JP6388344B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system.

  FIG. 9 shows a wireless communication system 100 that performs MIMO (Multiple-Input and Multiple-Output) wireless transmission with M branches (that is, M spatial multiplexing numbers). The wireless communication system 100 includes a wireless transmission device 50 and a wireless reception device 60. The wireless transmission device 50 includes a plurality of antenna elements Tx1 to TxM (M is an integer of 2 or more). The radio reception device 60 includes a plurality of antenna elements Rx1 to RxM. Radio frequency signals (hereinafter referred to as “RF signals”) 1 to M transmitted from all the antenna elements Tx1 to TxM of the radio transmission device 50 reach the antenna element Rxi of the radio reception device 60. At this time, due to the principle of superposition, an RF signal having an amplitude several times larger than the RF signal transmitted between the pair of transmitting antenna elements and the receiving antenna element is received by the antenna element Rxi. Become.

  Due to the declination of the transmission path response matrix of MIMO wireless transmission, that is, the relationship between the phase rotation amount due to the electrical length of the radio wave propagation path connecting each of the transmitting side antenna elements Tx1 to TxM and the receiving side antenna elements Rx1 to RxM, When the phases of the M RF signal trains that reach the receiving-side antenna element Rxi coincide with each other, the maximum amplitude value becomes extremely large due to superposition. If there is no propagation loss, the maximum amplitude is M times when the number of branches is M, and the PAPR (Peak to Average Power Ratio) of the RF signal is greatly increased.

  In short-distance MIMO wireless transmission in which the RF signal spatial propagation path is a line-of-sight propagation path, the difference in propagation loss in the radio wave propagation path connecting the transmitting and receiving antenna elements is very small. Therefore, when the number of branches is M, the amplitude of the RF signal reaching each antenna element Rx1 to RxM of the wireless reception device 60 is approximately M times according to the above principle, and the dynamic range required for the wireless reception device 60 Becomes very large. For example, the dynamic range required for an analog-digital converter (ADC) increases. Further, the increase in maximum amplitude may cause signal distortion due to saturation of a low noise amplifier (LNA) for reception, damage to the LNA, and the like. Further, when performing transmission beam forming, the required saturation power in the power amplifier at the final output stage is increased, and the power consumption in the RF circuit of the wireless transmission device 50 is also increased.

  FIG. 10 is a graph plotting the result of a trial calculation of how much the amplitude of the received signal increases in short-range MIMO wireless transmission. In FIG. 10, a binary rectangular wave is assumed as a transmission signal for simple estimation. In FIG. 10, a plurality of transmission signals (hereinafter referred to as “streams”) are spatially multiplexed from the wireless transmission device 50 and transmitted to the wireless reception device 60, and received by the antenna elements Rx <b> 1 to RxM of the wireless reception device 60. The time probability of the amplitude of the RF signal is estimated. FIG. 10 shows a trial calculation result when the number of branches is 16 and when the number of branches is 25. As shown in FIG. 10, in a symbol having an appearance probability of 98% or more, the maximum amplitude is about 8 times that of one stream in the case of 16 branches, and is about 16 times that of one stream in the case of 25 branches. That is, in order to accurately AD convert symbols with an appearance probability of 98% or more, it is necessary to add 3 bits in the case of 16 branches (16 multiplexes). In the case of 25 branches (25 multiplexes), it is necessary to add 4 bits. Similarly, it is necessary to add 2 bits for 4 multiplexing and 3 bits for 8 multiplexing.

Kenoka, et al., "Proposal of simple reception decoding method in short-distance MIMO transmission", IEICE Technical Report. A / P, Antenna & Propagation 111 (376), January 11, 2012, p. 153-158

  For the reasons described above, preventing the increase in the maximum amplitude is one problem in a wireless communication system that performs short-range MIMO wireless transmission. As a solution to this problem, for example, there is a simple decoding method as shown in Non-Patent Document 1 that separates a spatially multiplexed signal using only a passive circuit with no dynamic range restriction.

  However, in the method shown in Non-Patent Document 1, the above problem is solved by an analog weight circuit newly added to the receiving side without changing the amplitude of the signal to be transmitted. This is applicable only when there is no change in the environment, and there is a problem that the application range is limited.

  The present invention has been made to solve the above problem, and its purpose is to reduce the peak power of a signal received by the wireless reception device without adding a new configuration to the reception processing of the wireless reception device in MIMO wireless transmission. The purpose is to provide technology that can be reduced.

  One embodiment of the present invention is a wireless communication system including a wireless transmission device having a plurality of antenna elements and a wireless reception device having a plurality of antenna elements, wherein the wireless transmission device has the plurality of antenna elements included in the wireless communication device. When the plurality of antenna elements of the radio reception apparatus receive a plurality of radio frequency signals transmitted through the plurality of radio frequency signals, the plurality of radio frequency signals to be received have different phases. It is a radio | wireless communications system provided with the phase adjustment part which gives a phase difference.

  One aspect of the present invention is the above wireless communication system, in which the phase shift amount of the phase difference given to the plurality of radio frequency signals is a value of a radio wave propagation path between the wireless transmission device and the wireless reception device. When the phase difference is given to the channel response matrix indicating the characteristics, the phase shift amount is calculated by solving an optimization problem in which some of the plurality of radio frequency signals to be received have different phases. Is set in the phase adjustment unit.

  One aspect of the present invention is the above-described wireless communication system, in which the optimization problem in which some of the plurality of received radio frequency signals have different phases has the same frequency, the same phase, and the same maximum amplitude value. A signal in which the phase difference is given to the transmission line response matrix as a signal to supply a sine wave having the following to the phase adjustment unit, and the sine wave received by the plurality of antenna elements of the wireless reception device is superimposed, An optimization problem that minimizes the sum of the amplitude values of the signals or minimizes the maximum value of the amplitude values of the signals, and the phase shift amount is calculated and calculated by solving the optimization problem The phase shift amount is set in the phase adjustment unit.

  One aspect of the present invention is the above-described wireless communication system, in which the transmission is performed when a radio wave propagation path between the wireless transmission device and the wireless reception device is changed, or irregularly or periodically. A phase shift amount calculating unit configured to calculate a path response matrix, calculate the phase shift amount based on the calculated transmission path response matrix, and set the calculated phase shift amount in the phase adjustment unit;

  One aspect of the present invention is the above wireless communication system, wherein the wireless reception device includes a training signal transmission unit that transmits a training signal, and the phase shift amount calculation unit of the wireless transmission device receives the training signal. Receiving, estimating the transmission path response matrix based on the received training signal, calculating the phase shift amount based on the estimated transmission path response matrix, and setting the phase shift amount in the phase adjustment unit To do.

  One aspect of the present invention is the above-described wireless communication system, in which a radio wave propagation path between the wireless transmission device and the wireless reception device is a line-of-sight propagation path, and the wireless reception device is a position of its own device. The wireless transmission device further includes a positional relationship measurement unit that measures a positional relationship between the device itself and the wireless reception device using the position display unit. The phase shift amount calculation unit of the transmission device relates to the positional relationship measured by the positional relationship measurement unit, information about the arrangement of the plurality of antenna elements of the own device, and the arrangement of the plurality of antenna elements of the wireless reception device. The transmission path response matrix is estimated based on the information, the phase shift amount is calculated based on the estimated transmission path response matrix, and the phase shift amount is set in the phase adjustment unit.

  One aspect of the present invention is the above-described wireless communication system, in which the wireless reception device measures amplitude values of the radio frequency signals received by the plurality of antenna elements, and information on the measured amplitude values is obtained. A reception level feedback unit for transmitting to a wireless transmission device, wherein the wireless transmission device transmits a sine wave having the same frequency, the same phase, and the same maximum amplitude value through each of the plurality of antenna elements. Based on the amplitude value received from the signal transmission unit and the reception level feedback unit, determine whether or not the phase shift amount is appropriate, if it is determined that it is not appropriate, change the phase shift amount, A phase shift amount calculation unit that sets the changed phase shift amount in the phase adjustment unit.

  According to the present invention, in MIMO wireless transmission, it is possible to reduce the peak power of a signal received by the wireless reception device without adding a new configuration to the reception processing of the wireless reception device.

It is a block diagram which shows the structure of the radio | wireless communications system by 1st Embodiment of this invention. It is a figure explaining the transmission state of RF signal by the radio | wireless communications system of the embodiment. It is a figure explaining the effect of the embodiment compared with a prior art. It is a block diagram which shows the structure of the radio | wireless communications system by 2nd Embodiment. It is a sequence diagram which shows the process by the embodiment. It is a block diagram which shows the structure of the radio | wireless communications system by 3rd Embodiment. It is a block diagram which shows the structure of the radio | wireless communications system by 4th Embodiment. It is a sequence diagram which shows the process by the embodiment. It is a block diagram which shows the system of a near field MIMO radio transmission. It is a figure explaining the increase in the received signal amplitude by proximity | contact MIMO radio transmission.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a configuration of a wireless communication system 1 according to the first embodiment of the present invention. The radio communication system 1 performs, for example, MIMO radio transmission on a line-of-sight propagation path, that is, short-range MIMO radio transmission. Here, the line-of-sight propagation path refers to a propagation path in which no object that shields radio waves exists in the space between the transmission-side antenna and the reception-side antenna, for example. The wireless communication system 1 includes a wireless transmission device 10 and a wireless reception device 20.

The wireless transmission device 10 includes an information signal input unit 11, an information signal distribution unit 12, a local oscillator 13, a modulation unit 14, a phase adjustment unit 15, and antenna elements 16-1 to 16-M.
The information signal input unit 11 inputs information to be transmitted to the wireless transmission device 10.
The information signal distribution unit 12 distributes the information input by the information signal input unit 11 into M pieces. Information distributed to the M pieces by the information signal distributor 12 is referred to as information signals 1 to M. The information signal distributor 12 outputs the information signals 1 to M to the modulators 14-1 to 14-M, respectively.
The local oscillator 13 outputs a radio frequency sine wave frequency signal.

The modulation unit 14 includes M modulators 14-1 to 14-M. Each modulator 14-1 to 14-M includes a frequency converter to RF frequency. Each of the modulators 14-1 to 14 -M performs modulation by up-converting the information signal to the RF frequency based on the frequency signal supplied from the local oscillator 13. The modulation method used by the modulation unit 14 is amplitude modulation.
The phase adjustment unit 15 includes M phase adjusters 15-1 to 15-M. In each of the phase adjusters 15-1 to 15-M, a phase shift amount φi (i = 1 to M, the same applies hereinafter) calculated in advance is set in advance and modulated based on the phase shift amount φi. A phase difference is given to the information signals 1 to M. The antenna elements 16-1 to 16 -M transmit the RF signal modulated by the modulation unit 14 and given a phase difference based on the phase shift amount φi in the phase adjustment unit 15 to the radio reception device 20.

The wireless reception device 20 includes antenna elements 21-1 to 21 -M, a communication control unit 22, and an information signal output unit 23.
The antenna elements 21-1 to 21-M receive the RF signals that are transmitted from the antenna elements 16-1 to 16-M of the wireless transmission device 10 and propagate through the space.
The communication control unit 22 demodulates the M signals received by the antenna elements 21-1 to 21-M, and detects a MIMO radio transmission signal by matrix processing based on the demodulated signal and the transmission path response matrix H. The information signal is demodulated by separating a plurality of spatially multiplexed information signals.
The information signal output unit 23 outputs the information signal demodulated by the communication control unit 22.

FIG. 2 is a diagram conceptually illustrating a situation in which RF signals transmitted from the M antenna elements 16-1 to 16-M of the wireless transmission device 10 are superimposed on the antenna element 21-i of the wireless reception device 20. It is.
As a flow of transmission / reception processing of the wireless communication system 1, first, the information signal input unit 11 of the wireless transmission device 10 outputs information to be transmitted to the information signal distribution unit 12. The information signal distributor 12 distributes the information to M information signals 1 to M and outputs the information information to the modulators 14-1 to 14 -M. The modulators 14-1 to 14-M up-convert and modulate the information signals 1 to M with the radio frequency signals supplied from the local oscillator 13, respectively, and modulate the corresponding phase adjusters 15-1 to 15-1. Output to 15-M. The phase adjusters 15-1 to 15-M give a phase difference to a signal modulated based on a preset phase shift amount φi, and output an RF signal to the space through the antenna elements 16-1 to 16-M.

  Each of the antenna elements 21-1 to 21-M of the wireless reception device 20 receives M superimposed RF signals as shown in FIG. The communication control unit 22 of the wireless reception device 20 down-converts and demodulates the RF signal received by the antenna elements 21-1 to 21-M, and performs MIMO processing by matrix processing based on the demodulated signal and the transmission path response matrix H. A signal is detected and a plurality of spatially multiplexed information signals are separated to demodulate the information signal. The information signal output unit 23 outputs the information signal demodulated by the communication control unit 22.

  Here, the phase shift amount φi set in advance for each of the phase adjusters 15-1 to 15-M described above does not match the phases of the M RF signals received by the antenna element 21-i as much as possible. With such a phase shift amount, it is possible to suppress an increase in the maximum amplitude value (hereinafter also referred to as a peak) generated by overlapping M RF signals.

  In particular, in short-distance wireless transmission such as contactless transmission, since the transmission distance is short, the signal-to-noise ratio (SNR) is large, and the area where the wireless service is provided is also very narrow. Since it is limited, a wide band can be used. Therefore, when the configuration of the modem is simplified to reduce the signal processing cost, it is assumed that amplitude modulation is used. When amplitude modulation is performed, the phase of the RF signal at the time of transmission is preserved even at the time of reception. Therefore, if a phase difference that does not match the phase as much as possible is given to each RF signal to be transmitted, the peak amplitude Can be reduced. In the following, an example of a method for calculating the phase shift amount φi having such a phase difference will be described.

(Calculation method of phase shift amount φi: first method)
A transmission line response matrix of MIMO wireless transmission is assumed to be a matrix H, and a phase shift amount vector is assumed to be φ = [φ1, φ2,..., ΦM]. The RF signal vector t ′ (number of elements M) actually radiated from the antenna elements 16-1 to 16 -M of the wireless transmission apparatus 10 to the RF signal t to be transmitted is adjusted by the phase adjustment unit 15. By multiplying the phase shift amount φ set in the units 15-1 to 15-M as a Hadamard product, the following equation (1) is obtained.

In order to make the phase shift vector part of the channel response matrix, the φi phase is shifted with respect to all the i-th column components of the matrix H. Mathematically, the i-th column component of the matrix H is multiplied by exp (φi). The transmission path response matrix obtained in this way is defined as a matrix H_p.
Note that the matrix H, the phase shift amount vector φ, and the matrix H_p of the transmission path response matrix described above are all matrices or vectors, and therefore may be written in bold (bold) when described in mathematical expressions. However, in the present specification, terms such as “matrix” and “vector” such as “matrix X” and “vector X” are added.

  In order to make the phase of the received RF signal not match as much as possible in the antenna elements 21-1 to 21 -M of all the radio reception apparatuses 20, for example, in all the rows of the matrix H_p, M pieces in the row The declination angle of the elements should not be matched as much as possible. Such a matrix H_p can be obtained, for example, as an optimization problem that maximizes the sum total of M rows of the dispersion of the deviation angles of M elements.

(Calculation method of phase shift amount φi: second method)
As the second method, although the amount of calculation is larger than that of the first method, the amplitude that is the peak of the RF signal received by the antenna elements 21-1 to 21-M of the wireless reception device 20 is actually estimated by calculation. Thus, there is a method of calculating the phase shift amount φi that does not coincide as much as possible with high accuracy. First, the maximum value of the amplitude of the superimposed sine wave signal received by the antenna elements 21-1 to 21-M is calculated using the matrix H_p. Then, the value of the phase shift amount vector φ is optimized using an optimization algorithm with the largest value among the calculated maximum amplitude values as an evaluation function. As the optimization algorithm, an algorithm such as a steepest descent method may be used. Note that the optimization algorithm may be a full search. When transmitting a sine wave having the same frequency, the same phase, and the same maximum amplitude value from the wireless transmission device 10, the signal T supplied to the input terminals of the phase adjusters 15-1 to 15-M is expressed by the following equation (2 ).

  The change of the phase by the amount of phase shift set in advance in each of the phase adjusters 15-1 to 15-M is expressed by the following equation (3).

  After the phase is changed by the following equation (3), the antenna elements 21-1 to 21-M of the wireless reception device 20 pass through the radio wave propagation path and are received by the antenna elements 21- When the reception waveform R (t) received by 1 to 21-M is expressed using the transmission path response matrix H of the radio wave propagation path, the number of time waveforms is expressed as M vectors as in the following equation (4). .

  In Equation (4), each of the M waveforms of R (t) is a sine wave in which sine waves having the same maximum amplitude value at the same frequency are shifted in phase, so that the amplitude of each waveform can be easily set. Can be calculated. When the transmission line response matrix H does not change with time during wireless transmission, the matrix H becomes a constant. Therefore, the vector RP whose elements are the peak amplitudes of the M waveforms of R (t) is the time It is a vector having the number of elements M determined only by the vector Φ, which does not depend on. Here, as a method for optimizing the vector Φ, for example, “(1) Search for the value of the vector Φ that minimizes the sum of all elements of the vector RP. (2) The maximum value of the vector RP becomes minimum. A method such as “search for the value of Φ” can be applied. As a search method, a method of performing a full search may be used, but an algorithm such as a steepest descent method is applied because it causes an optimization problem.

  Note that the phase shift amount φi obtained by the first method and the second method described above changes with time because there is no change in the transmission line response matrix H as described above when there is no fluctuation in the transmission line. It is a constant that does not. On the other hand, when the transmission path changes, the transmission path response matrix H also changes. Therefore, the transmission path response matrix H is obtained again by means such as an embodiment described later, and the phase shift amount φi is recalculated. There is a need.

  With the configuration of the first embodiment described above, the phase adjustment unit 15 is provided, so that the phase of the RF signal transmitted through the antenna elements 16-1 to 16-M in the wireless transmission device 10 is adjusted to the phase adjusters 15-1 to 15-1. It can be changed by 15-M. The transmission path response matrix H that is information based on the propagation path difference between the antenna elements 16-1 to 16-M and the antenna elements 21-1 to 21-M is calculated and estimated, and the estimated transmission path response matrix H is used. When the RF signal reaches the antenna elements 21-1 to 21 -M of the wireless reception device 20, the phase shift amount φi having a phase as different as possible is calculated in advance. Then, the calculated phase shift amount φi is set in the phase adjusters 15-1 to 15-M. Thus, when M RF signals are received by each of the antenna elements 21-1 to 21-M of the wireless reception device 20, the phases of the M RF signals are different from each other as much as possible. Thus, it is possible to suppress an increase in the amplitude of the peak of the superimposed RF signal. Therefore, in MIMO wireless transmission, it is possible to reduce the peak power of a signal received by the wireless reception device without adding a new configuration to the reception processing of the wireless reception device. Needless to say, when the phases of the M RF signals are not all in phase, the peak amplitude of the superimposed RF signal can be reduced most, and the maximum effect can be obtained.

  As shown in FIG. 3, in the conventional wireless communication system 100, the power of about 3 dB peak is increased by superposition of the two RF signals of the RF signal 1 and the RF signal 2 in the first embodiment. In the wireless communication system 1, as described above, it is possible to reduce an increase in peak power. As a result, it is possible to reduce PAPR, transmit amplifier saturation level, receiver LNA saturation level, and ADC dynamic range, and to reduce power consumption by reducing the amount of digital signal processing. Is possible. Furthermore, it is possible to prevent the receiving side LNA from being damaged.

(Second Embodiment)
FIG. 4 is a block diagram showing a configuration of a radio communication system 1a according to the second embodiment of the present invention. In FIG. 4, the same components as those of the wireless communication system 1 of the first embodiment are denoted by the same reference numerals and description thereof is omitted. Hereinafter, a configuration different from the wireless communication system 1 of the first embodiment will be described.
The wireless communication system 1a includes a wireless transmission device 10a and a wireless reception device 20a.
In the wireless communication system 1a according to the second embodiment, the wireless reception device 20a transmits a training signal to the wireless transmission device 10a, and the wireless transmission device 10a calculates a transmission path response matrix H based on the training signal.

The wireless transmission device 10a includes an information signal input unit 11, an information signal distribution unit 12, a local oscillator 13, a modulation / demodulation unit 14a, a phase adjustment unit 15a, antenna elements 16-1 to 16-M, and a phase shift amount calculation unit 17.
The modem unit 14a includes modems 14a-1 to 14a-M. Each of the modems 14a-1 to 14a-M receives a frequency signal of a radio frequency sine wave supplied from the local oscillator 13, up-converts the information signals 1 to M, performs modulation, and adjusts the phase. To the unit 15a. Each of the modems 14a-1 to 14a-M receives the frequency signal supplied from the local oscillator 13, down-converts the received signal output from the phase adjustment unit 15a, and performs demodulation. Output to the phase shift amount calculation unit 17. The modulation method used by the modem unit 14a is amplitude modulation.

  The phase adjustment unit 15a includes phase adjusters 15a-1 to 15a-M. Each of the phase adjusters 15a-1 to 15a-M receives and sets the information of the phase shift amount φi output from the phase shift amount calculation unit 17 for each of the phase adjusters 15a-1 to 15a-M. Further, each of the phase adjusters 15a-1 to 15a-M gives a phase difference to the modulated information signals 1 to M based on the phase shift amount φi. When the received signals are output from the antenna elements 16-1 to 16-M, the phase adjusters 15a-1 to 15a-M convert the received received signals into the corresponding modulators / demodulators 14a-1 to 14a-. Output to M.

  The phase shift amount calculation unit 17 estimates the transmission path response matrix H based on the demodulated training signal output from the modem unit 14a. In addition, the phase shift amount calculation unit 17 shifts based on the estimated transmission path response matrix H and the calculation method (first method and second method) of the phase shift amount φi described in the first embodiment. The phase amount φi is calculated and output to the phase adjusters 15a-1 to 15a-M of the phase adjuster 15a to be set inside. The amount of phase shift represents the amount used to change the phase. Further, the phase shift amount calculation unit 17 outputs a notification that the MIMO wireless transmission can be started to the information signal input unit 11 after outputting the calculated phase shift amount φi to each of the phase adjusters 15a-1 to 15a-M.

The wireless reception device 20a includes antenna elements 21-1 to 21-M, a communication control unit 22a, an information signal output unit 23, and a training signal transmission unit 24.
The training signal transmission unit 24 generates a predetermined training signal, for example, M signals orthogonal to each other such as HT-LTF (High-Throughput Long Training Field) in an IEEE 802.1n wireless LAN (Local Area Network) system. .
The communication control unit 22a transmits the training signal generated by the training signal transmission unit 24 to the wireless transmission device 10 through the antenna elements 21-1 to 21-M.

FIG. 5 is a sequence diagram showing a processing flow of the wireless communication system 1a according to the second embodiment.
First, the training signal transmission unit 24 of the wireless reception device 20a generates a training signal, and transmits the generated training signal to the wireless transmission device 10a through the communication control unit 22a and the antenna elements 21-1 to 21-M (step). S101).
The antenna elements 16-1 to 16-M of the wireless transmission device 10a receive the training signals and output the received training signals to the corresponding phase adjusters 15a-1 to 15a-M. Each phase adjuster 15a-1 to 15a-M outputs a training signal to the corresponding modems 14a-1 to 14a-M. The modems 14 a-1 to 14 a -M demodulate the training signal and output it to the phase shift amount calculation unit 17. The phase shift amount calculation unit 17 estimates the transmission path response matrix H from the training signal (step S102).

  The phase shift amount calculation unit 17 is based on the estimated transmission path response matrix H and the phase shift amount φi calculation method (first method and second method) described in the first embodiment. φi is calculated (step S103). The phase shift amount calculation unit 17 outputs the calculated phase shift amount φi to the corresponding phase adjusters 15a-1 to 15a-M. Each of the phase adjusters 15a-1 to 15a-M sets the phase shift amount φi output from the phase shift amount calculation unit 17 inside. Further, the phase shift amount calculation unit 17 outputs a notification that the MIMO wireless transmission can be started to the information signal input unit 11 (step S104).

When the information signal input unit 11 of the wireless transmission device 10 a receives a notification from the phase shift amount calculation unit 17 that can start MIMO wireless transmission, the information signal input unit 11 outputs information to be transmitted to the information signal distribution unit 12. The information signal distribution unit 12 distributes the information to M pieces and outputs the information signals 1 to M to the modems 14a-1 to 14a-M. The modems 14a-1 to 14a-M modulate the information signals 1 to M based on the frequency signal supplied from the local oscillator 13 and output the modulated information signals to the corresponding phase adjusters 15a-1 to 15a-M. Each of the phase adjusters 15a-1 to 15a-M gives a phase difference to the information signals 1 to M modulated based on the phase shift amount φi set to each of the phase adjusters 15a-1 to 15a-M, and passes through the antenna elements 16-1 to 16-M. The information signals 1 to M to which the phase difference is given are transmitted to the radio receiver 20a (step S105).
The wireless reception device 20a receives the signal transmitted from the wireless transmission device 10 through the antenna elements 21-1 to 21-M, demodulates the communication control unit 22a, and outputs the demodulated signal to the information signal output unit 23 (step S106). .

  With the configuration of the second embodiment, the wireless communication system 1a transmits a training signal from the wireless reception device 20a, and the wireless transmission device 10a calculates a transmission path response matrix H based on the training signal. As a result, in addition to the effects obtained from the configuration of the first embodiment, even when the transmission path environment fluctuates and the transmission path response matrix H fluctuates, the fluctuating transmission path response matrix H is estimated. Thus, it is possible to calculate the phase shift amount φi with high accuracy based on the estimated transmission path response matrix H.

(Third embodiment)
FIG. 6 is a block diagram showing a configuration of a wireless communication system 1b according to the third embodiment of the present invention. In FIG. 6, the same components as those of the wireless communication system 1 of the first embodiment and the wireless communication system 1a of the second embodiment are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, a configuration different from either the wireless communication system 1 of the first embodiment or the wireless communication system 1a of the second embodiment will be described.

  The wireless communication system 1b includes a wireless transmission device 10b and a wireless reception device 20b. The wireless communication system 1b is applied when the radio wave propagation path is a line-of-sight propagation path, that is, a so-called short-distance MIMO wireless transmission transmission path. As described above, the line-of-sight propagation path is a propagation path in which no object that shields radio waves exists in the space between the transmission-side antenna and the reception-side antenna. In this embodiment, for example, a laser beam or the like arrives. It is a possible propagation path and a propagation path capable of taking a picture.

The wireless transmission device 10b includes an information signal input unit 11, an information signal distribution unit 12, a local oscillator 13, a modulation unit 14, a phase adjustment unit 15a, antenna elements 16-1 to 16-M, a phase shift amount calculation unit 17b, and a positional relationship. A measurement unit 18 is provided.
The positional relationship measurement unit 18 measures information indicating the positional relationship between the wireless transmission device 10b and the wireless reception device 20b, for example, positional information of each device in a three-dimensional space. For example, when measuring the information indicating the positional relationship using laser light, the positional relationship measurement unit 18 transmits laser light from the laser light irradiation device provided therein to the position display unit 25 of the wireless reception device 20b. The reflected light is received by a light receiving element, and information indicating the positional relationship is measured. In addition, for example, when measuring the information indicating the positional relationship using an image, the positional relationship measuring unit 18 captures the position display unit 25 of the wireless reception device 20b using an internal camera, and obtains the position obtained by the capturing. Image information including the display unit 25 is analyzed, and information indicating the positional relationship is measured. Further, the positional relationship measuring unit 18 outputs information indicating the measured positional relationship to the phase shift amount calculating unit 17b.

  The phase shift amount calculation unit 17b internally stores information on the arrangement of the array antennas configured by the transmission side antenna elements 16-1 to 16-M and the reception side antenna elements 21-1 to 21-M in advance. ing. The information related to the arrangement of the array antenna is, for example, information on the arrangement of the antenna elements 16-1 to 16-M in the radio transmission apparatus 10b and information on the arrangement of the antenna elements 21-1 to 21-M in the radio reception apparatus 20b. is there. By using the information on the arrangement of the array antennas, the antenna element 16− in the three-dimensional space is based on the information indicating the positional relationship between the wireless transmission device 10b and the wireless reception device 20b measured by the positional relationship measurement unit 18. Position information of 1 to 16-M and position information of the antenna elements 21-1 to 21-M are obtained. The phase shift amount calculation unit 17b also determines the environment of the line-of-sight (LOS) radio wave propagation path based on the information indicating the positional relationship measured by the positional relationship measuring unit 18 and the information on the arrangement of the array antenna. The phase rotation amount of each radio wave propagation path at is calculated. Further, the phase shift amount calculation unit 17b calculates and estimates the transmission line response matrix H based on the calculated phase rotation amount. Further, the phase shift amount calculation unit 17b performs the shift based on the estimated transmission path response matrix H and the calculation method (first method and second method) of the phase shift amount φi described in the first embodiment. The phase amount φi is calculated and output to the phase adjusters 15a-1 to 15a-M of the phase adjuster 15a to be set inside.

The wireless reception device 20b includes antenna elements 21-1 to 21-M, a communication control unit 22, an information signal output unit 23, and a position display unit 25.
The position display unit 25 is, for example, the target of laser light when using a laser for measuring the positional relationship described later, and is a subject such as a mark photographed by a photograph when using a camera.

A flow of processing by the wireless communication system 1b of the third embodiment will be described.
First, the positional relationship measurement unit 18 of the wireless transmission device 10b uses the position display unit 25 of the wireless reception device 20b to measure information indicating the positional relationship between the wireless transmission device 10b and the wireless reception device 20b. The positional relationship measurement unit 18 outputs the measurement result to the phase shift amount calculation unit 17b. The phase shift amount calculation unit 17b includes pre-stored information on the arrangement of the array antennas configured by the transmitting-side antenna elements 16-1 to 16-M and the receiving-side antenna elements 21-1 to 21-M. Based on the information indicating the positional relationship, the phase rotation amount of the radio wave propagation path is calculated, and the transmission line response matrix H is calculated and estimated from the calculated phase rotation amount. Next, the phase shift amount calculation unit 17b is based on the estimated transmission line response matrix H and the calculation method (first method and second method) of the phase shift amount φi described in the first embodiment. The phase shift amount φi is calculated and output to the phase adjusters 15a-1 to 15a-M of the phase adjuster 15a to be set inside. The phase shift amount calculation unit 17b outputs a notification that the MIMO wireless transmission can be started to the information signal input unit 11. Subsequent transmission processing is the same processing as in the first embodiment.

  Note that the positional relationship measurement unit 18 changes the transmission line response matrix H when the positional relationship between the wireless transmission device 10b and the wireless reception device 20b changes during transmission, so that the transmission path response matrix H also changes irregularly or periodically. Alternatively, each time the positional relationship changes, the positional relationship between the transmitting-side antenna elements 16-1 to 16-M and the receiving-side antenna elements 21-1 to 21-M may be measured. In this case, the phase shift amount calculation unit 17b recalculates the transmission path response matrix H based on the information indicating the newly measured positional relationship, and uses the recalculated transmission path response matrix H to use the phase adjuster 15a. The phase shift amount φi set for each of −1 to 15a-M is calculated.

  With the configuration of the third embodiment, the positional relationship measurement unit 18 and the position display unit 25 measure information indicating the positional relationship between the wireless transmission device 10b and the wireless reception device 20b, and the information indicating the measured positional relationship is obtained. Based on this, a transmission line response matrix H is calculated. Thereby, in addition to the effects obtained by the configuration of the first embodiment, even when the transmission line environment changes and the transmission line response matrix H changes, the changing transmission line response matrix H is estimated. Thus, it is possible to calculate the phase shift amount φi with high accuracy based on the estimated transmission path response matrix H.

(Fourth embodiment)
FIG. 7 is a block diagram showing a configuration of a wireless communication system 1c according to the fourth embodiment of the present invention. In FIG. 7, the same components as those of the wireless communication system 1 of the first embodiment, the wireless communication system 1a of the second embodiment, and the wireless communication system 1b of the third embodiment are denoted by the same reference numerals, and description thereof is omitted. . Hereinafter, a configuration different from any of the wireless communication system 1 of the first embodiment, the wireless communication system 1a of the second embodiment, and the wireless communication system 1b of the third embodiment will be described.

  The wireless communication system 1c includes a wireless transmission device 10c and a wireless reception device 20c. In the radio communication system 1c, the RF signals for training with the maximum amplitude are transmitted from all the antenna elements 16-1 to 16-M of the radio transmission apparatus 10c, and the antenna elements 21-1 to 21-M of the radio reception apparatus 20c are transmitted. The value of the amplitude that is the maximum value among the amplitudes of the RF signals received at is measured. The information indicating the maximum value of the measured amplitude (hereinafter also referred to as peak amplitude information) is fed back to the wireless transmission device 10c to calculate the phase shift amount φi.

The wireless transmission device 10c includes an information signal input unit 11, an information signal distribution unit 12, a local oscillator 13, a modulation / demodulation unit 14a, a phase adjustment unit 15a, antenna elements 16-1 to 16-M, a phase shift amount calculation unit 17c, and a peak amplitude. A detection training signal transmission unit 19 is provided.
The peak amplitude detection training signal transmission unit 19 outputs information for transmitting training RF signals from all the antenna elements 16-1 to 16 -M to the information signal input unit 11. Here, the training RF signal to be transmitted is, for example, a sine wave having the same frequency, the same phase, and the same maximum amplitude value before the phase difference is given by the phase adjusters 15a-1 to 15a-M. It is.

  The phase shift amount calculation unit 17c sets a predetermined initial phase shift amount φi in each of the phase adjusters 15a-1 to 15a-M. In addition, the phase shift amount calculation unit 17c is based on the amplitude information of the received signal when the antenna elements 21-1 to 21-M of the wireless reception device 20c receive the training RF signal. It is determined whether or not the phase shift amount φi set to 1 to 15a-M is an appropriate value. Further, the phase shift amount calculation unit 17c has a counter therein, stores the number of times of changing the phase, and whether or not the number of times of changing the phase has reached a predetermined upper limit number. The determination process is performed and the determination is performed.

The wireless reception device 20c includes antenna elements 21-1 to 21-M, a communication control unit 22c, an information signal output unit 23, and a reception level feedback unit 26.
The reception level feedback unit 26 measures the peak amplitude information of the training RF signal received by each of the antenna elements 21-1 to 21-M. For example, in the measurement of peak amplitude information by the reception level feedback unit 26, when the RF signal is amplitude-modulated, the reception level feedback unit 26 includes a rectifier capable of detecting at a radio frequency, and actually measures the envelope voltage. Measure with If not amplitude modulation, the peak amplitude information of the RF signal for training may be measured by digital signal processing. In addition, the reception level feedback unit 26 outputs the measured peak amplitude information to the communication control unit 22c.
The communication control unit 22c transmits the peak amplitude information to the wireless transmission device 10c through the antenna elements 21-1 to 21-M. Note that the transmission does not necessarily have to be MIMO wireless transmission, and may be SISO (Single-Input Single-Output) wireless transmission or wireless transmission using other frequencies (including optical transmission). Good.

FIG. 8 is a sequence diagram showing a processing flow of the wireless communication system 1c according to the fourth embodiment.
First, the phase shift amount calculation unit 17c sets the phase shift amount φi serving as an initial value stored in advance in each of the phase adjusters 15a-1 to 15a-M (step S201). The peak amplitude detection training signal transmission unit 19 transmits an RF signal for training to the information signal input unit 11, that is, M information signals that are sine waves having the same frequency, the same phase, and the same maximum amplitude value. To output information. The information signal input unit 11 outputs the information output from the peak amplitude detection training signal transmission unit 19 to the information signal distribution unit 12. The information signal distribution unit 12 distributes the information output from the information signal input unit 11 to M pieces and outputs information signals 1 to M. The modems 14a-1 to 14a-M up-convert the information signals 1 to M into RF signals based on the frequency signals supplied from the local oscillator 13, and perform modulation.

The phase adjusters 15a-1 to 15a-M give a phase difference to the RF signal based on the phase shift amount φi set by the phase shift amount calculation unit 17c. The antenna elements 16-1 to 16-M transmit the RF signal given the phase difference to the wireless reception device 20c (step S202).
The reception level feedback unit 26 of the wireless reception device 20c measures peak amplitude information indicating the maximum amplitude value among the training RF signals received by the antenna elements 21-1 to 21-M, and the measurement result ( The peak amplitude information indicating the maximum amplitude value) is output to the communication control unit 22c (step S203). The communication control unit 22c transmits the peak amplitude information output from the reception level feedback unit 26 to the wireless transmission device 10c (step S204).

  The modems 14a-1 to 14a-M of the wireless transmission device 10c down-convert RF signals including peak amplitude information received through the antenna elements 16-1 to 16-M and the phase adjusters 15a-1 to 15a-M. Demodulated and output to the phase shift amount calculation unit 17c. The phase shift amount calculation unit 17c reads the peak amplitude information for each of the antenna elements 21-1 to 21-M, and the phase shift amount φi is not appropriate based on the read peak amplitude information, and the phase adjustment is determined in advance. It is determined whether or not the upper limit number of times has been reached (step S205).

  The determination of whether or not the phase shift amount φi is appropriate is performed by, for example, comparing the maximum value of the amplitude indicated by the peak amplitude information with a predetermined threshold value, and determining whether the maximum value of the amplitude is equal to or greater than the threshold value. This is done by judging. That is, when the maximum amplitude value is equal to or greater than the threshold value, it is determined that the phase shift amount φi is not appropriate. When the maximum amplitude value does not exceed the threshold value, the phase shift amount φi is appropriate. judge. Here, for example, a value smaller than a value obtained by multiplying the maximum amplitude value of the training RF signal by M can be used as the threshold value.

  If the phase shift amount calculation unit 17c determines that the phase shift amount φi is not appropriate and has not reached the predetermined upper limit number of phase adjustments with reference to the internal counter (step S205—YES), The phase shift amount φi is changed by a fixed value that is determined to be increased or decreased, and set in the phase adjusters 15a-1 to 15a-M (step S206). Here, the phase adjusters whose phase shift amount φi is changed are all the phase adjusters 15a-1 to 15a-M. The phase shift amount calculation unit 17c updates the counter value by adding 1 to the value of the internal counter, and outputs an instruction signal that causes the peak amplitude detection training signal transmission unit 19 to repeat the processing from step S202. The peak amplitude detection training signal transmitter 19 that has received the instruction signal performs the process of step S202.

The phase shift amount calculation unit 17c determines that the phase shift amount φi is appropriate, or determines that the number of changes of the phase shift amount φi has reached a predetermined upper limit number (step S205— NO), the phase shift amount φi set in the phase adjusters 15a-1 to 15a-M at that time is set as the formal phase shift amount φi, and a notification that the MIMO wireless transmission can be started is output to the information signal input unit 11. (Step S207). The information signal input unit 11 transmits M information signals by spatial multiplexing transmission using MIMO (step S208).
When receiving the MIMO signal through the antenna elements 21-1 to 21-M, the communication control unit 22c of the wireless reception device 20c calculates and estimates the transmission path response matrix H (step S209), and estimates the transmission path response matrix H. The received signal is demodulated based on the information and output to the information signal output unit 23 (step S210).

  With the configuration of the fourth embodiment described above, for training received by the wireless reception device 20c using the signals having the same frequency, the same phase, and the same maximum amplitude value for training that are actually transmitted from the wireless transmission device 10c. It is possible to obtain an appropriate phase shift amount φi by repeatedly changing the phase shift amount φi based on the maximum value of the amplitude value of the signal overlaid with the RF signal and a predetermined threshold value. As a result, the phase of the RF signal to be transmitted can be made as different as possible, and when the RF signal superimposed on the antenna elements 21-1 to 21-M of the wireless reception device 20c is received, the maximum RF signal is received. The amplitude value of can be reduced. Therefore, in MIMO wireless transmission, it is possible to reduce the peak power of a signal received by the wireless reception device without adding a new configuration to the reception processing of the wireless reception device.

In the fourth embodiment, as in the first to third embodiments, the phase shift amount φi is calculated by estimating the transmission line response matrix H described in the first embodiment (first method). Regardless of the second method, the phase shift amount φi is obtained based on the training RF signal actually transmitted from the transmission side, so that it is possible to obtain the phase shift amount φi with higher accuracy. is there.
Further, as in the second and third embodiments, since the phase shift amount φi is finally obtained using the training signal transmitted from the wireless transmission device 10c, it is appropriate even if the environment of the radio wave propagation path varies. It is possible to obtain a simple phase shift amount φi.
Moreover, in said 4th Embodiment, since the upper limit frequency | count which changes phase shift amount (phi) i is defined, it becomes possible to prevent that a process is performed infinitely.

  In the fourth embodiment, the phase shift amount calculation unit 17c outputs the phase shift amount φi that is the initial value in step S201 to the phase adjusters 15a-1 to 15a-M. The phase shift amount φi can be any value. For example, it may be set to zero, that is, a setting that does not give a phase difference, or the transmission path response matrix in the initial state is estimated, and the calculation method (first method) of the phase shift amount φi described in the first embodiment The phase difference obtained by the second method) may be used as the initial value. By doing in this way, it is also possible to reduce the frequency | count of changing the phase shift amount (phi) i required in order to obtain | require suitable phase shift amount (phi) i.

In the fourth embodiment, the reception level feedback unit 26 measures the peak amplitude information indicating the maximum amplitude value among the training signals received by the antenna elements 21-1 to 21 -M and performs wireless communication. Although the feedback is made to the transmission device 10c, the configuration of the present invention is not limited to this embodiment.
For example, the reception level feedback unit 26 feeds back the amplitude values of the training signals received by the antenna elements 21-1 to 21-M to the wireless transmission device 10c, and the phase shift amount calculation unit 17c of the wireless transmission device 10c The maximum amplitude value may be selected from the amplitude values for each of the antenna elements 21-1 to 21-M and compared with the threshold value.

  Further, for example, the reception level feedback unit 26 feeds back the amplitude values of the training signals received by the antenna elements 21-1 to 21-M to the wireless transmission device 10c. Then, the phase shift amount calculation unit 17c of the wireless transmission device 10c calculates the total value of the amplitude values, and the phase shift amount φi is appropriate depending on whether the calculated total value is equal to or greater than a predetermined threshold. It may be determined whether or not. As threshold values in this case, for example, the number M of the transmitting side antenna elements 16-1 to 16-M and the receiving side antenna elements 21-1 to 21- with respect to the maximum amplitude value of the training RF signal. A value smaller than the maximum amplitude value multiplied by the number M of M × M × M may be applied.

Note that the total value of the amplitude values may be calculated by the reception level feedback unit 26, and the calculated total value of the amplitude values may be fed back to the wireless transmission device 10c.
Note that, in the determination process or the determination process in step S205 described above, whether or not the threshold value is exceeded or not and whether or not the upper limit number has been reached is an example, for example, whether or not the threshold value is exceeded. Alternatively, it may be a criterion for determining whether or not the threshold value has been exceeded, or a criterion for determining whether or not the upper limit number has been exceeded instead of whether or not the upper limit number has been reached.

  In the fourth embodiment, when it is determined in step S205 that the phase shift amount φi is not appropriate, the phase shift amount φi is changed by a predetermined amount of increase or decrease. The configuration of the present invention is not limited to the embodiment. For example, information that can identify the antenna elements 21-1 to 21-M corresponding to the peak amplitude information used for the determination is acquired, and each shift is performed according to the position of the antenna elements 21-1 to 21-M. The increment and decrement of the phase amount φi may be determined.

  In the configurations of the first to fourth embodiments described above, the same local oscillator 13 is used for the M modulators 14-1 to 14-M or the M modulators / demodulators 14a-1 to 14a-M. Since the radio frequency signal is supplied from the M RF signal, the phase relationship of the M RF signals is stored with respect to time. However, the configuration of the present invention is not limited to this embodiment. The phase relationship of M RF signals only needs to be preserved with respect to time. For example, M local oscillators may be replaced with M modulators 14-1 to 14-M or M modulators / demodulators 14a-1 to 14a-1. Each of the M local oscillators connected to each of 14a-M is connected to a source oscillator serving as one signal source that outputs, for example, a 10 MHz signal from which a radio frequency signal is generated. There may be.

  In the first, second, and third embodiments, the transmission path response matrix H used for demodulation on the reception side is the transmission side response matrix H estimated on the transmission side by wireless communication. May be transmitted to the receiving side for use, or may be estimated on the receiving side as in the fourth embodiment.

  In the first embodiment, the phase shift amount φi is calculated in advance and set in the phase adjusters 15-1 to 15-M. However, a calculation unit is provided inside the wireless transmission device 10. The phase shift amount φi calculated by the calculator and calculated by the calculator may be set in the phase adjusters 15-1 to 15-M. The calculation unit may be provided in the wireless transmission device 10 or may be connected to the wireless transmission device 10 from the outside.

  A program for realizing all or part of the functions of the wireless transmission devices 10, 10a, 10b, and 10c and the wireless reception devices 20, 20a, 20b, and 20c is recorded on a computer-readable recording medium. Processing of each unit may be performed by causing a computer system to read and execute a program recorded on a medium. Here, the “computer system” includes an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  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 designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c ... Wireless communication system, 10, 10a, 10b, 10c ... Wireless transmitter, 11 ... Information signal input part, 12 ... Information signal distribution part, 13 ... Local oscillator, 14 ... Modulation part, 14a ... Modulator / Demodulator, 14-1 to 14-M Modulator, 14a-1 to 14a-M Modulator / Demodulator, 15 and 15a Phase adjuster, 15-1 to 15-M, 15a-1 to 15a-M Phase Adjuster, 16-1 to 16-M ... antenna element, 17, 17b, 17c ... phase shift amount calculation unit, 18 ... positional relationship measurement unit, 19 ... peak amplitude detection training signal transmission unit, 20, 20a, 20b, 20c ... wireless receivers, 21-1 to 21-M ... antenna elements, 22, 22a, 22c ... communication control unit, 23 ... information signal output unit, 24 ... training signal transmission unit, 25 ... position display unit, 26 ... reception level Feedback Wards

Claims (6)

A wireless communication system comprising a wireless transmission device having a plurality of antenna elements and a wireless reception device having a plurality of antenna elements,
The wireless transmitting apparatus,
When the plurality of antenna elements of the radio reception apparatus receive a plurality of radio frequency signals transmitted through the plurality of antenna elements included in the own apparatus, some of the plurality of radio frequency signals received have different phases. A phase adjustment unit that gives a phase difference to the plurality of radio frequency signals ,
The amount of phase shift of the phase difference given to the plurality of radio frequency signals is obtained when the phase difference is given to a transmission path response matrix indicating characteristics of a radio wave propagation path between the radio transmission apparatus and the radio reception apparatus. A wireless communication system that is calculated by solving an optimization problem in which some of the plurality of received radio frequency signals have different phases, and the calculated phase shift amount is set in the phase adjustment unit . The optimization problem in which some of the received radio frequency signals have different phases is transmitted as a signal for supplying a sine wave having the same frequency, the same phase, and the same maximum amplitude value to the phase adjustment unit. Giving the phase difference to the path response matrix and minimizing the sum of the amplitude values of the signals with respect to the signal in which the sine waves received by the plurality of antenna elements of the wireless receiver are superimposed, or the signal The phase shift amount is calculated by solving the optimization problem, and the calculated phase shift amount is set in the phase adjustment unit. the wireless communication system according to 1. When the radio wave propagation path between the wireless transmission device and the wireless reception device changes, or irregularly or periodically, calculate the transmission line response matrix, and based on the calculated transmission line response matrix the phase shift is calculated, further comprising a phase shift amount calculation unit that sets the calculated the amount of phase shift to the phase adjustment unit, a wireless communication system according to claim 1 or 2 Te. The wireless receiver is
A training signal transmission unit that transmits a training signal is provided.
The phase shift amount calculation unit of the wireless transmission device,
The training signal is received, the transmission channel response matrix is estimated based on the received training signal, the phase shift amount is calculated based on the estimated transmission channel response matrix, and the phase adjustment unit receives the training signal. The wireless communication system according to claim 3 , wherein the phase amount is set. The radio wave propagation path between the radio transmission apparatus and the radio reception apparatus is a line-of-sight propagation path,
The wireless receiver is
It further includes a position display unit used for measuring the position of its own device,
The wireless transmission device
A positional relationship measuring unit that measures the positional relationship between the device itself and the wireless receiver using the position display unit;
The phase shift amount calculation unit of the wireless transmission device,
Based on the positional relationship measured by the positional relationship measuring unit, information on the arrangement of the plurality of antenna elements of the own device, and information on the arrangement of the plurality of antenna elements of the wireless reception device, the transmission path estimating the response matrix, based on the estimated the channel response matrix, the calculated amount of phase shift and sets the amount of phase shift to the phase adjustment unit, a wireless communication system according to claim 3. A wireless communication system comprising a wireless transmission device having a plurality of antenna elements and a wireless reception device having a plurality of antenna elements,
The wireless transmission device
When the plurality of antenna elements of the radio reception apparatus receive a plurality of radio frequency signals transmitted through the plurality of antenna elements included in the own apparatus, some of the plurality of radio frequency signals received have different phases. A phase adjustment unit that gives a phase difference to the plurality of radio frequency signals,
The wireless receiver is
A reception level feedback unit for measuring an amplitude value of the radio frequency signal received by the plurality of antenna elements included in the own device and transmitting information of the measured amplitude value to the radio transmission device;
The wireless transmission device
A peak amplitude detection training signal transmitter that transmits sine waves having the same frequency, the same phase, and the same maximum amplitude value through each of the plurality of antenna elements of the device itself ;
Based on the amplitude value received from the reception level feedback unit, it is determined whether or not the phase shift amount of the phase difference to be given to the plurality of radio frequency signals is appropriate. change the Airyo, further non-line communication system Ru comprising a phase shift amount calculation unit, the setting the phase shift amount is changed to the phase adjustment unit.

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