^jθX-1,Y , time X+1 - At carrier Y, baseband signal z2' after precoding in FIG. If the phase change applied to e ^jθX+1,Y is, then 0 radians≦ _θX,Y <2π, 0 radians≦ _θX−1,Y <2π, and 0 radians≦ _θX+1,Y <2π. Therefore, in <Condition #1>, θ _X,Y ≠θ _X−1,Y and θ _X,Y ≠θ _X+1,Y and θ _X+
1,Y ≠θ _X−1,Y holds true. Thinking in the same way, <condition #2> holds that θ _X,Y ≠θ _X,Y−1 and θ _X,Y ≠θ _X,Y+1 and θ _X,Y−1 ≠θ _X−1,Y+1. As a result, <
Condition #3>, θ _X,Y ≠θ _X−1,Y and θ _X,Y ≠θ _X+1,Y and θ X _{,Y ≠θ X} ,Y− ₁ and θ _{X,Y ≠} θ θ _X-1,Y ≠θ _X+1,Y and θ _X-1,Y ≠θ _X,Y-1 and θ _{X-1,Y ≠} θ _{X,Y+1 and} θ θ _X+1,Y ≠θ _X,Y+1 and θ _X,Y−1 ≠θ _X,Y+1 hold true.

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

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

That is, in FIG. 32, if data symbols exist in symbols adjacent in the time axis direction, <Condition #1> is satisfied for all Xs and all Ys.
Similarly, in FIG. 32, if data symbols exist in adjacent symbols in the frequency direction, <Condition #2> holds true for all Xs and all Ys.

Similarly, in FIG. 32, if data symbols exist in symbols adjacent in the frequency direction and data symbols exist in symbols adjacent in the time axis direction, <Condition #3> applies to all X, all It holds true for Y.

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

As method 1, the phase of the baseband signal z2' after precoding is changed as shown in FIG. 32, as described above. In FIG. 32, the phase of the baseband signal z2' after precoding is changed at a cycle of 10. However, as mentioned above, in order to satisfy <Condition #1><Condition#2><Condition#3>, (sub)carrier 1 applies precoding to the baseband signal z2'. The phase change is changing over time. (In FIG. 32, such a change is made, but the period may be 10 and another phase change method may be used.) Then, the phase change of the baseband signal z1' after precoding is as shown in FIG. In the phase change of the baseband signal z2' after precoding, the value of the phase change for one period of period 10 is constant. In FIG. 33, at time $1 that includes one cycle (of the phase change of the baseband signal z2' after precoding), the value of the phase change of the baseband signal z1' after precoding is e ^j0 , At time $2, which includes the next one period (of the phase change of the baseband signal z2' after precoding), the value of the phase change of the baseband signal z1' after precoding is e ^jπ/9 , ...and so on.

Note that the symbol shown in FIG. 33 has, for example, the description "e ^j0 ", which means that the signal z1' in FIG. 26 in this symbol is multiplied by "e ^j0 " to obtain the phase. means that it has been changed. That is, the value written in each symbol in FIG. 33 is the value of y ₁ (t) in z1 (t)=y ₁ (t)z1'(t) described in the second embodiment.

The phase change of the baseband signal z1' after precoding is as shown in FIG. 33, and the phase change of the baseband signal z2' after precoding is performed with the phase change value for one cycle of period 10 being constant. The value is changed together with the number for one cycle. (As mentioned above, in FIG. 33, the first period is e ^j0 , the second period is e ^jπ/9 , etc.)
By doing the above, the phase change of the baseband signal z2' after precoding is a period of 10, but the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are It is possible to obtain the effect that the period can be made larger than 10 when both phase changes are considered. This may improve the quality of data received by the receiving device.

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

Note that the symbol shown in FIG. 30 is labeled with, for example, "e ^j0 ", which means that the signal z1' in FIG. 26 in this symbol is multiplied by "e ^j0 " to obtain the phase. means that it has been changed. That is, the value written in each symbol in FIG. 30 is the value of y ₁ (t) in z1 (t)=y ₁ (t)z1'(t) described in the second embodiment.

By doing the above, the phase change of the baseband signal z2' after precoding is a period of 10, but the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are The period when both phase changes are considered is 30, and the period when both the phase change of the baseband signal z1' after precoding and the phase change of the baseband signal z2' after precoding are taken into account is greater than 10. The effect of being able to do this can be obtained. This may improve the quality of data received by the receiving device. One effective method of method 2 is to set the period of phase change of the baseband signal z1' after precoding as N, and to change the phase of the baseband signal z2 after precoding.
When the period of phase change of ' is M, in particular, if N and M are relatively prime, the phase change of baseband signal z1' after precoding and the phase of baseband signal z2' after precoding The period when both changes are taken into consideration has the advantage that it can be easily set to a large period of N×M, but it is possible to increase the period even if N and M are relatively prime.

Note that the phase change method of the third embodiment is an example, and is not limited to this. As explained in the first and second embodiments, the phase change method in the frequency axis direction or the time Changing the phase in the axial direction or in time-frequency blocks also has the effect of improving the quality of data reception at the receiving device.

In addition to the frame structure described above, pilot symbols (SP (Scattered Pilot)), symbols for transmitting control information, etc. may be inserted between data symbols. The phase change in this case will be explained in detail.

FIG. 47 shows the frame structure in the time-frequency axis of the modulation signal (baseband signal after precoding) z1 or z1' and the modulation signal (baseband signal after precoding) z2', and FIG. ) is the time-frame structure of the modulation signal (baseband signal after precoding) z1 or z1' on the frequency axis, and FIG. 47(b) is the time-frame structure of the modulation signal (baseband signal after precoding) z2'. This is a frame configuration on the frequency axis. In FIG. 47, 4701 indicates a pilot symbol, and 4702 indicates a data symbol. The data symbol 4702 is a symbol subjected to precoding or precoding and phase change.

FIG. 47 shows a symbol arrangement when the phase is changed for the baseband signal z2' after precoding as shown in FIG. 6 (no phase change is performed for the baseband signal z1 after precoding). ). (Although FIG. 6 shows a case where the phase is changed in the time axis direction, if we replace the time t with the carrier f in FIG. 6, this corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, replacing (t) with (t, f), this corresponds to changing the phase in a time-frequency block.) Therefore, after precoding in FIG. The numerical value written on the symbol of the baseband signal z2' indicates the phase change value. Note that the symbol of the baseband signal z1' (z1) after precoding in FIG. 47 does not undergo a phase change, so no numerical value is shown.

An important point in FIG. 47 is that the phase change to the baseband signal z2' after precoding is performed on the data symbol, that is, the symbol subjected to precoding. (Here, it is written as a symbol, but since the symbol described here has been precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z2' are not subjected to phase change.

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

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

The important point in FIG. 48 is that the phase change for the baseband signal z1' after precoding is performed on the data symbol, that is, the symbol subjected to precoding. The phase change for ' is applied to data symbols, that is, precoded symbols. (Here, it is written as a symbol, but since the symbol described here has been precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z1' is not subjected to phase change, and the pilot symbol inserted to z2' is not subjected to phase change.

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

FIG. 49 shows a symbol arrangement when the phase is changed for the baseband signal z2' after precoding as shown in FIG. 6 (the phase is not changed for the baseband signal z1 after precoding). ). (Although FIG. 6 shows a case where the phase is changed in the time axis direction, if we replace the time t with the carrier f in FIG. 6, this corresponds to changing the phase in the frequency direction. By replacing time t with time t and frequency f, that is, replacing (t) with (t, f), this corresponds to changing the phase in a time-frequency block.) Therefore, after precoding in Figure 49, The numerical value written on the symbol of the baseband signal z2' indicates the phase change value. Note that the symbol of the baseband signal z1' (z1) after precoding in FIG. 49 does not undergo a phase change, so no numerical value is shown.

The important point in FIG. 49 is that the phase change to the baseband signal z2' after precoding is performed on the data symbol, that is, the symbol to which precoding has been applied. (Here, it is written as a symbol, but since the symbol described here has been precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z2' are not subjected to phase change.

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

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

The important point in FIG. 50 is that the phase change for the baseband signal z1' after precoding is performed on the data symbol, that is, the symbol subjected to precoding. The phase change for ' is applied to data symbols, that is, precoded symbols. (Here, it is written as a symbol, but since the symbol described here has been precoded, it includes both the s1 symbol and the s2 symbol.) Therefore, , z1' is not subjected to phase change, and the pilot symbol inserted to z2' is not subjected to phase change.

FIG. 51 shows an example of the configuration of a transmitting device that generates and transmits a modulated signal having the frame configurations shown in FIGS. 47 and 49. Components that operate in the same manner as in FIG. 4 are given the same reference numerals. .
In FIG. 51, weighted synthesis units 308A, 308B and phase change unit 317B are as follows:
It operates only when the frame configuration signal 313 indicates the timing of a data symbol.

If the frame configuration signal 313 indicates a pilot symbol (and a null symbol), the pilot symbol (which also serves as a null symbol generator) generation unit 5101 in FIG. 51 generates a baseband signal 5102A of the pilot symbol, and Outputs 5102B.

Although not shown in the frame configurations of FIGS. 47 to 50, for example, a method in which a modulated signal is transmitted from one antenna (in this case, the other antenna When transmitting a control information symbol using a transmission method using a space-time code (particularly a space-time block code), the control information symbol 5104 is the control information 5103, the frame When the configuration signal 313 is input and the frame configuration signal 313 indicates a control information symbol, baseband signals 5102A and 5102B of the control information symbol are output.

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

FIG. 52 shows an example of the configuration of a transmitting device that generates and transmits a modulated signal with the frame structure shown in FIGS. 48 and 50. Components that operate in the same manner as in FIGS. are doing. The phase change unit 317A added to FIG. 51 operates only when the frame configuration signal 313 indicates the timing of a data symbol. The other operations are similar to those shown in FIG. 51.

FIG. 53 shows a configuration method of a transmitting device different from that shown in FIG. 51. The different points will be explained below. The phase modulation section 317B receives a plurality of baseband signals as input, as shown in FIG. Then, if the frame configuration signal 313 indicates that it is a data symbol, the phase modulation section 317B performs a phase change on the precoded baseband signal 316B. Then, if the frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, the phase modulation section 317B stops the phase change operation and outputs the baseband signal of each symbol. Output as is. (As an interpretation, it can be considered that a phase rotation corresponding to "e ^j0 " is forcibly performed.)
The selection unit 5301 receives a plurality of baseband signals as input, selects and outputs the baseband signal of the symbol indicated by the frame configuration signal 313.

FIG. 54 shows a configuration method of a transmitting device that is different from that in FIG. 52. The different points will be explained below. The phase modulation section 317B receives a plurality of baseband signals as input, as shown in FIG. Then, if the frame configuration signal 313 indicates that it is a data symbol, the phase modulation section 317B performs a phase change on the precoded baseband signal 316B. Then, if the frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, the phase modulation section 317B stops the phase change operation and outputs the baseband signal of each symbol. Output as is. (As an interpretation, it can be considered that a phase rotation corresponding to "e ^j0 " is forcibly performed.)
Similarly, the phase modulation section 5201 receives a plurality of baseband signals as input, as shown in FIG. If the frame configuration signal 313 indicates that it is a data symbol, the phase modulation section 5201 changes the phase of the precoded baseband signal 309A. Then, if the frame configuration signal 313 indicates that it is a pilot symbol (or null symbol) or a control information symbol, the phase modulation section 5201 stops the phase change operation and outputs the baseband signal of each symbol. Output as is. (As an interpretation, it can be considered that a phase rotation corresponding to "e ^j0 " is forcibly performed.)
In the above explanation, pilot symbols, control symbols, and data symbols are used as examples, but the explanation is not limited to this. Transmission methods other than precoding, such as 1-antenna transmission and transmission using space-time block codes Similarly, it is important not to change the phase if the symbol is to be transmitted using a method such as is important in the present invention.

Therefore, the present invention is characterized in that the phase is not changed for all symbols in the frame configuration on the time-frequency axis, but only for the signal that has been precoded.

(Embodiment 4)
In the first and second embodiments, it has been disclosed that the phase is changed regularly, and in the third embodiment, the degree of change in the phase of adjacent symbols is made different.

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

#1 in Table 1 is the modulation signal s1 of the first embodiment (baseband signal s1 of the modulation method set by the transmitter), and #2 is the modulation signal s2 (baseband signal s2 of the modulation method set by the transmitter) means. The coding rate column in Table 1 indicates the coding rate set for the error correction code for modulation schemes #1 and #2. The column of phase change patterns in Table 1 represents the phase change method applied to baseband signals z1 (z1') and z2 (z2') after precoding, as explained in Embodiments 1 to 3. The phase change pattern is defined as A, B, C, D, E, etc., but this is actually information indicating a change in the degree of phase change. For example, it is assumed that a change pattern as shown in the above equation (46) or equation (47) is shown. Note that in the example of the phase change pattern in Table 1, "-" is written, which means that no phase change is performed.

Note that the combinations of modulation methods and coding rates shown in Table 1 are just examples, and modulation methods other than those shown in Table 1 (e.g., 128QAM, 256QAM, etc.) and coding rates (e.g., 7/8 etc.) may be included. Furthermore, as shown in Embodiment 1, the error correction codes may be set separately for s1 and s2 (in the case of Table 1, as shown in FIG. ). Furthermore, a plurality of mutually different phase change patterns may be associated with the same modulation method and coding rate. The transmitting device transmits information indicating each phase change pattern to the receiving device, and the receiving device identifies the phase change pattern by referring to the information and Table 1, and performs demodulation and decoding. Become. Note that if the phase change pattern is uniquely determined for the modulation method and error correction method, the transmitting device can transmit information about the modulation method and error correction method to the receiving device, and the receiving device can receive that information. In this case, information on the phase change pattern is not necessarily required, since the phase change pattern can be known by obtaining the information.

In Embodiment 1 to Embodiment 3, a case has been described in which the phase is changed for the baseband signal after precoding, but not only the phase but also the amplitude is changed regularly with a period like the phase change. It is also possible. Therefore, Table 1 may also correspond to an amplitude change pattern that regularly changes the amplitude of the modulation signal. In this case, the transmitting device may include an amplitude changing section that changes the amplitude after the weighting and combining section 308A in FIGS. 3 and 4, and an amplitude changing section that changes the amplitude after the weighting and combining section 308B. Note that the amplitude may be changed to one of the baseband signals z1(t) and z2(t) after precoding (in this case, the amplitude changing unit may be installed after either the weighting synthesis unit 308A or 308B). ), the amplitude may be changed for both.

Furthermore, although not shown in Table 1 above, instead of regularly changing the phase, a configuration may be adopted in which the mapping section regularly changes the mapping method.
In other words, if the mapping method for modulated signal s1(t) is 16QAM and the mapping method for modulated signal s2(t) is 16QAM, for example, the mapping method applied to modulated signal s2(t) may be changed regularly to 16QAM. →16APSK (16 Amplitude Phase Shift Keying)
→The first mapping method has a signal point arrangement different from 16QAM and 16APSK on the IQ plane→The second mapping method has a signal point arrangement different from 16QAM and 16APSK on the IQ plane→... Similarly to the case where the phase is changed regularly as described above, it is possible to obtain the effect of improving the reception quality of data in the receiving device.

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

This embodiment can be implemented in either single-carrier transmission or multi-carrier transmission. Therefore, for example, spread spectrum communication system, OFDM (Orthogonal Frequency-Division Multiplexing) system, SC-FDMA (Single Carrier Frequency Division Multiple Access), SC -OFDM (Single Carrier Orthogonal Frequency-Division Multiplexing) method, Non-Patent Document 7, etc. It is also possible to implement the method using the wavelet OFDM method shown in FIG. As described above, in this embodiment, the phase change, amplitude change, and mapping change are explained in the case where the phase change, amplitude change, and mapping change are performed in the time t-axis direction. Similarly, in the same way as when changing the phase in the frequency axis direction, that is, in this embodiment, in the explanation of the phase change, amplitude change, and mapping change in the t direction, t is changed to f (f: frequency ((sub ) carrier)), the phase change, amplitude change, and mapping change described in this embodiment can be applied to the phase change, amplitude change, and mapping change in the frequency direction. Further, the phase change, amplitude change, and mapping change method of this embodiment can also be applied to phase change, amplitude change, and mapping change in the time-frequency direction, as described in Embodiment 1. It is.

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

(Embodiment A1)
In this embodiment, as shown in Non-Patent Documents 12 to 15, a QC (Quasi Cyclic) LDPC (Low-Density Prity-Check) code (an LDPC code that is not a QC-LDPC code) is used. regular phase changes when using block codes such as concatenated codes of LDPC code and BCH code (Bose-Chaudhuri-Hocquenghem code), turbo codes using tail biting, or Duo-Binary Turbo Codes We will explain in detail how to do this. Here, as an example, a case will be described in which two streams, s1 and s2, are transmitted. However, when encoding is performed using a block code and control information etc. are not required, the number of bits composing the block after encoding is the number of bits composing the block code (however, the number of bits composing the block code is may also include control information, etc. as described.). When encoding is performed using a block code, if control information, etc. (e.g. CRC (cyclic redundancy check), transmission parameters, etc.) is required, the number of bits constituting the block after encoding is determined by the block code. It may also be the sum of the number of constituent bits and the number of bits of control information, etc.

FIG. 34 is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when a block code is used. FIG. 34 shows, for example, a case where the transmitting device transmits two streams s1 and s2 and has one encoder as shown in the transmitting device of FIG. 2 is a diagram showing changes in the number of symbols and the number of slots required for one encoded block when used. (At this time, either single carrier transmission or multi-carrier transmission such as OFDM may be used as the transmission method.)
As shown in FIG. 34, it is assumed that the number of bits constituting one encoded block in the block code is 6000 bits. In order to transmit these 6000 bits, 3000 symbols are required when the modulation method is QPSK, 1500 symbols when the modulation method is 16QAM, and 1000 symbols when the modulation method is 64QAM.

In the transmitting device of FIG. 4, two streams are transmitted simultaneously, so when the modulation method is QPSK, the aforementioned 3000 symbols are allocated to s1 and 1500 symbols to s2. In order to transmit 1500 symbols to be transmitted in s1 and 1500 symbols to be transmitted in s2, 1500 slots (herein referred to as "slots") are required.

Thinking similarly, when the modulation method is 16QAM, 750 slots are required to transmit all the bits that make up one encoded block, and when the modulation method is 64QAM, all the bits that make up one block need to be sent. 500 slots are required to transmit the bits.

Next, in the method of regularly changing the phase, the relationship between the slot defined above and the phase to be multiplied will be explained.
Here, it is assumed that the number of phase change values (or phase change sets) prepared for the method of regularly changing the phase is five. In other words, five phase change values (or phase change sets) are prepared for the phase change unit of the transmitter in FIG. 4 (this is the "period" in Embodiments 1 to 4). (As shown in FIG. 6, when changing the phase of only the baseband signal z2' after precoding, in order to change the phase of period 5, it is sufficient to prepare five phase change values. The baseband signal z1' after precoding is
and z2', two phase change values are required for one slot. These two phase change values are called a phase change set. Therefore, in this case, in order to change the phase of period 5, it is sufficient to prepare five phase change sets). These five phase change values (or phase change sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE[4].

When the modulation method is QPSK, in the above-mentioned 1500 slots for transmitting 6000 bits constituting one encoded block, 300 slots use phase PHASE[0], and 300 slots use phase PHASE[0]. 1], 300 slots use phase PHASE[2], 300 slots use phase PHASE[3], and 300 slots use phase PHASE[4]. There is a need. This is because if the phases used are uneven, the influence of the phases used in large numbers is large, and the reception quality of data in the receiving device depends on this influence.

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

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

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

<Condition #A01>
K ₀ =K ₁ =...=K _i =...=K _N-1 , that is, K _a =K _b , (for∀a, ∀b, where a, b=0,1,2, ...,N-1, a≠b)

It would be good if it were.

If a communication system supports multiple modulation methods and selects and uses one of the supported modulation methods, it is better if <condition #A01> is satisfied for the supported modulation methods. .

However, when multiple modulation schemes are supported, the number of bits that can be transmitted in one symbol generally differs depending on each modulation scheme (in some cases, they may be the same). In some cases, there may be a modulation method that cannot satisfy <condition #A01>. In this case, instead of <condition #A01>, it is preferable to satisfy the following condition.

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

FIG. 35 is a diagram showing changes in the number of symbols and the number of slots required for two encoded blocks when block codes are used. FIG. 35 shows a case where the transmitting device transmits two streams s1 and s2 and has two encoders, as shown in the transmitting device of FIG. 3 and the transmitting device of FIG. 12. FIG. 2 is a diagram illustrating changes in the number of symbols and slots required for one encoded block when a block code is used. (At this time, either single carrier transmission or multi-carrier transmission such as OFDM may be used as the transmission method.)
As shown in FIG. 35, it is assumed that the number of bits constituting one encoded block in the block code is 6000 bits. In order to transmit these 6000 bits, 3000 symbols are required when the modulation method is QPSK, 1500 symbols when the modulation method is 16QAM, and 1000 symbols when the modulation method is 64QAM.

The transmitting device in FIG. 3 and the transmitting device in FIG. 12 transmit two streams at the same time, and since there are two encoders, the two streams transmit different code blocks. become. Therefore, when the modulation method is QPSK, two encoded blocks are transmitted within the same interval by s1 and s2, so for example, the first encoded block is transmitted by s1, and the second encoded block is transmitted by s2. Since two encoded blocks are to be transmitted, 3000 slots are required to transmit the first and second encoded blocks.

Thinking similarly, when the modulation method is 16QAM, 1500 slots are required to transmit all the bits that make up the two encoded blocks, and when the modulation method is 64QAM, the two encoded blocks 1000 slots are required to transmit all the bits that make up the .

Next, in the method of regularly changing the phase, the relationship between the slot defined above and the phase to be multiplied will be explained.
Here, it is assumed that the number of phase change values (or phase change sets) prepared for the method of regularly changing the phase is five. In other words, it is assumed that five phase change values (or phase change sets) are prepared for the phase change unit of the transmitting device in FIGS. 3 and 12 ("period" in Embodiments 1 to 4) ) (As shown in FIG. 6, when changing the phase only to the baseband signal z2' after precoding, in order to change the phase of period 5, it is sufficient to prepare five phase change values. , as shown in FIG. 26, when performing phase changes on both baseband signals z1' and z2' after precoding, two phase change values are required for one slot.These two phase changes The value is called a phase change set. Therefore, in this case, in order to perform a phase change of period 5, it is sufficient to prepare five phase change sets). These five phase change values (or phase change sets) are expressed as PHASE[0], PHASE[1], PHASE[2], PHASE[3], and PHASE[4].

When the modulation method is QPSK, the number of slots using phase PHASE[0] is 600 slots and 600 slots use PHASE[1], 600 slots use PHASE[2], 600 slots use PHASE[3], 600 slots use PHASE[4] It must be. This is because if the phases used are uneven, the influence of the phases used in large numbers is large, and the reception quality of data in the receiving device depends on this influence.

Also, to transmit the first coded block, there are 600 slots using phase PHASE[0], 600 slots using phase PHASE[1], and 600 slots using phase PHASE[2]. 600 slots using phase PHASE[3], 600 slots using phase PHASE[4], and 600 slots using phase PHASE[4] to transmit the second coded block. 600 slots using [0], 600 slots using phase PHASE[1], 600 slots using phase PHASE[2], 600 slots using phase PHASE[3], It is preferable that the number of slots using phase PHASE[4] is 600 times.

Similarly, when the modulation method is 16QAM, the number of slots using phase PHASE[0] is 300 in the 1500 slots mentioned above for transmitting 6000 x 2 bits that constitute two encoded blocks. 300 slots using phase PHASE[1], 300 slots using phase PHASE[2], 300 slots using phase PHASE[3], 300 slots using phase PHASE[4] must be 300 slots.

Also, in order to transmit the first coded block, there are 300 slots using phase PHASE[0], 300 slots using phase PHASE[1], and 300 slots using phase PHASE[2]. 300 slots using phase PHASE[3], 300 slots using phase PHASE[4], and 300 slots using phase PHASE[4] to transmit the second coded block. 300 slots using [0], 300 slots using phase PHASE[1], 300 slots using phase PHASE[2], 300 slots using phase PHASE[3], It is preferable that the number of slots using phase PHASE[4] is 300 times.

Similarly, when the modulation method is 64QAM, the number of slots using phase PHASE[0] is 200 in the above-mentioned 1000 slots for transmitting 6000 x 2 bits, which constitute two encoded blocks. slots, 200 slots using phase PHASE[1], 200 slots using phase PHASE[2], 200 slots using phase PHASE[3], slots using phase PHASE[4] must be 200 slots.

Also, in order to transmit the first coded block, there are 200 slots using phase PHASE[0], 200 slots using phase PHASE[1], and 200 slots using phase PHASE[2]. 200 slots using phase PHASE[3], 200 slots using phase PHASE[4], and 200 slots using phase PHASE[4] to transmit the second coded block. 200 slots using [0], 200 slots using phase PHASE[1], 200 slots using phase PHASE[2], 200 slots using phase PHASE[3], It is preferable that the number of slots using phase PHASE[4] is 200 times.

As described above, in the method of regularly changing the phase, the phase change values (or phase change set) to be prepared are PHASE[0], PHASE[1], PHASE[2],..., PHASE[N -2], PHASE[N-1]), the number of slots using phase PHASE[0] when transmitting all bits constituting two encoded blocks is K. ₀ , the number of slots using phase PHASE[1] is K _1, the number of slots using phase PHASE[i] is K _i (i=0,1,2,...,N-1), phase PHASE[ N-1], when the number of slots used is K _N-1 ,

<Condition #A03>
K ₀ =K ₁ =...=K _i =...=K _N-1 , that is, K _a =K _b , (for∀a, ∀b, where a, b=0,1,2, ...,N-1, a≠b)

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

<Condition #A04>
K _0,1 =K _1,1 =...=K _i,1 =...=K _N-1,1 , that is, K _a,1 =K _b,1 , (for∀a, ∀b, However, a, b=0,1,2,...,N-1, a≠b)

When transmitting all bits constituting the second encoded block, the number of times the phase PHASE[0] is used is K _0,2 , and the number of times the phase PHASE[1] is used is K1 _{, 2.} The number of times to use phase PHASE[i] is K _{i, 2} (i=0,1,2,...,N-1), and the number of times to use phase PHASE[N-1] is K _{N-1. ,2} ,

<Condition #A05>
K _0,2 =K _1,2 =...=K _i,2 =...=K _N-1,2 , that is, K _a,2 =K _b,2 , (for∀a, ∀b, However, a, b=0,1,2,...,N-1, a≠b)

It would be good if it were.

If the communication system supports multiple modulation methods and selects and uses them from the supported modulation methods, <Condition #A03> <Condition #A04> <Condition It is good if #A05> holds true.

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

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

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

<Condition #A08>
The difference between K _a,2 and K _b,2 is 0 or 1, that is, |K _a,2 −K _b,2 | is 0 or 1
(for∀a, ∀b, where a, b=0,1,2,...,N-1, a≠b)

As described above, by associating the encoded block with the phase to be multiplied, there is no imbalance in the phase used to transmit the encoded block, which improves the quality of data reception at the receiving device. This effect can be obtained.

In this embodiment, in the method of regularly changing the phase, N phase change values (or phase change sets) are required for a phase change method with period N. At this time, N phase change values (or phase change sets) are PHASE[0], PHASE[1], PHASE[2],...
PHASE[N-2], PHASE[N-1] will be prepared, but in the frequency axis direction PHASE[0], PHASE[1], PHASE[2], ..., PHASE[N-2] , PHASE[N-1], but this is not necessarily the only method. N phase change values (or phase change sets) PHASE[0], PHASE[1]
, PHASE[2], ..., PHASE[N-2], PHASE[N-1] can be calculated by arranging symbols in blocks on the time axis and frequency-time axis in the same way as in Embodiment 1. , the phase can also be changed. Although this is explained as a phase change method with period N, the same effect can also be obtained by randomly using N phase change values (or phase change sets). Although it is not necessary to use N phase change values (or phase change sets) to have a period of , becomes important.

Additionally, a spatial multiplexing MIMO transmission method, a MIMO transmission method with a fixed precoding matrix, a space-time block coding method, a method of transmitting only one stream, and a method of regularly changing the phase (described in Embodiments 1 to 4) are also available. There are several transmission methods (transmission methods), and the transmitting device (broadcasting station, base station) may be able to select one of these transmission methods.

Note that the spatial multiplexing MIMO transmission method is a method in which signals s1 and s2 mapped using a selected modulation method are transmitted from different antennas, as shown in Non-Patent Document 3, and the precoding matrix is fixed. The MIMO transmission method is a method that performs only precoding (does not change phase) in Embodiments 1 to 4. Further, the space-time block encoding method is a transmission method shown in Non-Patent Documents 9, 16, and 17. Transmitting only one stream is a method in which the signal s1 mapped using the selected modulation method is subjected to predetermined processing and transmitted from the antenna.

In addition, a multi-carrier transmission method such as OFDM is used, and a first carrier group made up of multiple carriers, a second carrier group different from the first carrier group made up of multiple carriers, etc. Multi-carrier transmission is realized using multiple carrier groups, and for each carrier group, spatial multiplexing MIMO transmission method, MIMO transmission method with a fixed precoding matrix, space-time block coding method, only one stream transmission, It may be set to any method that changes the phase regularly,
In particular, this embodiment is preferably implemented in a (sub)carrier group in which a method of regularly changing the phase is selected.

In addition, when changing the phase of one of the baseband signals after precoding, for example, when the phase change value of PHASE[i] is set to "X radians", Figs. 3, 4, 6, and 12 ，
In the phase change unit in FIG. 25, FIG. 29, FIG. 51, and FIG. 53, the baseband signal z2' after precoding is multiplied by e ^jX . When the phase is changed for the baseband signals after precoding of both, for example, when the phase change set of PHASE[i] is set to "X radian" and "Y radian", FIGS. 26, 27, In the phase change unit in FIGS. 28, 52, and 54, e ^jX is converted into baseband signal z2 after precoding.
', and the baseband signal z1' after precoding is multiplied by e ^jY .

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

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

A signal transmitted from the broadcast station 3601 is received by an antenna (for example, antennas 3660, 3640) built into each receiver or installed externally and connected to the receiver. Each receiver demodulates the signal received by the antenna using the reception method described in each of the above embodiments, and obtains multiplexed data. Thereby, the digital broadcasting system 3600 can obtain the effects 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, MPEG4-AVC (Advanced
Video Coding), VC-1, and other standards. The audio data included in the multiplexed data is, for example, Dolby AC (Audio Coding)-3, Dolby Digital Plus, MLP (Meridian Lossless Packing), DTS (Digital Theater Systems), DTS-HD, Linear PC. M (Pulse Coding
Modulation).

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

The receiver 3700 also includes a stream input/output unit 3720 that separates video data and audio data from the multiplexed data obtained by the demodulation unit 3702, and a stream input/output unit 3720 that separates video data and audio data from the multiplexed data obtained by the demodulation unit 3702. A signal processing unit 3704 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. 3706, and a video display section 3707 such as a display that displays the decoded video signal.

For example, the user uses a remote control (remote controller) 3750 to transmit information on the selected channel (selected (television) program, selected audio broadcast) to the operation input unit 3710. Then, the receiver 3700 performs processing such as demodulation and error correction decoding on the received signal corresponding to the selected channel in the received signal received by the antenna 3760, and obtains received data. At this time, the receiver 3700 transmits the transmission method (transmission method, modulation method, error correction method, etc. described in the above embodiment) included in the signal corresponding to the selected channel (this is explained in FIG. By obtaining information on control symbols including information on It becomes possible to obtain the data contained in the data symbol. In the above example, the user selects a channel using the remote control 3750, but even if the user selects a channel using the channel selection key installed in the receiver 3700, the same operation as above will occur. Become.

With the above configuration, the user can view the program that the receiver 3700 receives using the receiving method shown in each of the above embodiments.
In addition, the receiver 3700 of this embodiment performs demodulation in the demodulation section 3702 and performs error correction decoding to obtain multiplexed data (in some cases, the signal obtained by demodulation in the demodulation section 3702). In addition, the receiver 3700 may perform other signal processing after error correction decoding.This point will also be made in the following sections where similar expressions are used. ), or data equivalent to that data (for example, data obtained by compressing data), or data obtained by processing video or audio, onto a magnetic disk. , a recording unit (drive) 3708 for recording on a recording medium such as an optical disc or a non-volatile semiconductor memory. Here, the optical disc is a recording medium, such as a DVD (Digital Versatile Disc) or a BD (Blu-ray (registered trademark) Disc), in which information is stored and read using laser light. A magnetic disk is a recording medium, such as an FD (Floppy Disk) (registered trademark) or a hard disk (Hard Disk), that stores information by magnetizing a magnetic material using magnetic flux. Non-volatile semiconductor memory is a recording medium composed of semiconductor elements, such as flash memory and ferroelectric random access memory, and includes SD cards and Flash SSDs (Solid State Drives) using flash memory. ), etc. Note that the types of recording media mentioned here are just examples, and it goes without saying that recording may be performed using recording media other than the above-mentioned recording media.

With the above configuration, the user can record and save the program that the receiver 3700 receives using the reception method shown in each of the above embodiments, and can record and save the program that is recorded at any time after the time when the program is being broadcast. can be read and viewed.

In the above description, it is assumed that the receiver 3700 records the multiplexed data obtained by demodulating in the demodulating unit 3702 and performing error correction decoding in the recording unit 3708, but the data included in the multiplexed data Part of the data may be extracted and recorded. For example, if the multiplexed data obtained by demodulating in the demodulating section 3702 and performing error correction decoding includes content of a data broadcasting service other than video data and audio data, the recording section 3708 New multiplexed data may be recorded by extracting video data and audio data from the multiplexed data demodulated in . The recording unit 3708 also generates new multiplexed data obtained by multiplexing only one of the video data and audio data included in the multiplexed data obtained by demodulating the demodulating unit 3702 and performing error correction decoding. may be recorded. Then, the recording unit 3708 may record the content of the data broadcasting service included in the multiplexed data described above.

Furthermore, if the receiver 3700 described in the present invention is installed in a television, a recording device (for example, a DVD recorder, a Blu-ray (registered trademark) recorder, an HDD recorder, an SD card, etc.), or a mobile phone, the demodulation The multiplexed data obtained through demodulation and error correction decoding in the section 3702 includes data, personal information, and records for correcting defects (bugs) in software used to operate televisions and recording devices. If the software contains data to fix software defects (bugs) to prevent data leakage, installing these data may fix software defects in televisions and recording devices. . If the data includes data for correcting a software defect (bug) in the receiver 3700, the defect in the receiver 3700 can also be corrected using this data. This allows the television, recording device, and mobile phone equipped with the receiver 3700 to operate more stably.

Here, the process of extracting and multiplexing some data from a plurality of data included in the multiplexed data obtained by demodulating and performing error correction decoding in the demodulator 3702 is performed by, for example, the stream input/output unit 3703. It will be held in Specifically, the stream input/output unit 3703 converts the multiplexed data demodulated by the demodulation unit 3702 into video data, audio data, data broadcasting service content, etc. based on instructions from a control unit such as a CPU (not shown). Separates data into multiple pieces of data, extracts only specified data from the separated data, and multiplexes it to generate new multiplexed data. Note that which data to extract from the separated data may be determined, for example, by the user, or may be determined in advance for each type of recording medium.

With the above configuration, the receiver 3700 can extract and record only the data necessary when viewing a recorded program, so the data size of the data to be recorded can be reduced.

Furthermore, in the above description, the recording unit 3708 records the multiplexed data obtained by demodulating in the demodulating unit 3702 and performing error correction decoding. The video data included in the multiplexed data obtained by performing New multiplexed data may be recorded by converting the converted video data into encoded video data using a coding method and multiplexing the converted video data. At this time, the video encoding method applied to the original video data and the video encoding method applied to the converted video data may be based on different standards, or may be based on the same standard. Only the parameters used during encoding may be different. Similarly, the recording unit 3708 demodulates the audio data included in the multiplexed data obtained by performing error correction decoding in the demodulating unit 3702 so that the data size or bit rate is lower than that of the audio data. , the audio data may be converted into audio data encoded using a different audio encoding method than the audio encoding method applied to the audio data, and new multiplexed data obtained by multiplexing the converted audio data may be recorded.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating in the demodulation unit 3702 and performing error correction decoding into video data and audio data with different data sizes or bit rates is performed. , for example, is performed by the stream input/output unit 3703 and the signal processing unit 3704. Specifically, the stream input/output unit 3703 demodulates the multiplexed data obtained by demodulating the data in the demodulating unit 3702 and performs error correction decoding according to instructions from a control unit such as a CPU, and converts the multiplexed data into video data, audio data, Separate data into multiple pieces of data, such as content of data broadcasting services. The signal processing unit 3704 performs a process of converting the separated video data into video data encoded using a video encoding method different from the video encoding method applied to the video data, according to instructions from the control unit. , and converts the separated audio data into audio data encoded using a different audio encoding method from the audio encoding method applied to the audio data. The stream input/output unit 3703 multiplexes the converted video data and the converted audio data to generate new multiplexed data according to instructions from the control unit. Note that the signal processing unit 3704 may perform conversion processing on only one of the video data and audio data, or may perform conversion processing on both of them, in accordance with instructions from the control unit. 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 determined in advance for each type of recording medium.

With the above configuration, the receiver 3700 changes the data size or bit rate of video data and audio data according to the data size that can be recorded on the recording medium and the speed at which the recording unit 3708 records or reads data. can do. As a result, if the data size that can be recorded on the recording medium is smaller than the data size of multiplexed data obtained by demodulating in the demodulation unit 3702 and performing error correction decoding, or when the recording unit is unable to record or read data, Even if the bit rate of the multiplexed data demodulated by the demodulation unit 3702 is lower than the bit rate of the multiplexed data demodulated by the demodulation unit 3702, the recording unit can record the program. It becomes possible to read and view the data recorded on the .

The receiver 3700 also includes a stream output IF (Interface) 3709 that transmits the multiplexed data demodulated by the demodulator 3702 to an external device via a communication medium 3730. Examples of the stream output IF 3709 include Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Zigbee (registered trademark), etc. An example of a wireless communication device is a wireless communication device that transmits multiplexed data modulated using a wireless communication method compliant with the wireless communication standard, to an external device via a wireless medium (corresponding to the communication medium 3730). In addition, the stream output IF3709 supports Ethernet (registered trademark), USB (Universal Serial Bus), PLC (Power Line
The multiplexed data modulated using a communication method compliant with wired communication standards such as HDMI (registered trademark) and HDMI (High-Definition Multimedia Interface) is transmitted through a wired transmission path (communication medium 3730) connected to the stream output IF 3709. It may also be a wired communication device that transmits the data to an external device via a

With the above configuration, the user can use the multiplexed data received by the receiver 3700 using the receiving method shown in each of the embodiments above with an 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 on a recording unit equipped with the external device, or record the multiplexed data from the external device. This includes transmitting multiplexed data to another external device.

Note that in the above description, it is assumed that the stream output IF 3709 of the receiver 3700 outputs the multiplexed data obtained by demodulating the demodulating unit 3702 and performing error correction decoding, but the data included in the multiplexed data Part of the data may be extracted and output. For example, if the multiplexed data obtained by demodulating in the demodulating unit 3702 and performing error correction decoding includes content of a data broadcasting service other than video data and audio data, the stream output IF 3709 New multiplexed data may be output by extracting video data and audio data from the multiplexed data obtained by demodulating the data and performing error correction decoding. Furthermore, the stream output IF 3709 may output new multiplexed data obtained by multiplexing only one of the video data and audio data included in the multiplexed data demodulated by the demodulator 3702.

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

With the above configuration, the receiver 3700 can extract and output only the data required by the external device, so that the communication band consumed by outputting multiplexed data can be reduced.

Furthermore, in the above description, the stream output IF 3709 outputs multiplexed data obtained by demodulating in the demodulating section 3702 and performing error correction decoding. The video data included in the multiplexed data obtained by performing It is also possible to convert the video data into encoded video data using a coding method, and output new multiplexed data by multiplexing the video data after the conversion. At this time, the video encoding method applied to the original video data and the video encoding method applied to the converted video data may be based on different standards, or may be based on the same standard. Only the parameters used during encoding may be different. Similarly, the stream output IF 3709 converts the audio data included in the multiplexed data obtained by demodulating the demodulating unit 3702 and performing error correction decoding so that the data size or bit rate is lower than that of the audio data. , the audio data may be converted into audio data encoded using a different audio encoding method than the audio encoding method applied to the audio data, and new multiplexed data obtained by multiplexing the converted audio data may be output.

Here, the process of converting the video data and audio data included in the multiplexed data obtained by demodulating in the demodulation unit 3702 and performing error correction decoding into video data and audio data with different data sizes or bit rates is performed. , for example, is performed by the stream input/output unit 3703 and the signal processing unit 3704. Specifically, the stream input/output unit 3703 demodulates the multiplexed data obtained by demodulating the data in the demodulating unit 3702 and performs error correction decoding according to instructions from the control unit, and outputs the multiplexed data to video data, audio data, and data broadcasting services. Separate the data into multiple pieces of data such as content. The signal processing unit 3704 performs a process of converting the separated video data into video data encoded using a video encoding method different from the video encoding method applied to the video data, according to instructions from the control unit. , and converts the separated audio data into audio data encoded using a different audio encoding method from the audio encoding method applied to the audio data. The stream input/output unit 3703 multiplexes the converted video data and the converted audio data to generate new multiplexed data according to instructions from the control unit. Note that the signal processing unit 3704 may perform conversion processing on only one of the video data and audio data, or may perform conversion processing on both of them, in accordance with instructions from the control unit. Also good. Furthermore, the data size or bit rate of the converted video data and audio data may be determined by the user or may be determined in advance for each type of stream output IF 3709.

With the above configuration, the receiver 3700 can change the bit rate of video data and audio data in accordance with 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 in the demodulator 3702 and performing error correction decoding, the external device can receive new multiplexed data from the stream output IF. Since the multiplexed data can be output, the user can use the new multiplexed data in other communication devices.

The receiver 3700 also includes an AV (Audio and Visual) output IF (Interface) 3711 that outputs the video signal and audio signal decoded by the signal processing unit 3704 to an external device to an external communication medium. Examples of the AV output IF 3711 include wireless communication standards such as Wi-Fi (registered trademark) (IEEE802.11a, IEEE802.11b, IEEE802.11g, IEEE802.11n, etc.), WiGiG, WirelessHD, Bluetooth (registered trademark), Gigbee, etc. Examples include a wireless communication device that transmits a video signal and an audio signal modulated using a wireless communication method based on the above to an external device via a wireless medium. In addition, the stream output IF3709 connects video and audio signals modulated using a communication method compliant with wired communication standards such as Ethernet (registered trademark), USB, PLC, and HDMI (registered trademark) to the stream output IF3709. It may also be a wired communication device that transmits to an external device via a wired transmission path. Furthermore, the stream output IF 3709 may be a terminal for connecting a cable that outputs the video signal and the audio signal as analog signals.

With the above configuration, the user can use the video signal and audio signal decoded by the signal processing unit 3704 with an external device.
Furthermore, the receiver 3700 includes an operation input unit 3710 that receives user operation input. The receiver 3700 can switch the power ON/OFF, switch the reception channel, display subtitles or not, and switch the display language based on a control signal input to the operation input unit 3710 in response to a user's operation. , to switch various operations such as changing the volume output from the audio output unit 3706, and to change settings such as setting receivable channels.

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

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

Note that in the above description, the receiver 3700 is provided with an audio output section 3706, a video display section 3707, a recording section 3708, a stream output IF 3709, and an AV output IF 3711. It is not necessary to have all of the above. If the receiver 3700 has at least one of the above configurations, the user can use the multiplexed data obtained by demodulating in the demodulating section 3702 and performing error correction decoding. , each receiver may be provided with any combination of the above configurations depending on its purpose.
(Multiplexed data)
Next, an example of the structure of multiplexed data will be described in detail. The data structure commonly used for broadcasting is MPEG2-Transport Stream (TS), and here M
This will be explained using PEG2-TS as an example. However, the data structure of multiplexed data transmitted by the transmission method and reception method shown in each of the above embodiments is not limited to MPEG2-TS, and any other data structure may be used as described in each of the above embodiments. Needless to say, you can get the same effect.

FIG. 38 is a diagram illustrating an example of the configuration of multiplexed data. As shown in FIG. 38, the multiplexed data includes elements constituting programs (programs or events that are part of programs) currently provided by each service, such as video streams, audio streams, and presentation graphics streams (PGs). ), interactive graphics streams (IG), etc., by multiplexing one or more of them. If the program provided as multiplexed data is a movie, the video stream is the main video and sub-video of the movie, the audio stream is the main audio part of the movie and the sub-audio to be mixed with the main audio, and the presentation graphics stream is indicates the subtitles of each movie. Here, the main image refers to the normal image displayed on the screen, and the sub-image refers to the image displayed on a small screen within the main image (for example, a text data image showing the synopsis of the movie). be. Furthermore, the interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen.

Each stream included in the multiplexed data is identified by a PID, which is an identifier assigned to each stream. For example, a video stream used for movie footage uses 0x1011, an audio stream uses 0x1100 to 0x111F, presentation graphics uses 0x1200 to 0x121F, and an interactive graphics stream uses 0x1400 to 0x141F. 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. 39 is a diagram schematically showing an example of how multiplexed data is multiplexed. First, a video stream 3901 consisting of a plurality of video frames and an audio stream 3904 consisting of a plurality of audio frames are converted into PES packet sequences 3902 and 3905, and then into TS packets 3903 and 3906, respectively. Similarly, the data of presentation graphics stream 3911 and interactive graphics 3914 are converted into PES packet sequences 3912 and 3915, respectively, and further converted into TS packets 3913 and 3916. Multiplexed data 3917 is constructed by multiplexing these TS packets (3903, 3906, 3913, 3916) into one stream.

FIG. 40 shows in more detail how video streams are stored in PES packet sequences. The first row in FIG. 40 shows a video frame sequence of the video stream. The second row shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, and yy4 in FIG. 40, I pictures, B pictures, and P pictures, which are a plurality of Video Presentation Units in a video stream, are divided into picture units and stored in the payload of a PES packet. . Each PES packet has a PES header, and the PES header stores a PTS (Presentation Time-Stamp), which is a picture display time, and a DTS (Decoding Time-Stamp), which is a picture decoding time.

FIG. 41 shows the format of the TS packet finally written into the multiplexed data. A TS packet is a 188-byte fixed-length packet consisting of a 4-byte TS header with information such as a PID that identifies a stream, and a 184-byte TS payload that stores data, and the above 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, forming a 192-byte source packet, which is written into multiplexed data. Information such as ATS (Arrival_Time_Stamp) is written in TP_Extra_Header. ATS indicates the start time of transfer of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 41, and the number incremented from the beginning of the multiplexed data is called an SPN (source packet number).

In addition to each stream such as a video stream, audio stream, and presentation graphics stream, the TS packets included in the multiplexed data also include PAT (Program Association Table) and PMT (Program Association Table).
Map Table), PCR (Program Clock Reference), etc. The PAT indicates what the PID of the PMT used in multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has the PID of each stream such as video, audio, subtitles, etc. included in the multiplexed data and attribute information (frame rate, aspect ratio, etc.) of the stream corresponding to each PID, and also various descriptors regarding the multiplexed data. have The descriptor includes copy control information that instructs whether copying of multiplexed data is permitted or not. PCR corresponds to an ATS in which the PCR packet is transferred to a decoder in order to synchronize the ATC (Arrival Time Clock), which is the time axis of ATS, and the STC (System Time Clock), which is the time axis of PTS/DTS. Contains STC time information.

FIG. 42 is a diagram illustrating the data structure of PMT in detail. A PMT header that describes the length of data included in the PMT is placed at the beginning of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The above copy control information and the like are written as a descriptor. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information includes a stream descriptor that describes a stream type for identifying the compression codec of the stream, a PID of the stream, and attribute information of the stream (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 a multiplexed data information file.
FIG. 43 is a diagram showing the structure of the multiplexed data information file. The multiplexed data information file, as shown in FIG. 43, is management information for multiplexed data, has a one-to-one correspondence with multiplexed data, and is composed of multiplexed data information, stream attribute information, and an entry map.

As shown in FIG. 43, the multiplexed data information is composed of a system rate, a playback start time, and a playback end time. The system rate indicates the maximum transfer rate of multiplexed data to a PID filter of a system target decoder, which will be described later. The interval between ATSs included in the multiplexed data is set to be less than or equal to the system rate. The playback start time is set to the PTS of the first video frame of the multiplexed data, and the playback end time is set to the PTS of the last video frame of the multiplexed data plus a playback interval of one frame.

FIG. 44 is a diagram showing the structure of stream attribute information included in the multiplexed data information file. As for the stream attribute information, as shown in FIG. 44, attribute information for each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. Video stream attribute information includes information such as what kind of 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 what the frame rate is. It has information such as how much. Audio stream attribute information includes information such as what compression codec the audio stream was compressed with, how many channels it contains, what language it supports, what the sampling frequency is, etc. has information on. This information is used for initializing the decoder before playback by the player.

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

FIG. 45 shows an example of the configuration of a video and audio output device 4500 including a receiving device 4504 that receives video and audio data transmitted from a broadcasting station (base station) or a modulated signal containing data for data broadcasting. It shows. Note that the configuration of receiving device 4504 corresponds to receiving device 3700 in FIG. 37. The video/audio output device 4500 is equipped with, for example, an OS (Operating System), and also has a communication device 4506 for connecting to the Internet (for example, a wireless LAN (Local Area Network) or Ethernet). communication equipment) is installed. As a result, the video display portion 4501 displays video and audio data, or video 4502 in data for data broadcasting, and hypertext (World Wide Web: WWW) provided on the Internet. ) 4503 can be displayed simultaneously. Then, by operating a remote control (which may be a mobile phone or keyboard) 4507, either the video 4502 in the data for data broadcasting or the hypertext 4503 provided on the Internet is selected and the operation is changed. I will do it. For example, when hypertext 4503 provided on the Internet is selected, the displayed WWW site can be changed by operating the remote control. In addition, when the video 4502 in video and audio data or data for data broadcasting is selected, the remote control 4507 can be used to select the selected channel (selected (TV) program, selected audio broadcast). Submit information. Then, the IF 4505 acquires the information transmitted by the remote control, and the receiving device 4504 performs processing such as demodulation and error correction decoding on the signal corresponding to the selected channel to obtain received data. At this time, the receiving device 4504 receives information on a control symbol including information on a transmission method (as described in FIG. 5) included in a signal corresponding to the selected channel. By correctly setting the operation, demodulation method, error correction decoding method, etc., it becomes possible to obtain the data included in the data symbols transmitted by the broadcast station (base station). In the above example, the user selects a channel using the remote controller 4507. However, even if the user selects a channel using the channel selection key installed in the video/audio output device 4500, the same result as described above will occur. It becomes an action.

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

(Other supplements)
In this specification, communication/broadcasting equipment such as a broadcasting station, base station, access point, terminal, mobile phone, etc. may be equipped with a transmitting device, and in this case, Communication devices such as televisions, radios, terminals, personal computers, mobile phones, access points, and base stations may be equipped with receiving devices. Further, the transmitting device and the receiving device in the present invention are devices having a communication function, and the device is connected to a device for executing an application such as a television, a radio, a personal computer, a mobile phone, etc. through some kind of interface ( For example, it may be possible to connect via USB.

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

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

Symbols for control information also contain information that needs to be transmitted to the communication partner in order to realize communication other than data (such as applications) (for example, the modulation method, error correction coding method, etc. used for communication). This is a symbol for transmitting information such as the coding rate of the error correction coding method, setting information in upper layers, etc.

Note that the present invention is not limited to all the embodiments, and can be implemented with various changes. For example, in the above embodiment, a case is described in which the communication method is implemented as a communication device, but the communication method is not limited to this, and it is also possible to implement this communication method as software.

In addition, although the phase change method in the method of transmitting two modulated signals from two antennas has been described above, the method is not limited to this, and precoding and phase change are performed on the four mapped signals. The method is modified to generate four modulated signals and transmit them from four antennas. In other words, precoding is performed on N mapped signals, N modulated signals are generated, and N antennas are transmitted. Similarly, in the method of transmitting data from a source, the phase can be similarly implemented as a phase changing method in which the phase is changed regularly.

Further, in the system example shown in the above embodiment, a MIMO communication system is disclosed in which two modulated signals are transmitted from two antennas and each is received by two antennas, but the present invention naturally applies to MISO It can also be applied to (Multiple Input Single Output) communication systems. In the case of the MISO method, the receiving device has a configuration shown in FIG. 7 that does not include the antenna 701_Y, the radio section 703_Y, the channel fluctuation estimation section 707_1 for the modulated signal z1, and the channel fluctuation estimation section 707_2 for the modulated signal z2. Even in this case, it is possible to estimate each of r1 and r2 by executing the process shown in Embodiment 1 above. Note that it is well known that multiple signals transmitted in the same frequency band and at the same time can be received and decoded with one antenna, and in this specification, the phase changed on the transmitting side in the signal processing unit is The process for returning the data is added to the conventional technology.

Further, in the system example shown in the explanation of the present invention, a MIMO communication system is disclosed in which two modulated signals are transmitted from two antennas and each is received by two antennas, but the present invention naturally applies to MISO It can also be applied to (Multiple Input Single Output) communication systems. In the case of the MISO method, as described above, precoding and phase change are applied in the transmitter. On the other hand, the receiving device has a configuration shown in FIG. 7 that does not include the antenna 701_Y, the radio section 703_Y, the channel fluctuation estimation section 707_1 for the modulated signal z1, and the channel fluctuation estimation section 707_2 for the modulated signal z2. However, by executing the processing described in this specification, it is possible to estimate the data transmitted by the transmitting device. It is well known that multiple signals transmitted in the same frequency band and at the same time can be received and decoded with one antenna. ), and in the present invention, the signal processing unit 711 in FIG. 7 only needs to perform demodulation (detection) in consideration of the precoding and phase change used on the transmitting side.

In this specification, terms such as "precoding,""precodingweight," and "precoding matrix" are used, but they may be called in any way (for example, they may be called a codebook). ), the signal processing itself is important in the present invention.
In addition, in this specification, explanations are made using ML calculation, APP, Max-log APP, ZF, MMSE, etc. in the receiving device, but as a result, the soft decision result of each bit of data transmitted by the transmitting device (log-likelihood, log-likelihood ratio) and hard decision results (“0” or “1”) are obtained, but these may be collectively called detection, demodulation, detection, estimation, and separation.

The streams s1(t) and s2(t) (s1(i), s2(i)) may transmit different data or may transmit the same data.
In addition, regular phase changes and precoding are performed on two streams of baseband signals s1(i) and s2(i) (where i represents the order (of time or frequency (carrier)). In the baseband signals z1(i) and z2(i) after both signal processing, which are generated by performing the process (the order does not matter which one comes first), the baseband signal z1(i) after both signal processing is The in-phase I component is I ₁ (i), the orthogonal component is Q ₁ (i), the in-phase I component of the baseband signal z2(i) after signal processing of both is I ₂ (i), and the orthogonal component is Q ₂ ( i). At this time, the baseband components are replaced,
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), the in-phase component of the baseband signal r2(i) after replacement is I ₂ (i), The orthogonal component is Q ₁ (i)
The modulated signal corresponding to the replaced baseband signal r1(i) is sent from the transmitting antenna 1, and the modulated signal equivalent to the replaced baseband signal r2(i) is sent from the transmitting antenna 2 at the same time using the same frequency. Assume that the modulated signal corresponding to the replaced baseband signal r1(i) and the replaced baseband signal r2(i) are transmitted from different antennas at the same time using the same frequency. Good too. Also,
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (i
), the in-phase component of the replaced baseband signal r2(i) is Q ₁ (i), and the orthogonal component is Q ₂ (i).
・The in-phase component of the baseband signal r1(i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (i
), the in-phase component of the replaced baseband signal r2(i) is Q ₁ (i), and the orthogonal component is Q ₂ (i).
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (i
), the in-phase component of the replaced baseband signal r2(i) is Q ₂ (i), and the quadrature component is Q ₁ (i).
・The in-phase component of the baseband signal r1(i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (i
), the in-phase component of the replaced baseband signal r2(i) is Q ₂ (i), and the quadrature component is Q ₁ (i).
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), the in-phase component of the baseband signal r2(i) after replacement is Q ₁ (i), The orthogonal component is I ₂ (i)
・The in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i), the orthogonal component is I ₁ (i), the in-phase component of the baseband signal r2(i) after replacement is I ₂ (i), The orthogonal component is Q ₁ (i)
・The in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), the in-phase component of the baseband signal r2(i) after replacement is Q ₁ (i), The orthogonal component is I ₂ (i)
・The in-phase component of baseband signal r2(i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (i
), the in-phase component of the replaced baseband signal r1(i) is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of baseband signal r2(i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (i
), the in-phase component of the replaced baseband signal r1(i) is Q ₁ (i), and the quadrature component is Q ₂ (i).
・The in-phase component of baseband signal r2(i) after replacement is I ₁ (i), and the orthogonal component is I ₂ (i
), the in-phase component of the replaced baseband signal r1(i) is Q ₂ (i), and the orthogonal component is Q ₁ (i).
・The in-phase component of baseband signal r2(i) after replacement is I ₂ (i), and the orthogonal component is I ₁ (i
), the in-phase component of the replaced baseband signal r1(i) is Q ₂ (i), and the orthogonal component is Q ₁ (i).
・The in-phase component of the baseband signal r2(i) after replacement is I ₁ (i), the quadrature component is Q ₂ (i), the in-phase component of the baseband signal r1(i) after replacement is I ₂ (i), The orthogonal component is Q ₁ (i)
・The in-phase component of the baseband signal r2(i) after swapping is I ₁ (i), the orthogonal component is Q ₂ (i), the in-phase component of the baseband signal r1(i) after swapping is Q ₁ (i), The orthogonal component is I ₂ (i)
・The in-phase component of the baseband signal r2(i) after replacement is Q ₂ (i), the quadrature component is I ₁ (i), the in-phase component of the baseband signal r1(i) after replacement is I ₂ (i), The orthogonal component is Q ₁ (i)
・The in-phase component of the baseband signal r2(i) after replacement is Q ₂ (i), the orthogonal component is I ₁ (i), the in-phase component of the baseband signal r1(i) after replacement is Q ₁ (i), The orthogonal component is I ₂ (i)
You can also use it as Furthermore, in the above description, we have explained how to perform both signal processing on two streams of signals and replace the in-phase components and quadrature components of the signals after both signal processing, but this is not limited to this, and there are more than two streams. It is also possible to perform both signal processing on the signal and to replace the in-phase component and quadrature component of the signal after both signal processing.

Furthermore, although the above example describes the replacement of baseband signals at the same time (same frequency ((sub)carrier)), the replacement of baseband signals at the same time may not be the case. As an example, it can be written as follows: The in-phase component of the baseband signal r1(i) after swapping is I ₁ (i+v), the quadrature component is Q ₂ (i+w), and the baseband signal r2(i) after swapping. The in-phase component of i) is I ₂ (i+w), and the orthogonal component is Q ₁ (i+v).
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i+v), and the orthogonal component is I ₂
(i+w), the in-phase component of baseband signal r2(i) after swapping is Q ₁ (i+v), and the orthogonal component is Q ₂ (i+w)
・The in-phase component of the baseband signal r1(i) after replacement is I ₂ (i+w), and the orthogonal component is I ₁
(i+v), the in-phase component of baseband signal r2(i) after swapping is Q ₁ (i+v), and the orthogonal component is Q ₂ (i+w)
・The in-phase component of the baseband signal r1(i) after replacement is I ₁ (i+v), and the orthogonal component is I ₂
(i+w), the in-phase component of baseband signal r2(i) after swapping is Q ₂ (i+w), and the orthogonal component is Q ₁ (i+v).
・The in-phase component of the baseband signal r1(i) after replacement is I ₂ (i+w), and the orthogonal component is I ₁
(i+v), the in-phase component of the baseband signal r2(i) after swapping is Q ₂ (i+w), and the orthogonal component is Q ₁ (i+v).
・The in-phase component of the baseband signal r1(i) after swapping is I ₁ (i+v), the orthogonal component is Q ₂ (i+w), the in-phase component of the baseband signal r2(i) after swapping is Q ₁ (i+v), The orthogonal component is I ₂ (i+w)
・The in-phase component of the baseband signal r1(i) after replacement is Q ₂ (i+w), the quadrature component is I ₁ (i+v), the in-phase component of the baseband signal r2(i) after replacement is I ₂ (i+w), The orthogonal component is Q ₁ (i+v)
・The in-phase component of the baseband signal r1(i) after swapping is Q ₂ (i+w), the orthogonal component is I ₁ (i+v), the in-phase component of the baseband signal r2(i) after swapping is Q ₁ (i+v), The orthogonal component is I ₂ (i+w)
・The in-phase component of the baseband signal r2(i) after replacement is I ₁ (i+v), and the orthogonal component is I ₂
(i+w), the in-phase component of the baseband signal r1(i) after swapping is Q ₁ (i+v), and the orthogonal component is Q ₂ (i+w).
・The in-phase component of the baseband signal r2(i) after replacement is I ₂ (i+w), and the orthogonal component is I ₁
(i+v), the in-phase component of the replaced baseband signal r1(i) is Q ₁ (i+v), and the quadrature component is Q ₂ (i+w).
・The in-phase component of the baseband signal r2(i) after replacement is I ₁ (i+v), and the orthogonal component is I ₂
(i+w), the in-phase component of baseband signal r1(i) after swapping is Q ₂ (i+w), and the orthogonal component is Q ₁ (i+v).
・The in-phase component of the baseband signal r2(i) after replacement is I ₂ (i+w), and the orthogonal component is I ₁
(i+v), the in-phase component of the baseband signal r1(i) after swapping is Q ₂ (i+w), and the orthogonal component is Q ₁ (i+v).
・The in-phase component of the baseband signal r2(i) after replacement is I ₁ (i+v), the quadrature component is Q ₂ (i+w), the in-phase component of the baseband signal r1(i) after replacement is I ₂ (i+w), The orthogonal component is Q ₁ (i+v)
・The in-phase component of the baseband signal r2(i) after swapping is I ₁ (i+v), the quadrature component is Q ₂ (i+w), the in-phase component of the baseband signal r1(i) after swapping is Q ₁ (i+v), The orthogonal component is I ₂ (i+w)
・The in-phase component of the baseband signal r2(i) after replacement is Q ₂ (i+w), the quadrature component is I ₁ (i+v), the in-phase component of the baseband signal r1(i) after replacement is I ₂ (i+w), The orthogonal component is Q ₁ (i+v)
・The in-phase component of the baseband signal r2(i) after swapping is Q ₂ (i+w), the orthogonal component is I ₁ (i+v), the in-phase component of the baseband signal r1(i) after swapping is Q ₁ (i+v), The orthogonal component is I ₂ (i+w)
FIG. 55 is a diagram showing a baseband signal replacement unit 5502 for explaining the above description. As shown in FIG. 55, in the baseband signals z1(i) 5501_1 and z2(i) 5501_2 after both signal processing, the in-phase I component of the baseband signal z1(i) 5501_1 after both signal processing is I ₁ (i), the orthogonal component is Q ₁ (i), the in-phase I component of the baseband signal z2(i) 5501_2 after both signal processing is I ₂ (i), and the orthogonal component is Q ₂ (i). Then, the in-phase component of the replaced baseband signal r1(i) 5503_1 is I _r1 (i), the quadrature component is Q _r1 (i), and the in-phase component of the replaced baseband signal r2(i) 5503_2 is I _r2 ( i), the orthogonal component is Q _r2 (i), the in-phase component I _r1 (i) of the baseband signal r1(i) 5503_1 after replacement, the orthogonal component Q _r1 (i), and the baseband signal r2 (i) after replacement. i) It is assumed that the in-phase component I _r2 (i) and the orthogonal component Q _r2 (i) of 5503_2 are expressed by either of the above-mentioned expressions. In addition, in this example, we have explained the swapping of baseband signals after signal processing for both signals at the same time (same frequency ((sub)carrier)), but as mentioned above, at different times (different frequencies ((sub)carriers) )) The baseband signals after both signal processing may be replaced.

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

Furthermore, in this specification, the unit of phase, such as argument, in a complex plane is "radian".
By using the complex plane, complex numbers can be displayed in polar form as represented by polar coordinates. 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 expressed as [r, θ] in polar coordinates. If it is expressed as
a=r×cosθ,
b=r×sinθ

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

FIG. 46 shows an example of a broadcasting system using the phase changing method described in this specification. In FIG. 46, a video encoding unit 4601 receives video as input, performs video encoding, and outputs data 4602 after video encoding. The audio encoding unit 4603 receives audio as input, performs audio encoding, and outputs data 4604 after audio encoding. The data encoding unit 4605 receives data as input, performs data encoding (for example, data compression), and outputs data 4606 after data encoding. These are collectively referred to as an information source encoding unit 4600.

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

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

In addition, in the embodiment in which the present invention is explained, in a multi-carrier transmission method such as the OFDM method, as explained previously, how many encoders does the transmitter have? You can. 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 multicarrier transmission method such as the OFDM method. At this time, the wireless units 310A and 310B in FIG. 4 may be replaced with the OFDM system related processing units 1301A and 1301B in FIG. 12. At this time, the description of the OFDM system related processing section is the same as in the first embodiment.

Further, in the first embodiment, equation (36) is given as an example of a precoding matrix, but an alternative method may be to use the following equation as a precoding matrix.

Note that in precoding equation (36) and equation (50), it has been described that equation (37) and equation (38) are set as the value of α, but this is not limited to this, and α = 1. When set, it becomes a simple precoding matrix, so this value is also one of the valid values.

In addition, in the embodiment A1, the phase change value for the period N (FIG. 3, FIG. 4, Figure 6,
In FIG. 12, FIG. 25, FIG. 29, FIG. 51, and FIG. 53, the phase change is given only to one of the baseband signals after precoding, so it becomes a phase change value. ) and expressed as PHASE[i] (i=0,1,2,...,N-2,N-1). In this specification, when the phase is changed for one of the baseband signals after precoding (that is, FIG. 3, FIG. 4, FIG. 6, FIG. 12, FIG. 25, FIG. 29, FIG. 51, FIG. ), FIG. 3, FIG. 4, FIG. 6, FIG. 12, FIG. 25, FIG. 29, FIG. 51, and FIG. 53, the phase change is given only to the baseband signal z2' after precoding. At this time, PHASE[k] is given as follows.

At this time, k=0,1,2,...,N-2,N-1. If N=5, 7, 9, 11, 15, good data reception quality can be obtained in the receiving device.
In addition, although this specification has explained in detail the phase change method when two modulated signals are transmitted using multiple antennas, the method is not limited to this, and is based on mapping of three or more modulation schemes. The same method can be applied to a case where precoding and phase change are performed on a band signal, predetermined processing is performed on the baseband signal after precoding and phase change, and the signal is transmitted from a plurality of antennas.

Note that, for example, a program for executing the above communication method may be stored in advance in a ROM (Read Only).
The program may be stored in a CPU (Central Processor Unit) and operated by a CPU (Central Processor Unit).

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

Each configuration of each of the embodiments described above 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 part of the configuration of each embodiment. Although it is referred to as an LSI here, it may also be called an IC (Integrated Circuit), system LSI, super LSI, or ultra LSI depending on the degree of integration. Moreover, the method of circuit integration is not limited to LSI, and may be implemented using a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used after the LSI is manufactured.

Furthermore, if an integrated circuit technology that replaces LSI emerges due to advancements in semiconductor technology or other derived technology, then of course the functional blocks may be integrated using that technology. Possibilities include the application of biotechnology.

The present invention is widely applicable to wireless systems that transmit 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 MIMO transmission in wired communication systems with multiple transmission points (for example, PLC (Power Line Communication) systems, optical communication systems, DSL (Digital Subscriber Line) systems). In this case, a plurality of transmission points are used to transmit a plurality of modulated signals as described in the present invention. Also, the modulated signal may be transmitted from multiple transmission locations.

302A, 302B Encoder 304A, 304B Interleaver 306A, 306B Mapping section 314 Signal processing method information generation section 308A, 308B Weighting combining section 310A, 310B Radio section 312A, 312B Antenna 317A, 317B Phase change section 402 Encoder 404 Distribution section 504 #1, 504 #2 Transmitting antennas 505 #1, 505 #2 Receiving antenna 600 Weighting combining section 701_X, 701_Y Antenna 703_X, 703_Y Radio section 705_1 Channel fluctuation estimation section 705_2 Channel fluctuation estimation section 707_1 Channel fluctuation estimation section 707_2 Channel fluctuation estimation Section 709 Control information decoding section 711 Signal processing section 803 INNER MIMO detection section 805A, 805B Log likelihood calculation section 807A, 807B Deinterleaver 809A, 809B Log likelihood ratio calculation section 811A, 811B Soft-in/soft-out decoder 813A, 813B Interleaver 815 Storage section 819 Coefficient generation section 901 Soft-in/soft-out decoder 903 Distributor 1201A, 1201B OFDM system related processing section 1302A, 1302A Serial parallel conversion section 1304A, 1304B Sorting section 1306A, 1306B Inverse fast Fourier transform section 1308A, 1308B Radio section

Claims (4)

A transmission method,
Here, j is is an index number of the first modulation signal and the second modulation signal, and for each set of the first modulation signal s1 and the second modulation signal s2 having the same index number,
Precoding processing that performs precoding on the first modulation signal s1 and the second modulation signal s2;
a phase change process of changing the phase of at least one of the signals subjected to the precoding process;
to generate a first transmission signal sequence z1(j) including a plurality of first transmission signals z1 and a second transmission signal sequence z2(j) including a plurality of second transmission signals z2,
transmitting the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) using a plurality of antennas,
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching N types of phase change amounts at a cycle N according to the index number, and the N types of phase change amounts are such that the minimum value of the difference between the mutual phase change amounts is 2π/ N, and in the N types of phase changes, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. When, the difference between the first phase change amount and the second phase change amount is not 2π/N, and the difference between the third phase change amount and the fourth phase change amount is 2π/N. can be,
The first modulated signal and the second modulated signal are generated using the same modulation method. A transmitting device,
Here, j is is an index number of the first modulation signal and the second modulation signal, and for each set of the first modulation signal s1 and the second modulation signal s2 having the same index number,
Precoding processing that performs precoding on the first modulation signal s1 and the second modulation signal s2;
a phase change process of changing the phase of at least one of the signals subjected to the precoding process;
signal processing to generate a first transmission signal sequence z1(j) including a plurality of first transmission signals z1 and a second transmission signal sequence z2(j) including a plurality of second transmission signals z2. Department and
a transmitter that transmits the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) using a plurality of antennas;
Equipped with
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching N types of phase change amounts at a cycle N according to the index number, and the N types of phase change amounts are such that the minimum value of the difference between the mutual phase change amounts is 2π/ N, and in the N types of phase changes, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. When, the difference between the first phase change amount and the second phase change amount is not 2π/N, and the difference between the third phase change amount and the fourth phase change amount is 2π/N. can be,
The first modulated signal and the second modulated signal are generated using the same modulation method. The transmitting device. A receiving method,
A received signal is obtained, the received signal is obtained by receiving a first transmission signal sequence z1(j) and a second transmission signal sequence z2(j) transmitted using a plurality of antennas, One transmission signal sequence z1(j) includes a plurality of first transmission signals z1, and the second transmission signal sequence z2(j) includes a plurality of second transmission signals z2, where j is the first transmission signal z1. 1 transmission signal and the second transmission signal, and the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) are the index numbers of the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j). is generated by performing predetermined signal processing on a first modulated signal sequence s1(j) including s1 and a second modulated signal sequence s2(j) including a plurality of second modulated signals s2,
A process of generating received data by performing demodulation processing on the acquired received signal according to the predetermined signal processing,
The predetermined signal processing includes:
A set of the first modulated signal s1 and the second modulated signal s2 having the same index number with respect to the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j). For each
Precoding processing that performs precoding on the first modulation signal s1 and the second modulation signal s2;
a phase change process of changing the phase of at least one of the signals subjected to the precoding process;
including;
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching N types of phase change amounts at a cycle N according to the index number, and the N types of phase change amounts are such that the minimum value of the difference between the mutual phase change amounts is 2π/ N, and in the N types of phase changes, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. When, the difference between the first phase change amount and the second phase change amount is not 2π/N, and the difference between the third phase change amount and the fourth phase change amount is 2π/N. can be,
The first modulated signal and the second modulated signal are generated using the same modulation method. A receiving device,
A received signal is obtained, the received signal is obtained by receiving a first transmission signal sequence z1(j) and a second transmission signal sequence z2(j) transmitted using a plurality of antennas, One transmission signal sequence z1(j) includes a plurality of first transmission signals z1, and the second transmission signal sequence z2(j) includes a plurality of second transmission signals z2, where j is the first transmission signal z1. 1 transmission signal and the second transmission signal, and the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j) are the index numbers of the first transmission signal sequence z1(j) and the second transmission signal sequence z2(j). generated by performing predetermined signal processing on a first modulated signal sequence s1(j) including s1 and a second modulated signal sequence s2(j) including a plurality of second modulated signals s2, a receiving section;
a demodulation unit that performs demodulation processing on the acquired received signal according to the predetermined signal processing to generate received data;
Equipped with
The predetermined signal processing includes:
A set of the first modulated signal s1 and the second modulated signal s2 having the same index number with respect to the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j). For each
Precoding processing that performs precoding on the first modulation signal s1 and the second modulation signal s2;
a phase change process of changing the phase of at least one of the signals subjected to the precoding process;
including;
In the precoding process, common precoding is performed on the first modulated signal sequence s1(j) and the second modulated signal sequence s2(j),
In the phase change processing, the phase change is performed by switching N types of phase change amounts at a cycle N according to the index number, and the N types of phase change amounts are such that the minimum value of the difference between the mutual phase change amounts is 2π/ N, and in the N types of phase changes, the second phase change amount is used after the first phase change amount, and the fourth phase change amount is used after the third phase change amount. When, the difference between the first phase change amount and the second phase change amount is not 2π/N, and the difference between the third phase change amount and the fourth phase change amount is 2π/N. can be,
The first modulated signal and the second modulated signal are generated using the same modulation method. The receiving device.

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