WO2016080087A1 - Radio communication device and method of determining weighting matrix - Google Patents

Abstract

A radio communication device is provided with: a baseband unit which generates a plurality of transmission signals directed at the same region; an antenna having a plurality of antenna elements; and a signal processing unit with which each of the plurality of transmission signals generated by the baseband unit is associated with and distributed to each of the plurality of antenna elements, and which multiplies each of the plurality of distributed transmission signals by a corresponding component of a weighting matrix, after which said signal processing unit combines together the transmission signals corresponding to each antenna element.

Description

Wireless communication apparatus and weight matrix determination method

The present invention relates to a wireless communication apparatus and a weight matrix determination method.

The multi-antenna technique is a technique for improving communication capacity, frequency utilization efficiency, power consumption, and the like by performing transmission / reception using a plurality of antennas in wireless communication. Even if the number of antennas on either the transmission side or the reception side is one, it is possible to improve the communication quality according to the number of antennas on the other side.
There is MIMO (Multiple Input Multiple Output) as a term relating to such multi-antenna technology. MIMO, when used as a communication term, often refers to a communication method in which both the transmission side and the reception side use a plurality of antennas, but is sometimes used to refer to general multi-antenna technology (for example, non-patent literature). 1).

Advantages obtained by the multi-antenna signal processing algorithm include the following four.
(1) Spatial Diversity
(2) Coherent gain
(3) Interference mitigation
(4) Spatial Multiplexing

The space diversity is to reduce deterioration in communication quality due to the influence of multipath or the like by using spatially separated antennas.
The combined gain is obtained by applying a weight (weight) using propagation path information (amplitude and phase change) to the signal of each antenna on the reception side and transmission side, so that the received power and noise from the desired direction can be reduced. To increase the ratio.

In the interference wave removal, a received signal from each antenna is combined with a weight so as to cancel an incoming signal (interference signal) other than the desired signal. The number of interference signals that is one smaller than the number of receiving antennas can be removed. If the propagation coefficient of the incoming signal is unknown, some learning algorithm must be used.
The spatial multiplexing is a method of establishing a plurality of communication paths simultaneously by applying interference wave cancellation. There are a method in which a single user transmits different signals from a plurality of antennas to increase the communication capacity, and a method in which a plurality of users simultaneously communicate to increase frequency utilization efficiency. The latter method is called SDMA (Space Division Multiple Access).

In MIMO communication, in order to transmit a plurality of baseband signals for the same sector, for example, it is necessary to install a plurality of antennas corresponding to each of the plurality of baseband signals. For this reason, there is a problem that aesthetics are impaired by the installation of a plurality of antennas at the antenna site, and a problem that it is difficult to secure an antenna site that can install a plurality of antennas.

The present invention has been made in view of such circumstances, and an object of the present invention is to enable a plurality of transmission signals for the same region to be transmitted with a smaller number of antennas than the number of transmission signals. And

A wireless communication device according to one embodiment of the present invention includes a baseband unit that generates a plurality of transmission signals for the same region, an antenna having a plurality of antenna elements, and a plurality of transmission signals generated by the baseband unit. A signal processing unit that distributes each corresponding to each of the plurality of antenna elements, and multiplies each of the plurality of distributed transmission signals by a corresponding component of a weight matrix and then combines the transmission signals corresponding to the antenna elements; , A wireless communication device.

A weight matrix determination method according to an aspect of the present invention is a weight matrix determination method for multiplying a plurality of transmission signals for the same region generated in a baseband unit, and the baseband in the weight matrix As a candidate of weight row vector or weight column vector corresponding to each of a plurality of transmission signals generated by the unit, a larger number of weight candidates than the number of the weight row vector or weight column vector are tilted to the region. A weight matrix comprising: a selection step that selects based on a corner; and a determination step that determines, as the weight row vector or the weight column vector, a weight candidate that satisfies a desired communication quality among the weight candidates selected in the selection step This is the method of determination.

According to the present invention, a plurality of transmission signals for the same region can be transmitted with a smaller number of antennas than the number of transmission signals.

It is a figure which shows the radio | wireless communication apparatus which concerns on 1st Embodiment of this invention. It is the block diagram which showed the structure by the side of transmission of an antenna system. It is a block diagram which shows the control structure of a radio | wireless communication apparatus. It is a flowchart which shows the determination procedure of the weight matrix which a control part performs. It is a figure which shows the vertical surface directivity of an antenna at the time of producing | generating a weight matrix based on a DFT matrix. It is a figure which shows the vertical surface directivity of an antenna at the time of producing | generating a weight matrix based on a DCT matrix. It is a block diagram which shows the structure by the side of the transmission of the antenna system with which the radio | wireless communication apparatus which concerns on 2nd Embodiment of this invention is provided. It is a block diagram which shows an example of a structure of the Butler matrix circuit with which the antenna system of FIG. 7 is provided. It is a block diagram which shows the structure by the side of the transmission of the antenna system with which the radio | wireless communication apparatus which concerns on 3rd Embodiment of this invention is provided. It is a block diagram which shows the control structure of the radio | wireless communication apparatus of FIG. It is a block diagram which shows the structure by the side of the transmission of the antenna system with which the radio | wireless communication apparatus which concerns on 4th Embodiment of this invention is provided.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
(1) A wireless communication apparatus according to an embodiment of the present invention includes a baseband unit that generates a plurality of transmission signals for the same region, an antenna having a plurality of antenna elements, and a plurality of baseband units generated by the baseband unit. The transmission signals corresponding to each of the plurality of antenna elements are distributed corresponding to each of the plurality of antenna elements, and the transmission signals corresponding to the respective antenna elements are combined after multiplying each of the distributed transmission signals by the corresponding component of the weight matrix. And a processing unit.
Here, the “area” is a single cell or a single cell that is not divided into a plurality of sectors, and a mobile terminal that performs radio communication with a radio communication apparatus can move without handover. Means an area.

According to the wireless communication device, a plurality of transmission signals for the same region generated in the baseband unit are distributed corresponding to a plurality of antenna elements of one antenna, and a plurality of distributed transmissions are performed. Each signal is multiplied by a weight matrix to synthesize transmission signals corresponding to the antenna elements. For this reason, it is possible to transmit a plurality of transmission signals for the same region by sharing one antenna. As a result, a plurality of transmission signals for the same region can be transmitted by a smaller number of antennas than the number of transmission signals.

(2) In the wireless communication device, the signal processing unit includes a plurality of digital / analog converters that convert each of the plurality of digital transmission signals generated by the baseband unit into an analog transmission signal, and the converted transmission. A plurality of distributors that distribute each signal corresponding to each of the plurality of antenna elements, a plurality of phase shifters that perform phase adjustment on each of the distributed transmission signals based on components corresponding to the weight matrix, and a phase A plurality of synthesizers that synthesize the transmission signals corresponding to the antenna elements among the adjusted transmission signals, and the antenna amplifies and corresponds to each of the transmission signals synthesized by the synthesizer It is preferable to further include a plurality of amplifiers provided to the antenna element.

In this case, the plurality of digital / analog converters are provided in front of the plurality of distributors. For this reason, the digital-to-analog converter may be provided corresponding to each of a plurality of transmission signals for the same region, and the number of digital-to-analog converters may be larger than when a digital-to-analog converter is provided for each of a plurality of antenna elements Can be reduced. As a result, the cost can be reduced.
In addition, since the phase shifter is provided in front of the amplifier, the transmission signal before amplification is given to the phase shifter. Since the transmission signal before amplification has lower power compared to the transmission signal after amplification, it is possible to use a phase shifter having a relatively low value of signal power that can be handled. As a result, it is possible to use a smaller and lower cost phase shifter, and it is possible to reduce the cost and reduce the size.

(3) In the wireless communication device, the signal processing unit includes a plurality of digital / analog converters that convert each of the plurality of digital transmission signals generated by the baseband unit into an analog transmission signal, and the converted transmission. A plurality of distributors that distribute each signal corresponding to each of the plurality of antenna elements, a plurality of phase shifters that perform phase adjustment on each of the distributed transmission signals based on components corresponding to the weight matrix, and a phase A plurality of combiners for combining the transmission signals corresponding to the antenna elements among the adjusted transmission signals, and a plurality of combiners that are provided on the front side of the antenna and amplify each of the plurality of transmission signals An amplifier may be further provided.

In this case, the plurality of digital / analog converters are provided on the upstream side of the plurality of distributors. For this reason, the digital-to-analog converter may be provided corresponding to each of a plurality of transmission signals for the same region, and the number of digital-to-analog converters may be larger than when a digital-to-analog converter is provided for each of a plurality of antenna elements Can be reduced. As a result, the cost can be reduced.

(4) In the wireless communication device, the signal processing unit distributes each of a plurality of digital transmission signals generated by the baseband unit corresponding to each of the plurality of antenna elements, and distributes the plurality of distributed digitals. Is a digital signal processing unit that synthesizes transmission signals corresponding to each antenna element after multiplying each transmission signal by a corresponding component of the weight matrix, and the antenna is a transmission signal synthesized by the digital signal processing unit A plurality of amplifiers may be further provided that amplify each and supply the amplified antenna element to the corresponding antenna element.
In this case, since signal processing from distribution to synthesis of transmission signals generated in the baseband unit can be performed by digital signal processing, advanced communication control can be performed compared to the case where the signal processing is performed by analog signal processing. It can be carried out.

(5) In the wireless communication device, the signal processing unit distributes each of the plurality of digital transmission signals generated by the baseband unit corresponding to each of the plurality of antenna elements, and distributes the plurality of distributed digital signals. A digital signal processing unit that synthesizes the transmission signals corresponding to each antenna element after multiplying each transmission signal by a corresponding component of the weight matrix,
A plurality of amplifiers may be further provided that are provided on the front side of the antenna and amplify each of the plurality of transmission signals.
In this case, since signal processing from distribution to synthesis of transmission signals generated in the baseband unit can be performed by digital signal processing, advanced communication control can be performed compared to the case where the signal processing is performed by analog signal processing. It can be carried out.

(6) In the wireless communication device, in the weight matrix, it is preferable that weight row vectors or weight column vectors corresponding to a plurality of transmission signals generated in the baseband unit are orthogonal to each other.
Here, the weight row vectors or the weight column vectors are “orthogonal” to each other means that the sum of the cross correlations of the two weight row vectors or weight column vectors becomes zero.
In this case, the cross-correlation of a plurality of transmission signals for the same region can be reduced.

(7) When the weight matrix is generated based on a discrete Fourier transform matrix, a mobile terminal that receives a plurality of transmission signals transmitted from one antenna strongly receives only a specific transmission signal depending on the reception position. There is a case. In this case, since the power between transmission signals varies, the effect of the MIMO communication cannot be exhibited sufficiently.
For this reason, it is preferable that the weight matrix is generated based on a discrete cosine transform matrix. In this case, the mobile terminal can receive a plurality of transmission signals transmitted from one antenna with good balance. As a result, since the power between transmission signals does not vary when the mobile terminal receives a plurality of transmission signals, the effect of MIMO communication is exhibited compared with the case where weight row examples are generated based on the discrete Fourier transform matrix. It becomes easy.

(8) In the wireless communication apparatus, as a weight row vector or weight column vector candidate corresponding to each of a plurality of transmission signals generated in the baseband section in the weight matrix, the weight row vector or weight column vector A selection unit that selects a number of weight candidates greater than the number based on a tilt angle of a beam to the region, and a weight candidate that satisfies a desired communication quality among the weight candidates selected by the selection unit. It is preferable to further include a determination unit that determines a row vector or a weight column vector.

In this case, the selection unit selects a number of weight candidates that are candidates for weight row vectors or weight column vectors corresponding to each of a plurality of transmission signals generated in the baseband unit, based on the tilt angle of the beam to the region. Therefore, these weight candidates can be narrowed down easily and quickly. Moreover, since the determination unit determines a weight candidate satisfying a desired communication quality from among a large number of weight candidates as a weight row vector or a weight column vector, the desired communication quality can be obtained.

(9) In the wireless communication apparatus, as a weight row vector or weight column vector candidate corresponding to each of a plurality of transmission signals generated in the baseband unit in the weight matrix, the weight row vector or weight column vector A selection unit that selects a number of weight candidates greater than the number based on a tilt angle of a beam to the region, and a weight candidate that satisfies a desired communication quality among the weight candidates selected by the selection unit. A decision unit that decides as a row vector or a weight column vector, and the row vector or column vector of the discrete cosine transform matrix is preferably the weight candidate selected by the selection unit.

In this case, the selection unit selects a number of weight candidates that are candidates for weight row vectors or weight column vectors corresponding to each of a plurality of transmission signals generated in the baseband unit, based on the tilt angle of the beam to the region. Therefore, these weight candidates can be narrowed down easily and quickly. In addition, since the row vector or the column vector of the discrete cosine transform matrix is a weight candidate selected by the selection unit, a weight matrix can be easily generated based on the discrete cosine transform matrix. Furthermore, since the determination unit determines a weight candidate satisfying a desired communication quality from among a large number of weight candidates as a weight row vector or a weight column vector, the desired communication quality can be obtained.

(10) A method for determining a weight matrix according to an embodiment of the present invention is a method for determining a weight matrix for multiplying a plurality of transmission signals for the same region generated in a baseband unit, in the weight matrix, As a weight row vector or weight column vector candidate corresponding to each of a plurality of transmission signals generated in the baseband unit, a larger number of weight candidates than the number of the weight row vector or weight column vector are assigned to the region. A selection step for selecting based on the tilt angle of the beam, and a determination step for determining, as the weight row vector or the weight column vector, a weight candidate that satisfies a desired communication quality among the weight candidates selected in the selection step. Including.

According to the weight matrix determination method, in the selection step, a number of weight candidates that are candidates for weight row vectors or weight column vectors corresponding to each of a plurality of transmission signals generated in the baseband unit are transmitted to a region. Since the selection is made based on the tilt angle, the weight candidates can be narrowed down easily and quickly. Further, in the determining step, the weight candidate satisfying the desired communication quality among the many weight candidates is determined as the weight row vector or the weight column vector, so that the desired communication quality can be obtained.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Overall configuration of wireless communication device>
FIG. 1 is a diagram illustrating a wireless communication apparatus according to the first embodiment of the present invention. In the figure, a wireless communication device 1 is used as a base station device in a wireless communication system for mobile phones to which LTE (Long Term Evolution) is applied, for example, and is a mobile terminal (not shown) such as a mobile phone. It has a function of performing wireless communication.
As shown in FIG. 1, the wireless communication device 1 includes a baseband unit (BBU) 2 that is a baseband unit, and an antenna system 3.

The baseband unit 2 is connected to the antenna system 3 by a signal transmission path (optical transmission path or electrical transmission path) 4 extending from the baseband unit 2.
The baseband unit 2 has a function of performing digital modulation processing on transmission data given from a higher-level network and generating a plurality of transmission baseband signals for the same cell C (described later) as digital signals. .
The baseband unit 2 gives a transmission baseband signal (I / Q signal) obtained by modulating transmission data to the antenna system 3 via the signal transmission path 4.

Further, the baseband unit 2 acquires a reception baseband signal (I / Q signal) which is a digital signal given from the antenna system 3 via the signal transmission path 4, and performs digital demodulation processing on the reception baseband signal. To generate received data. The baseband unit 2 gives the received data obtained by demodulating the received baseband signal to the upper network.
As described above, the baseband unit 2 has a function of performing processing such as digital modulation / demodulation processing on data and baseband signals transmitted and received by wireless communication.

The antenna system 3 includes a plurality (three in the illustrated example) of antennas 6 that are supported upward by support columns 5.
Each antenna 6 is set as a cell C in which one area when the periphery of the wireless communication apparatus 1 is divided into three is an area where communication with a mobile terminal is possible.
The antenna system 3 includes the three antennas 6, thereby forming a cell C that can communicate with the mobile terminal around the antenna system 3.

As will be described later, each antenna 6 of the present embodiment includes a plurality of antenna elements, and the tilt angle (directivity) of the antenna 6 is adjusted by adjusting the phase and gain of each signal transmitted by each antenna element. Control). Thereby, each antenna 6 can transmit a plurality (two in the illustrated example) of transmission signals along the direction away from the antenna 6 at different tilt angles toward the same region (cell).
The “area” in the present embodiment is a single cell C without sector division. However, when the single cell C is divided into a plurality of sectors, the single sector is designated as “area”. It is also good. That is, the “area” may be an area where a mobile terminal that performs radio communication with the radio communication apparatus 1 can move without handover.

<About the antenna system configuration>
FIG. 2 is a block diagram showing a configuration on the transmission side of the antenna system 3 according to the first embodiment. The antenna system 3 in the present embodiment includes an active antenna system configured to perform signal processing such as transmission signal distribution, phase adjustment, and synthesis by analog signal processing.
The antenna system 3 includes a digital signal processing unit 10, an analog signal processing unit 7, and an antenna 6. The antenna 6 includes a plurality (six in the illustrated example) of antenna elements 9 and a plurality (six in the illustrated example) of power amplifiers 18 corresponding to the respective antenna elements 9.

The digital signal processing unit 10 is provided with a plurality (two in the illustrated example) of transmission baseband signals for the same region from the baseband unit 2. Hereinafter, one of these two transmission baseband signals is also referred to as a first transmission baseband signal, and the other is also referred to as a second transmission baseband signal.
The digital signal processing unit 10 performs digital signal processing on the first transmission baseband signal and the second transmission baseband signal as necessary, and then supplies the transmission baseband signal to the analog signal processing unit 7.

The analog signal processing unit 7 distributes each of the plurality of transmission signals given from the digital signal processing unit 10 corresponding to each of the plurality of antenna elements 9, and performs gain adjustment and phase adjustment on each of the plurality of distributed transmission signals. It functions as a signal processing unit that synthesizes transmission signals corresponding to the antenna elements 9 after multiplying corresponding components of a weight matrix (described later).
The analog signal processing unit 7 includes a plurality of digital-analog converters 11, a plurality of up-converters 12, a distributor 14, a plurality of variable attenuators 15, a plurality of phase shifters 16, and a plurality of synthesizers 17. It has.

A pair of digital-analog converters 11 is provided corresponding to each of the two transmission baseband signals. One digital-to-analog converter 11a is supplied with a first transmission baseband signal from the digital signal processing unit 10, and the other digital-to-analog converter 11b is supplied with a second transmission baseband signal from the digital signal processing unit 10. It is done.

The digital-analog converter 11a has a function of converting the first transmission baseband signal, which is a digital signal, into an analog signal. The digital-analog converter 11b has a function of converting the second transmission baseband signal, which is a digital signal, into an analog signal.
The digital-analog converter 11 (11a, 11b) supplies the first transmission baseband signal and the second transmission baseband signal converted into analog signals to the up-converter 12.

A pair of up-converters 12 are provided corresponding to each of the pair of digital-analog converters 11. One upconverter 12a is supplied with a first transmission baseband signal converted into an analog signal, and the other upconverter 12b is supplied with a second transmission baseband signal converted into an analog signal.

The up-converter 12a multiplies the first transmission baseband signal by the radio frequency local signal generated by the oscillator 13 to convert the first transmission baseband signal into a radio frequency signal (first radio frequency signal) (up-conversion). ) Function.
The up-converter 12b multiplies the second transmission baseband signal by the radio frequency local signal generated by the oscillator 13 to convert the second transmission baseband signal into a radio frequency signal (second radio frequency signal) (up-conversion). ) Function.
The up-converter 12 (12a, 12b) includes a first radio frequency signal obtained by frequency-converting the first transmission baseband signal and a second radio frequency signal obtained by frequency-converting the second transmission baseband signal. Is applied to the distributor 14.

A pair of distributors 14 is provided corresponding to each of the pair of digital-analog converters 11. One distributor 14a is supplied with the first radio frequency signal from the up converter 12a, and the other distributor 14b is supplied with the second radio frequency signal from the up converter 12b.

The distributor 14a distributes the first radio frequency signal into a plurality of parts corresponding to the plurality of antenna elements 9 respectively.
The distributor 14b distributes the second radio frequency signal to a plurality of antenna elements 9 corresponding to each of the plurality of antenna elements 9.
In this embodiment, since the antenna 6 includes six antenna elements 9, the distributors 14a and 14b distribute the radio frequency signal supplied from the up-converter 12 to six.

A plurality of synthesizers 17 are provided in the subsequent stage of both distributors 14a and 14b. A plurality (six) of combiners 17 are provided corresponding to each of the plurality of antenna elements 9. Each combiner 17 is connected to each distributor 14 via a plurality of phase shifters 16 and a plurality of variable attenuators 15.

The radio frequency signals distributed by both distributors 14a and 14b are given to the combiner 17 after gain adjustment by the variable attenuator 15 and phase adjustment by the phase shifter 16.

Among the radio frequency signals distributed by the distributors 14a and 14b, each of the combiners 17 is given a radio frequency signal distributed corresponding to the same antenna element.
Each combiner 17 is configured to synthesize radio frequency signals distributed corresponding to the same antenna element.

For example, in FIG. 2, the synthesizer 17 located at the uppermost position on the paper surface is provided corresponding to the antenna element 9 positioned at the uppermost position on the paper surface. The synthesizer 17 located on the uppermost side of the paper surface includes a radio frequency signal distributed corresponding to the antenna element 9 located on the uppermost side of the paper surface by the distributor 14a and the uppermost position on the paper surface by the distributor 14b. And a radio frequency signal distributed corresponding to the antenna element 9 to be transmitted.

Thus, each synthesizer 17 is provided with the radio frequency signal from the distributor 14a and the radio frequency signal from the distributor 14b, which are signals corresponding to the same antenna element 9.
Each combiner 17 combines the radio frequency signals corresponding to these same antenna elements 9 and outputs the combined signal.

The combined signal output from each combiner 17 is supplied to the power amplifier 18 of the antenna 6, amplified by the power amplifier 18, and then supplied to the antenna element 9.
The combined signal given to each antenna element 9 is radiated into the space from each antenna element 9 and transmitted as a radio signal.

The plurality of variable attenuators 15 are provided after the distributor 14 and between the distributor 14 and the phase shifter 16. The plurality of variable attenuators 15 are connected between the plurality of first variable attenuators 15 a connected between one distributor 14 a and the phase shifter 16, and between the other distributor 14 b and the phase shifter 16. A plurality of second variable attenuators 15b.
A plurality (six) of first variable attenuators 15a and second variable attenuators 15b are provided corresponding to the plurality of antenna elements 9, respectively.

The plurality of first variable attenuators 15a is provided with the first radio frequency signal distributed by one distributor 14a.
The plurality of first variable attenuators 15a perform gain adjustment for each of the first radio frequency signals distributed by the distributor 14a.

The plurality of second variable attenuators 15b are supplied with the second radio frequency signal distributed by the other distributor 14b.
The plurality of second variable attenuators 15b perform gain adjustment on each of the second radio frequency signals distributed by the distributor 14b.
Thus, the variable attenuator 15 performs gain adjustment for each of the plurality of transmission signals (the first radio frequency signal and the second radio frequency signal) in the plurality of antenna elements 9.

The plurality of phase shifters 16 are provided after the distributor 14 and between the variable attenuator 15 and the combiner 17. The plurality of phase shifters 16 include a plurality of first phase shifters 16 a connected between the first variable attenuator 15 a and each combiner 17, a second variable attenuator 15 b, and each combiner 17. And a plurality of second phase shifters 16b connected to each other. A plurality (six) of first phase shifters 16a and second phase shifters 16b are provided corresponding to the plurality of antenna elements 9, respectively. Further, the first phase shifter 16a and the second phase shifter 16b are formed of a semiconductor phase shifter configured to switch a line by a semiconductor switch.

The plurality of first phase shifters 16a are supplied with the first radio frequency signal whose gain is adjusted by the first variable attenuator 15a.
The plurality of first phase shifters 16a perform phase adjustment for each of the first radio frequency signals whose gains are adjusted by the first variable attenuator 15a. Accordingly, the plurality of first phase shifters 16a can control the tilt angle (directivity) of the antenna element 9 when the first radio frequency signal is transmitted from each of the plurality of antenna elements 9.

The plurality of second phase shifters 16b are provided with the second radio frequency signal whose gain is adjusted by the second variable attenuator 15b.
The plurality of second phase shifters 16b perform phase adjustment on each of the second radio frequency signals whose gains are adjusted by the second variable attenuator 15b. Thus, the plurality of second phase shifters 16b can control the tilt angle (directivity) of the antenna element 9 when the second radio frequency signal is transmitted from each of the plurality of antenna elements 9.

The plurality of first phase shifters 16 a and the plurality of second phase shifters 16 b include the tilt angle when the first radio frequency signal is transmitted from the plurality of antenna elements 9, and the second radio frequency signal is transmitted to the plurality of antenna elements 9. The phase adjustment is performed so that the tilt angles at the time of transmission are different from each other.

As described above, the phase shifter 16 has a tilt angle (directivity) for each of the plurality of transmission signals (the first radio frequency signal and the second radio frequency signal) in the plurality of antenna elements 9 corresponding to each of the plurality of transmission signals. The phase adjustment is performed for each of the plurality of transmission signals (the first radio frequency signal and the second radio frequency signal) so as to obtain a tilt angle.

As described above, the first radio frequency signal distributed by the distributor 14a and the second radio frequency signal distributed by the distributor 14b are respectively adjusted in gain by the variable attenuator 15 and phase adjusted by the phase shifter 16. Is applied to each synthesizer 17.
Each combiner 17 combines the first radio frequency signal and the second radio frequency signal corresponding to the same antenna element 9 and outputs a combined signal.

The combined signal output from each combiner 17 is amplified by the power amplifier 18 of the antenna 6 and given to each antenna element 9, and transmitted from each antenna element 9 as a radio signal. Each antenna element 9 can transmit the first radio frequency signal and the second radio frequency signal by transmitting a synthesized signal obtained by synthesizing the first radio frequency signal and the second radio frequency signal.

The first radio frequency signal transmitted from each antenna element 9 is transmitted by controlling the tilt angle by the plurality of first phase shifters 16a.
Further, the second radio frequency signal transmitted from each antenna element 9 is transmitted by controlling the tilt angle by the plurality of second phase shifters 16b to be different from the tilt angle by the plurality of first phase shifters 16a. Is done.
Thereby, the antenna system 3 can transmit a plurality of transmission signals at different tilt angles toward the same region.

<Regarding control configuration of wireless communication device>
FIG. 3 is a block diagram illustrating a control configuration of the wireless communication device 1.
The wireless communication device 1 includes a control unit 30 that individually controls the plurality of variable attenuators 15 and the plurality of phase shifters 16.
The control unit 30 is configured by a computer including a CPU, a storage unit, and the like. The control unit 30 reads out a program stored in the storage unit, realizes each functional unit of the control unit 30 described below, and performs various processes. Has the function to execute.

The control unit 30 is connected to the baseband unit 2 and receives control information including a control command for changing the tilt angle of each antenna element 9 and a carrier frequency from the baseband unit 2.
The control unit 30 has a function of determining a weight matrix to be multiplied by the plurality of radio frequency signals distributed by the distributor 14 based on the control information received from the baseband unit 2. Then, the control unit 30 multiplies a plurality of radio frequency signals distributed by the distributor 14 by each component of the determined weight matrix, so that the corresponding variable attenuator 15 and phase shifter based on each component 16 is controlled.

When the radio frequency signal given from the baseband unit 2 is x and the transmission signal radiated from the antenna element 9 is y, the relationship between each signal x, y and the weight matrix w is expressed by the following equation (1). Is done.
y = w ^H x (1)
Here, the superscript H represents a complex conjugate transpose.

The weight matrix w of this embodiment is generated based on a Discrete Cosine Transform (DCT) matrix B. This DCT matrix B is represented by a row example of N rows and N columns (N × N), where N is the number of transmission signals y. A component B _mn of m rows and n columns of the DCT matrix B is expressed by the following equations (2) and (3).

Here, equation (2) shows a case where n = 1, and equation (3) shows a case where n ≠ 1.

The weight matrix w includes M row vectors selected and determined from N row vectors of the DCT matrix B, where M is the number of radio frequency signals x. That is, the weight matrix w is represented by a matrix of M rows and N columns (M × N). When Expression (1) is expressed as a matrix, it is expressed as Expression (4) below.

In the present embodiment, the number (M) of radio frequency signals given from the baseband unit 2 is two, and the number (N) of transmission signals radiated from the antenna element 9 is six. ) Is represented by the following formula (5).

Here, x ₁ is the first radio frequency signal, x ₂ represents the second radio frequency signal.

In the weight matrix w of the present embodiment, each component of _one weight row vector w ₁ (w ₁₁ ... W ₁₆ ) is multiplied by each of the six first radio frequency signals distributed by the distributor 14a. That is, the control unit 30 controls the corresponding variable attenuator 15a and phase shifter 16a based on each component of the weight row vector w ₁ (w ₁₁ ... W ₁₆ ).
For example, the control unit 30 multiplies the first radio frequency signal distributed to the uppermost side in FIG. 3 by one component w ₁₁ of the weight row vector w ₁ (w ₁₁ ... W ₁₆ ). in order to control on the basis of the variable attenuator 15a and the phase shifter 16a located most on the upper side in the component w _11.

In the weight matrix w of the present embodiment, each component of the other weight row vector w ₂ (w ₂₁ ... W ₂₆ ) is multiplied by each of the six second radio frequency signals distributed by the distributor 14b. The That is, the control unit 30 controls the corresponding variable attenuator 15b and phase shifter 16b based on each component of the weight row vector w ₂ (w ₂₁ ... W ₂₆ ).
For example, the control unit 30 multiplies the second radio frequency signal distributed to the lowermost side in FIG. 3 by one component w ₂₆ of the weight row vector w ₂ (w ₂₁ ... W ₂₆ ). to be controlled based on the variable attenuator 15b and the phase shifter 16b located on paper lowermost in component w _26.

The weight row vector w ₁ (w ₁₁ ... W ₁₆ ) and the weight row vector w ₂ (w ₂₁ ... W ₂₆ ) of the weight matrix w are orthogonal to each other. That is, the control unit 30 controls the plurality of variable attenuators 15 and the plurality of phase shifters 16 so that the two weight row vectors w ₁ and w ₂ are orthogonal to each other. Here, “perpendicular” means that the sum of the cross-correlation between the _two weight row vectors w ₁ and w ₂ becomes zero.
The weight matrix w of the present embodiment is set to multiply the radio frequency signal by the weight row vector, but may be set to multiply the weight column vector.

<Determination of weight matrix>
3, the control unit 30, each weight row vector w ₁ of the weight matrix w, w a selection unit 31 for selecting a plurality of weight candidates as _second candidate, the weight row vector w ₁ from among the selected weights candidates , W ₂ .

The selection unit 31 has a function of selecting a larger number of weight candidates than the number of weight row vectors of the weight matrix w from among a plurality of weight candidates (here, weight row vectors) stored in advance in the storage unit. is doing. At that time, the selection unit 31 selects weight candidates based on the tilt angle of the beam toward the region (cell C) included in the control information received from the baseband unit 2.

In the present embodiment, N (six) row vectors of the discrete cosine transform matrix B corresponding to an angle range of 180 degrees from the upward direction to the downward direction of the tilt angle of the antenna element 9 are stored as weight candidates. Previously stored in the unit. The selection unit 31 selects and selects weight candidates corresponding to an angle range close to the tilt angle of the beam to the region (cell C) from these six weight candidates. At that time, the selection unit 31 selects three or more weight candidates so that the number is larger than the number of weight row vectors (two) in the weight matrix w.

Note that all weight candidates stored in the storage unit satisfy the relationship of the following formula (6) so as to be orthogonal to each other.

The determination unit 32 of the control unit 30 determines weight candidates satisfying a desired communication quality among the plurality of weight candidates selected by the selection unit 31 as the weight row vectors w ₁ and w ₂ of the weight matrix w. It has a function.
Specifically, the determination unit 32 first performs wireless communication using two arbitrary weight candidates as two weight row vectors w ₁ and w ₂ from among a plurality of selected weight candidates, The communication quality is determined.

The determination of the communication quality is repeatedly performed for all combinations that can be combined as a set of two of the selected plurality of weight candidates.
Then, the determination unit 32 determines a set that satisfies the most desired communication quality as the weight row vectors w ₁ and w ₂ .

FIG. 4 is a flowchart showing a procedure for determining the weight matrix w executed by the control unit 30.
First, the selection unit 31 of the control unit 30 uses N row vectors of the discrete cosine transform matrix B as candidates for the weight row vectors w ₁ and w ₂ corresponding to the first radio frequency signal and the second radio frequency signal, respectively. , K weight candidates larger than the number of weight row vectors w ₁ and w ₂ are selected based on the tilt angle of the beam (step S1, selection step).

Next, the determination unit 32 of the control unit 30 sets the variable i = 1 as an initial setting (step S2) and then sets the variable j = i + 1 (step S3). Then, the determination unit 32 sets weight row vectors w _i and w _j that are a set of two weight candidates from the selected weight candidates as temporary weight row vectors w ₁ and w ₂ (step S4). .

Next, the determination unit 32 controls the corresponding variable attenuator 15 and phase shifter 16 based on the weight row vectors w _i and w _j and actually performs wireless communication to determine the communication quality (step S5). ). Thereafter, the determination unit 32 determines whether or not the variable j = k (step S6).

When the determination result of step S6 is negative, the determination unit 32 sets the variable j = j + 1 (step S7), and then returns to step S4.
On the other hand, if the determination result of step S6 is affirmative, the determination unit 32 determines whether or not the variable i = k after setting the variable i = i + 1 (step S8) (step S9).

When the determination result of step S9 is negative, the determination unit 32 returns to step S3.
On the other hand, when the determination result in step S9 is affirmative, that is, when the determination of the communication quality for all the combinations that can be combined as two sets of the selected k weight candidates is completed, the determination unit 32 Determines a set of weight candidates satisfying the most desired communication quality as weight row vectors w ₁ and w ₂ of the weight matrix w (step S10, determination step).

<About modification>
The weight matrix w of the present embodiment is generated based on a DCT matrix, but may be generated based on a discrete Fourier transform (DFT) matrix. In this case, the component B ′ _mn of m rows and n columns of the DFT matrix B ′ is expressed as the following equation (7).

Here, j is an imaginary unit.

As described above, when the weight example w is generated based on the DFT matrix B ′, the control unit 30 does not need to perform gain adjustment, and thus the variable attenuator 15 (see FIG. 2) is not necessary. For this reason, compared with the case where the weight row example w is generated based on the DCT matrix B, a reduction in power loss can be suppressed.

The weight matrix w may be generated based on a Hadamard transformation matrix other than the DCT matrix and the DFT matrix. In this case, the Hadamard transform matrix H is an example of N rows and N columns (N × N), like the DCT matrix B, and is represented by the following equation (8).

Here, H ₂ is a 2 × 2 matrix having “1” and “−1” as components, and k is an integer of 2 or more.

In this way, when the weight row example w is generated based on the Hadamard transform matrix H, the components of the matrix H are only “1” and “−1”, so that phase adjustment and the like can be easily performed. This simplifies the implementation of the function of multiplying each of the plurality of transmission signals by the corresponding component of the weight matrix w.
The weight matrix w may be generated based on a matrix other than the DCT matrix, the DFT matrix, and the Hadamard transform matrix.

<About antenna performance>
FIG. 5 is a diagram illustrating the vertical directivity of the antenna when the weight matrix is generated based on the DFT matrix. FIG. 6 is a diagram illustrating the vertical plane directivity of the antenna when the weight matrix is generated based on the DCT matrix.
5 and 6 show the vertical plane directivity when four transmission signals are transmitted, and the vertical plane directivity of each transmission signal indicates the line type as a thick solid line, a dotted line, It is divided into a thin solid line and a broken line.

As shown in FIG. 5, in the vertical plane directivity of the antenna when the weight matrix is generated based on the DFT matrix, the portion of the four main beams that overlap in the horizontal direction in the drawing between adjacent beams is small. For this reason, it turns out that a mobile terminal receives only a specific transmission signal strongly by the receiving position.

On the other hand, as shown in FIG. 6, in the antenna vertical plane directivity when the weight matrix is generated based on the DCT matrix, compared to the vertical plane directivity shown in FIG. The portion where the adjacent beams overlap in the horizontal direction in the figure is large. For this reason, it can be seen that the mobile terminal can receive four transmission signals transmitted from one antenna in a balanced manner.

<About effect>
As described above, according to the wireless communication device 1 of the present embodiment, each of the plurality of transmission signals for the same region generated by the baseband unit 2 corresponds to each of the plurality of antenna elements 9 included in one antenna 6. The transmission signals corresponding to the antenna elements 9 are synthesized by dividing each of the distributed transmission signals and multiplying each of the distributed transmission signals by a weight matrix. For this reason, it is possible to transmit a plurality of transmission signals for the same region by sharing one antenna 6. As a result, a plurality of transmission signals for the same region can be transmitted by a smaller number of antennas 6 than the number of transmission signals.

Further, the plurality of digital / analog converters 11 are provided in front of the plurality of distributors 14. For this reason, the digital-analog converter 11 may be provided corresponding to each of a plurality of transmission signals for the same region, and the digital-analog conversion is performed as compared with the case where the digital-analog converter 11 is provided for each of the plurality of antenna elements 9. The number of vessels 11 can be reduced. As a result, the cost can be reduced.

Further, since the phase shifter 16 is provided in a stage prior to the power amplifier 18, the transmission signal before amplification is given to the phase shifter 16. Since the transmission signal before amplification has lower power compared to the transmission signal after amplification, the phase shifter 16 using a semiconductor phase shifter having a relatively low value of signal power that can be handled is configured. be able to. As a result, it is possible to use the phase shifter 16 that is smaller and lower in cost, and can be further reduced in cost and size.

In the weight matrix w, the weight row vectors w ₁ and w ₂ corresponding to the plurality of transmission signals generated by the baseband unit 2 are orthogonal to each other. Cross-correlation can be reduced.
Further, since the weight matrix w is generated based on the DCT matrix B, the mobile terminal can receive a plurality of transmission signals transmitted from one antenna 6 with good balance. As a result, since the power between transmission signals does not vary when the mobile terminal receives a plurality of transmission signals, the effect of MIMO communication can be easily achieved compared to the case where the weight row example w is generated based on the DFT matrix. Become.

In addition, in the selection unit 31 of the control unit 30, a large number of weight candidates that are candidates for the weight row vectors w ₁ and w ₂ corresponding to the plurality of transmission signals generated by the baseband unit 2 are obtained. Since the selection is based on the tilt angle, these weight candidates can be narrowed down easily and quickly. In addition, since the row vector of the discrete cosine transform matrix B is a weight candidate selected by the selection unit 31, the weight matrix w can be easily generated based on the DCT matrix B. Furthermore, since the determination unit 32 of the control unit 30 determines the weight candidates satisfying the desired communication quality from among the many weight candidates as the weight row vectors w ₁ and w ₂ , the desired communication quality can be obtained.

<About the second embodiment>
FIG. 7 is a block diagram illustrating a configuration on the transmission side of the antenna system 3 included in the wireless communication device 1 according to the second embodiment of the present invention.
The antenna system 3 in the present embodiment includes a passive antenna system configured to perform signal processing such as distribution, phase adjustment, and synthesis of transmission signals by analog signal processing. That is, the antenna system 3 of the present embodiment is different from the antenna system 3 of the first embodiment in that the power amplifier 18 is provided on the upstream side of the antenna 6.

In FIG. 7, the power amplifier 18 of the present embodiment is provided between the up converter 12 (12a, 12b) and the distributor 14 (14a, 14b) of the analog signal processing unit 7.
The up-converter 12 (12a, 12b) includes a first radio frequency signal obtained by frequency-converting the first transmission baseband signal and a second radio frequency signal obtained by frequency-converting the second transmission baseband signal. Is supplied to the power amplifier 18.

A pair of power amplifiers 18 is provided corresponding to each of the pair of digital-analog converters 11. One power amplifier 18a is supplied with the first radio frequency signal from the up converter 12a, and the other power amplifier 18b is supplied with the second radio frequency signal from the up converter 12b. The power amplifier 18a amplifies the first radio frequency signal and supplies it to the distributor 14a. In addition, the power amplifier 18b amplifies the second radio frequency signal and supplies it to the distributor 14b.
The power amplifier 18 is included in the analog signal processing unit 7, but between the analog signal processing unit 7 and the antenna 6, that is, between the plurality of antenna elements 9 corresponding to the plurality of combiners 17. It may be provided.

The antenna 6 of the present embodiment is composed of only a plurality of antenna elements 9. Each antenna element 9 is provided with a synthesized signal synthesized by a corresponding synthesizer 17.
The combined signal given to each antenna element 9 is radiated into the space from each antenna element 9 and transmitted as a radio signal.

The antenna system 3 of the present embodiment is also different from the antenna system 3 of the first embodiment in that the configuration between the distributor 14 and the combiner 17 of the analog signal processing unit 7 is different.
The analog signal processing unit 7 of the present embodiment has a Butler matrix circuit 21 for multiplying each of a plurality of radio frequency signals distributed by both distributors 14a and 14b by corresponding components of the weight matrix w. . By this Butler matrix circuit 21, the weight matrix w is made a DFT matrix.

FIG. 8 is a block diagram showing an example of the configuration of the Butler matrix circuit 21. FIG. 8 illustrates a general Butler matrix circuit that performs phase adjustment for four radio frequency signals.
The Butler matrix circuit 21 includes four 90 degree hybrids 22 to 25 and two −45 degree phase shifters 26 and 27.

A pair of input terminals 28A and 28B are connected to the 90-degree hybrid 22, and a pair of input terminals 28C and 28D are connected to the 90-degree hybrid 23. The input terminals 28A to 28D are connected to the corresponding distributor 14 (see FIG. 7).
A pair of output terminals 29B and 29B are connected to the 90-degree hybrid 24, and a pair of output terminals 29C and 29D are connected to the 90-degree hybrid 25. The output terminals 29A to 29D are connected to the corresponding combiner 17 (see FIG. 7).

One of the outputs of the 90-degree hybrid 22 is connected to the 90-degree hybrid 24 via the −45-degree phase shifter 26, and the other output is connected to the 90-degree hybrid 25.
One of the outputs of the 90-degree hybrid 23 is connected to the 90-degree hybrid 25 via the −45-degree phase shifter 27, and the other output is connected to the 90-degree hybrid 24.
With the above configuration, the radio frequency signals input to the input terminals 28A to 28D are adjusted to phases different from each other and output from the output terminals 29A to 29D.

Other points of the present embodiment are the same as those of the first embodiment.
Note that the weight matrix w of the present embodiment may be generated based on a DCT matrix, a Hadamard transform matrix, or the like other than the DFT matrix. In this case, the analog signal processing unit 7 may use the variable attenuator 15 and the phase shifter 16 as in the first embodiment, instead of the Butler matrix circuit 21.

As described above, according to the wireless communication device 1 of the present embodiment, the plurality of digital / analog converters 11 are provided on the upstream side of the plurality of distributors 14. For this reason, the digital-analog converter 11 may be provided corresponding to each of a plurality of transmission signals for the same region, and the digital-analog conversion is performed as compared with the case where the digital-analog converter 11 is provided for each of the plurality of antenna elements 9. The number of vessels 11 can be reduced. As a result, the cost can be reduced.

<About the third embodiment>
FIG. 9 is a block diagram illustrating a configuration on the transmission side of the antenna system 3 included in the wireless communication device 1 according to the third embodiment of the present invention.
The antenna system 3 in the present embodiment includes an active antenna system configured to perform signal processing such as transmission signal distribution, phase adjustment, and synthesis by digital signal processing.

In FIG. 9, the digital signal processing unit 10 of the present embodiment distributes each of the plurality of transmission signals given from the baseband unit 2 corresponding to each of the plurality of antenna elements 9, and distributes each of the plurality of distributed transmission signals. It functions as a signal processing unit that synthesizes transmission signals corresponding to each antenna element 9 after multiplying corresponding components of the weight matrix.

Specifically, the digital signal processing unit 10 distributes the first transmission baseband signal and the second transmission baseband signal given from the baseband unit 2 to six corresponding to the six antenna elements 9 respectively.
The digital signal processing unit 10 performs gain adjustment and phase adjustment for each distributed first transmission baseband signal, and performs gain adjustment and phase adjustment for each distributed second transmission baseband signal.
Further, the digital signal processing unit 10 transmits a transmission baseband signal distributed corresponding to the same antenna element 9 among the first transmission baseband signal and the second transmission baseband signal subjected to gain adjustment and phase adjustment. These are synthesized and these synthesized signals are given to the analog signal processing unit 7.

The analog signal processing unit 7 of the present embodiment includes a plurality of digital / analog converters 11 and a plurality of up-converters 12.
Six digital-analog converters 11 are provided corresponding to the six antenna elements 9 respectively. Each digital-analog converter 11 has a function of converting a synthesized signal of a corresponding digital signal into an analog signal. Each digital-to-analog converter 11 supplies the up-converter 12 with the combined signal converted into an analog signal.

Six up-converters 12 are provided corresponding to the six antenna elements 9 respectively. Each up-converter 12 has a function of converting (up-converting) a synthesized signal into a radio frequency signal (first radio frequency signal) by multiplying a corresponding synthesized signal by a radio frequency local signal generated by the oscillator 13. is doing.
Each up-converter 12 provides a radio frequency signal obtained by frequency-converting the corresponding combined signal to the corresponding power amplifier 18 of the antenna 6.

Six power amplifiers 18 of the antenna 6 are provided corresponding to each of the six antenna elements 9. Each power amplifier 18 amplifies the radio frequency signal and applies it to the corresponding antenna element 9. The radio frequency signal given to each antenna element 9 is radiated into the space from each antenna element 9 and transmitted as a radio signal.

FIG. 10 is a block diagram illustrating a control configuration of the wireless communication apparatus 1 according to the present embodiment.
The control unit 30 of the present embodiment has a function of determining a weight matrix for multiplying a plurality of transmission baseband signals distributed in the digital signal processing unit 10 based on the control information received from the baseband unit 2. Yes. The control unit 30 has a function of controlling the digital signal processing unit 10 to perform gain adjustment and phase shift adjustment of the corresponding transmission baseband signal based on each component of the determined weight matrix. . Other points are the same as in the first embodiment.
Note that the weight matrix w of the present embodiment may be generated based on a DFT matrix, a Hadamard transform matrix, or the like other than the DCT matrix.

As described above, according to the wireless communication device 1 of the present embodiment, since signal processing from distribution to synthesis of transmission signals generated by the baseband unit 2 can be performed by digital signal processing, the signal processing is performed by analog signal processing. Compared with the case where it performs by this, advanced communication control can be performed.

<About the fourth embodiment>
FIG. 11 is a block diagram showing a configuration on the transmission side of the antenna system 3 included in the wireless communication device 1 according to the fourth embodiment of the present invention.
The antenna system 3 in the present embodiment is a modification of the antenna system 3 in the third embodiment, and is a passive antenna system configured to perform signal processing such as distribution, phase adjustment, and synthesis of transmission signals by digital signal processing. Consists of.

That is, the antenna system 3 of the present embodiment is different from the antenna system 3 of the third embodiment in that the power amplifier 18 is included in the analog signal processing unit 7 that is on the upstream side of the antenna 6. Therefore, the antenna 6 of the present embodiment is configured by only a plurality of antenna elements 9. The other points are the same as in the third embodiment.
The analog signal processing unit 7 according to the present embodiment includes the digital-analog converter 11, the up-converter 12, and the power amplifier 18. However, if the analog-signal processing unit 7 includes at least the digital-analog converter 11 and the up-converter 12. good. Further, the weight matrix w of the present embodiment may be generated based on a DFT matrix, a Hadamard transform matrix, or the like other than the DCT matrix.

As described above, also in the wireless communication device 1 according to the present embodiment, signal processing from distribution to synthesis of transmission signals generated by the baseband unit 2 can be performed by digital signal processing. Therefore, the signal processing is performed by analog signal processing. Compared with the case where it performs, advanced communication control can be performed.

<Others>
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Wireless communication device 2 Baseband unit (baseband part)
3 antenna system 4 signal transmission path 5 support 6 antenna 7 analog signal processing unit 9 antenna element 10 digital signal processing unit 11 digital analog converter 11a digital analog converter 11b digital analog converter 12 up converter 12a up converter 12b up converter 13 oscillator 14 distributor 14 a distributor 14 b distributor 15 variable attenuator 15 a first variable attenuator 15 b second variable attenuator 16 phase shifter 16 a first phase shifter 16 b second phase shifter 17 combiner 18 power amplifier 21 Butler matrix Circuit 22 90 degree hybrid 23 90 degree hybrid 24 90 degree hybrid 25 90 degree hybrid 26 -45 degree phase shifter 27 -45 degree phase shifter 28A Input terminal 28B Input terminal 28C Input terminal 28D Input terminal 29A Output terminal 29B Power terminal 29C output terminal 29D output terminal 30 control unit 31 selecting unit 32 determining section C cell (region)

Claims (10)

1. A baseband unit that generates a plurality of transmission signals for the same region;
   An antenna having a plurality of antenna elements;
   Each of the plurality of transmission signals generated in the baseband unit is distributed corresponding to each of the plurality of antenna elements, and each of the plurality of distributed transmission signals is multiplied by a corresponding component of the weight matrix and then transmitted to each antenna element. A signal processing unit for combining corresponding transmission signals;
   A wireless communication device comprising:
2. The signal processing unit
   A plurality of digital-to-analog converters for converting each of a plurality of digital transmission signals generated in the baseband unit into an analog transmission signal;
   A plurality of distributors for distributing each of the converted transmission signals corresponding to each of the plurality of antenna elements;
   A plurality of phase shifters that perform phase adjustment based on corresponding components of the weight matrix for each of the distributed transmission signals;
   A plurality of combiners for combining the transmission signals corresponding to the antenna elements among the phase-adjusted transmission signals;
   The wireless communication apparatus according to claim 1, wherein the antenna further includes a plurality of amplifiers that amplify each of the transmission signals combined by the combiner and apply the amplified signals to the corresponding antenna elements.
3. The signal processing unit
   A plurality of digital-to-analog converters for converting each of a plurality of digital transmission signals generated in the baseband unit into an analog transmission signal;
   A plurality of distributors for distributing each of the converted transmission signals corresponding to each of the plurality of antenna elements;
   A plurality of phase shifters that perform phase adjustment based on corresponding components of the weight matrix for each of the distributed transmission signals;
   A plurality of combiners for combining the transmission signals corresponding to the antenna elements among the phase-adjusted transmission signals;
   The wireless communication apparatus according to claim 1, further comprising a plurality of amplifiers provided on a front side of the antenna and amplifying each of the plurality of transmission signals.
4. The signal processing unit distributes each of the plurality of digital transmission signals generated by the baseband unit corresponding to each of the plurality of antenna elements, and each of the plurality of digital transmission signals distributed includes the weight matrix. A digital signal processing unit that synthesizes transmission signals corresponding to each antenna element after multiplying corresponding components,
   The radio communication apparatus according to claim 1, wherein the antenna further includes a plurality of amplifiers that amplify each of the transmission signals combined by the digital signal processing unit and apply the amplified signals to the corresponding antenna elements.
5. The signal processing unit distributes each of the plurality of digital transmission signals generated by the baseband unit corresponding to each of the plurality of antenna elements, and each of the plurality of digital transmission signals distributed includes the weight matrix. A digital signal processing unit that synthesizes transmission signals corresponding to each antenna element after multiplying corresponding components,
   The wireless communication apparatus according to claim 1, further comprising a plurality of amplifiers provided on a front side of the antenna and amplifying each of the plurality of transmission signals.
6. 6. The weight matrix according to claim 1, wherein weight row vectors or weight column vectors corresponding to a plurality of transmission signals generated in the baseband section are orthogonal to each other in the weight matrix. Wireless communication device.
7. The wireless communication apparatus according to claim 6, wherein the weight matrix is generated based on a discrete cosine transform matrix.
8. As weight row vectors or weight column vector candidates corresponding to each of a plurality of transmission signals generated in the baseband part in the weight matrix, a number of weight candidates larger than the number of weight row vectors or weight column vectors is selected. A selection unit that selects based on the tilt angle of the beam to the region;
   The determination unit according to any one of claims 1 to 7, further comprising: a determination unit that determines, as the weight row vector or the weight column vector, a weight candidate that satisfies a desired communication quality among the weight candidates selected by the selection unit. The wireless communication device according to claim 1.
9. As weight row vectors or weight column vector candidates corresponding to each of a plurality of transmission signals generated in the baseband part in the weight matrix, a number of weight candidates larger than the number of weight row vectors or weight column vectors is selected. A selection unit that selects based on the tilt angle of the beam to the region;
   A determination unit that determines a weight candidate that satisfies a desired communication quality from among the weight candidates selected by the selection unit as the weight row vector or the weight column vector;
   The radio communication apparatus according to claim 7, wherein a row vector or a column vector of the discrete cosine transform matrix is the weight candidate selected by the selection unit.
10. A method for determining a weight matrix for multiplying a plurality of transmission signals for the same region generated in a baseband part,
    As weight row vectors or weight column vector candidates corresponding to each of a plurality of transmission signals generated in the baseband part in the weight matrix, a number of weight candidates larger than the number of weight row vectors or weight column vectors is selected. A selection step of selecting based on the tilt angle of the beam to the region;
    Determining a weight candidate satisfying a desired communication quality among the weight candidates selected in the selection step as the weight row vector or the weight column vector.

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