Wireless communication apparatus and wireless communication method

Abstract

To reduce interference from a leakage signal leaked and radiated from a radio communication device to a calibration signal of a neighboring radio communication device.SOLUTION: A wireless communication device according to the present disclosure is a wireless communication device disposed near another wireless communication device, and includes a plurality of transmitters, a plurality of receivers, and a controller. The control unit stores in advance a transmission beamforming weight different from that of another wireless communication device, and multiplies a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight in a predetermined transmission period. The control unit stores in advance a reception beamforming weight different from that of the other wireless communication device, and multiplies a signal passing through each of the plurality of receivers by the stored reception beamforming weight in a predetermined reception period.SELECTED DRAWING: Figure 24

Description

[Technical Field]

[0001] The present disclosure relates to a wireless communication device and a wireless communication method. [Background technology]

[0002] In 5th Generation (5G) mobile communications, operation in the sub-6GHz band (6GHz or lower) is gaining attention due to its wide-area propagation capability suitable for mobile communications. Traffic is also growing at a rate of 1.3 times annually, making it necessary to meet this demand. However, frequency constraints mean that securing frequency bandwidth below sub-6GHz is not easy. Given this background, it is considered effective to use an active antenna system (AAS) employing a fully digital beamforming method as a base station and apply spatial multiplexing and massive MIMO (multi-input, multi-output) via AAS.

[0003] For this reason, commercialization of AAS is being promoted both domestically and internationally to increase capacity (high cell throughput) through Massive MIMO and expand coverage areas through beamforming. Furthermore, in order to realize the Stand Alone (SA) 5G System that will underpin Beyond 5G / 6G, which is expected to be introduced in 2030, it will become increasingly important to deploy AAS across a wide area.

[0004] However, although the Sub-6GHz band can use a wider bandwidth than the LTE (Long Term Evolution) band, its propagation performance is inferior to that of the Low Band (800MHz Platinum Band) and Mid Band (2GHz Band). Therefore, in order to expand the coverage area while maintaining stable communication performance, it is important to use three AASs in the base station, creating a three-sector configuration where each of the three AASs covers 120 degrees in a 360-degree horizontal direction, and to arrange such base stations repeatedly in a planar configuration to eliminate blind spots, just like with LTE.

[0005] In addition, in AAS, the degradation of the SINR (Signal-to-Interference-plus-Noise Ratio) of DL signals at high output power is determined by the radiation of nonlinearly distorted signals emitted in the same direction as the desired signal to the desired terminal. Therefore, to improve nonlinear distortion, AAS is equipped with a function that performs distortion compensation using DPD (Digital Pre-distortion) on DL signals transmitted from all TXs (transmitters) within the AAS. By implementing both nonlinear distortion reduction and full digital beamforming, AAS significantly improves spatial multiplexing performance at high output power.

[0006] In addition, in an AAS, the null depth in the direction of terminals other than the desired terminal is determined by the amplitude and phase characteristics of the TX (transmitter) and RX (receiver) within the AAS. Therefore, the AAS performs DL (Downlink) CAL (Calibration) to match the amplitude and phase characteristics among multiple TXs within the AAS, and UL (Uplink) CAL to match the amplitude and phase characteristics among multiple RXs within the AAS. Hereinafter, DL CAL and UL CAL will be collectively referred to as DL / UL CAL. DL and UL will also be collectively referred to as DL / UL. Furthermore, in an AAS, after SINR improvement by DPD and at low output power, the accuracy of DL / UL CAL becomes dominant and determines the SINR of the DL signal. Therefore, the AAS employs a dual compensation configuration of DPD and DL / UL CAL to achieve high spatial multiplexing performance and high throughput over a wide output dynamic range.

[0007] In addition, in AAS, a DL / UL CAL signal is placed after the DL slot to perform DL / UL CAL, and an AMP stabilization signal is inserted before the DL slot to improve the start-up characteristics of the transmit AMP. Note that if there are no problems with the start-up characteristics of the transmit AMP, a DL / UL CAL signal may be placed only before the DL slot without using an AMP stabilization signal, and DL / UL CAL may be performed. The technology related to AAS is disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2022 / 137593 Summary of the Invention [Problem to be solved by the invention]

[0009] Due to the above circumstances, the spatial multiplexing performance of AAS will become even more important in the future. Therefore, as mentioned above, it is important for AAS to adopt a dual compensation configuration of DPD and DL / UL CAL to improve the SINR of DL signals and achieve large transmission capacity through high throughput. For this purpose, it is important for AAS to perform DL / UL CAL with high accuracy.

[0010] However, in the related technology, if the DL / UL CAL signal or AMP stabilization signal transmitted and received by the AAS is leaked, the leaked signal will interfere with the DL / UL CAL signal of a nearby AAS, degrading the accuracy of the DL / UL CAL of the nearby AAS.

[0011] Therefore, an object of the present disclosure is to solve the above-mentioned problems and provide a wireless communication device and a wireless communication method that can reduce interference from a leakage signal leaked and radiated from a wireless communication device to a calibration signal of a nearby wireless communication device. [Means for solving the problem]

[0012] According to one aspect, a wireless communication device includes: A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; A receiving beamforming weight different from that of the other wireless communication device is stored in advance, and during a predetermined reception period, a signal passing through each of the plurality of receivers is multiplied by the stored receiving beamforming weight.

[0013] According to another aspect, a wireless communication device includes: A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit a plurality of transmit beamforming weights are stored in advance, and during a predetermined transmission period, a transmit beamforming weight that minimizes an error in amplitude phase characteristics between the plurality of transmitters is selected from the plurality of stored transmit beamforming weights, and a signal passing through each of the plurality of transmitters is multiplied by the selected transmit beamforming weight; A plurality of receiving beamforming weights are stored in advance, and during a predetermined receiving period, a receiving beamforming weight that minimizes the error in amplitude phase characteristics between the plurality of receivers is selected from the plurality of stored receiving beamforming weights, and the selected receiving beamforming weight is multiplied by the signals passing through each of the plurality of receivers.

[0014] According to one aspect, a wireless communication method includes: A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; The method includes pre-storing a receiving beamforming weight that is different from that of the other wireless communication devices, and multiplying the stored receiving beamforming weight by a signal passing through each of the plurality of receivers during a predetermined receiving period.

[0015] Another aspect of the wireless communication method includes: A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a plurality of transmit beamforming weights in advance, selecting a transmit beamforming weight that minimizes an error in amplitude-phase characteristics between the plurality of transmitters from among the plurality of stored transmit beamforming weights during a predetermined transmission period, and multiplying a signal passing through each of the plurality of transmitters by the selected transmit beamforming weight; storing a plurality of receiving beamforming weights in advance, selecting a receiving beamforming weight from the stored plurality of receiving beamforming weights during a predetermined receiving period that minimizes an error in amplitude phase characteristics between the plurality of receivers, and multiplying a signal passing through each of the plurality of receivers by the selected receiving beamforming weight. Wireless communication method. [Effects of the Invention]

[0016] According to the above-described aspect, it is possible to provide a wireless communication device and a wireless communication method that can reduce interference of a leaked signal leaked and radiated from a wireless communication device with a calibration signal of a nearby wireless communication device. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a top view illustrating a configuration example of a base station according to the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating an example of the arrangement of base stations according to the present disclosure. [Figure 3] FIG. 1 is a diagram illustrating a problem in the related art. [Figure 4] FIG. 1 is a diagram illustrating an overview of a first embodiment. [Figure 5] A diagram showing an example configuration of an interfering AAS and an interfered AAS according to the present disclosure. [Figure 6] 10A and 10B are diagrams illustrating examples of DL CAL operation and DPD operation of an interfering AAS and an interfered AAS according to the present disclosure. [Figure 7] A diagram illustrating an example of DL operation and DPD operation of an interfering AAS and an interfered AAS according to the present disclosure. [Figure 8] FIG. 10 is a diagram illustrating an example of UL CAL operation of an interfering AAS and an interfered AAS according to the present disclosure. [Figure 9] A diagram illustrating an example of UL operation of an interfering AAS and an interfered AAS according to the present disclosure. [Figure 10] 10 is a diagram illustrating an example of the configuration of a part that multiplies a signal passing through RX by a beamforming weight in an interfering AAS and an interfered AAS according to the present disclosure. FIG. [Figure 11] 10 is a diagram illustrating an example of the configuration of a part that multiplies a signal passing through RX by a beamforming weight in an interfering AAS and an interfered AAS according to the present disclosure. FIG. [Figure 12] A diagram showing an example configuration of a part that multiplies a signal passing through TX by a beamforming weight in an interfering AAS and an interfered AAS according to the present disclosure. [Figure 13] A diagram showing an example configuration of a part that multiplies a signal passing through TX by a beamforming weight in an interfering AAS and an interfered AAS according to the present disclosure. [Figure 14] FIG. 2 is a diagram illustrating the effects of the first embodiment in comparison with the related art. [Figure 15] FIG. 10 is a diagram illustrating an outline of a second embodiment. [Figure 16] FIG. 10 is a diagram illustrating an outline of a second embodiment. [Figure 17] 7A and 7B are diagrams illustrating an example of an operation performed when the error in amplitude-phase characteristics between TX and TX is equal to or greater than the allowable error in the DL CAL operation shown in FIG. 6 in the interfered AAS according to the present disclosure. [Figure 18]9 is a diagram illustrating an example of an operation performed when the error in amplitude-phase characteristics between RX in the UL CAL operation shown in FIG. 8 is equal to or greater than the allowable error in the interfered AAS according to the present disclosure. [Figure 19] 10 is a diagram illustrating an example of the configuration of a part that multiplies a UL CAL signal passing through RX by a beamforming weight in an interfered AAS according to the present disclosure. FIG. [Figure 20] 10 is a diagram illustrating an example of the configuration of a part that multiplies a UL CAL signal passing through RX by a beamforming weight in an interfered AAS according to the present disclosure. FIG. [Figure 21] FIG. 10 is a diagram illustrating an example of the configuration of a part that multiplies a DL CAL signal passing through a TX by a beamforming weight in an interfered AAS according to the present disclosure. [Figure 22] FIG. 10 is a diagram illustrating an example of the configuration of a part that multiplies a DL CAL signal passing through a TX by a beamforming weight in an interfered AAS according to the present disclosure. [Figure 23] FIG. 10 is a diagram illustrating the effects of the second embodiment in comparison with the related art. [Figure 24] FIG. 1 is a diagram illustrating an example configuration of a wireless communication device according to the present disclosure. [Figure 25] FIG. 10 is a block diagram illustrating an example of the hardware configuration of a computer that realizes some of the functions of the wireless communication device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings have been omitted and simplified as appropriate for clarity of explanation. In addition, in each of the following drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, specific numerical values ​​etc. shown below are merely examples to facilitate understanding of the present disclosure, and are not limited thereto.

[0019] FIG. 1 is a top view showing an example configuration of a base station 150 according to the present disclosure. 1, base station 150 according to the present disclosure is configured to be able to apply Massive MIMO and Beamforming. Specifically, base station 150 includes three AASs 100-1 to 100-3, and employs a three-sector configuration in which the three AASs 100-1 to 100-3 each cover 120 degrees in a 360-degree horizontal direction. Hereinafter, when it is not necessary to specify which of AASs 100-1 to 100-3 is being referred to, it will be referred to as AAS 100.

[0020] FIG. 2 is a diagram illustrating an example of the arrangement of base stations 150 according to the present disclosure. 2, the base station 150 according to the present disclosure has a three-sector configuration that covers 360 degrees horizontally, and multiple base stations 150 are repeatedly arranged in a plane. This enables a design that eliminates blind spots, similar to LTE.

[0021] Here, in the AAS 100, DL CAL is performed to match the amplitude and phase characteristics between a plurality of TXs in the AAS 100, and UL CAL is performed to match the amplitude and phase characteristics between a plurality of RXs in the AAS 100.

[0022] However, the related technology has a problem in that leakage signals emitted from an AAS 100 interfere with DL / UL CAL signals transmitted and received by neighboring AASs 100, degrading the accuracy of the DL / UL CALs of the neighboring AASs 100.

[0023] FIG. 3 is a diagram illustrating the problems of the related art. Hereinafter, the AAS that causes interference will be referred to as an “interfering AAS,” and the AAS that is subjected to interference will be referred to as an “interfered AAS.” In the example of Fig. 3, an interfering AAS 100a and an interfered AAS 100b are provided.

[0024] The interfering AAS 100a performs beamforming for each of the terminals 300a1, 300a2, and 300a3, while the interfered AAS 100b performs beamforming for each of the terminals 300b1, 300b2, and 300b3.

[0025] 3, in the interfering AAS 100a, a DL / UL CAL signal or an AMP stabilization signal transmitted and received within a Transmit On / Off Period (e.g., 10 μsec) before and after the DL slot leaks out. Also, in the interfered AAS 100b, a DL / UL CAL signal is transmitted and received within the same Transmit On / Off Period.

[0026] At this time, the beam of the leaked signal leaked and radiated from the interfering AAS 100a and the beam of the DL / UL CAL signal transmitted and received by the interfered AAS 100b are in an on-beam opposing state. The on-beam opposing state is defined as a state in which the radiation direction of the beam at each of the two points, the transmitting point and the receiving point, is the radiation direction in which the radiation power is maximum. On the other hand, the off-beam opposing state is defined as a state in which the radiation direction of the beam is off the axis of the radiation direction in the on-beam opposing state.

[0027] Of the four diagrams near the center of Fig. 3, the two diagrams on the left side show the azimuth and elevation of the beam of the leaked signal leaked and radiated from the interfering AAS 100a, and the two diagrams on the right side show the azimuth and elevation of the beam of the DL / UL CAL signal transmitted and received by the interfered AAS 100b. In the diagrams of azimuth angles, the horizontal axis represents the azimuth angle, and the vertical axis represents the antenna gain. In the diagrams of elevation angles, the horizontal axis represents the altitude, and the vertical axis represents the antenna gain (the same applies to Figs. 4 and 16 below).

[0028] 3, the beam of the leaked signal leaked and radiated from the interfering AAS 100a and the beam of the DL / UL CAL signal transmitted and received by the interfered AAS 100b are in an on-beam opposing state. Therefore, the azimuth angles and altitudes of both beams are almost the same, and as a result, the radiation directions of both beams are almost the same.

[0029] Therefore, the leakage signal leaked from the interfering AAS 100a interferes with the DL / UL CAL signal of the interfered AAS 100b, causing the SINR of the DL / UL CAL signal of the interfered AAS 100b to fall below the allowable SINR required for DL / UL CAL accuracy, resulting in a problem of significant degradation in the DL / UL CAL accuracy of the interfered AAS 100b.

[0030] Furthermore, if the DL / UL CAL accuracy of the interfered AAS 100b deteriorates, the amplitude and phase characteristics between TX and between RX will no longer be aligned, which will deteriorate the Beamforming / Null accuracy required for MU-MIMO, etc., and reduce the DL / UL Throughput between terminals. Furthermore, if the interfered AAS 100b detects through DL / UL CAL that the error in the amplitude and phase characteristics between TX and between RX has exceeded the allowable error, it will activate an alarm and stop the TRX (transmitter / receiver) including the corresponding TX or RX. The following embodiments are intended to solve the problems of the related art described above.

[0031] <First Embodiment> First, an outline of the first embodiment will be described. FIG. 4 is a diagram illustrating an outline of the first embodiment. In the interfering AAS 100a, the DL / UL CAL signal or AMP stabilization signal transmitted and received within the Transmit On / Off Period (for example, 10 μsec) before and after the DL slot may leak and be radiated to the outside from the antenna of the interfering AAS 100a.

[0032] In this case, when a nearby interfered AAS 100b performs DL / UL CAL within the same Transmit On / Off Period, the beams of the leakage signal from the interfering AAS 100a and the DL / UL CAL signal of the interfered AAS 100b may become on-beam opposing each other (see FIG. 3). In this case, the leakage signal from the interfering AAS 100a interferes with the DL / UL CAL signal of the interfered AAS 100b, degrading the accuracy of the DL / UL CAL of the interfered AAS 100b.

[0033] Therefore, in this first embodiment, as shown in Fig. 4, when the DL / UL CAL signal or the AMP stabilization signal passes through TX or RX in the interfering AAS 100a, and when the DL / UL CAL signal passes through TX or RX in the interfered AAS 100b, the baseband (BB) units of the interfering AAS 100a and the interfered AAS 100b are set in advance to multiply the beamforming weights different from each other in the interfering AAS 100a and the interfered AAS 100b. Note that the BB units may perform the above multiplication in the time domain or in the frequency domain.

[0034] As a result, even if the interfered AAS 100b performs DL / UL CAL within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal of the interfered AAS 100b are not in an on-beam opposing state but in an off-beam opposing state. Therefore, interference from the interfering AAS 100a to the DL / UL CAL signal of the interfered AAS 100b is reduced. As a result, deterioration of the SINR of the DL / UL CAL signal of the interfered AAS 100b can be avoided, and deterioration of the DL / UL CAL accuracy of the interfered AAS 100b can be avoided.

[0035] Next, the first embodiment will be described in detail. First, the configurations of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure will be described. Fig. 5 is a diagram showing an example of the configuration of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. Note that, in Fig. 5, the interfering AAS 100a and the interfered AAS 100b are described as having 32 antennas 41-1 to 41-32, but the number of antennas provided in the interfering AAS 100a and the interfered AAS 100b is not limited to this and may be any number as long as it is plural.

[0036] As shown in FIG. 5, the interfering AAS 100a and the interfered AAS 100b according to the present disclosure include an optical transceiver 10, a baseband (BB) unit 20, a frontend (FE) unit 30, 32 antennas 41-1 to 41-32, a calibration transceiver (CAL-TRX) 51, a switch (SW) 52, and a calibration network (CAL Network) 60.

[0037] The BB unit 20 also includes 32 DPD units 21-1 to 21-32 corresponding to the 32 antennas 41-1 to 41-32, respectively. The FE unit 30 also includes 32 transceivers (TRX) 31-1 to 31-32, 32 transmitting amplifiers 32-1 to 32-32, 32 receiving amplifiers 33-1 to 33-32, 32 couplers 34-1 to 34-32, 32 SWs 35-1 to 35-32, and 32 band-pass filters (BPFs) 36-1 to 36-32 corresponding to the 32 antennas 41-1 to 41-32, respectively.

[0038] In the following, when it is not necessary to specify which antenna 41-1 to 41-32 it is, it will be referred to as antenna 41-n (n=1, . . . , 32). Similarly, the DPD units 21-1 to 21-32, TRXs 31-1 to 31-32, transmitting amplifiers 32-1 to 32-32, receiving amplifiers 33-1 to 33-32, couplers 34-1 to 34-32, SWs 35-1 to 35-32, and BPFs 36-1 to 36-32 will be referred to as DPD unit 21-n, TRX 31-n, transmitting amplifier 32-n, receiving amplifier 33-n, coupler 34-n, SWs 35-n, and BPF 36-n, respectively.

[0039] The optical transceiver 10 performs optical-electrical conversion of signals transmitted and received between a distribution unit (DU) 200 and the BB section 20, and vice versa.

[0040] When performing a DL CAL operation, the BB unit 20 outputs a DL CAL signal to each TRX 31-n in the FE unit 30. When performing a UL CAL operation, the BB unit 20 outputs a UL CAL signal to the CAL-TRX 51.

[0041] When performing DL operation, the BB unit 20 outputs a DL signal (e.g., a BF (Beam Forming) signal) output from the optical transceiver 10 to each TRX 31-n in the FE unit 30. When performing UL operation, the BB unit 20 outputs a UL signal output from each TRX 31-n in the FE unit 30 to the optical transceiver 10.

[0042] As described above, the BB unit 20 includes 32 DPD units 21-n. The DPD units 21-n receive the signals that have passed through the transmission amplifiers 32-n as feedback from the couplers 34-n. Using the fed-back signals, the DPD units 21-n perform DPD distortion compensation on the signals (DL signals or DL ​​CAL signals) that pass through the transmission amplifiers 32-n.

[0043] As described above, the FE unit 30 includes 32 TRXs 31-n, 32 transmitting amplifiers 32-n, 32 receiving amplifiers 33-n, 32 couplers 34-n, 32 SWs 35-n, and 32 BPFs 36-n.

[0044] The TRX31-n includes a transmitter (TX) and a receiver (RX), both not shown. Hereinafter, the TX in the TRX31-n will be referred to as TX311-n, and the RX in the TRX31-n will be referred to as RX312-n. The TX311-n converts the signal (DL signal or DL ​​CAL signal) output from the BB unit 20 from an IQ (In-phase and Quadrature) signal to an RF (Radio Frequency) signal, and outputs the signal to the transmitting amplifier 32-n. In addition, the RX312-n converts the signal (UL signal or UL CAL signal) output from the receiving amplifier 33-n from an RF signal to an IQ signal, and outputs the signal to the BB unit 20.

[0045] The transmission amplifier 32-n amplifies the signal (DL signal or DL ​​CAL signal) output from the TX 311-n in the TRX 31-n, and outputs the amplified signal to the SW 35-n. The coupler 34-n feeds back the signal that has passed through the transmission amplifier 32-n to the DPD unit 21-n in the BB unit 20 via the RX 312-n in the TRX 31-n. The receiving amplifier 33-n amplifies the signal (UL signal or UL CAL signal) output from the SW35-n and outputs the amplified signal to the RX312-n in the TRX31-n.

[0046] SW35-n is a switch that switches the connection between TRX 31-n and antenna 41-n and CAL Network 60. When performing DL CAL operation, SW35-n outputs the DL CAL signal output from the transmit amplifier 32-n to the CAL Network 60. When performing UL CAL operation, SW35-n outputs the UL CAL signal output from the CAL Network 60 to the receive amplifier 33-n. When performing DL operation, SW35-n outputs the DL signal output from the transmit amplifier 32-n to the antenna 41-n. When performing UL operation, SW35-n outputs the UL signal output from the antenna 41-n to the receive amplifier 33-n.

[0047] The BPF 36-n passes only signals in a predetermined frequency band among signals transmitted and received between the TRX 31-n and the antenna 41-n and the CAL Network 60.

[0048] When performing DL CAL operation, the CAL Network 60 combines the DL CAL signals output from each SW 35-n and outputs the combined signal to the SW 52. When performing UL CAL operation, the CAL Network 60 distributes the UL CAL signal output from the SW 52 and outputs the combined signal to each SW 35-n.

[0049] The SW52 is a switch that switches the connection between the CAL-TRX51 and the CAL Network 60. When performing a DL CAL operation, the SW52 outputs a DL CAL signal output from the CAL Network 60 to the CAL-TRX51. When performing a UL CAL operation, the SW52 outputs a UL CAL signal output from the CAL-TRX51 to the CAL Network 60.

[0050] The CAL-TRX 51 includes a calibration transmitter (CAL-TX) and a calibration receiver (CAL-RX), both of which are not shown. Hereinafter, the CAL-TX within the CAL-TRX 51 will be referred to as the CAL-TX 511, and the CAL-RX within the CAL-TRX 51 will be referred to as the CAL-RX 512. When performing a DL CAL operation, the CAL-RX 512 converts the DL CAL signal output from the SW 52 from an RF signal to an IQ signal and sends it to the BB unit 20. When performing a UL CAL operation, the CAL-TX 511 converts the UL CAL signal output from the BB unit 20 from an IQ signal to an RF signal and outputs it to the SW 52.

[0051] When performing DL CAL operation, the BB unit 20 calculates the DL CAL weight of each TX 311-n based on the DL CAL signal output from the CAL-RX 512. When performing UL CAL operation, the BB unit 20 calculates the UL CAL weight of each RX 312-n based on the UL CAL signal output from each RX 312-n.

[0052] When performing DL operation, the antenna 41-n transmits the DL signal output from the SW35-n to a UE (User Equipment) (not shown). When performing UL operation, the antenna 41 receives the UL signal from the UE and outputs it to the SW35-n.

[0053] Next, the DPD operation, DL / UL CAL operation, and DL / UL operation in the interfering AAS 100a and the interfered AAS 100b according to the present disclosure will be described. FIG. 6 is a diagram illustrating an example of the DL CAL operation and the DPD operation of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. As shown in FIG. 6 , the BB unit 20 outputs a DL CAL signal to each TX 311-n in each TRX 31-n. Each TX 311-n converts the DL CAL signal from an IQ signal to an RF signal and outputs it. The DL CAL signal output from each TX 311-n is amplified by each transmission amplifier 32-n and then output to the CAL Network 60. At this time, each coupler 34-n feeds back the DL CAL signal that has passed through the transmission amplifier 32-n to the DPD unit 21-n in the BB unit 20. Each DPD unit 21-n uses the fed-back signal to perform DPD distortion compensation on the DL CAL signal that subsequently passes through the transmission amplifier 32-n. The DL CAL signal output to the CAL Network 60 is transmitted to the CAL-RX 512 in the CAL-TRX 51 via the SW 52. The CAL-RX 512 converts the DL CAL signal transmitted from the CAL Network 60 from an RF signal to an IQ signal and outputs it to the BB unit 20.

[0054] The BB unit 20 calculates the DL CAL Weight of each TX 311-n based on the DL CAL signal output from the CAL-RX 512. Here, the DL CAL Weight of the TX 311-n is calculated by multiplying the amplitude-phase characteristic [TX#n] of the TX 311-n by the amplitude-phase characteristic [CAL-RX] of the CAL-RX 512, as expressed in the following Equation 1.

number

[0055] FIG. 7 is a diagram illustrating an example of DL operation and DPD operation of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. As shown in FIG. 7, the BF signal transmitted from the DU 200 is input to the BB unit 20 via the optical transceiver 10. The BB unit 20 corrects the BF signal using the DL CAL Weight of each TX 311-n in each TRX 31. Specifically, the BB unit 20 multiplies the BF signal by a fraction having the DL CAL Weight as the denominator and the fixed amplitude-phase characteristic [CAL-RX (average)] of the CAL-RX 512 as the numerator. The corrected BF signal is expressed as in Equation 2 below. Note that [CAL-RX (average)] is pre-stored in the BB unit 20.

number

[0056] The BF signals corrected by the BB unit 20 are converted from IQ signals to RF signals in each TX 311-n, amplified by each transmission amplifier 32-n, and then output to each antenna 41-n from the FE unit 30. At this time, each coupler 34-n feeds back the BF signals that have passed through the transmission amplifier 32-n to the DPD unit 21-n in the BB unit 20. Each DPD unit 21-n uses the fed-back signal to perform DPD distortion compensation on the BF signals that subsequently pass through the transmission amplifier 32-n.

[0057] Here, the BF signal output from the FE unit 30 to each antenna 41-n passes through each TX 311-n, and is therefore expressed as in the following Equation 3.

number

[0058] Furthermore, when [TX#n] is deleted from Equation 3, it is expressed as Equation 4 below.

number

[0059] FIG. 8 is a diagram illustrating an example of the UL CAL operation of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. 8, the BB unit 20 outputs a UL CAL signal to the CAL-TX 511 in the CAL-TRX 51. The CAL-TX 511 converts the UL CAL signal from an IQ signal to an RF signal and outputs it. The UL CAL signal output from the CAL-TX 511 is distributed by the CAL Network 60 to each RX 312-n.

[0060] The UL CAL signal distributed by the CAL Network 60 is amplified by each receiving amplifier 33-n, then converted from an RF signal to an IQ signal by each RX312-n in each TRX31, and output from the FE unit 30 to the BB unit 20.

[0061] The BB unit 20 calculates the UL CAL Weight of each RX 312-n based on the UL CAL signal output from each RX 312-n. Here, the UL CAL Weight of RX 312-n is calculated by multiplying the amplitude-phase characteristic [RX#n] of RX 312-n by the amplitude-phase characteristic [CAL-TX] of CAL-TX 511, as expressed in the following Equation 5.

number

[0062] FIG. 9 is a diagram illustrating an example of UL operation of the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. 9, each antenna 41-n receives and outputs a UL signal, which is a UL Ch estimation wave, from the UE. The UL signal output from each antenna 41-n is amplified by each receiving amplifier 33-n, and then converted from an RF signal to an IQ signal by each RX 312-n in each TRX 31, and output from the FE unit 30 to the BB unit 20. The UL signal output from the FE unit 30 passes through each RX 312-n, and is therefore expressed by the following Equation 6.

number

[0063] The BB unit 20 corrects the UL signal using the UL CAL Weight of each RX 312-n. Specifically, the BB unit 20 multiplies the UL signal by a fraction whose denominator is the UL CAL Weight and whose numerator is the fixed amplitude-phase characteristic [CAL-TX (average)] of the CAL-TX 511. The UL signal after correction is expressed as in Equation 7 below. Note that [CAL-TX (average)] is pre-stored in the BB unit 20.

number

[0064] Furthermore, when [RX#n] is deleted from Equation 7, it is expressed as Equation 8 below.

number

[0065] Next, we will explain example configurations of the part that multiplies the signal passing through TX311-n by the beamforming weight and the part that multiplies the signal passing through RX312-n by the beamforming weight in the interfering AAS 100a and the interfered AAS 100b according to the present disclosure.

[0066] Fig. 10 is a diagram showing an example of the configuration of a part that multiplies a signal passing through RX 312-n by a beamforming weight in the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. Note that Fig. 10 shows only the components of the part that multiplies the beamforming weight, and other components (for example, antennas, etc.) are not shown (the same applies to Figs. 11 to 13 below).

[0067] 10, the BB unit 20 includes 32 reception processing units 22-1 to 22-32 corresponding to the 32 antennas 41-1 to 41-32, respectively. Each of the reception processing units 22-1 to 22-32 includes an FFT (Fast Fourier Transform) unit 221, a storage unit 222, and a multiplier 223.

[0068] The reception processing units 22-1 to 22-32 perform substantially the same operations, so the operation of the reception processing unit 22-1 will be described below as a representative example. The FFT unit 221 converts the signal that has passed through the RX 312-1 from a time domain signal to a frequency domain signal. The storage unit 222 stores a beamforming weight that is set in advance in its own AAS 100 , and outputs the stored beamforming weight to the multiplier 223 . The multiplier 223 multiplies the signal that has passed through the RX 312-1 by the beamforming weight output from the storage unit 222 in the time domain.

[0069] Note that the reception processing unit 22-1 multiplies the signal after passing through RX 312-1 by the beamforming weight in the time domain, but this is not limited to this. The reception processing unit 22-1 may also multiply the signal after passing through RX 312-1 by the beamforming weight in the frequency domain. The configuration in this case is shown in FIG. 11.

[0070] For example, in the case of the interfering AAS 100a, during the UL CAL execution period (for example, within 10 μsec of the Transmit On / Off Period), the UL CAL signal that has passed through the RX 312-1 is multiplied by the Beamforming Weight.

[0071] Furthermore, in the case of the interfered AAS 100b, during the UL CAL execution period (for example, within 10 μsec of the Transmit On / Off Period), the UL CAL signal that has passed through the RX 312-1 is multiplied by the Beamforming Weight.

[0072] FIG. 12 is a diagram illustrating an example of the configuration of a part that multiplies a signal passing through the TX 311-n by a beamforming weight in the interfering AAS 100a and the interfered AAS 100b according to the present disclosure. 12, the BB unit 20 includes 32 transmission processing units 23-1 to 23-32 corresponding to the 32 antennas 41-1 to 41-32, respectively. Each of the transmission processing units 23-1 to 23-32 includes an IFFT (Inverse Fast Fourier Transform) unit 231, a storage unit 232, and a multiplier 233.

[0073] The transmission processing units 23-1 to 23-32 perform substantially the same operations, so the operation of the transmission processing unit 23-1 will be described below as a representative example. The IFFT unit 231 converts the signal before passing through the TX 311-1 from a frequency domain signal to a time domain signal. The storage unit 232 stores a beamforming weight that is set in advance in its own AAS 100 , and outputs the stored beamforming weight to the multiplier 233 . The multiplier 233 multiplies the signal before passing through the TX 311-1 by the beamforming weight output from the storage unit 232 in the time domain.

[0074] Note that the transmission processing unit 23-1 multiplies the signal before passing through the TX 311-1 by the beamforming weight in the time domain, but this is not limited to this. The transmission processing unit 23-1 may also multiply the signal before passing through the TX 311-1 by the beamforming weight in the frequency domain. The configuration in this case is shown in FIG. 13.

[0075] For example, in the case of the interfering AAS 100a, during the period in which DL CAL or AMP stabilization operation is performed (for example, within 10 μsec of the Transmit On / Off Period), the DL CAL signal or AMP stabilization signal before passing through TX 311-1 is multiplied by the beamforming weight.

[0076] Furthermore, in the case of the interfered AAS 100b, during the DL CAL implementation period (for example, within 10 μsec of the Transmit On / Off Period), the DL CAL signal before passing through the TX 311-1 is multiplied by the beamforming weight.

[0077] As described above, according to the first embodiment, the interfering AAS 100a is configured in advance to multiply the interfering AAS 100a and the interfered AAS 100b by different beamforming weights when the DL / UL CAL signal or the AMP stabilization signal passes through TX or RX, and the interfered AAS 100b is configured in advance to multiply the interfering AAS 100a and the interfered AAS 100b by different beamforming weights when the DL / UL CAL signal passes through TX or RX.

[0078] As a result, even if DL / UL CAL is performed in the interfered AAS 100b within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal of the interfered AAS 100b are not in an on-beam opposing state but in an off-beam opposing state. Therefore, interference from the interfering AAS 100a to the DL / UL CAL signal of the interfered AAS 100b is reduced. As a result, deterioration of the SINR of the DL / UL CAL signal of the interfered AAS 100b can be avoided, and deterioration of the DL / UL CAL accuracy of the interfered AAS 100b can be avoided.

[0079] Fig. 14 is a diagram illustrating the effects of the first embodiment in comparison with the related art. In Fig. 14, the upper diagram shows the Beam Pattern (New) of the leaked signal from the interfering AAS 100a and the Beam Pattern (Ref) of the UL CAL signal from the interfered AAS 100b in the time domain for each of the first embodiment and the related art. The lower diagram shows the Beam Pattern (New) of the leaked signal from the interfering AAS 100a and the Beam Pattern (Ref) of the UL CAL signal from the interfered AAS 100b in the frequency domain for each of the first embodiment and the related art. In the upper diagram, the horizontal axis represents time and the vertical axis represents signal amplitude. In the lower diagram, the horizontal axis represents frequency and the vertical axis represents signal amplitude.

[0080] 14, in the present embodiment 1, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal from the interfered AAS 100b are in an off-beam opposing state. Therefore, in the present embodiment 1, the signal amplitude of the leakage signal from the interfering AAS 100a is reduced compared to the related art in which both beam patterns are in an on-beam opposing state. Therefore, the interference from the interfering AAS 100a to the UL CAL signal of the interfered AAS 100b is reduced.

[0081] <Embodiment 2> First, an outline of the second embodiment will be described. 15 and 16 are diagrams for explaining an outline of the second embodiment. In the interfering AAS 100a, the DL / UL CAL signal and AMP stabilization signal transmitted and received within the Transmit On / Off Period (for example, 10 μsec) before and after the DL slot may leak and be radiated to the outside from the antenna of the interfering AAS 100a.

[0082] In this case, when a nearby interfered AAS 100b performs DL / UL CAL within the same Transmit On / Off Period, the beams of the leakage signal from the interfering AAS 100a and the DL / UL CAL signal of the interfered AAS 100b may become on-beam opposing each other (see FIG. 3). In this case, the leakage signal from the interfering AAS 100a interferes with the DL / UL CAL signal of the interfered AAS 100b, degrading the accuracy of the DL / UL CAL of the interfered AAS 100b.

[0083] Therefore, in this second embodiment, the interfered AAS 100b detects, based on the result of DL / UL CAL, that the SINR of the CAL signal of the interfered AAS 100b exceeds a threshold and that degradation of the CAL signal is expected. Specifically, the interfered AAS 100b calculates the error in the amplitude-phase characteristics between TX 311-n based on the result of DL CAL, and if the calculated error is equal to or greater than the allowable error, determines that the DL CAL signal will be degraded. Also, the interfered AAS 100b calculates the error in the amplitude-phase characteristics between RX 312-n based on the result of UL CAL, and if the calculated error is equal to or greater than the allowable error, determines that the UL CAL signal will be degraded.

[0084] When the interfered AAS 100b determines that the DL / UL CAL signal will be degraded, as shown in Fig. 15 , the BB unit 20 of the interfered AAS 100b cyclically multiplies the DL / UL CAL signal by multiple beamforming weights when the DL / UL CAL signal passes through TX 311-n or RX 312-n. Then, the interfered AAS 100b autonomously selects a beamforming weight that optimizes the SINR of the DL / UL CAL signal, that is, a beamforming weight that minimizes the error in the amplitude-phase characteristics between TX 311-n and between RX 312-n, and sets the selected beamforming weight in the BB unit 20. Note that the BB unit 20 may perform the above multiplication in the time domain or the frequency domain.

[0085] 16, even if the interfered AAS 100b performs DL / UL CAL within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal of the interfered AAS 100b are not in an on-beam opposing state but in an off-beam opposing state. Therefore, interference from the interfering AAS 100a to the DL / UL CAL signal of the interfered AAS 100b is reduced. As a result, deterioration of the SINR of the DL / UL CAL signal of the interfered AAS 100b can be avoided, and therefore deterioration of the DL / UL CAL accuracy of the interfered AAS 100b can be avoided.

[0086] Next, the second embodiment will be described in detail. First, an operation performed in the interfered AAS 100b according to the present disclosure when the error in the amplitude-phase characteristics between the TXs 311-n is equal to or greater than the allowable error in the DL CAL operation shown in FIG. 6 will be described.

[0087] FIG. 17 is a diagram illustrating an example of an operation performed in the interfered AAS 100b according to the present disclosure when the error in the amplitude-phase characteristics between TX 311-n is equal to or greater than the allowable error in the DL CAL operation shown in FIG. 6.

[0088] During the DL CAL period, the interfered AAS 100b performs the DL CAL operation shown in Fig. 6. After the DL CAL signal output from each TX 311-n is received by CAL-RX 512 in CAL-TRX 51, the interfered AAS 100b calculates the error in the amplitude-phase characteristics between TX 311-n based on the DL CAL signal from each TX 311-n, and if the calculated error is equal to or greater than the allowable error, performs the operation shown in Fig. 17 during the DL CAL period.

[0089] That is, when the DL CAL signal passes through TX 311-n, the interfered AAS 100b cyclically multiplies the DL CAL signal by multiple beamforming weights in the BB section 20 of the interfered AAS 100b, and selects the beamforming weight that minimizes the error in the amplitude phase characteristics between TX 311-n.

[0090] Specifically, the BB unit 20 pre-stores multiple beamforming weights, which are fractions with the DL CAL Weight as the denominator and the fixed amplitude-phase characteristic of CAL-RX 512 [CAL-RX (average)] as the numerator.

[0091] Therefore, first, the BB unit 20 selects one of a plurality of beamforming weights and multiplies the DL CAL signal by the selected beamforming weight. The DL CAL signal multiplied by the beamforming weight is expressed by the following Equation 9.

number

[0092] The DL CAL signal multiplied by the beamforming weight by the BB unit 20 is converted from an IQ signal to an RF signal by each TX 311-n, amplified by each transmission amplifier 32-n, and then output from the FE unit 30 to the CAL Network 60.

[0093] Here, the DL CAL signal output from the FE unit 30 to the CAL Network 60 passes through each TX 311-n, and is therefore expressed as in the following Equation 10.

number

[0094] Furthermore, when [TX#n] is deleted from Equation 10, it can be expressed as Equation 11 below.

number

[0095] The DL CAL signal output to the CAL Network 60 is transmitted to the CAL-RX 512 in the CAL-TRX 51 via the SW 52. The CAL-RX 512 converts the DL CAL signal transmitted from the CAL Network 60 from an RF signal to an IQ signal, and outputs the converted signal to the BB unit 20.

[0096] The BB unit 20 calculates the error in amplitude and phase characteristics between the TXs 311-n based on the DL CAL signal from each TX 311-n in the same way as during DL CAL operation. Thereafter, the BB unit 20 selects another beamforming weight, multiplies the DL CAL signal by the selected beamforming weight, and repeats the above operation.

[0097] After that, when the cyclic multiplication of the pre-stored multiple beamforming weights is completed, the BB unit 20 selects from the multiple beamforming weights the beamforming weight that minimizes the error in the amplitude phase characteristics between TX311-n, and sets the selected beamforming weight in the BB unit 20 only for the DL CAL period.

[0098] As a result, even if the interfered AAS 100b performs DL CAL within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL CAL signal of the interfered AAS 100b are in an off-beam opposing state, thereby reducing interference from the interfering AAS 100a to the DL CAL signal of the interfered AAS 100b.

[0099] Next, an operation performed in the interfered AAS 100b according to the present disclosure when the error in the amplitude-phase characteristics between the RXs 312-n in the UL CAL operation shown in FIG. 8 is equal to or greater than the allowable error will be described.

[0100] Figure 18 is a diagram illustrating an example of the operation performed in the interfered AAS 100b according to the present disclosure when the error in the amplitude-phase characteristics between RX312-n in the UL CAL operation shown in Figure 8 is equal to or greater than the allowable error.

[0101] During the UL CAL implementation period, the interfered AAS 100b performs the UL CAL operation shown in Fig. 8. After the UL CAL signal output from CAL-TX 511 in CAL-TRX 51 is received by each RX 312-n, the interfered AAS 100b calculates the error in the amplitude-phase characteristics between RX 312-n based on the UL CAL signal received by each RX 312-n, and if the calculated error is equal to or greater than the allowable error, performs the operation shown in Fig. 18 during the UL CAL implementation period.

[0102] That is, when the UL CAL signal passes through RX312-n, the interfered AAS 100b cyclically multiplies the UL CAL signal by multiple beamforming weights in the BB section 20 of the interfered AAS 100b, and selects the beamforming weight that minimizes the error in the amplitude phase characteristics between RX312-n.

[0103] Specifically, the BB unit 20 pre-stores multiple beamforming weights, which are fractions with the UL CAL Weight as the denominator and the fixed amplitude-phase characteristic of CAL-TX 511 [CAL-TX (average)] as the numerator.

[0104] The UL CAL signal output from CAL-TX 511 in CAL-TRX 51 is amplified by each receiving amplifier 33-n, then converted from an RF signal to an IQ signal by each RX 312-n in each TRX 31, and output from the FE unit 30 to the BB unit 20. The UL CAL signal output from the FE unit 30 passes through each RX 312-n, and is therefore expressed by the following equation 12.

number

[0105] First, the BB unit 20 selects one of a plurality of beamforming weights and multiplies the UL CAL signal by the selected beamforming weight. The UL CAL signal multiplied by the beamforming weight is expressed by the following Equation 13.

number

[0106] Furthermore, when [RX#n] is eliminated from Equation 13, it is expressed as Equation 14 below.

number

[0107] The BB unit 20 calculates the error in amplitude and phase characteristics between the RXs 312-n based on the UL CAL signal received by each RX 312-n in the same way as during UL CAL operation. Thereafter, the BB unit 20 selects another beamforming weight, multiplies the UL CAL signal by the selected beamforming weight, and repeats the above operation.

[0108] After that, when the cyclic multiplication of the pre-stored multiple beamforming weights is completed, the BB unit 20 selects from the multiple beamforming weights the beamforming weight that minimizes the error in the amplitude phase characteristics between RX312-n, and sets the selected beamforming weight in the BB unit 20 only during the UL CAL implementation period.

[0109] As a result, even if the interfered AAS 100b performs UL CAL within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the UL CAL signal of the interfered AAS 100b are in an off-beam opposing state, thereby reducing interference from the interfering AAS 100a to the UL CAL signal of the interfered AAS 100b.

[0110] Next, an example configuration of a part that multiplies a signal passing through TX 311-n by a beamforming weight and an example configuration of a part that multiplies a signal passing through RX 312-n by a beamforming weight in the interfered AAS 100b according to the present disclosure will be described.

[0111] Fig. 19 is a diagram showing an example of the configuration of a part that multiplies a UL CAL signal passing through RX 312-n by a beamforming weight in an interfered AAS 100b according to the present disclosure. Note that Fig. 19 shows only the components of the part that multiplies the beamforming weight, and other components (for example, antennas, etc.) are not shown (the same applies to the following Figs. 20 to 22).

[0112] 19, the BB unit 20 includes a selection unit 24, as well as 32 reception processing units 25-1 to 25-32 corresponding to the 32 antennas 41-1 to 41-32, respectively. Each of the reception processing units 25-1 to 25-32 includes an FFT unit 251, a storage unit 252, and a multiplier 253.

[0113] The selector 24 calculates the error in the amplitude and phase characteristics between the RX 312-n during the UL CAL execution period (for example, within 10 μsec of the Transmit On / Off Period). If the error in the amplitude and phase characteristics between the RX 312-n is equal to or greater than the allowable error, the selector 24 designates one of the multiple beamforming weights to each of the reception processing units 25-1 to 25-32 in order to perform cyclic multiplication of the multiple beamforming weights.

[0114] The reception processing units 25-1 to 25-32 perform substantially the same operations, so the operation of the reception processing unit 25-1 will be described below as a representative. The FFT unit 251 converts the UL CAL signal that has passed through the RX 312-1 from a time domain signal to a frequency domain signal. The storage unit 252 stores a plurality of beamforming weights in advance, and outputs the beamforming weight designated by the selection unit 24 from among the plurality of beamforming weights to the multiplier 253 . The multiplier 253 multiplies the UL CAL signal that has passed through the RX 312-1 by the beamforming weight output from the storage unit 252 in the time domain.

[0115] The selector 24 calculates the error in amplitude and phase characteristics between the RX 312-n. In this way, the selector 24 sequentially assigns a plurality of pre-stored beamforming weights to each of the reception processors 25-1 to 25-32 one by one, and calculates the error in amplitude-phase characteristics between the RX 312-n each time.

[0116] After that, when the cyclic multiplication of the pre-stored multiple beamforming weights is completed, the selection unit 24 selects from the multiple beamforming weights the beamforming weight that minimizes the error in the amplitude phase characteristics between RX312-n, and thereafter assigns the selected beamforming weight to each of the reception processing units 25-1 to 25-32.

[0117] Note that the reception processing unit 25-1 multiplies the UL CAL signal after passing through RX 312-1 by a beamforming weight in the time domain, but this is not limited to this. The reception processing unit 25-1 may also multiply the UL CAL signal after passing through RX 312-1 by a beamforming weight in the frequency domain. The configuration in this case is shown in FIG. 20.

[0118] FIG. 21 is a diagram illustrating an example of the configuration of a part that multiplies a DL CAL signal passing through a TX 311-n by a beamforming weight in an interfered AAS 100b according to the present disclosure. 21, the BB unit 20 includes a selection unit 26 and 32 transmission processing units 27-1 to 27-32 corresponding to the 32 antennas 41-1 to 41-32, respectively. Each of the transmission processing units 23-1 to 23-32 includes an IFFT unit 271, a storage unit 272, and a multiplier 273.

[0119] The selector 26 calculates the error in amplitude and phase characteristics between the TX 311-n during the DL CAL implementation period (for example, within 10 μsec of the Transmit On / Off Period). If the error in amplitude and phase characteristics between the TX 311-n is equal to or greater than the allowable error, the selector 26 designates one of the multiple beamforming weights to each of the transmission processors 27-1 to 27-32 in order to perform cyclic multiplication of the multiple beamforming weights.

[0120] The transmission processing units 27-1 to 27-32 perform substantially the same operations, so the operation of the transmission processing unit 27-1 will be described below as a representative example. The IFFT unit 271 converts the DL CAL signal before passing through the TX 311-1 from a frequency domain signal to a time domain signal. The storage unit 272 stores a plurality of beamforming weights in advance, and outputs the beamforming weight designated by the selection unit 26 from among the plurality of beamforming weights to the multiplier 273 . The multiplier 273 multiplies the DL CAL signal before passing through the TX 311-1 by the beamforming weight output from the storage unit 272 in the time domain.

[0121] The selector 26 calculates the error in amplitude and phase characteristics between the TXs 311-n. In this way, the selector 26 sequentially assigns a plurality of pre-stored beamforming weights to each of the transmission processors 27-1 to 27-32 one by one, and calculates the error in amplitude-phase characteristics between the TXs 311-n each time.

[0122] After that, when the cyclic multiplication of the pre-stored multiple beamforming weights is completed, the selection unit 26 selects from the multiple beamforming weights the beamforming weight that minimizes the error in the amplitude phase characteristics between TX311-n, and thereafter assigns the selected beamforming weight to each of the transmission processing units 27-1 to 27-32.

[0123] Note that the transmission processing unit 27-1 multiplies the DL CAL signal before passing through the TX 311-1 by a beamforming weight in the time domain, but this is not limited to this. The transmission processing unit 27-1 may also multiply the DL CAL signal before passing through the TX 311-1 by a beamforming weight in the frequency domain. The configuration in this case is shown in FIG. 22.

[0124] As described above, according to the second embodiment, when the interfered AAS 100b determines that the DL / UL CAL signal is degraded, it cyclically multiplies the DL / UL CAL signal by a plurality of beamforming weights when the DL / UL CAL signal passes through TX 311-n or RX 312-n. Then, the interfered AAS 100b autonomously selects a beamforming weight that minimizes the error in the amplitude-phase characteristics between TX 311-n and the error in the amplitude-phase characteristics between RX 312-n, and sets the selected beamforming weight.

[0125] As a result, even if DL / UL CAL is performed in the interfered AAS 100b within the same Transmit On / Off Period, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal of the interfered AAS 100b are not in an on-beam opposing state but in an off-beam opposing state. Therefore, interference from the interfering AAS 100a to the DL / UL CAL signal of the interfered AAS 100b is reduced. As a result, deterioration of the SINR of the DL / UL CAL signal of the interfered AAS 100b can be avoided, and deterioration of the DL / UL CAL accuracy of the interfered AAS 100b can be avoided.

[0126] Fig. 23 is a diagram illustrating the effects of the second embodiment in comparison with the related art. In Fig. 23, the upper diagram shows the Beam Pattern (New) of the leaked signal from the interfering AAS 100a and the Beam Pattern (Ref) of the UL CAL signal from the interfered AAS 100b in the time domain for each of the second embodiment and the related art. The lower diagram shows the Beam Pattern (New) of the leaked signal from the interfering AAS 100a and the Beam Pattern (Ref) of the UL CAL signal from the interfered AAS 100b in the frequency domain for each of the second embodiment and the related art. In the upper diagram, the horizontal axis represents time and the vertical axis represents signal amplitude. In the lower diagram, the horizontal axis represents frequency and the vertical axis represents signal amplitude.

[0127] 23, in the present embodiment 2, the beam pattern of the leakage signal from the interfering AAS 100a and the beam pattern of the DL / UL CAL signal from the interfered AAS 100b are in an off-beam opposing state. Therefore, in the present embodiment 1, the signal amplitude of the leakage signal from the interfering AAS 100a is reduced compared to the related art in which both beam patterns are in an on-beam opposing state. Therefore, the interference from the interfering AAS 100a to the UL CAL signal of the interfered AAS 100b is reduced.

[0128] <Third Embodiment> The third embodiment corresponds to an embodiment that conceptually illustrates the first and second embodiments described above. FIG. 24 is a diagram illustrating an example configuration of a wireless communication device 100X according to the present disclosure. As shown in FIG. 24, a wireless communication device 100X according to the present disclosure includes a control unit 20X, m (m is an integer of 2 or more) transmitters (TX) 311-1 to 311-m, and m receivers (RX) 312-1 to 312-m.

[0129] In the following description, when it is not necessary to specify which of the TXs 311-1 to 311-m is being referred to, the TXs will be referred to as TX311-n (n=1, . . . , m). Similarly, the RXs 312-1 to 312-m will be referred to as RX312-n.

[0130] The control unit 20X corresponds to the BB unit 20 described above. The m TXs 311-n and m RXs 312-n are provided corresponding to the m antennas (not shown), respectively.

[0131] For example, the wireless communication device 100X is the interfered AAS 100b of the first embodiment described above. In this case, the control unit 20X pre-stores a transmission beam-forming weight different from that of the nearby interfering AAS 100a. Then, the control unit 20X multiplies the signals passing through each of the m TXs 311-n by the pre-stored transmission beam-forming weight during a predetermined transmission period. The control unit 20X also pre-stores a reception beam-forming weight different from that of the nearby interfering AAS 100a. Then, the control unit 20X multiplies the signals passing through each of the m RXs 312-n by the pre-stored reception beam-forming weight during a predetermined reception period.

[0132] In this case, the wireless communication device 100X may further include a calibration transceiver (CAL-TRX). The predetermined transmission period may be a period during which downlink calibration (DL CAL) is performed to match the amplitude and phase characteristics between the m TXs 311-n. The signal passing through each of the m TXs 311-n may be a downlink calibration signal (DL CAL signal) transmitted from each of the m TXs 311-n to the CAL-TRX. The predetermined reception period may be a period during which uplink calibration (UL CAL) is performed to match the amplitude and phase characteristics between the m RXs 312-n. The signal passing through each of the m RXs 312-n may be an uplink calibration signal (UL CAL signal) transmitted from the CAL-TRX to each of the m RXs 312-n.

[0133] Alternatively, the wireless communication device 100X is the interfering AAS 100a of the first embodiment described above. In this case, the control unit 20X pre-stores a transmission beam-forming weight different from that of the nearby interfered AAS 100b. Then, the control unit 20X multiplies the signals passing through each of the m TXs 311-n by the pre-stored transmission beam-forming weight during a predetermined transmission period. The control unit 20X also pre-stores a reception beam-forming weight different from that of the nearby interfered AAS 100b. Then, the control unit 20X multiplies the signals passing through each of the m RXs 312-n by the pre-stored reception beam-forming weight during a predetermined reception period.

[0134] In this case, the wireless communication device 100X may further include m transmit amplifiers provided corresponding to the m TXs 311-n, respectively, and a calibration transceiver (CAL-TRX). The predetermined transmission period may be a period during which downlink calibration (DL CAL) is performed to match the amplitude and phase characteristics between the m TXs 311-n, or a period during which a stabilization operation is performed to stabilize the characteristics of the m transmit amplifiers. The signal passing through each of the m TXs 311-n may be a downlink calibration signal (DL CAL signal) transmitted from each of the m TXs 311-n to the CAL-TRX, or a stabilization signal transmitted to each of the m transmit amplifiers. The predetermined reception period may be a period during which uplink calibration (UL CAL) is performed to match the amplitude and phase characteristics between the m RXs 312-n. The signal passing through each of the m RXs 312-n may be an uplink calibration signal (UL CAL signal) transmitted from the CAL-TRX to each of the m RXs 312-n.

[0135] Alternatively, the wireless communication device 100X is the interfered AAS 100b of the second embodiment described above. In this case, the control unit 20X stores a plurality of transmit beam-forming weights in advance. Then, during a predetermined transmission period, the control unit 20X selects a transmit beam-forming weight that minimizes the error in amplitude and phase characteristics between the m number of TXs 311-n from among the plurality of transmit beam-forming weights stored in advance, and multiplies signals passing through each of the m number of TXs 311-n by the selected transmit beam-forming weight. The control unit 20X also stores a plurality of receive beam-forming weights in advance. Then, during a predetermined reception period, the control unit 20X selects a receive beam-forming weight that minimizes the error in amplitude and phase characteristics between the m number of RXs 312-n from among the plurality of receive beam-forming weights stored in advance, and multiplies signals passing through each of the m number of RXs 312-n by the selected receive beam-forming weight.

[0136] In this case, when the error in the amplitude-phase characteristics between the m number of TXs 311-n becomes equal to or greater than the allowable error during a predetermined transmission period, the control unit 20X may repeat the steps of multiplying a signal passing through each of the m number of TXs 311-n by one of a plurality of pre-stored transmit beam-forming weights and calculating the error in the amplitude-phase characteristics between the m number of TXs 311-n at that time. Furthermore, the control unit 20X may determine the transmit beam-forming weight that minimizes the error in the amplitude-phase characteristics between the m number of TXs 311-n through this repeated process. Furthermore, when the error in the amplitude-phase characteristics between the plurality of receivers becomes equal to or greater than the allowable error during a predetermined reception period, the control unit 20X may repeat the steps of multiplying a signal passing through each of the m number of RXs 312-n by one of a plurality of pre-stored receive beam-forming weights and calculating the error in the amplitude-phase characteristics between the m number of RXs 312-n at that time. Furthermore, the control unit 20X may determine the beamforming weight for reception that minimizes the error in the amplitude-phase characteristics among the m RXs 312-n by repeating this process.

[0137] In this case, the wireless communication device 100X may further include a calibration transceiver (CAL-TRX). The predetermined transmission period may be a period during which downlink calibration (DL CAL) is performed to match the amplitude and phase characteristics between the m TXs 311-n. The signal passing through each of the m TXs 311-n may be a downlink calibration signal (DL CAL signal) transmitted from each of the m TXs 311-n to the CAL-TRX. The predetermined reception period may be a period during which uplink calibration (UL CAL) is performed to match the amplitude and phase characteristics between the m RXs 312-n. The signal passing through each of the m RXs 312-n may be an uplink calibration signal (UL CAL signal) transmitted from the CAL-TRX to each of the m RXs 312-n.

[0138] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. For example, each embodiment can be combined with other embodiments as appropriate. Furthermore, some of the functions of the wireless communication device (including the AAS) according to the present disclosure can be realized by causing a processor such as a CPU (Central Processing Unit) to execute a program. FIG. 25 is a diagram illustrating an example of the hardware configuration of a computer 100Y that implements some of the functions of the wireless communication device according to the present disclosure. As shown in FIG. 25, the computer 100Y includes a processor 71 and a memory 72.

[0139] The processor 71 may be, for example, a microprocessor, a CPU, or an MPU (Micro Processing Unit). The processor 71 may include multiple processors.

[0140] The memory 72 is configured by a combination of volatile memory and non-volatile memory. The memory 72 may include storage located remotely from the processor 71. In this case, the processor 71 may access the memory 72 via an I (Input) / O (Output) interface (not shown).

[0141] A program is stored in the memory 72. When the program is loaded into the computer 100Y, it includes a set of instructions (or software code) that causes the computer 100Y to perform some of the functions of the wireless communication device described above. The components of the wireless communication device described above may be realized by the processor 71 reading and executing the program stored in the memory 72. Furthermore, the components of the wireless communication device described above that have a storage function may be realized by the memory 72.

[0142] The above-described programs may also be stored on non-transitory computer-readable media or tangible storage media. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The programs may also be transmitted on transitory computer-readable media or communication media. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0143] Furthermore, each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessarily required to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0144] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. (Appendix 1) A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; storing a receiving beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of receivers by the stored receiving beamforming weight during a predetermined reception period; Wireless communication device. (Appendix 2) further comprising a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers. 2. The wireless communication device of claim 1. (Appendix 3) a plurality of transmitting amplifiers provided corresponding to the plurality of transmitters, respectively; a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters or a period during which a stabilization operation is performed to stabilize characteristics of the plurality of transmission amplifiers, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver or a stabilization signal transmitted to each of the plurality of transmission amplifiers, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers. 2. The wireless communication device of claim 1. (Appendix 4) A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit a plurality of transmit beamforming weights are stored in advance, and during a predetermined transmission period, a transmit beamforming weight that minimizes an error in amplitude phase characteristics between the plurality of transmitters is selected from the plurality of stored transmit beamforming weights, and a signal passing through each of the plurality of transmitters is multiplied by the selected transmit beamforming weight; a method for multiplying a signal passing through each of the plurality of receivers by the selected beamforming weight; a method for multiplying a signal passing through each of the plurality of receivers by the selected beamforming weight; Wireless communication device. (Appendix 5) The control unit when an error in amplitude and phase characteristics among the plurality of transmitters becomes equal to or greater than an allowable error during the predetermined transmission period, multiplying a signal passing through each of the plurality of transmitters by one of the plurality of stored transmit beamforming weights and calculating the error in amplitude and phase characteristics among the plurality of transmitters at that time, thereby determining a transmit beamforming weight that minimizes the error in amplitude and phase characteristics among the plurality of transmitters; When an error in amplitude and phase characteristics between the plurality of receivers becomes equal to or greater than an allowable error during the predetermined reception period, a signal passing through each of the plurality of receivers is multiplied by one of the plurality of stored reception beamforming weights, and an error in amplitude and phase characteristics between the plurality of receivers at that time is calculated, and this is repeated to determine a reception beamforming weight that minimizes the error in amplitude and phase characteristics between the plurality of receivers. 5. The wireless communication device of claim 4. (Appendix 6) further comprising a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers. 6. The wireless communication device according to claim 4 or 5. (Appendix 7) A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; storing a receiving beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of receivers by the stored receiving beamforming weight during a predetermined reception period. Wireless communication method. (Appendix 8) A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a plurality of transmit beamforming weights in advance, selecting a transmit beamforming weight that minimizes an error in amplitude-phase characteristics between the plurality of transmitters from among the plurality of stored transmit beamforming weights during a predetermined transmission period, and multiplying a signal passing through each of the plurality of transmitters by the selected transmit beamforming weight; storing a plurality of receiving beamforming weights in advance, selecting a receiving beamforming weight from the stored plurality of receiving beamforming weights during a predetermined receiving period that minimizes an error in amplitude phase characteristics between the plurality of receivers, and multiplying a signal passing through each of the plurality of receivers by the selected receiving beamforming weight. Wireless communication method.

[0145] Note that some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 and 3 that are dependent on Supplementary Notes 1 may also be dependent on Supplementary Notes 7 in the same dependency relationship as Supplementary Notes 2 and 3. Also, some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 5 and 6 that are dependent on Supplementary Notes 4 may also be dependent on Supplementary Notes 8 in the same dependency relationship as Supplementary Notes 5 and 6. Some or all of the elements described in any Supplementary Notes may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0146] 10 Optical Transceiver 20 Baseband (BB) section 20X control unit 21-1~21-32 DPD Section 22-1 to 22-32, 25-1 to 25-32 Receiving processing section 221,251 FFT section 222,252 Storage area 223,253 multiplier 23-1 to 23-32, 27-1 to 27-32 Transmission processing unit 231,271 IFFT section 232,272 Storage area 233,273 multiplier 24,26 Selection section 30 Front end (FE) section 31-1~31-32 Transceiver (TRX) 311-1~311-m Transmitter (TX) 312-1~312-m Receiver (RX) 32-1~32-32 Transmitting amplifier 33-1~33-32 Receiving amplifier 34-1~34-32 Coupler 35-1~35-32 Switch (SW) 36-1 to 36-32 Band-pass filter (BPF) 41-1~41-32 Antenna 51 Calibration transmitter / receiver (CAL-TRX) 52 Switch (SW) 60 Calibration Network (CAL Network) 71 processors 72 memory 100-1~100-3 AAS 100a Interfering AAS 100b Interfered AAS 100X Wireless Communication Device 100Y Computer 150 base station 200 Distribution Unit (DU) 300a1, 300a2, 300a3, 300b1, 300b2, 300b3 terminals

Claims

1. A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; storing a receiving beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of receivers by the stored receiving beamforming weight during a predetermined reception period; Wireless communication device.

2. further comprising a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers. The wireless communication device according to claim 1 .

3. a plurality of transmitting amplifiers provided corresponding to the plurality of transmitters, respectively; a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters or a period during which a stabilization operation is performed to stabilize characteristics of the plurality of transmission amplifiers, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver or a stabilization signal transmitted to each of the plurality of transmission amplifiers, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers. The wireless communication device according to claim 1 .

4. A wireless communication device located in the vicinity of another wireless communication device, a plurality of transmitters; a plurality of receivers; a control unit, The control unit a plurality of transmit beamforming weights are stored in advance, and during a predetermined transmission period, a transmit beamforming weight that minimizes an error in amplitude phase characteristics between the plurality of transmitters is selected from the plurality of stored transmit beamforming weights, and a signal passing through each of the plurality of transmitters is multiplied by the selected transmit beamforming weight; a method for multiplying a signal passing through each of the plurality of receivers by the selected beamforming weight; a method for multiplying a signal passing through each of the plurality of receivers by the selected beamforming weight; Wireless communication device.

5. The control unit when an error in amplitude-phase characteristics among the plurality of transmitters becomes equal to or greater than an allowable error during the predetermined transmission period, multiplying a signal passing through each of the plurality of transmitters by one of the plurality of stored transmit beamforming weights and calculating the error in amplitude-phase characteristics among the plurality of transmitters at that time, thereby determining a transmit beamforming weight that minimizes the error in amplitude-phase characteristics among the plurality of transmitters; When an error in amplitude and phase characteristics between the plurality of receivers becomes equal to or greater than an allowable error during the predetermined reception period, a signal passing through each of the plurality of receivers is multiplied by one of the plurality of stored reception beamforming weights, and an error in amplitude and phase characteristics between the plurality of receivers at that time is calculated, and this is repeated to determine a reception beamforming weight that minimizes the error in amplitude and phase characteristics between the plurality of receivers.

5. The wireless communication device according to claim 4.

6. further comprising a calibration transceiver; the predetermined transmission period is a period during which downlink calibration is performed to match amplitude and phase characteristics between the plurality of transmitters, and the signal passing through each of the plurality of transmitters is a downlink calibration signal transmitted from each of the plurality of transmitters to the calibration transceiver, the predetermined reception period is a period during which uplink calibration is performed to match amplitude and phase characteristics among the plurality of receivers, and the signal passing through each of the plurality of receivers is an uplink calibration signal transmitted from the calibration transceiver to each of the plurality of receivers.

6. The wireless communication device according to claim 4 or 5.

7. A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a transmission beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of transmitters by the stored transmission beamforming weight during a predetermined transmission period; storing a receiving beamforming weight different from that of the other wireless communication device in advance, and multiplying a signal passing through each of the plurality of receivers by the stored receiving beamforming weight during a predetermined reception period. Wireless communication method.

8. A wireless communication method executed by a wireless communication device located in the vicinity of another wireless communication device, The wireless communication device a plurality of transmitters; a plurality of receivers; The wireless communication method includes: storing a plurality of transmit beamforming weights in advance, selecting a transmit beamforming weight that minimizes an error in amplitude-phase characteristics between the plurality of transmitters from among the plurality of stored transmit beamforming weights during a predetermined transmission period, and multiplying a signal passing through each of the plurality of transmitters by the selected transmit beamforming weight; storing a plurality of receiving beamforming weights in advance, selecting a receiving beamforming weight from the stored plurality of receiving beamforming weights during a predetermined receiving period that minimizes an error in amplitude phase characteristics between the plurality of receivers, and multiplying a signal passing through each of the plurality of receivers by the selected receiving beamforming weight. Wireless communication method.

Images