JP5788860B2 - Wireless communication system and wireless communication method - Google Patents

Description

  The present invention relates to a radio communication system and a radio communication method, and more particularly, to a radio communication technique using an array antenna including a plurality of antenna elements.

  In recent years, it has been required to realize gigabit-class high-speed wireless communication in a limited frequency band. One of the implementation methods is a MIMO (Multiple-Input Multiple-Output) transmission technology. In MIMO transmission, different signals are transmitted at the same frequency from multiple transmitting antennas at the same time, and each signal is separated by signal processing on the receiver side by using a multipath environment between the transmitter and the receiver. And decrypt. Thereby, it is possible to improve the communication speed according to the number of transmitting / receiving antenna elements without expanding the use frequency band.

  On the other hand, near field communication represented by RF-ID (Radio Frequency-IDentification) has been studied, and near field / high speed communication using millimeter wave or UWB (Ultra-Wide-Band) communication has been attracting attention. Yes. Also, it is possible to apply MIMO transmission technology to short-range communication, and a short-range ultrahigh-speed wireless relay system using the inside of an obstacle such as a concrete wall as a propagation path has been proposed. For example, in the near field, it is known that high-speed communication is possible using the MIMO transmission technique even when the transmission / reception array antenna is not visible due to a wall or the like. According to MIMO transmission, since a wide frequency band is not required, it is possible to effectively use frequency resources.

  In addition, in the Non-Patent Document 1 and Non-Patent Document 2, the inventors of the present application have shown the basic characteristics of short-distance MIMO transmission in which the transmitting array antenna and the receiving array antenna are close to each other compared to the aperture size. For example, in Non-Patent Document 1, each array is considered by considering the relationship between the spatial correlation characteristic with respect to the distance between the transmitting array antenna and the receiving array antenna and the signal-to-noise ratio (SNR). The optimum element spacing of the antenna elements constituting the antenna is obtained.

  Further, in Non-Patent Document 1, a study for increasing the channel capacity in short-distance MIMO transmission is performed. However, in order to realize actual MIMO transmission, in addition to a technique for increasing the channel capacity, a signal processing technique in the transceiver is required. Regarding this signal processing technique, Non-Patent Document 2 is known as a characteristic of eigenmode transmission (hereinafter referred to as EM-BF) known as an optimal transmission / reception method of MIMO transmission and a method of performing signal processing only on the receiving side. The characteristics of zero forcing (hereinafter referred to as ZF) are being studied. It is shown that the characteristics of the EM-BF and the characteristics of the ZF substantially coincide with each other at the optimum element spacing of the array antenna shown in Non-Patent Document 1.

FIG. 6 is a diagram illustrating an arrangement example of antenna elements in short-range MIMO transmission. In FIG. 6, a plurality of transmitting antenna elements Tx _j (j is a positive integer of 1 ≦ j ≦ M and M is a positive integer of M ≧ 2) arranged in a matrix on the plane PT are transmitted. A plurality of receiving antenna elements Rx _i (i is a positive integer of 1 ≦ i ≦ M) arranged in a matrix on a plane PR that is parallel to the plane PT constitute an array on the receiving side. Configure the antenna. The number of transmitting antenna elements Tx _{j and} the number of receiving antenna elements Rx _i are both M. The plurality of transmitting antenna elements Tx _j and the plurality of receiving antenna elements Rx _i are arranged at positions facing each other. The distance between the plane PT and the plane PR is the distance D. Hereinafter, the distance D between the plane PT and the plane PR is referred to as “transmission / reception interval D”. Further, the antenna element interval of the transmitting antenna element Tx _{j and} the antenna element interval of the receiving antenna element Rx _i are both distance d. In the following, a case where M = 3, that is, 3 × 3 (3-input 3-output) short-range MIMO transmission will be described as an example.

FIG. 7 is a model diagram of 3 × 3 short-range MIMO transmission.
In the example of FIG. 7, the transmitting antenna elements Tx _{1 to} Tx ₃ are arranged on the plane PT shown in FIG. 6 so that one side is positioned at the apex of the regular triangle with the antenna element interval d. That is, the transmission antenna elements Tx _{1 to} Tx ₃ are arranged at equal intervals with an antenna element interval d. The receiving antenna elements _Rx 1 to Rx ₃ respectively, so as to face the transmitting antenna element _Tx 1 _{~Tx 3,} are arranged on a plane PR shown in FIG. 6 above. Accordingly, the receiving antenna elements Rx _{1 to} Rx ₃ are also arranged at equal intervals separated by the antenna element interval d.

In the 3 × 3 short-range MIMO transmission shown in FIG. 7, a channel matrix H representing the propagation characteristics of the channel between the transmitting antenna elements Tx _{1 to} Tx ₃ and the receiving antenna elements Rx _{1 to} Rx ₃ is expressed by Expression (1). And a received signal is represented by Formula (2).

Here, in Equation (1), the element h _ij (i, j is a positive integer of 3 or less) of the channel matrix H is the signal of the signal propagated through the channel from the transmitting antenna element Tx _j to the receiving antenna element Rx _i . The change rate of the phase and amplitude is indicated by, for example, complex number expression. In Expression (2), s _j represents a signal transmitted from the transmitting antenna element Tx _j , r _i represents a signal received by the receiving antenna element Rx _i , and n _i represents a received signal r _i. Represents the noise added to.

  Further, when a reception weight matrix W for signal separation in 3 × 3 MIMO transmission is expressed as in Expression (3), a signal output to each receiving circuit after calculation of reception weight is expressed in Expression (4).

In equation (4), the elements w _ij (i, j are positive integers of 3 or less) of the reception weight matrix W extract the data series s ′ _i corresponding to the data series transmitted by the transmission antenna element Tx _j. Therefore, a weight to be multiplied with the signal r _i received by the antenna element Rx _i is shown.

  In 3 × 3 short-range MIMO transmission, the channel capacity is maximized when the channel matrix H is expressed by Equation (5) or Equation (6). Hereinafter, the element spacing d when the channel capacitance is maximized is referred to as “optimal element spacing dopt”.

When the channel matrix H is expressed by the equation (5), that is, the channel between the transmitting antenna element Tx _j and the receiving antenna element Rx _i that are in a mutually opposing arrangement relationship, and the arrangement that is positioned obliquely to each other When the phase difference θ _H between the transmission antenna element Tx _j and the channel between the reception antenna element Rx _i is 90 degrees, the reception weight matrix W _{ZF in ZF} is expressed by Expression (7). .

Further, when the channel matrix H is expressed by Equation (6), the reception weight matrix W _{ZF in ZF} is expressed by Equation (8).

Therefore, Expression (9) is derived from Expression (5) and Expression (7), or Expression (6) and Expression (8). As shown in Expression (9), the product of the channel matrix H and the reception weight matrix W _ZF is represented by a diagonal matrix. This is because the signals transmitted from the transmitting antenna elements Tx _j are separated by being received by the receiving antenna element Rx _{i and} multiplied by the receiving weight w _ij in the receiver, and demodulated without causing interference with each other. Means that.

Seki, Nishimori, Honma, Nishikawa, “Short-range Ultra High-speed Relay System”, IEICE Technical Report, AP2008-124, Nov. 2008. Honma, Nishimori, Seki, Mizoguchi, "Evaluation of transmission capacity in nearby MIMO communication", IEICE Technical Report, AP2008-125, Nov. 2008.

  As described above, EM-BF and ZF require heavy load signal processing such as inverse matrix calculation and singular value decomposition at the digital signal level. If the signal processing load required for the short-distance MIMO transmission can be reduced, it is possible to reduce the manufacturing cost and power consumption of the communication system and the size of the apparatus.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a radio communication system and a radio communication method capable of realizing near field transmission by signal processing with a smaller load. is there.

A wireless communication system according to an aspect of the present invention includes a first communication device including first, second, and third transmitting antenna elements, and a second including first, second, and third receiving antenna elements. And the first, second, and third transmitting antenna elements and the first, second, and third receiving antenna elements are respectively disposed at opposing positions, and the first to third Among the transmission antenna elements and the first to third reception antenna elements, the channels formed between the transmission antenna elements and the reception antenna elements that are in a mutually opposing arrangement relationship are positioned obliquely to each other The first to third so that the amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element in the positional relationship is 1 and the phase difference between the channels is 90 degrees. Before the transmitting antenna element From a first to a third wireless communication system and receiving antenna elements are arranged in the second communications apparatus is, each of the third signal input from the receiving antenna element from said first 1: 2 ^-1/2 : The signal is branched by weighting with an amplitude ratio of 2 ^{-1/2, and the} amplitude ratio is input from one of the first to third receiving antenna elements among the signals obtained by the branching. A weighting unit that applies a -135 degree phase rotation to the weighted signal corresponding to the first term, a signal that is provided with the phase rotation by the weighting unit, and the first to third receiving antenna elements A decoding unit that synthesizes and decodes the signals that are input from the remaining two and weighted by the weighting unit respectively corresponding to the second and third terms of the amplitude ratio. Wireless communication system It has a configuration systems out.

  In the wireless communication system, for example, the decoding unit is input from the first receiving antenna element among the signals branched by the weighting unit, and is weighted corresponding to the first term of the amplitude ratio. A signal to which the phase rotation of the degree is given, a signal input from the second receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and the amplitude input from the third receiving antenna element A first decoding unit that synthesizes and decodes a weighted signal corresponding to the third term of the ratio, and among the signals branched by the weighting unit, the amplitude input from the second receiving antenna element A signal weighted corresponding to the first term of the ratio and given a phase rotation of -135 degrees and corresponding to the second term of the amplitude ratio input from the first receiving antenna element A second decoding unit that synthesizes and decodes the found signal and a signal input from the third receiving antenna element and weighted corresponding to the third term of the amplitude ratio; and the weighting unit Among the signals branched by the first receiving antenna element, the signal weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −135 degrees, and the first reception A signal inputted from an antenna element and weighted corresponding to the second term of the amplitude ratio is combined with a signal inputted from the second receiving antenna element and weighted corresponding to the third term of the amplitude ratio. And a third decoding unit for decoding.

A wireless communication system according to an aspect of the present invention includes a first communication device including first, second, and third transmission antenna elements, and first, second, and third reception antenna elements. A second communication device, wherein the first, second, and third transmission antenna elements and the first, second, and third reception antenna elements are respectively disposed at opposing positions, and Of the third transmitting antenna element and the first to third receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship with each other in an oblique direction ^So that the amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element in the positional relationship is 2 ^-1/2 , and the phase difference between the channels is 135 degrees. The first to third transmissions A wireless communication system in which an antenna element and the first to third receiving antenna elements are arranged, wherein each of the signals input from the first to third receiving antenna elements is received by the second communication device. Is weighted with an amplitude ratio of 1: 1: 1, and the signal obtained by the branching is input from one of the first to third receiving antenna elements and the first term of the amplitude ratio. , A weighting unit that applies a phase rotation of −90 degrees to the weighted signal, a signal that has been subjected to the phase rotation by the weighting unit, and the remaining two of the first to third receiving antenna elements. And a decoding unit that synthesizes and decodes the signals weighted corresponding to the second and third terms of the amplitude ratio by the weighting unit. System It has the configuration.

  In the wireless communication system, for example, the decoding unit receives a weight corresponding to the first term of the amplitude ratio input from the first receiving antenna element among the signals branched by the weighting unit, and is −90. A signal to which the phase rotation of the degree is given, a signal input from the second receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and the amplitude input from the third receiving antenna element A first decoding unit that synthesizes and decodes a weighted signal corresponding to the third term of the ratio, and among the signals branched by the weighting unit, the amplitude input from the second receiving antenna element A signal weighted corresponding to the first term of the ratio and given a phase rotation of −90 degrees, and a weight input from the first receiving antenna element and corresponding to the second term of the amplitude ratio A second decoding unit that synthesizes and decodes the injured signal and a weighted signal corresponding to the third term of the amplitude ratio input from the third receiving antenna element; and branching by the weighting unit Among the received signals, a signal input from the third receiving antenna element and weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −90 degrees, and the first receiving antenna element And a signal weighted corresponding to the second term of the amplitude ratio and a signal weighted corresponding to the third term of the amplitude ratio input from the second receiving antenna element A third decoding unit for decoding.

A wireless communication system according to an aspect of the present invention includes a first communication device including a transmission antenna element and a second communication device including first to third reception antenna elements, and the transmission antenna. An element and one of the first to third receiving antenna elements are arranged at positions facing each other, and the transmitting antenna element and the first to third receiving antenna elements are in an arrangement relationship facing each other. The amplitude ratio between the channel formed between the transmitting antenna element and the receiving antenna element and the channel formed between the transmitting antenna element and the receiving antenna element that are disposed in an oblique direction is 1 And the transmission antenna element and the first to third reception antenna elements are arranged so that the phase difference between the channels is 90 degrees. A is, the second communication device, each of the third signal input from the receiving antenna element from said first 1: 2 ^-1/2: weighted with 2 ^-1/2 becomes the amplitude ratio Of the signals obtained by branching, a signal input from one of the first to third receiving antenna elements and weighted corresponding to the first term of the amplitude ratio is −135 degrees. A weighting unit for applying phase rotation; a signal to which the phase rotation has been applied by the weighting unit; and the remaining two of the first to third receiving antenna elements, and the amplitude ratio of the amplitude ratio by the weighting unit. A wireless communication system comprising: a decoding unit configured to synthesize and decode the weighted signals corresponding to the second term and the third term, respectively.

A wireless communication system according to an aspect of the present invention includes a first communication device including a transmission antenna element, and a second communication device including first, second, and third reception antenna elements. The transmitting antenna element and one of the first, second, and third receiving antenna elements are arranged to face each other, and the transmitting antenna element and the first to third receiving antenna elements face each other. A channel formed between the transmitting antenna element and the receiving antenna element that are in an arrangement relationship to each other, and a channel formed between the transmission antenna element and the receiving antenna element in an arrangement relation that are located obliquely to each other The transmission antenna element and the first to third reception antenna elements are arranged so that the amplitude ratio is ^{2−1 / 2} and the phase difference between the channels is 135 degrees. In the wireless communication system, the second communication device branches each of the signals input from the first to third receiving antenna elements by weighting with an amplitude ratio of 1: 1: 1, Of the signals obtained by the branching, a signal that is input from one of the first to third receiving antenna elements and is weighted corresponding to the first term of the amplitude ratio is subjected to a phase rotation of −90 degrees. A weighting unit to be applied, a signal to which the phase rotation is imparted by the weighting unit, and the remaining two of the first to third receiving antenna elements, and a second term of the amplitude ratio by the weighting unit. And a decoding unit that synthesizes and decodes the weighted signals respectively corresponding to the third term, and has a configuration of a wireless communication system.

A wireless communication method according to an aspect of the present invention includes a first communication device including first, second, and third transmission antenna elements, and a second including first, second, and third reception antenna elements. And the first, second, and third transmitting antenna elements and the first, second, and third receiving antenna elements are respectively disposed at opposing positions, and the first to third Among the transmission antenna elements and the first to third reception antenna elements, the channels formed between the transmission antenna elements and the reception antenna elements that are in a mutually opposing arrangement relationship are positioned obliquely to each other The first to third so that the amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element in the positional relationship is 1 and the phase difference between the channels is 90 degrees. The transmitting antenna element and the first To a third receiving antenna element, wherein the signal processing by the second communication device is performed on the signals input from the first to third receiving antenna elements. Each is branched by weighting with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 and input from one of the first to third receiving antenna elements among the signals obtained by the branching And a weighting procedure for applying a -135 degree phase rotation to the weighted signal corresponding to the first term of the amplitude ratio, a signal to which the phase rotation is given by the weighting procedure, and the first to second signals. A decoding procedure for synthesizing and decoding the signals input from the remaining two of the three receiving antenna elements and weighted in accordance with the second and third terms of the amplitude ratio by the weighting procedure; Having a configuration of a wireless communication method, which comprises.

A wireless communication method according to an aspect of the present invention includes a first communication device including first, second, and third transmission antenna elements, and a second including first, second, and third reception antenna elements. And the first, second, and third transmitting antenna elements and the first, second, and third receiving antenna elements are respectively disposed at opposing positions, and the first to third Among the transmission antenna elements and the first to third reception antenna elements, the channels formed between the transmission antenna elements and the reception antenna elements that are in a mutually opposing arrangement relationship are positioned obliquely to each other The amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element in the arrangement relationship is ^{2−1 / 2} , and the phase difference between the channels is 135 degrees. 1 to 3 transmit antenna elements A wireless communication method using a wireless communication system in which a child and the first to third receiving antenna elements are arranged, wherein signal processing by the second communication device is performed from the first to third receiving antenna elements. Each of the inputted signals is branched by weighting with an amplitude ratio of 1: 1: 1, and among the signals obtained by the branching, the signals are inputted from one of the first to third receiving antenna elements and A weighting procedure for applying a -90 degree phase rotation to a weighted signal corresponding to the first term of the amplitude ratio, a signal to which the phase rotation is given by the weighting procedure, and the first to third receptions A decoding procedure for synthesizing and decoding signals input from the remaining two antenna elements and weighted corresponding to the second and third terms of the amplitude ratio by the weighting procedure, respectively. Having a configuration of a wireless communication method characterized.

The present invention can be paraphrased as follows.
That is, the wireless communication device according to one aspect of the present invention includes the first to third transmission antenna elements included in the first communication device and the first to third reception antenna elements included in the second communication device. Each of the transmitting antenna elements arranged in an oblique direction with respect to a channel formed between the transmitting antenna element and the receiving antenna element that are arranged in opposing positions, A wireless communication device arranged so that an amplitude ratio with a channel formed with a receiving antenna element is 1 and a phase difference is 90 degrees, wherein the second communication device includes the first to the first communication devices. Each of the signals input from the third receiving antenna element is branched with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and a phase rotation of −135 degrees is performed on the signal branched with an amplitude ratio of 1 And phase rotation is applied. Weighting means for outputting two signals that are not and a signal to which a phase rotation of −135 degrees is applied, and among the signals output by the weighting means, the input is from the first receiving antenna element and −135 degrees Combining the signal with phase rotation, the signal input from the second receiving antenna element and without phase rotation, and the signal input from the third receiving antenna element and without phase rotation. First decoding means for decoding, a signal output from the second receiving antenna element among the signals output from the weighting means, and a signal to which phase rotation of −135 degrees is given, and the first receiving antenna The second decoding is performed by synthesizing and decoding the signal inputted from the element and not given phase rotation and the signal inputted from the third receiving antenna element and not given phase rotation. And a signal input from the third receiving antenna element to which a phase rotation of -135 degrees is given and a phase rotation inputted from the first receiving antenna element among the signals output from the weighting means And a third decoding means for synthesizing and decoding the signal that has not been phased and the signal that has been input from the second receiving antenna element and has not been subjected to phase rotation. It has a configuration.

The wireless communication device according to one embodiment of the present invention includes first to third transmission antenna elements included in the first communication device and first to third reception antenna elements included in the second communication device. The transmitting antenna elements that are arranged in positions opposite to each other and that are arranged in an oblique direction with respect to a channel that is formed between the transmitting antenna elements and the receiving antenna elements that are in an opposing arrangement relation. And the receiving antenna element are arranged so that an amplitude ratio of a channel is ^{2−1 / 2} and a phase difference is 135 degrees, and the second communication device is Each of the signals input from the first to third receiving antenna elements is branched at an amplitude ratio of 1: 1: 1, and phase rotation of −90 degrees is given to one of the branched signals. Phase rotation is applied Weighting means for outputting two signals that are not and a signal to which a phase rotation of −90 degrees is applied, and among the signals that are output by the weighting means, input from the first receiving antenna element is −90 degrees Combining the signal with phase rotation, the signal input from the second receiving antenna element and without phase rotation, and the signal input from the third receiving antenna element and without phase rotation. Among the signals output from the weighting means, the signal input from the second receiving antenna element and given a phase rotation of -90 degrees, and the first receiving antenna A fifth decoding means for synthesizing and decoding the signal input from the element and not subjected to phase rotation and the signal input from the third receiving antenna element and not subjected to phase rotation; Of the signals output from the weighting means, a signal inputted from the third receiving antenna element and given a phase rotation of −90 degrees, and a signal inputted from the first receiving antenna element and not given a phase rotation And a sixth decoding unit configured to synthesize and decode the signal and a signal input from the second receiving antenna element and not subjected to phase rotation, and having a configuration of a wireless communication device .

The wireless communication method according to one embodiment of the present invention includes the first to third transmission antenna elements included in the first communication device and the first to third reception antenna elements included in the second communication device. Each of the transmitting antenna elements arranged in an oblique direction with respect to a channel formed between the transmitting antenna element and the receiving antenna element that are arranged in opposing positions, A wireless communication method using a wireless communication device arranged so that an amplitude ratio with a channel formed between the receiving antenna element and the phase difference is 90 degrees, wherein the second communication device includes: Each of the signals input from the first to third receiving antenna elements is branched with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and a signal branched with an amplitude ratio of 1 is −135. Phase rotation of degrees A weighting procedure for outputting two signals to which phase rotation is not applied and a signal to which phase rotation of −135 degrees is applied, and among the signals output by the weighting procedure, from the first receiving antenna element An input signal with -135 degree phase rotation applied, a signal input from the second receiving antenna element without phase rotation, and an input from the third receiving antenna element with phase rotation applied. A first decoding procedure for synthesizing and decoding a signal that has not been received, and a signal that has been input from the second receiving antenna element and that has been given a phase rotation of −135 degrees out of the signals output by the weighting procedure, , A signal input from the first receiving antenna element without phase rotation and a signal input from the third receiving antenna element without phase rotation. Among the signals output by the weighting procedure, the signals input from the third receiving antenna element and given a phase rotation of −135 degrees, and A first decoding procedure for synthesizing and decoding a signal input from one receiving antenna element and not subjected to phase rotation and a signal input from the second receiving antenna element and not subjected to phase rotation; It has the structure of the radio | wireless communication method characterized by comprising.

The wireless communication method according to one embodiment of the present invention includes the first to third transmission antenna elements included in the first communication device and the first to third reception antenna elements included in the second communication device. The transmitting antenna elements that are arranged in positions opposite to each other and that are arranged in an oblique direction with respect to a channel that is formed between the transmitting antenna elements and the receiving antenna elements that are in an opposing arrangement relation. And a radio communication method using a radio communication device arranged so that an amplitude ratio of a channel formed between the receiving antenna element and the receiving antenna element is 2 ^-1/2 and a phase difference is 135 degrees, Of the first to third receiving antenna elements branches each signal with an amplitude ratio of 1: 1: 1, and one of the branched signals has a phase of -90 degrees. Give rotation, A weighting procedure for outputting two signals to which phase rotation is not applied and a signal to which phase rotation of −90 degrees is applied, and among the signals output by the weighting procedure, from the first receiving antenna element An input signal with -90 degree phase rotation, a signal input from the second receiving antenna element and no phase rotation, and a phase rotation input from the third receiving antenna element A fourth decoding procedure for synthesizing and decoding a signal that has not been received, and a signal that has been input from the second receiving antenna element and that has been given a phase rotation of -90 degrees out of the signals output by the weighting procedure, The signal input from the first receiving antenna element and not subjected to phase rotation is combined with the signal input from the third receiving antenna element and not subjected to phase rotation. Among the signals output by the weighting procedure, the signal input from the third receiving antenna element and given the phase rotation of −90 degrees, and the first reception And a sixth decoding procedure for synthesizing and decoding the signal input from the antenna element and not subjected to phase rotation and the signal input from the second reception antenna element and not subjected to phase rotation. The configuration of the wireless communication method is characterized.

  According to the present invention, a weight calculation circuit can be configured only with an analog device, and an increase in hardware scale and power consumption can be suppressed. Therefore, it is possible to realize short-distance transmission by signal processing with a smaller load.

It is a block diagram which shows schematic structure of the radio | wireless communications system by 1st Embodiment of this invention. It is explanatory drawing which shows the mode of the signal synthesis | combination in the combiner | synthesizer of the radio | wireless communications system by the embodiment. It is a flowchart which shows the process sequence which determines arrangement | positioning of the antenna element in the radio | wireless communications system by the embodiment. It is a flowchart which shows the process sequence which determines arrangement | positioning of the antenna element in the radio | wireless communications system by 2nd Embodiment of this invention. It is a block diagram which shows schematic structure of the modification of the radio | wireless communications system by 1st Embodiment or 2nd Embodiment of this invention. It is explanatory drawing which shows the example of arrangement | positioning of the antenna element in short distance MIMO transmission. It is a model diagram of 3 × 3 short-range MIMO transmission.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<First Embodiment>
[Description of configuration]
FIG. 1 is a configuration diagram showing a schematic configuration of a wireless communication system 1 according to the first embodiment of the present invention. The wireless communication system 1 is configured to perform data communication by transmitting three data sequences S1, S2, and S3 from the communication device 100 to the communication device 200 by 3 × 3 MIMO (three-input three-output MIMO) transmission. ing.

  Specifically, the wireless communication system 1 includes a communication device 100 (first communication device) and a communication device 200 (second communication device). The communication device 100 transmits three data series S1, S2, and S3. In the present embodiment, since the communication device 100 does not need to perform signal weighting, a general communication device in 3 × 3 MIMO near field communication can be used as the communication device 100. The communication device 100 includes transmission units 111, 112, and 113 and transmission antenna elements 121, 122, and 123. The transmission antenna elements 121, 122, and 123 are connected to the output units of the transmission units 111, 112, and 113, respectively.

  The communication device 200 extracts and demodulates each series of data from the signal transmitted from the communication device 100. The communication device 200 includes receiving antenna elements 211, 212, and 213, a weight calculation circuit 220, and receiving units 231, 232, and 233. The weight calculation circuit 220 includes distributors 2211, 2122, 2213, phase shifters 2221, 2222, 2223, and combiners 2231, 2232, 2233.

  Here, the receiving antenna element 211 is connected to the input unit of the distributor 2211. The first output unit of distributor 2211 is connected to the input unit of phase shifter 2221, and the second output unit and third output unit of distributor 2211 are the first input unit of combiner 2232 and combiner 2233, respectively. Is connected to the first input section. The output unit of the phase shifter 2221 is connected to the first input unit of the synthesizer 2231. The output unit of the combiner 2231 is connected to the input unit of the receiving unit 231.

  The receiving antenna element 212 is connected to the input unit of the distributor 2212. The second output unit of distributor 2212 is connected to the input unit of phase shifter 2222, and the first output unit and third output unit of distributor 2212 are the second input unit of combiner 2231 and combiner 2233, respectively. Connected to the second input section. The output unit of the phase shifter 2222 is connected to the second input unit of the combiner 2232. The output unit of the combiner 2232 is connected to the input unit of the receiving unit 232.

  The receiving antenna element 213 is connected to the input unit of the distributor 2213. The third output unit of distributor 2213 is connected to the input unit of phase shifter 2223, and the first output unit and second output unit of distributor 2213 are the third input unit of combiner 2231 and combiner 2232, respectively. To the third input unit. The output unit of the phase shifter 2223 is connected to the third input unit of the synthesizer 2233. The output unit of the combiner 2233 is connected to the input unit of the receiving unit 233.

  The transmitting antenna elements 121, 122, 123 are arranged on a plane corresponding to the plane PT shown in FIG. 6, and the receiving antenna elements 211, 212, 213 are on a plane corresponding to the plane PR shown in FIG. Is arranged. Hereinafter, an antenna having a plurality of antenna elements arranged on the same plane is referred to as an array antenna. The transmission antenna elements 121, 122, and 123 constitute a transmission array antenna 120, and the reception antenna elements 211, 212, and 213 constitute a reception array antenna 210.

Here, in this embodiment, the transmission antenna element 121, the transmission antenna element 122, and the transmission antenna element 123 correspond to the transmission antenna elements Tx _{1 to} Tx ₃ shown in FIG. 7 described above, and are mutually optimal elements in the same plane. They are arranged at positions separated by a distance dopt. That is, the transmission antenna element 121, the transmission antenna element 122, and the transmission antenna element 123 are located at the apexes of an equilateral triangle whose one side length corresponds to the optimum element interval dott. The optimum element interval dopt is a predetermined distance determined according to the distance between the transmitting array antenna 120 and the receiving array antenna 210, that is, the transmission / reception interval D (the distance at which the channel capacity in the EM-BF of MIMO transmission is maximized, Alternatively, the distance at which the channel capacity in the ZF of MIMO transmission is maximized), and the channel matrix H at this time is expressed by the above equation (5).

If the antenna elements are arranged so as to satisfy Expression (5), the distance between the antenna elements at that time becomes a predetermined optimum element interval dopt that maximizes the channel capacity in the EM-BF or ZF of MIMO transmission. . Specifically, a channel formed between a transmitting antenna element and a receiving antenna element that are in an arrangement relationship facing each other, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction with respect to each other Phase difference between the channel formed between them and θ _H (= tan ⁻¹ (h ₂₁ / h ₁₁ ) = tan ⁻¹ (h ₃₁ / h ₁₁ ) = tan ⁻¹ (h ₁₂ / h ₂₂ ) = tan ⁻¹ (h ₃₂ / h ₂₂ ) = tan ⁻¹ (h ₁₃ / h ₃₃ ) = tan ⁻¹ (h ₂₃ / h ₃₃ )) is −90 degrees, and transmissions are in an arrangement relationship facing each other. The amplitude ratio between the channel formed between the antenna element and the receiving antenna element and the channel formed between the transmitting antenna element and the receiving antenna element that are disposed in an oblique direction with respect to each other is 1. Like Each antenna element may be arranged in the box. In the present embodiment, the transmission array antenna 120 and the reception array antenna 210 are arranged so as to satisfy Expression (5).

The reception antenna element 211, the reception antenna element 212, and the reception antenna element 213 correspond to the reception antenna elements Rx _{1 to} Rx ₃ shown in FIG. 7, and the transmission antenna element 121, the transmission antenna element 122, and the transmission described above. Similar to the antenna element 123, the antenna elements 123 are arranged at positions separated from each other by the optimum element interval dopt in the same plane. In other words, the receiving antenna element 211, the receiving antenna element 212, and the receiving antenna element 213 are positioned at the apexes of an equilateral triangle whose side length corresponds to the optimum element interval dott.

  The receiving antenna elements 211, 212, and 213 are arranged at positions facing the transmitting antenna elements 121, 122, and 123, respectively. That is, the receiving antenna element 211 is disposed at a position facing the transmitting antenna element 121 and spaced from the transmitting antenna element 121 by a transmission / reception interval D. The receiving antenna element 212 is disposed at a position facing the transmitting antenna element 122 and spaced from the transmitting antenna element 122 by a transmission / reception interval D. Further, the reception antenna element 213 is disposed at a position facing the transmission antenna element 123 and separated from the transmission antenna element 123 by a transmission / reception interval D.

  In the present embodiment, a case where the wireless communication system 1 performs data communication from the communication device 100 to the communication device 200 will be described as an example. In addition, the wireless communication system 1 is changed from the communication device 200 to the communication device 100. Data communication may be performed. In this case, various methods can be used as a communication method from the communication device 200 to the communication device 100. For example, the communication from the communication device 200 to the communication device 100 may be performed using the communication method to which the present invention is applied, similarly to the communication from the communication device 100 to the communication device 200. The communication method may be used.

[Description of operation]
The communication device 100 transmits three series of data series S1, S2, and S3. Specifically, the transmission unit 111 included in the communication apparatus 100 acquires the data sequence S1, performs processing such as encoding and modulation, generates a transmission signal of the data sequence S1, and transmits the generated transmission signal. Output to the antenna element 121. Similarly, the transmission unit 112 acquires the data sequence S 2, performs processing such as encoding and modulation, generates a transmission signal of the data sequence S 2, and outputs the generated transmission signal to the transmission antenna element 122. Similarly, the transmission unit 113 acquires the data sequence S3, performs processing such as encoding and modulation, generates a transmission signal of the data sequence S3, and outputs the generated transmission signal to the transmission antenna element 123. Here, the data series S1, the data series S2, and the data series S3 may be independent from each other or may be series having correlation.

  The transmission antenna element 121 wirelessly transmits the transmission signal output from the transmission unit 111. Similarly, the transmission antenna element 122 wirelessly transmits the transmission signal output from the transmission unit 112, and the transmission antenna element 123 wirelessly transmits the transmission signal output from the transmission unit 113.

  The communication device 200 extracts and demodulates each series of data from the signal transmitted from the communication device 100. Specifically, the reception antenna element 211, the reception antenna element 212, and the reception antenna element 213 all include a radio signal transmitted from the transmission antenna element 121, a radio signal transmitted from the transmission antenna element 122, and a transmission The radio signal transmitted from the antenna element 123 is received as a radio signal in which all radio signals are combined. That is, each of the reception antenna elements 211, 212, 213 receives all the radio signals of the data series S 1, S 2, S 3 transmitted from the transmission antenna elements 121, 122, 123 and outputs them to the weight calculation circuit 220. Specifically, the receiving antenna elements 211, 212, and 213 output the received signals to the distributors 2211, 2122, and 2213 in the weight calculation circuit 220, respectively.

The weight calculation circuit 220 separates the signals of each data series by performing distribution, phase rotation, and synthesis on the signals received by the receiving antenna elements 211, 212, and 213, respectively. Specifically, the divider 2211 included in the weight calculation circuit 220 divides the signal received by the receiving antenna element 211 into three, and outputs the signal to the phase shifter 2221, the combiner 2232, and the combiner 2233. At this time, distributor 2211 has an amplitude ratio of a signal output to phase shifter 2221, a signal output to combiner 2232, and a signal output to combiner 2233 as 1: 2 ^−1/2 : 2 ^−1/2 . Distribute to

The distributor 2212 divides the signal received by the receiving antenna element 212 into three and outputs it to the phase shifter 2222, the combiner 2231, and the combiner 2233. At this time, the distributor 2212 has an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 between the signal output to the phase shifter 2222, the signal output to the combiner 2231, and the signal output to the combiner 2233. Distribute to The distributor 2213 distributes the signal received by the receiving antenna element 213 into three and outputs the signal to the phase shifter 2223, the combiner 2231, and the combiner 2232. At this time, the distributor 2213 has an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 between the signal output to the phase shifter 2223, the signal output to the combiner 2231, and the signal output to the combiner 2232. Distribute to

  The phase shifter 2221 gives a phase rotation of −135 degrees to the signal distributed from the distributor 2211 (that is, delays the phase by 135 degrees), and outputs it to the combiner 2231. In addition, the phase shifter 2222 gives a phase rotation of −135 degrees to the signal distributed from the distributor 2212 and outputs it to the combiner 2232. Further, the phase shifter 2223 gives a phase rotation of −135 degrees to the signal distributed from the distributor 2213 and outputs it to the combiner 2233.

Here, distributors 2211, 2122, 2213 and phase shifters 2221, 2222, 2223 convert signals input from receiving antenna elements 211, 212, 213 to 1: 2 ^−1/2 : 2 ^−1/2. The signal is branched by weighting with a predetermined amplitude ratio, and the signal obtained by this branching is input from one of the receiving antenna elements 211, 212, 213, and corresponds to the first term “1” of the amplitude ratio. A weighting unit is provided that applies a -135 degree phase rotation to the weighted signal. Among these, the distributor 2211 and the phase shifter 2221 constitute a first weighting unit, the distributor 2212 and the phase shifter 2222 constitute a second weighting unit, and the distributor 2213 and the phase shifter 2223 Constitutes a third weighting unit.

According to the first weighting unit, the distributor 2211 distributes the signal input from the receiving antenna element 211 into three at the amplitude ratio. Then, the phase shifter 2221 gives a phase rotation of −135 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals divided into three by the distributor 2211. Output to the synthesizer 2231, and a phase rotation is applied to the weighted signals corresponding to the second term “2 ^−1/2 ” and the third term “2 ^−1/2 ” of the amplitude ratio. Without output to the combiners 2232 and 2233, respectively.

According to the second weighting unit, the divider 2212 divides the signal input from the receiving antenna element 212 into three at the amplitude ratio. Then, the phase shifter 2222 gives a phase rotation of −135 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals divided into three by the distributor 2212. Output to the synthesizer 2232, and a phase rotation is applied to the weighted signals corresponding to the second term “2 ^−1/2 ” and the third term “2 ^−1/2 ” of the amplitude ratio. Without output to the combiners 2231 and 2233, respectively.

According to the third weighting unit, the divider 2213 divides the signal input from the receiving antenna element 213 into three at the amplitude ratio. Then, the phase shifter 2223 gives a phase rotation of −135 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals distributed by the distributor 2213. Output to the synthesizer 2233, and a phase rotation is applied to the weighted signals corresponding to the second term “2 ^−1/2 ” and the third term “2 ^−1/2 ” of the amplitude ratio. Without output to the combiners 2231 and 2232, respectively.

  The combiner 2231 combines the signal input from the phase shifter 2221, the signal distributed from the distributor 2212, and the signal distributed from the distributor 2213. Signal synthesis here is signal superposition (addition). The same applies to the synthesis of signals by the synthesizers 2232 and 2233 below. The combiner 2231 generates a signal of the data sequence S1 ′ corresponding to the signal of the data sequence S1 transmitted by the transmission antenna element 121 by the combination. The combiner 2231 outputs the signal obtained by the combination to the receiving unit 231.

  Similarly, the combiner 2232 combines the signal input from the phase shifter 2222, the signal distributed from the distributor 2211, and the signal distributed from the distributor 2213. The combiner 2232 generates a signal of the data sequence S2 ′ corresponding to the signal of the data sequence S2 transmitted by the transmission antenna element 122 by the combination. The combiner 2232 outputs the signal obtained by the combining to the receiving unit 232.

  Similarly, the combiner 2233 combines the signal input from the phase shifter 2223, the signal distributed from the distributor 2211, and the signal distributed from the distributor 2212. The combiner 2233 generates a signal of the data sequence S3 ′ corresponding to the signal of the data sequence S3 transmitted by the transmission antenna element 123 by the combination. The combiner 2233 outputs the signal obtained by combining to the receiving unit 233.

  The receiving unit 231 performs processing such as demodulation and decoding on the signal of the data sequence S1 'input from the combiner 2231 to generate data of the data sequence S1'. The receiving unit 232 performs processing such as demodulation and decoding on the signal of the data series S2 'input from the combiner 2232, and generates data of the data series S2'. The receiving unit 233 performs processing such as demodulation and decoding on the signal of the data series S3 'input from the combiner 2233, and generates data of the data series S3'.

Here, the synthesizers 2231, 2232, 2233 and the receiving units 231, 232, 233 are input from one of the receiving antenna elements 211, 212, 213, and are converted into the first term “1” of the amplitude ratio by the weighting unit. The corresponding weighted signal having the phase rotation applied thereto and the remaining two of the receiving antenna elements 211, 212, and 213 are input and the weighting unit ^applies the second term “2 ^−1/2 ” of the amplitude ratio. ”And a signal weighted corresponding to the third term“ 2 ^−1/2 ”, respectively, to compose a decoding unit. Among these, the synthesizer 2231 and the receiving unit 231 constitute a first decoding unit, the synthesizer 2232 and the receiving unit 232 constitute a second decoding unit, and the synthesizer 2233 and the receiving unit 233 form a third decoding unit. The decoding unit is configured.

The first decoding unit is input from the receiving antenna element 211 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −135 degrees. , The signal input from the receiving antenna element 212 and weighted corresponding to the second term “2 ^−1/2 ” of the amplitude ratio, and the third term of the amplitude ratio input from the receiving antenna element 213. The weighted signal corresponding to “2 ^−1/2 ” is synthesized and decoded.

The second decoding unit is input from the receiving antenna element 212 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −135 degrees. , The signal input from the receiving antenna element 211 and weighted corresponding to the second term “2 ^−1/2 ” of the amplitude ratio, and the third term of the amplitude ratio input from the receiving antenna element 213. The weighted signal corresponding to “2 ^−1/2 ” is synthesized and decoded.

The third decoding unit is input from the receiving antenna element 213 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −135 degrees. , The signal input from the receiving antenna element 211 and weighted corresponding to the second term “2 ^−1/2 ” of the amplitude ratio, and the third term of the amplitude ratio input from the receiving antenna element 212. The weighted signal corresponding to “2 ^−1/2 ” is synthesized and decoded.

According to the configuration of the present embodiment described above, the distributors 2211, 2122, 2213, the phase shifters 2221, 2222, 2223, and the combiners 2231, 2232, 2233 can be realized using analog devices. By using an analog device, it is possible to realize matrix calculation processing equivalent to the reception weight matrix W _ZF in ZF shown in the above equation (7). In addition, since the antenna elements constituting each of the transmission array antenna 120 and the reception array antenna 210 are arranged with the optimum element spacing dopt so as to satisfy the equation (5), the characteristics of the EM-BF and the characteristics of the ZF are Almost matches. Therefore, according to the wireless communication system 1, the arithmetic processing required for the digital signal processing of ZF or EM-BF can be omitted, and the same channel capacity as in the case of ZF or EM-BF can be obtained.

  In the configuration of FIG. 1, the receiving-side communication device 200 includes the weight calculating circuit 220. However, the weight calculating circuit 220 is provided in the transmitting-side communication device 100, and the receiving-side communication device 200 receives the weight calculating circuit. 220 may be deleted, and the receiving antenna elements 211, 212, and 213 and the receiving units 231, 232, and 233 may be directly connected.

Next, with reference to FIG. 2, a mechanism for extracting a desired signal and removing an interference signal, which is performed by combining signals in the combiners 2231, 2232, and 2233 described above, will be described. Here, the synthesis of signals in the synthesizer 2231 in FIG. 1 will be described as an example.
FIG. 2 is an explanatory diagram illustrating how signals are combined in the combiner 2231 of the wireless communication system 1.
The signal of the data series S1 transmitted from the transmitting antenna element 121 (desired signal component for the receiving antenna element 211) is received by the receiving antenna elements 211, 212, and 213, respectively, and is distributed by the weight calculation circuit 220 described above. And input to the combiner 2231 after the phase rotation process. Further, each signal of the other data series S2 and S3 transmitted from the other transmitting antenna element 122 and the transmitting antenna element 123 (interference signal component for the receiving antenna element 211) is received by the receiving antenna elements 211, 212, 213 and received by the combiner 2231 after the above-described distribution and phase rotation processing. That is, the synthesizer 2231 receives three signals: a signal input from the phase shifter 2221, a signal distributed from the distributor 2212, and a signal distributed from the distributor 2213.

  Here, when the state of synthesis of the desired signal component in the synthesizer 2231 is seen on the IQ plane shown in FIG. 2A, the three signals input to the synthesizer 2231 (the signal input from the phase shifter 2221) The desired signal component of the signal distributed from the distributor 2212 and the signal distributed from the distributor 2213 is strengthened by vector synthesis. In the example of FIG. 2A, the vector VC1 represents the signal component input from the phase shifter 2221, and the vector VC2 and the vector VC3 are the signal component distributed from the distributor 2212 and the signal component distributed from the distributor 2213, respectively. The vector VC4 represents a combined vector of the vectors VC1, VC2 and VC3. As shown by the vector VC4, the synthesizer 2231 combines the signal input from the phase shifter 2221, the signal distributed from the distributor 2212, and the signal distributed from the distributor 2213, thereby obtaining the data sequence S1. A signal having a large amplitude is obtained as a desired signal component corresponding to.

  On the other hand, when the state of the synthesis of the interference signal components in the combiner 2231 is seen on the IQ plane shown in FIG. 2B, the interference signal components cancel each other out by vector synthesis, and the amplitude becomes zero. FIG. 2B shows a vector of interference signal components by each signal of the data series S2 transmitted from the transmission antenna element 122 or the data series S3 transmitted from the transmission antenna element 123.

  Here, the synthesis of interference signal components by the signal of the data series S2 transmitted from the transmission antenna element 122 will be described as an example. In this case, in FIG. 2B, a vector VCA represents an interference signal component when a signal transmitted from the transmission antenna element 122 is received by the reception antenna element 211, and a vector VCB is transmitted from the transmission antenna element 122. Represents the interference signal component when the received signal is received by the receiving antenna element 212, and the vector VCC represents the interference signal component when the signal transmitted from the transmitting antenna element 122 is received by the receiving antenna element 213. Yes.

  Among these, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 211 is − on the channel as indicated by the element “−j” in the first row and the second column of the above-described equation (5). The signal is received by the receiving antenna element 211 with a phase rotation of 90 degrees. The received signal is weighted by the distributor 2211 corresponding to the first term “1” of the amplitude ratio and input to the phase shifter 2221. The phase shifter 2221 further outputs a phase of −135 degrees. The rotation is given and supplied to the combiner 2231. As a result, as indicated by the vector VCA in FIG. 2B, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 211 is given an amplitude of “1” and a phase rotation of −225 degrees. Expressed as an interference signal component.

On the other hand, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 212 has a phase on the channel as indicated by the element “1” in the second row and second column of the above equation (5). No rotation is given, and the weight corresponding to the second term “1 ^{/ 2−1} / ² ” of the amplitude ratio is given by the distributor 2212 and supplied to the combiner 2231. As a result, as shown in the vector VCB in FIG. 2B, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 212 has an amplitude of “1 ^{/ 2−1} / ² ” and 0 degree. It is expressed as an interference signal component to which phase rotation is applied.

In addition, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 213 is −90 on the channel as indicated by the element “−j” in the third row and second column of Equation (5) described above. The distributor 2213 assigns a weight corresponding to the third term “1 ^{/ 2−1} / ² ” of the amplitude ratio and supplies it to the combiner 2231. As a result, as indicated by the vector VCC in FIG. 2B, the signal transmitted from the transmitting antenna element 122 and received by the receiving antenna element 213 has an amplitude of “1 ^{/ 2−1} / ² ” and −90 degrees. It is expressed as an interference signal component to which the phase rotation is given.

  Here, the length of the combined vector obtained by combining the three vectors VCA, VCB, and VCC is zero. That is, the interference signal components transmitted from the transmitting antenna element 122 and received by the receiving antenna elements 211, 212, and 213 are canceled by the signal combining in the combiner 2231 and become zero. Similarly, the interference signal components transmitted from the transmitting antenna element 123 and received by the receiving antenna elements 211, 212, and 213 are canceled by the signal combining in the combiner 2231 and become zero. Thereby, only the desired signal component transmitted from the transmitting antenna element 121 is extracted as a signal of the data series S1 'by the combiner 2231. Similarly, in the combiners 2232 and 2233, the interference signal components are canceled by signal combining, and the desired signal components transmitted from the transmission antenna elements 122 and 123, respectively, are transmitted to the data series S2 ′ and S3 ′ by the combiners 2232 and 2233. Extracted as a signal.

Next, with reference to FIG. 3, a method for determining the arrangement of the antenna elements of the transmission antenna elements 121, 122, 123 and the reception antenna elements 211, 212, 213 will be described.
FIG. 3 is a flowchart showing a processing procedure for determining the arrangement of the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 in the wireless communication system 1. Schematically, the arrangement of the transmission antenna elements 121, 122, and 123 and the reception antenna elements 211, 212, and 213 is determined so that the channel propagation characteristics shown in the above equation (5) can be obtained.

First, the transmission / reception interval D in the environment where the wireless communication system 1 is used is determined (step S11). For example, when data communication is performed across a wall of a building, transmitting antenna elements 121, 122, and 123 and receiving antenna elements 211, 212, and 213 are arranged to face each other on both surfaces of the wall. In this case, the wall thickness is determined as the transmission / reception interval D.
Next, while gradually changing the antenna element interval d, the amplitude ratio and phase difference of each propagation channel between the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 in each antenna element interval d θ _H is estimated (step S12).

  The channel matrix between the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 is searched for an antenna element interval dopt that satisfies the channel matrix H represented by the equation (5). The antenna element interval d is set to the optimum element interval dopt obtained by the search. Thereby, the arrangement of the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 is determined so that the channel matrix between the transmitting and receiving antenna elements satisfies the channel matrix H represented by the equation (5). Is done.

  As described above, according to the wireless communication system 1, the processing equivalent to the matrix operation represented by the equation (7) can be performed without performing a complicated matrix operation, and therefore the equation (5) is satisfied. If the arrangement of the transmission / reception antennas is determined as described above, the characteristics of the EM-BF and the characteristics of the ZF substantially coincide with each other, and the data of each series can be separated on the reception side without causing interference. Therefore, near field MIMO transmission can be realized by signal processing with a smaller load. Therefore, according to the present embodiment, it is possible to configure a wait calculation circuit with only analog devices, and it is possible to suppress an increase in hardware scale and power consumption.

<Second Embodiment>
Next, the second embodiment of the present invention will be described with reference to the drawings in the first embodiment.
In the first embodiment described above, each antenna element is arranged so that the channel matrix between the transmitting and receiving antenna elements is a channel matrix represented by Expression (5), and the weight 2210 of the communication apparatus 200 is configured to have a distributor 2211. , 2212, 2213, phase shifters 2221, 2222, 2223, and combiners 2231, 2232, 2233, a reception weight matrix equivalent to the reception weight matrix W _ZF in ZF shown in equation (7) is obtained. However, in the second embodiment, the antenna elements are arranged so that the channel matrix between the transmitting and receiving antenna elements becomes the channel matrix represented by the above-described equation (6), and distributed in the weight calculation circuit 220 of the communication device 200. The devices 2211, 2122, 2213, phase shifters 2221, 222, 2223, and combiners 2231, 2232, 2233 are used. There are as configured to obtain a reception weight matrix _{W ZF} equivalent receive weight matrix in the ZF shown in equation (8), performs a 3 × 3 short range MIMO transmission. However, in this embodiment, since it is necessary to obtain a reception weight matrix equivalent to the reception weight matrix W _ZF shown in Expression (8), the value of the amplitude ratio used in signal distribution by the distributors 2211, 2122, and 2213 as described later. And the value of the phase rotation given to the signal in the phase shifters 2221, 2222, 2223 is different from that in the first embodiment.

In this embodiment, regarding the arrangement of the antenna elements, specifically, the channels formed between the transmitting antenna elements and the receiving antenna elements that are in a mutually opposing arrangement relationship, and the arrangement relation that is positioned obliquely to each other The phase difference θ _H (= tan ⁻¹ (h ₂₁ / h ₁₁ ) = tan ⁻¹ (h ₃₁ / h ₁₁ ) = tan between the channel formed between the transmitting antenna element and the receiving antenna element in FIG. ⁻¹ (h ₁₂ / h ₂₂ ) = tan ⁻¹ (h ₃₂ / h ₂₂ ) = tan ⁻¹ (h ₁₃ / h ₃₃ ) = tan ⁻¹ (h ₂₃ / h ₃₃ )) is −135 degrees, In addition, a channel formed between the transmitting antenna element and the receiving antenna element that are in an arrangement relationship facing each other, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction with respect to each other The antenna elements are arranged so that the amplitude ratio with the channel formed between them is 2 ^-1/2 . In the present embodiment, the transmission array antenna 120 and the reception array antenna 210 are arranged so as to satisfy Expression (6).

  In this embodiment, the divider 2211 included in the weight calculation circuit 220 divides the signal received by the receiving antenna element 211 into three and outputs the signal to the phase shifter 2221, the combiner 2232, and the combiner 2233. At this time, the distributor 2211 distributes the signals so that the amplitude ratio of the signal output to the phase shifter 2221, the signal output to the combiner 2232, and the signal output to the combiner 2233 is 1: 1: 1. The distributor 2212 distributes the signal received by the receiving antenna element 212 into three and outputs the signal to the phase shifter 2222, the combiner 2231, and the combiner 2233. At this time, the distributor 2212 distributes the signals so that the amplitude ratio of the signal output to the phase shifter 2222, the signal output to the combiner 2231, and the signal output to the combiner 2233 is 1: 1: 1. Further, distributor 2213 distributes the signal received by receiving antenna element 213 into three, and outputs the signal to phase shifter 2223, combiner 2231, and combiner 2232. At this time, the distributor 2213 distributes the signals so that the amplitude ratio of the signal output to the phase shifter 2223, the signal output to the combiner 2231, and the signal output to the combiner 2232 is 1: 1: 1.

  Further, in this embodiment, the phase shifter 2221 gives a phase rotation of −90 degrees to the signal input from the distributor 2211 (that is, delays the phase by 90 degrees) to the combiner 2231. Output. In addition, the phase shifter 2222 gives a phase rotation of −90 degrees to the signal input from the distributor 2212 and outputs it to the combiner 2232. Further, the phase shifter 2223 gives a phase rotation of −90 degrees to the signal input from the distributor 2213 and outputs it to the combiner 2233.

  Here, distributors 211, 212, and 213 and phase shifters 2221, 212, and 2213 branch by weighting each of the signals input from receiving antenna elements 211, 212, and 213 with an amplitude ratio of 1: 1: 1. Of the signals obtained by this branching, the signal input from one of the receiving antenna elements 211, 212, and 213 and weighted corresponding to the first term of the amplitude ratio is subjected to phase rotation of −90 degrees. A weighting unit to be assigned is configured. Among these, the divider 2211 and the phase shifter 2221 constitute a fourth weighting unit, and the divider 2212 and the phase shifter 2222 constitute a fifth weighting unit, and the divider 2213 and the phase shifter 2223 Constitutes a sixth weighting unit.

  According to the fourth weighting unit, the divider 2211 divides the signal input from the receiving antenna element 211 into three at the amplitude ratio “1: 1: 1”. In addition, the phase shifter 2221 gives a phase rotation of −90 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals divided into three by the distributor 2211. To the combiner 2231. The weighted signals corresponding to the second term “1” and the third term “1” of the amplitude ratio are output to the combiners 2232 and 2233, respectively, without applying phase rotation.

  Further, according to the fifth weighting unit, the distributor 2212 distributes the signal input from the receiving antenna element 212 into three at the amplitude ratio “1: 1: 1”. Further, the phase shifter 2222 gives a phase rotation of −90 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals distributed by the distributor 2212 in three. Output to the combiner 2232. The weighted signals corresponding to the second term “1” and the third term “1” of the amplitude ratio are respectively output to the combiners 2231 and 2233 without being subjected to phase rotation.

  Further, according to the sixth weighting unit, the distributor 2213 distributes the signal input from the receiving antenna element 213 into three at the amplitude ratio “1: 1: 1”. In addition, the phase shifter 2223 gives a phase rotation of −90 degrees to the signal weighted corresponding to the first term “1” of the amplitude ratio among the signals divided into three by the distributor 2213. And output to the combiner 2233. The weighted signals corresponding to the second term “1” and the third term “1” of the amplitude ratio are output to the combiners 2231 and 2232 without being subjected to phase rotation.

  The combiner 2231 combines the signal input from the phase shifter 2221, the signal input from the distributor 2212, and the signal input from the distributor 2213. The combiner 2231 generates a signal of the data sequence S1 ′ corresponding to the signal of the data sequence S1 transmitted by the transmission antenna element 121 by the combination. The combiner 2231 outputs the signal obtained by the combination to the receiving unit 231.

  Similarly, the combiner 2232 combines the signal input from the phase shifter 2222, the signal input from the distributor 2211, and the signal input from the distributor 2213. The combiner 2232 generates a signal of the data sequence S2 ′ corresponding to the signal of the data sequence S2 transmitted by the transmission antenna element 122 by the combination. The combiner 2232 outputs the signal obtained by the combining to the receiving unit 232.

  Similarly, the combiner 2233 combines the signal output from the phase shifter 2223, the signal output from the distributor 2211, and the signal output from the distributor 2212. The combiner 2233 generates a signal of the data sequence S3 ′ corresponding to the signal of the data sequence S3 transmitted by the transmission antenna element 123 by the combination. The combiner 2233 outputs the signal obtained by combining to the receiving unit 233.

  Also in the present embodiment, the combiners 2231, 2232, 2233 and the receiving units 231, 232, 233 are inputted from one of the receiving antenna elements 211, 212, 213, and the first term “ 1 ”and the second phase“ 1 ”of the amplitude ratio input from the remaining two of the receiving antenna elements 211, 212, and 213 by the weighting unit. And a decoding unit configured to synthesize and decode the weighted signals respectively corresponding to the third term “1”. Among these, the synthesizer 2231 and the receiving unit 231 form a fourth decoding unit, the synthesizer 2232 and the receiving unit 232 form a fifth decoding unit, and the synthesizer 2233 and the receiving unit 233 form a sixth decoding unit. The decoding unit is configured.

  The fourth decoding unit is input from the receiving antenna element 211 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −90 degrees. And the weighted signal corresponding to the second term “1” of the amplitude ratio inputted from the receiving antenna element 212 and the third term “1” of the amplitude ratio inputted from the receiving antenna element 213. The corresponding weighted signal is synthesized and decoded.

  The fifth decoding unit is input from the receiving antenna element 212 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −90 degrees. And the weighted signal corresponding to the second term “1” of the amplitude ratio inputted from the receiving antenna element 211 and the third term “1” of the amplitude ratio inputted from the receiving antenna element 213. The corresponding weighted signal is synthesized and decoded.

  The sixth decoding unit is input from the receiving antenna element 213 among the signals branched by the weighting unit, is weighted corresponding to the first term “1” of the amplitude ratio, and is given a phase rotation of −90 degrees. And the weighted signal corresponding to the second term “1” of the amplitude ratio inputted from the receiving antenna element 211 and the third term “1” of the amplitude ratio inputted from the receiving antenna element 212. The corresponding weighted signal is synthesized and decoded.

Other configurations are the same as those in the first embodiment.
Similarly to the first embodiment, the weight calculation circuit 220 included in the communication device 200 on the reception side is provided in the communication device 100 on the transmission side, and the weight calculation circuit 220 is deleted from the communication device 200 on the reception side. The antenna elements 211, 212, 213 and the receiving units 231, 232, 233 may be directly connected.

According to the configuration of the second embodiment described above, the distributors 2211, 2122, 2213, the phase shifters 2221, 2222, 2223, and the combiners 2231, 2232, 2233 can be realized using analog devices, By using these analog devices, it is possible to realize matrix calculation processing equivalent to the reception weight matrix W _ZF in the ZF shown in the above equation (8). In addition, since the antenna elements constituting each of the transmission array antenna 120 and the reception array antenna 210 are arranged with the optimum element spacing dopt so as to satisfy the equation (6), the characteristics of the EM-BF and the characteristics of the ZF are Almost matches. Therefore, according to the wireless communication system according to the present embodiment, similarly to the first embodiment, the arithmetic processing required for the digital signal processing of ZF or EM-BF can be omitted, and the same channel as in the case of ZF or EM-BF. Capacity can be obtained. Therefore, according to the present embodiment, it is possible to configure a wait calculation circuit with only analog devices, and it is possible to suppress an increase in hardware scale and power consumption.

Next, a method for determining the arrangement of antenna elements will be described with reference to FIG.
FIG. 4 is a flowchart showing a processing procedure for determining the arrangement of the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 in the wireless communication system according to the present embodiment. Schematically, the arrangement of the transmission antenna elements 121, 122, 123 and the reception antenna elements 211, 212, 213 is determined so that the channel propagation characteristics shown in the above equation (6) can be obtained.

First, the transmission / reception interval D in the environment where the wireless communication system according to the present embodiment is used is determined (step S21). For example, when data communication is performed across a wall of a building, transmitting antenna elements 121, 122, and 123 and receiving antenna elements 211, 212, and 213 are arranged to face each other on both surfaces of the wall. In this case, the wall thickness is determined as the transmission / reception interval D.
Next, while gradually changing the antenna element interval d, the amplitude ratio and phase difference of each propagation channel between the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 in each antenna element interval d θ _H is estimated (step S22).

  The channel matrix between the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 is searched for an antenna element interval dopt that satisfies the channel matrix H represented by the equation (6). The antenna element interval d is set to the optimum element interval dopt obtained by the search. Thereby, the arrangement of the transmitting antenna elements 121, 122, 123 and the receiving antenna elements 211, 212, 213 is determined so that the channel matrix between the transmitting and receiving antenna elements satisfies the channel matrix H represented by the equation (6). Is done.

  As described above, also in the present embodiment, the processing equivalent to the matrix operation represented by the equation (8) can be performed without performing a complicated matrix operation, so that the equation (6) is satisfied. If the arrangement of the transmission / reception antennas is determined, the characteristics of the EM-BF and the characteristics of the ZF substantially coincide with each other, and the data of each series can be separated without causing interference. Therefore, near field MIMO transmission can be realized by signal processing with a smaller load.

Next, a modification of the first and second embodiments described above will be described with reference to FIG.
FIG. 5 is a configuration diagram showing a schematic configuration of the wireless communication system 2 according to a modification of the first or second embodiment of the present invention described above. Schematically, the wireless communication system 2 according to the present modification is one in which the present invention is applied to a single-input multiple-output (SIMO) transmission technique.

  The wireless communication system 2 illustrated in FIG. 5 includes a communication device 1000 and a communication device 2000. The communication apparatus 1000 includes the transmission unit 111 and the transmission antenna element 121 that are required for transmitting the signal of the data series S1 by the transmission antenna 121 in the configuration of the communication apparatus 100 shown in FIG. The configuration has been deleted.

  The communication device 2000 includes the configuration necessary for demodulating the signal of the data sequence S1 'by the receiving unit 231 in the configuration of the communication device 200 illustrated in FIG. 1 described above, and other configurations are omitted. Specifically, the communication device 2000 includes receiving antenna elements 211, 212, 213, a weight calculation circuit 2200, and a receiving unit 231. Among these, the weight calculation circuit 2200 is configured to include distributors 2211, 2122, 2213, a phase shifter 2221, and a combiner 2231 in the configuration of the weight calculation circuit 220 of FIG. Has been deleted.

The operation of this modification example is the same as that of the first or second embodiment described above when attention is paid to the transmission of the data series S1.
In this modification, one of the three data series S1, S2, and S3 is transmitted. However, the present invention is not limited to this. Of the three data series S1, S2, and S3, Any two data sequences can be transmitted.

Among the above-described modifications, the wireless communication system according to the modification corresponding to the first embodiment includes a first communication device including a transmission antenna element and first to third reception antenna elements. Two communication devices, wherein the transmitting antenna element and one of the first to third receiving antenna elements are arranged to face each other, and the transmitting antenna element and the first to third receiving antenna elements Among these, the channel formed between the transmitting antenna element and the receiving antenna element that are in an arrangement relationship facing each other, and between the transmitting antenna element and the receiving antenna element that are in an oblique relationship with each other. The transmission antenna element and the first to third reception antennas are set so that the amplitude ratio with respect to the channel formed at 1 is 1 and the phase difference between the channels is 90 degrees. A wireless communication system in which a device is disposed, said second communication device, each of the signal input from the third receiving antenna elements from said first 1: 2 ^-1/2: 2 ^{-1 / 2} is weighted with an amplitude ratio of ² and branched, and the weight corresponding to the first term of the amplitude ratio inputted from one of the first to third receiving antenna elements among the signals obtained by the branching Are input from the weighting unit for applying -135 degree phase rotation to the signal subjected to the signal, the signal to which the phase rotation is applied by the weighting unit, and the remaining two of the first to third receiving antenna elements. And a decoding unit that synthesizes and decodes the signals weighted corresponding to the second and third terms of the amplitude ratio by the weighting unit, respectively. The

In addition, a wireless communication system according to a modification corresponding to the second embodiment includes a first communication device including a transmission antenna element, and a second communication including first, second, and third reception antenna elements. The transmitting antenna element and one of the first, second, and third receiving antenna elements are arranged at positions facing each other, and the transmitting antenna element and the first to third receiving antenna elements Among these, the channel formed between the transmitting antenna element and the receiving antenna element that are in an arrangement relationship facing each other, and between the transmitting antenna element and the receiving antenna element that are in an oblique relationship with each other. The transmission antenna element and the first to third reception antennas have an amplitude ratio of 2 to ^1/2 and a phase difference between the channels of 135 degrees. The second communication device weights each of the signals input from the first to third receiving antenna elements with an amplitude ratio of 1: 1: 1. -90 of the signals obtained by branching and weighted corresponding to the first term of the amplitude ratio inputted from one of the first to third receiving antenna elements. A weighting unit for applying a degree of phase rotation; a signal to which the phase rotation has been applied by the weighting unit; and the amplitude received by the weighting unit from the remaining two of the first to third receiving antenna elements A wireless communication system comprising: a decoding unit that combines and decodes signals weighted corresponding to the second and third terms of the ratio, respectively.

In the first and second embodiments described above, the present invention is expressed as a wireless communication system, but the present invention can also be expressed as a wireless communication method. In this case, the present invention corresponds to the first embodiment, the first communication device including the first, second, and third transmitting antenna elements, and the first, second, and third receiving antennas. A second communication device including an element, wherein the first, second, and third transmission antenna elements and the first, second, and third reception antenna elements are respectively disposed at opposing positions. Of the first to third transmitting antenna elements and the first to third receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship, So that the amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element located in an oblique direction is 1 and the phase difference between the channels is 90 degrees. The first to third transmitting antenna elements And the first to third receiving antenna elements are wireless communication methods using a wireless communication system, wherein signal processing by the second communication device is input from the first to third receiving antenna elements. Each of the received signals is branched by weighting with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and among the signals obtained by the branching, the first to third receiving antenna elements A weighting procedure for applying a phase rotation of −135 degrees to a signal input from one and weighted corresponding to the first term of the amplitude ratio, a signal to which the phase rotation is applied by the weighting procedure, The decoding is performed by synthesizing and decoding the signals input from the remaining two of the first to third receiving antenna elements and weighted respectively corresponding to the second and third terms of the amplitude ratio by the weighting procedure. Include a procedure, a can be expressed as a wireless communication method according to claim.

Further, the present invention corresponds to the second embodiment, the first communication device including the first, second, and third transmitting antenna elements, and the first, second, and third receiving antenna elements. The first, second, and third transmitting antenna elements and the first, second, and third receiving antenna elements are respectively disposed at positions facing each other, and Of the first to third transmitting antenna elements and the first to third receiving antenna elements, channels formed between the transmitting antenna elements and the receiving antenna elements that are in a mutually opposing arrangement relationship with each other, The amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element that are disposed in an oblique direction is ^{2−1 / 2} , and the phase difference between the channels is 135 degrees. The first to third transmission amplifiers A wireless communication method using a wireless communication system in which a tena element and the first to third receiving antenna elements are arranged, wherein signal processing by the second communication device is performed by the first to third receiving antenna elements. Each of the signals input from is branched by weighting with an amplitude ratio of 1: 1: 1, and among the signals obtained by the branching, the signals are input from one of the first to third receiving antenna elements. A weighting procedure for applying a -90 degree phase rotation to a weighted signal corresponding to the first term of the amplitude ratio, a signal to which the phase rotation is applied by the weighting procedure, and the first to third signals A decoding procedure for synthesizing and decoding the signals input from the remaining two receiving antenna elements and weighted respectively corresponding to the second and third terms of the amplitude ratio by the weighting procedure. It can be expressed as a wireless communication method characterized by.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be arbitrarily modified or modified without departing from the gist of the present invention.
For example, in the above-described embodiment, the example in which the present invention is applied to the MIMO transmission technology has been described. In the modification, the example in which the present invention is applied to the SIMO transmission technology has been described. However, the present invention is not limited to MISO (Multiple- The present invention can also be applied to an input single-output transmission technique.
The present invention can also be applied to MIMO transmissions other than 3 × 3 MIMO transmission, such as 2 × 2 MIMO transmission or 4 × 4 MIMO transmission. In this case, the antenna elements of the transmission / reception array antenna are arranged so that a specific channel matrix is obtained according to each transmission, and the distributors, phase shifters, and combiners of the weight calculation circuit (220, 2200) are arranged accordingly. By selecting each circuit constant, MIMO reception decoding can be easily performed as in the above-described embodiment.

100, 1000 ... communication device (transmission side)
111, 112, 113 ... transmitting unit 120 ... transmitting array antenna 121, 122, 123 ... transmitting antenna element 200, 2000 ... communication apparatus (receiving side)
210: receiving array antenna 211, 212, 213 ... receiving antenna element 220, 2200 ... weight calculation circuit 231, 232, 233 ... receiving unit 2211, 2122, 2213 ... distributor 2221, 2222, 2223 ... phase shifter 2231, 2322 2233 ... Synthesizer S1, S2, S3, S1 ', S2', S3 '... Data series S11, S12, S13, S21, S22, S23 ... Processing steps

Claims (8)

A first communication device including first, second, and third transmission antenna elements; and a second communication device including first, second, and third reception antenna elements, wherein the first, The second and third transmitting antenna elements and the first, second, and third receiving antenna elements are arranged at positions facing each other, and the first to third transmitting antenna elements and the first to third elements Among the receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction relative to each other The first to third transmitting antenna elements and the first to third so that the amplitude ratio with the channel formed between the first and second channels is 1 and the phase difference between the channels is 90 degrees. The receiving antenna element is placed The A wireless communication system,
The second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and among the signals obtained by the branching A weighting unit that applies a -135 degree phase rotation to a signal input from one of the first to third receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
The signal to which the phase rotation is given by the weighting unit and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting unit, respectively. A decoding unit that combines and decodes the corresponding weighted signals;
A wireless communication system comprising: The decoding unit
Among the signals branched by the weighting unit, a signal input from the first receiving antenna element and weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −135 degrees, and the first A signal input from the second receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal input from the third receiving antenna element and weighted corresponding to the third term of the amplitude ratio A first decoding unit that combines and decodes
Of the signals branched by the weighting unit, a signal input from the second receiving antenna element, weighted corresponding to the first term of the amplitude ratio and given a phase rotation of -135 degrees, and the first A signal input from one receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal input from the third receiving antenna element and weighted corresponding to the third term of the amplitude ratio A second decoding unit that combines and decodes
Among the signals branched by the weighting unit, a signal input from the third receiving antenna element and weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −135 degrees, and the first A signal inputted from one receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal inputted from the second receiving antenna element and weighted corresponding to the third term of the amplitude ratio A third decoding unit that combines and decodes,
The wireless communication system according to claim 1, further comprising: A first communication device including first, second, and third transmission antenna elements; and a second communication device including first, second, and third reception antenna elements, wherein the first, The second and third transmitting antenna elements and the first, second, and third receiving antenna elements are arranged at positions facing each other, and the first to third transmitting antenna elements and the first to third elements Among the receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction relative to each other The first to third transmission antenna elements and the first transmission antenna element so that the amplitude ratio with ^respect to the channel formed between the first and second channels is ^{2−1 / 2} and the phase difference between the channels is 135 degrees. 1st to 3rd receiving antenna elements A wireless communication system in which a child is arranged,
The second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 1: 1, and among the signals obtained by the branching, the first to third signals A weighting unit for applying a -90 degree phase rotation to a signal input from one of the receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
The signal to which the phase rotation is given by the weighting unit and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting unit, respectively. A decoding unit that combines and decodes the corresponding weighted signals;
A wireless communication system comprising: The decoding unit
Of the signals branched by the weighting unit, a signal input from the first receiving antenna element and weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −90 degrees, and the first A signal input from the second receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal input from the third receiving antenna element and weighted corresponding to the third term of the amplitude ratio A first decoding unit that combines and decodes
Of the signals branched by the weighting unit, a signal input from the second receiving antenna element and weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −90 degrees, and the first A signal input from one receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal input from the third receiving antenna element and weighted corresponding to the third term of the amplitude ratio A second decoding unit that combines and decodes
Of the signals branched by the weighting unit, a signal input from the third receiving antenna element, weighted corresponding to the first term of the amplitude ratio and given a phase rotation of −90 degrees, and the first A signal inputted from one receiving antenna element and weighted corresponding to the second term of the amplitude ratio, and a signal inputted from the second receiving antenna element and weighted corresponding to the third term of the amplitude ratio A third decoding unit that combines and decodes,
The wireless communication system according to claim 3, further comprising: A first communication device including a transmission antenna element; and a second communication device including first to third reception antenna elements, wherein the transmission antenna element and the first to third reception antenna elements One of the transmitting antenna elements and the first to third receiving antenna elements are disposed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship. And an amplitude ratio of the channel formed between the transmitting antenna element and the receiving antenna element, which are arranged in an oblique direction with respect to each other, and a phase difference between the channels is 90. A wireless communication system in which the transmitting antenna element and the first to third receiving antenna elements are arranged so that
The second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and among the signals obtained by the branching A weighting unit that applies a -135 degree phase rotation to a signal input from one of the first to third receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
The signal to which the phase rotation is given by the weighting unit and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting unit, respectively. A decoding unit that combines and decodes the corresponding weighted signals;
A wireless communication system comprising: A first communication device including a transmission antenna element; and a second communication device including first, second, and third reception antenna elements, the transmission antenna element and the first, second, and second communication devices. The transmitting antenna element and the receiving antenna element, which are arranged at positions facing one of the three receiving antenna elements, and are in a positional relationship facing each other among the transmitting antenna element and the first to third receiving antenna elements. And an amplitude ratio between the channel formed between the transmitting antenna element and the receiving antenna element that are disposed in an oblique direction with respect to each other is 2 ^-1/2 , And the wireless communication system in which the transmitting antenna element and the first to third receiving antenna elements are arranged so that the phase difference between the channels is 135 degrees,
The second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 1: 1, and among the signals obtained by the branching, the first to third signals A weighting unit for applying a -90 degree phase rotation to a signal input from one of the receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
The signal to which the phase rotation is given by the weighting unit and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting unit, respectively. A decoding unit that combines and decodes the corresponding weighted signals;
A wireless communication system comprising: A first communication device including first, second, and third transmission antenna elements; and a second communication device including first, second, and third reception antenna elements, wherein the first, The second and third transmitting antenna elements and the first, second, and third receiving antenna elements are arranged at positions facing each other, and the first to third transmitting antenna elements and the first to third elements Among the receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction relative to each other The first to third transmitting antenna elements and the first to third so that the amplitude ratio with the channel formed between the first and second channels is 1 and the phase difference between the channels is 90 degrees. The receiving antenna element is placed A wireless communication method according to the radio communication system,
Signal processing by the second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 2 ^−1/2 : 2 ^−1/2 , and among the signals obtained by the branching A weighting procedure for applying a -135 degree phase rotation to a signal input from one of the first to third receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
A signal given the phase rotation by the weighting procedure and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting procedure, respectively. A decoding procedure for combining and decoding the corresponding weighted signals;
A wireless communication method comprising: A first communication device including first, second, and third transmission antenna elements; and a second communication device including first, second, and third reception antenna elements, wherein the first, The second and third transmitting antenna elements and the first, second, and third receiving antenna elements are arranged at positions facing each other, and the first to third transmitting antenna elements and the first to third elements Among the receiving antenna elements, a channel formed between the transmitting antenna element and the receiving antenna element that are in a mutually opposing arrangement relationship, and a transmitting antenna element and a receiving antenna element that are arranged in an oblique direction relative to each other The first to third transmission antenna elements and the first transmission antenna element so that the amplitude ratio with ^respect to the channel formed between the first and second channels is ^{2−1 / 2} and the phase difference between the channels is 135 degrees. 1st to 3rd receiving antenna elements A wireless communication method by a wireless communication system in which a child is arranged,
Signal processing by the second communication device is
Each of the signals input from the first to third receiving antenna elements is branched by weighting with an amplitude ratio of 1: 1: 1, and among the signals obtained by the branching, the first to third signals A weighting procedure for applying a -90 degree phase rotation to a signal input from one of the receiving antenna elements and weighted corresponding to the first term of the amplitude ratio;
A signal given the phase rotation by the weighting procedure and the remaining two of the first to third receiving antenna elements are input to the second and third terms of the amplitude ratio by the weighting procedure, respectively. A decoding procedure for combining and decoding the corresponding weighted signals;
A wireless communication method comprising:

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