JP2006025328A - Transmission method and apparatus for spatial multiplex transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spatial multiplex/orthogonal frequency division multiplex transmission technique applicable even to an environment wherein a transfer function estimate error is high. <P>SOLUTION: A propagation environment estimate section 801 estimates an arrival wave direction in each propagation environment, the number of arrival waves, a level, and a delay on the basis of transfer coefficient matrices H1 to HF. A weight storage section 802 stores a plurality of weights corresponding to propagation environments in advance. A weight selection section 803 selects a weight from the weight storage section 802 on the basis of an estimate result by the propagation environment estimate section 801 and provides an output of the selected weight as a weight multiplied by a multi-beam forming apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission method and apparatus for spatial multiplexing transmission that performs transmission by F frequency multiplexing using orthogonal frequency division multiplexing and L spatial multiplexing using N antenna elements.

  An orthogonal wave frequency division multiplex transmission device is a transmission device that can use a plurality of carriers having different center frequencies by using orthogonality and allowing overlap on the frequency axis, thereby realizing high frequency efficiency. The spatial multiplexing transmission apparatus is a transmission apparatus that realizes high-speed transmission without increasing the frequency band by transmitting different signals from a plurality of antenna elements.

  Conventionally, as described in Non-Patent Document 1, there is a spatial multiplexing transmission apparatus that improves transmission quality by forming a multi-beam.

  FIG. 7 shows a conventional spatial multiplexing transmission apparatus of this type. Serial-parallel conversion device 700, transmission devices 711-71L, multi-beam forming devices 721-72L, signal synthesis devices 731-73N, switching devices 741-74N, transmission antenna elements 751-75N, weights It is comprised from the determination apparatus 760.

  The transmission signal generates a plurality of signal sequences T1 to TL by the serial-parallel converter 700, L transmission signal sequences are formed by the transmission devices 711 to 71L, and weight determination devices are respectively formed by the multi-beam forming devices 721 to 72L. Using the weights determined by 760, output signals to the respective antenna elements for forming different directivities are formed, and the signals output to the same antenna elements by the signal synthesizers 731 to 73N are added and switched. The signals are transmitted from the devices 741 to 74N to the transmitting antenna elements 751 to 75N and transmitted at the same time and the same frequency. Here, the weight determination device 760 determines the weight applied to the transmission signal by the multi-beam forming device as follows.

ここで、伝達係数行列の要素Ｈijは送信アンテナｊで送信され、受信アンテナｉで受信したときの伝達係数となっている。 First, singular value decomposition (H = UDV ^H ) of the transfer coefficient matrix H is performed to obtain a diagonal matrix having the unitary matrix V and the singular value √λ as diagonal elements. The number of transmission antennas N, a number of smaller one of the number of receive antennas M, the X M and _N, the column vector of u 1 ~u _x a column vector of M × _1, v 1 ~v _x a N × 1 Assuming that the superscript H represents conjugate transpose, the transfer coefficient matrix is represented by the following equation.

Here, element Hij of the transmission coefficient matrix is a transmission coefficient when transmitted by transmission antenna j and received by reception antenna i.

ユニタリ行列Vは、その複素共役転置行列Ｈ^Ｈと伝達係数行列Hとの積Ｈ^ＨHの固有ベクトルとなっている。 Next, L is selected from the larger singular values, the column vectors v _{1 to} v _x of the unitary matrix V corresponding to the singular values are selected as weights, and each column vector is selected from the L signals T _{1 to} T _L. Are used to form signals S _{1 to} S _N to be transmitted from each antenna element according to the following equation.

The unitary matrix V is an eigenvector of the product H ^H H of the complex conjugate transpose matrix H ^H and the transfer coefficient matrix H.

In the receiving station, for example, decoding is performed using receiving antennas having a number L or more of beams transmitted from the transmitting station. An example of a decoding method when the number of reception antennas is N and the number of reception antennas and the number of beams is L (L ≦ N, L ≦ M, X = L) is shown below. Assuming that signals received at the receiving station antenna element are R _{1 to} R _L , and noise in each received signal is n _{1 to} n _L , the received signals R _{1 to} R _L are as follows when a signal is transmitted by the spatial multiplexing transmission apparatus: It can be expressed as follows.

と表すことができる。ここでＴ´_１〜Ｔ´_Ｌは受信装置で推定した送信信号である。 Therefore, the reception apparatus can decode the transmission signal by performing the following calculation.

It can be expressed as. Here, T ′ _{1 to} T ′ _L are transmission signals estimated by the receiving apparatus.

By doing so, it is possible to realize a transmission speed that is several times the number of antennas without increasing the frequency band, to obtain a directivity gain, and to form an L beam from N elements (N ≧ L). Therefore, since a good beam can be selected, a diversity effect can also be obtained.
Miyashita, K.; Nishimura, T.; Ohgane, T.; Ogawa, Y.; Takatori, Y.; KeizoCho; "High data-rate transmission with eigenbeam-space division multiplexing (E-SDM) in a MIMO channel," Vehicular Technology Conference, 2002.Proceedings.VTC2002-Fall.2002 IEEE 56th, Volume: 3,24-28 Sept.2002 Pages: 1302-1306 vol.3

However, since the above conventional method is formed only by the estimated transfer coefficient matrix, if there is an error in the transfer function estimation, there is a problem that the transmission quality is greatly degraded. Can not. In addition, there is a problem that the calculation for obtaining the eigenvector has a large load, and the calculation amount becomes very large when it is obtained in each frequency band of orthogonal frequency division multiplexing.
The present invention has been made in view of such circumstances, and an object thereof is to prevent communication quality deterioration due to propagation environment estimation error and to reduce the amount of calculation.

  In order to solve the above-described problem, the present invention includes a plurality of transmission / reception means, determines transmission weights suitable for the propagation environment, weights each transmission sequence, and performs orthogonal frequency division multiplexing for transmission. A method of performing orthogonal frequency division multiplexing demodulation on a received signal, estimating a propagation environment in each frequency band of orthogonal frequency division multiplexing, and setting in advance based on propagation environment information of the estimated plurality of frequency bands The present invention provides a transmission method for spatial multiplexing transmission, wherein a transmission weight of a corresponding frequency band is selected from a plurality of transmission weights.

The present invention is also a method comprising a plurality of transmission / reception means, determining a transmission weight suitable for the propagation environment, weighting each transmission sequence, performing orthogonal frequency division multiplexing, and transmitting the received signal to the received signal. Perform orthogonal frequency division multiplexing demodulation, estimate transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, determine transmission weight of each signal sequence from transmission coefficient matrix of multiple frequency bands, and determine transmission weight In this case, the product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix is obtained in each frequency band, and a plurality of the products are selected, and the eigenvector of the matrix obtained by calculating the average is obtained from the signal sequence of the frequency band. The present invention provides a transmission method for spatial multiplexing transmission characterized in that transmission weights are used.

  The present invention is also a method comprising a plurality of transmission / reception means, determining a transmission weight suitable for the propagation environment, weighting each transmission sequence, performing orthogonal frequency division multiplexing, and transmitting the received signal to the received signal. Perform orthogonal frequency division multiplexing demodulation, estimate transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, determine transmission weight of each signal sequence from transmission coefficient matrix of multiple frequency bands, and determine transmission weight First, obtain a product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix in each frequency band, select a plurality of those products, and determine the weight corresponding to the frequency difference from the frequency band for which the transmission weight is to be determined. Provided is a spatial multiplexing transmission method characterized in that an eigenvector of a matrix obtained by multiplying the product and taking the sum is used as a transmission weight of a signal sequence in the frequency band.

  The present invention is also a method comprising a plurality of transmission / reception means, determining a transmission weight suitable for the propagation environment, weighting each transmission sequence, performing orthogonal frequency division multiplexing, and transmitting the received signal to the received signal. Perform orthogonal frequency division multiplexing demodulation, estimate transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, determine transmission weight of each signal sequence from transmission coefficient matrix of multiple frequency bands, and determine transmission weight In this case, the complex conjugate transpose matrix of the transfer coefficient matrix and the product of the transfer coefficient matrix are obtained in each frequency band, a plurality of these products are selected, the weight corresponding to each product is multiplied by the product, and the sum is obtained. The spatial multiplexing transmission method is characterized in that the eigenvector of the matrix obtained in this way is used as the transmission weight of the signal sequence of the frequency band.

  The present invention is also a method comprising a plurality of transmission / reception means, determining a transmission weight suitable for the propagation environment, weighting each transmission sequence, performing orthogonal frequency division multiplexing, and transmitting the received signal to the received signal. Perform orthogonal frequency division multiplexing demodulation, estimate transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, determine transmission weight of each signal sequence from transmission coefficient matrix of multiple frequency bands, and determine transmission weight In this case, a product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix is obtained in each frequency band, and a plurality of these products are selected, and the weight corresponding to each product is the value of the frequency band to which the transmission weight is applied. It is determined by the correlation value between the transfer coefficient matrix or parameters obtained from the transfer coefficient matrix and the parameters obtained from the transfer coefficient matrix or transfer coefficient matrix of the selected product frequency band. Multiplied by the weight to the product, there is provided a spatial multiplexing transmission transmitting method characterized by the eigenvectors of the matrix obtained by taking the sum and the transmission weight of the signal sequence of the frequency band.

  Further, the present invention is a method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, performing orthogonal frequency division multiplexing, and transmitting the spatial multiplexing Spatial multiplexing characterized in that the transmission weight described in the transmission method for transmission or the information necessary for determining the transmission weight is fed back from the communication partner station to be used as the transmission weight of the signal sequence in the frequency band. A transmission method for transmission is provided.

  The present invention is also characterized in that, in the spatial multiplexing transmission method, a common transmission weight is used for a plurality of frequency bands.

  Further, the present invention provides a spatial multiplexing transmission apparatus that uses N antenna elements, performs F frequency multiplexing using orthogonal frequency division multiplexing, and L spatial multiplexing, and is connected to each antenna element. , A switching device that switches between a received signal and a transmission signal, and a signal that is connected to the switching device and that is output from the switching device at the time of reception is an input signal, performs a Fourier transform on the input signal, and converts each into F received signals N Fourier transform apparatuses, a transfer coefficient matrix estimation apparatus for estimating a transfer coefficient matrix in the frequency band, using a received signal in a frequency band corresponding to the Fourier transform apparatus as an input signal, and the transfer coefficient matrix estimation means A plurality of transfer coefficient matrices are selected from the estimated F transfer coefficient matrices, and the transmission weight of the multi-beamforming apparatus in the corresponding frequency band is determined. A transmission weight determination device, a Fourier transform device, a transmission coefficient matrix estimation device, a transmission weight determination block generically referred to as a transmission weight determination device, and a serial-parallel conversion on an input signal to be transmitted, and a frequency division multiplexing number F A serial-parallel conversion device that distributes to a spatial multiplexing number L, an F × L transmission device that uses an output signal of the serial-parallel conversion device as an input signal and outputs a transmission signal system to a multi-beam forming device, and the transmission The signal input from the device is used as an input signal, divided into N signals, weighted by the transmission weight determining device, and then output to the corresponding ports of the N × F signal synthesizers And superimposing signals input to L ports from the corresponding L multi-beam forming apparatuses among the multi-beam forming apparatuses. A signal synthesizer that outputs to the corresponding port of the inverse Fourier transform device, and performs an inverse Fourier transform on the F signals output from the signal synthesizer, and outputs an output to the other port of the switching device. The present invention provides a spatial multiplexing transmission apparatus characterized by comprising N inverse Fourier transform apparatuses.

  Further, the present invention provides Mt (≦ F) transmissions in which the transmission weight determining device selects a transmission weight by which the corresponding t-th frequency band is multiplied by the multibeam forming device from the F transmission coefficient matrices. A product of each complex conjugate transpose matrix and a transfer coefficient matrix is obtained from the coefficient matrix, and is output as an eigenvector of a matrix obtained by taking Mt averages.

  Further, the present invention provides the transmission weight determining device that multiplies the corresponding t-th frequency band by the multi-beam forming device from the Mt transfer coefficient matrices selected from the F transfer coefficient matrices. The product of each of the complex conjugate transpose matrix and the transfer coefficient matrix is obtained, the obtained k-th matrix is multiplied by the weight wk, and the result is output as an eigenvector of the matrix obtained by taking the sum.

  According to the present invention, the transmission weight determining apparatus multiplies the corresponding t-th frequency band by the multi-beam forming apparatus from the Mt transmission coefficient matrices selected from the F transmission coefficient matrices. A product of each complex conjugate transpose matrix and a transfer coefficient matrix is obtained, multiplied by a weight wtk corresponding to each frequency band, and output as an eigenvector of a matrix obtained by taking the sum.

  According to the present invention, the transmission weight determining apparatus multiplies the corresponding t-th frequency band by the multi-beam format apparatus from Mt transmission coefficient matrices selected from the F transmission coefficient matrices. Obtain the product of each complex conjugate transpose matrix and the transfer coefficient matrix, multiply by the weight wtk according to the correlation value with the transfer coefficient matrix of the tth frequency band, and output as the eigenvector of the matrix obtained by taking the sum It is characterized by doing.

According to the present invention, in the transmission weight determination block, a signal output from the switching device at the time of reception is set as an input signal, and a result of performing all or a part of the calculation for determining the transmission weight from the input signal. A feedback information extraction device that extracts field-back information including information, and a transmission weight determination device that performs an operation to determine the transmission weight using an output of the feedback information extraction device as an input signal. .
Further, the present invention is characterized in that the transmission weight determination device outputs a transmission weight common to a plurality of frequency bands.

  According to the present invention, when orthogonal frequency division multiplexing is performed, weights are determined from a propagation environment in a wide frequency band, and transmission is performed using multi-beams, thereby reducing transmission quality degradation due to propagation environment estimation errors. If the same transmission weight is applied to a plurality of frequency bands, the amount of calculation can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3, 8, and 9.
FIG. 1 is a block diagram showing a spatial multiplexing transmission apparatus using orthogonal wave frequency division multiplexing forming a multi-beam in the first embodiment of the present invention. This embodiment shows a configuration that makes it possible to prevent deterioration in transmission quality of spatial multiplexing transmission in an environment where there is a propagation environment error.

  In the figure, reference numeral 100 is a serial-parallel (S / P) converter, 1111 to 11LF is a transmitter, 1211 to 12NF is a reverse Fourier converter, 1311 to 13NF is a signal synthesizer, and 1141 to 14N are reverse buffers. -Fourier transform device, 151 to 15N are switching devices, 161 to 16N are antenna elements, 171 to 17N are Fourier transform devices, 181 to 18F are transfer coefficient matrix estimation devices, 190 is a transmission weight determination device, and 001 is a transmission weight It is a decision block.

  The transmission signals serial-parallel converted by the serial-parallel conversion device 100 and distributed to the frequency division multiplexing number F × the spatial multiplexing number L are encoded by the transmission devices 1111 to 11LF, respectively, and 1211 to 12LF multi-bit signals are transmitted. Output to each of the image forming apparatuses. A signal input to the multi-beam forming apparatus is multiplied by analog or digital transmission weights Vtk (t = 1 to F, k = 1 to L) determined by the transmission weight determining apparatus, and F-numbers are inverted. It is output to the lie converters 141 to 14N. The input signal is subjected to inverse Fourier transform and transmitted from the antenna elements 161 to 16N via the switching devices 151 to 15N.

  The transmission weight determination block 1 includes a Fourier transform device 171 to 17N, a transfer coefficient matrix estimation device 181 to 18F, and a transmission weight determination device 190. The Fourier transform devices 171 to 17N receive the switching devices 151 to 15N. The Fourier transform is performed using the output of the time as an input signal, separated for each frequency band, and output to the transfer coefficient matrix estimation devices 181 to 18F. Moreover, the transmission coefficient matrix estimation apparatuses 181 to 18F calculate a transmission coefficient matrix in each frequency band and output the transmission coefficient matrix to the transmission weight determination apparatus 190. The transmission weight determination device 190 determines a transmission weight that satisfies a predetermined transmission quality from the estimated transfer coefficient matrix.

  Here, orthogonal wave frequency division multiplexing and spatial multiplexing were used in the case where the transmission environment having N antenna elements and the reception apparatus having M antenna elements can be considered to have the same uplink and downlink propagation environments. Think about communication.

下りの伝達係数行列Ｈ(Ｍ×Ｎ行列)は上り伝達係数行列の転置をとることで

として与えられる。Ｈ_ｉｊは送信装置のアンテナ素子＃ｊから受信装置のアンテナ素子＃ｉ間の伝達係数の推定結果を表わしている。 When paying attention to a certain frequency band, the transmission apparatus first receives a known signal T ′ (M × N matrix), and from the received signal R ′ (N × N matrix) obtained by the transfer coefficient matrix estimation apparatus, the frequency band The uplink transmission coefficient matrix G (N × M matrix) at is estimated as follows.

The downlink transmission coefficient matrix H (M × N matrix) is obtained by transposing the uplink transmission coefficient matrix.

As given. H _ij represents the estimation result of the transfer coefficient between the antenna element #j of the transmitting apparatus and the antenna element #i of the receiving apparatus.

  FIG. 8 is a block diagram showing an outline of the transmission weight determination apparatus in the first embodiment. In the figure, for example, the propagation environment estimation unit 801 selects a plurality of transfer coefficient matrices in each frequency band from the transfer coefficient matrices Hk (k = 1 to F) obtained in all the 1st to Fth frequency bands, Estimating the direction, number, level, and delay of the propagation environment of the propagation environment using MUSIC (Multiple Signal Classification) and ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) (Paulaj et al, ESPRIT-a subspace rotation approach to signal parameter estimation ', IEEE Proceeding, 74 (7), 1044-1045, July 1986).

  The weight storage unit 802 stores weights corresponding to a plurality of propagation environment models. The propagation environment is categorized and a weight that maximizes a predetermined transmission quality standard in each environment is set in advance and stored in the weight storage unit 803. The weight selection unit 803 selects a weight from the weight storage unit 802 based on the estimation result of the propagation environment estimation unit 801, and outputs the weight as a weight multiplied in the multi-beam forming apparatuses 1211 to 12LF.

  Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing a transmission weight determination apparatus in the second embodiment. As shown in the figure, in the second embodiment, the transmission weight determination device is composed of transfer coefficient matrix calculation devices 211 to 21F, a selective distribution device 220, and transmission weight calculation devices 231 to 23F. Other configurations are the same as those of the first embodiment.

In the above-described configuration, the transfer coefficient calculation devices 211 to 21F obtain, for example, the transfer coefficient matrix from the corresponding kth (k = 1 to F) frequency band transfer coefficient matrix H _k output from the transfer coefficient matrix estimation device. A product H _K ^H H _K of the complex conjugate transpose matrix and the transfer coefficient matrix is obtained and output to the selective distribution device. The selective distribution device 220 receives F computed matrices as input signals, and transmits M _t (1) out of matrices computed in the F frequency bands to the transmission weight computing device 23 t in the t th frequency band. ≦ M _t ≦ F) is selected and output. Also, the transmission weight calculation devices 231 to 23F calculate the average or sum of the plurality of input matrices, and apply the obtained eigenvector of the matrix as the transmission weight of the t-th frequency band. By determining the weights in this way, it is possible to reduce deterioration in transmission quality due to propagation environment estimation errors.

  Next, a third embodiment of the present invention will be described. FIG. 9 is a block diagram showing a transmission weight determination apparatus in the third embodiment. In this embodiment, the selection / distribution device 900 uses the F calculated matrices output from the transfer coefficient matrix calculation device as input signals, and the transmission weight calculation device 23t (1 ≦ t ≦ F) for each frequency band. On the other hand, M (1 ≦ M ≦ F) matrices are selected, and the k-th (1 ≦ k ≦ M) matrix is multiplied by the weight wk and output. The rest is the same as in the second embodiment.

Next, a fourth embodiment of the present invention will be described. FIG. 3 is a block diagram showing a transmission weight determination apparatus in the fourth embodiment. In this embodiment, the selection / distribution device 300 uses the F calculated matrices output from the transfer coefficient matrix calculation device as input signals, and performs F number of transmission weight calculation devices 23t in the t-th frequency band. M _t (1 ≦ M _t ≦ F) matrices are selected from the matrices calculated in the frequency band, and the k-th (1 ≦ k ≦ M) matrix is multiplied by the weight w _tk and output. .

Here, the weight _{w tk} multiplying the _H ^K H _{H K} of the plurality of frequency bands is selected, parameters of example _{H k} or eigenvalues obtained from the _{H k,,} etc. eigenvectors - and _{motor, H} t or _{H t,} The eigenvalues of the matrix obtained by summing w _tk H _K ^H H _K are applied as transmission weights of the t-th frequency band. The rest is the same as in the second embodiment.

  Next, a fifth embodiment of the present invention will be described. FIG. 4 is a block diagram showing a spatial multiplexing transmission apparatus according to the fifth embodiment. This embodiment corresponds to the case where the downlink transmission coefficient matrix cannot be estimated from the uplink transmission coefficient matrix in the transmission apparatus. In this embodiment, the transmission weight determination block 1 includes a feedback information extraction device 410 and a transmission weight determination device 420. The rest is the same as in the first embodiment. Here, it is assumed that the transfer coefficient matrix can be estimated in the communication partner station, and the transmission apparatus is fed back.

  In the above configuration, feedback information extraction apparatus 410 determines transmission weights to be multiplied by the multi-beam forming apparatus at the time of transmission from a signal sequence obtained by using outputs upon reception of switching apparatuses 151 to 15N as input signals. Information is received from the communication partner station and output to the transmission weight determination apparatus. Further, the transmission weight determining apparatus uses the information for obtaining the transmission weight as an input signal, and determines the transmission weight by the above-described calculation.

  Further, the calculation for obtaining the transmission weight described so far can use the same transmission weight in a plurality of frequency bands, thereby reducing the transmission quality degradation due to the propagation environment estimation error and reducing the calculation amount.

Next, computer simulation performed to verify the effect of the present invention will be described.
Consider a communication using orthogonal wave frequency division multiplexing and space division multiplexing, where the number of transmission antenna elements is 4, the number of reception antenna elements is 2, and a frequency of 5.2 MHz is used for uplink and downlink. As a propagation path model, the incoming wave is 100 waves, and as shown in FIG. 5, five clusters, which are a collection of scattered objects, exist around the transmitter and the receiver, and the angular spread is 25 °. The propagation environment was Nakagami-Rice fading, the K factor was 3 [dB], the delay spread of the scattered wave was 100 nsec, and the power distribution of the delayed wave was given as an index. The average received power was set to 30 dB, the center direction of the cluster and the arrival direction and phase of each incoming wave were randomly assigned, and the error rate was accumulated 1000 times to obtain the cumulative probability of error rate.

Focusing on the t-th frequency band among the subcarriers having a spatial multiplexing number of 2 and a frequency bandwidth of 400 kHz, the conventional example is based on the estimated transfer coefficient matrix of the t-th frequency band. A multi-beam is formed by value decomposition, and according to the present embodiment, a product H _K ^{H of} three transfer coefficient matrix complex conjugate transpose matrices and transfer coefficient matrices obtained from the t-th frequency band and the preceding and subsequent frequency bands is used. A multi-beam based on singular value decomposition is formed using a transfer coefficient matrix obtained by frequency from an average matrix of H _K (k = t−1, t, t + 1).

FIG. 6 shows the transmission capacity obtained from the CNR obtained on the receiving side of the beam having a large eigenvalue when there is a propagation environment estimation error. It was shown that the proposed method is effective when the propagation environment estimation error is larger than ^10-2 .

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

  Each of the above devices has a computer system inside. The process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing this program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

1 is a block diagram showing a spatial multiplexing transmission apparatus according to a first embodiment of the present invention. The block diagram which shows the transmission weight determination apparatus in the 2nd Embodiment of this invention. The block diagram which shows the transmission weight determination apparatus in the 4th Embodiment of this invention. FIG. 10 is a block diagram showing a spatial multiplexing transmission apparatus according to a fifth embodiment of the present invention. The figure of the propagation environment model in the computer simulation used by verification of this invention. The figure which shows the relationship between CNR and the transmission capacity of the received signal in computer simulation. The block diagram which shows the transmitter for spatial multiplexing transmission which forms the conventional multi-beam. The block diagram which shows the transmission weight determination apparatus in the 1st Embodiment of this invention. The block diagram which shows the transmission weight determination apparatus in the 3rd Embodiment of this invention.

Explanation of symbols

1 Transmission Weight Determination Block 100, 700 Serial-Parallel Converters 1111-11LF, 711-71L Transmitters 1211-12LF, 721-72L Multibeam Forming Devices 1311-13NF, 731-73N Signal Synthesizers 141-14N Rie transform devices 151 to 15N, 741 to 74N Switching devices 161 to 16N, 751 to 75N Antenna elements 171 to 17N Fourier transform devices 181 to 18F Transfer coefficient matrix estimation devices 190, 760, 420 Transmission weight determination devices 211 to 21F Coefficient matrix calculation device 220, 300, 900 Select distribution device 231-23F Transmission weight calculation device 410 Feedback information extraction device

Claims (14)

A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
Perform orthogonal frequency division multiplexing demodulation on the received signal, estimate the propagation environment in each frequency band of orthogonal frequency division multiplexing, and set a plurality of transmission weights set in advance based on the propagation environment information of the estimated multiple frequency bands. A spatial multiplexing transmission method for selecting a transmission weight of a corresponding frequency band from among them. A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
Perform orthogonal frequency division multiplexing demodulation on the received signal, estimate the transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, and determine the transmission weight of each signal sequence from the transmission coefficient matrix of multiple frequency bands,
When determining the transmission weight, find the product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix in each frequency band, select multiple products, and calculate the average of the eigenvectors of the matrix at the frequency. A transmission method for spatial multiplexing transmission, characterized in that a transmission weight of a band signal sequence is used. A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
Perform orthogonal frequency division multiplexing demodulation on the received signal, estimate the transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, and determine the transmission weight of each signal sequence from the transmission coefficient matrix of multiple frequency bands,
In determining the transmission weight, obtain the product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix in each frequency band, select multiple products, and the frequency difference from the frequency band for which the transmission weight is to be determined. A transmission method for spatial multiplexing transmission, wherein a weight corresponding to is multiplied by the product, and an eigenvector of a matrix obtained by taking the sum is used as a transmission weight of a signal sequence of the frequency band. A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
Perform orthogonal frequency division multiplexing demodulation on the received signal, estimate the transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, and determine the transmission weight of each signal sequence from the transmission coefficient matrix of multiple frequency bands,
In determining the transmission weight, the complex conjugate transpose matrix of the transfer coefficient matrix and the product of the transfer coefficient matrix are obtained in each frequency band, a plurality of these products are selected, and the product is multiplied by the weight corresponding to each product. A transmission method for spatial multiplexing transmission, characterized in that an eigenvector of a matrix obtained by taking the sum is used as a transmission weight of a signal sequence in the frequency band. A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
Perform orthogonal frequency division multiplexing demodulation on the received signal, estimate the transmission coefficient matrix in each frequency band of orthogonal frequency division multiplexing, and determine the transmission weight of each signal sequence from the transmission coefficient matrix of multiple frequency bands,
When determining the transmission weight, obtain the product of the complex conjugate transpose matrix of the transfer coefficient matrix and the transfer coefficient matrix in each frequency band, select multiple products, and apply the transmission weight to the weight corresponding to each product. And a parameter obtained from the transmission coefficient matrix of the corresponding frequency band, or a parameter obtained from the transmission coefficient matrix of the selected product and a parameter obtained from the transmission coefficient matrix of the selected product frequency band, or the transmission coefficient matrix. A transmission method for spatial multiplexing transmission, characterized in that an eigenvector of a matrix obtained by multiplying a product and taking the sum is used as a transmission weight of a signal sequence of the frequency band. A method comprising a plurality of transmission / reception means, determining a transmission weight suitable for a propagation environment, weighting each transmission sequence, and performing orthogonal frequency division multiplexing for transmission,
The transmission weight according to any one of claims 1 to 5, or information necessary for determining the transmission weight is fed back from a communication partner station, so that the transmission weight of the signal sequence of the frequency band A transmission method for spatial multiplexing transmission. The transmission method for spatial multiplexing transmission according to any one of claims 1 to 6, wherein a common transmission weight is used for a plurality of frequency bands. In a spatial multiplexing transmission apparatus that uses N antenna elements, performs F frequency multiplexing using orthogonal wave frequency division multiplexing, and L spatial multiplexing, and is connected to each of the antenna elements, and receives signals and transmissions. A switching device for switching signals;
N number of Fourier transform devices connected to the switching device and having a signal output from the switching device at the time of reception as an input signal, performing Fourier transform on the input signal, and converting each of the signals into F received signals;
A transfer coefficient matrix estimation device for estimating a transfer coefficient matrix in the frequency band, using a received signal in a corresponding frequency band of the Fourier transform device as an input signal;
A transmission weight determination device that selects a plurality of transmission coefficient matrices from the F transmission coefficient matrices estimated by the transmission coefficient matrix estimation means, and determines the transmission weights of the multi-beamforming apparatus in the corresponding frequency band;
A transmission weight determination block that collectively refers to the Fourier transform device, a transfer coefficient matrix estimation device, and a transmission weight determination device;
A serial-parallel conversion device that performs serial-parallel conversion on an input signal to be transmitted and distributes the divided signal into frequency division multiplexing number F × spatial multiplexing number L;
F × L transmitters that use the output signal of the serial-parallel converter as an input signal and output a transmission signal system to the multi-beam forming device;
The signal input from the transmission device is used as an input signal, divided into N signals, weighted by the transmission weight determination device, and the corresponding ports of the N × F signal synthesis devices. A multi-beam forming device that outputs to
A signal synthesizer that superimposes signals input to L ports from the corresponding L multi-beam forming devices among the multi-beam forming devices and outputs them to the corresponding ports of the inverse Fourier transform device. When,
N inverse Fourier transform devices that perform an inverse Fourier transform on the F signals output from the signal synthesizer and output to the other port of the switching device;
A spatial multiplexing transmission apparatus characterized by comprising: The transmission weight determination device includes:
A transmission weight for multiplying the corresponding t-th frequency band by the multi-beamformer,
A product of each complex conjugate transpose matrix and a transfer coefficient matrix is obtained from Mt (≦ F) transfer coefficient matrices selected from the F transfer coefficient matrices, and output as an eigenvector of an Mt averaged matrix. The transmission device for spatial multiplexing transmission according to claim 8. The transmission weight determining apparatus is configured to transmit transmission weights to be multiplied by a corresponding t-th frequency band by the multi-beam forming apparatus from Mt transfer coefficient matrices selected from the F transfer coefficient matrices, respectively, and complex conjugate transpose thereof. 9. The space according to claim 8, wherein a product of a matrix and a transfer coefficient matrix is obtained, the obtained k-th matrix is multiplied by a weight wk, and the result is output as an eigenvector of the matrix obtained by taking the sum. Multiplex transmission device. The transmission weight determination device includes:
A transmission weight for multiplying the corresponding t-th frequency band by the multi-beamforming apparatus is calculated from Mt transfer coefficient matrices selected from the F transfer coefficient matrices, and each complex conjugate transpose matrix and transfer coefficient matrix 9. The transmitter for spatial multiplexing transmission according to claim 8, wherein the product is obtained, multiplied by a weight wtk corresponding to each frequency band, and output as an eigenvector of a matrix obtained by taking the sum. The transmission weight determination device includes:
From the Mt transfer coefficient matrices selected from the F transfer coefficient matrices, transmission weights for multiplying the corresponding t-th frequency band by the multi-beam format apparatus are used to calculate the respective complex conjugate transpose matrix and transfer coefficient matrix. 9. The product according to claim 8, wherein the product is obtained, multiplied by a weight wtk corresponding to a correlation value with a transfer coefficient matrix of the t-th frequency band, and output as an eigenvector of a matrix obtained by taking the sum. A transmitter for spatial multiplexing transmission. In the transmission weight determination block, a signal output from the switching device at the time of reception is used as an input signal,
A feedback information extraction device that extracts field back information including information on the result of performing all or part of the calculation for determining the transmission weight according to any one of claims 1 to 5, from an input signal;
The output of the feedback information extraction device as an input signal, a transmission weight determination device that performs a calculation to determine the transmission weight according to any one of claims 8 to 12,
A spatial multiplexing transmission apparatus characterized by comprising: The transmission weight determination device includes:
The transmission device for spatial multiplexing transmission according to any one of claims 8 to 13, wherein a transmission weight common to a plurality of frequency bands is output.

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