WO2021024611A1 - Wireless communication system, phase control reflector, and wireless communication method - Google Patents

Abstract

This phase control reflector reflects a wireless signal from a radio base station or a terminal. The phase control reflector controls the phase of a wireless signal reflected toward the terminal or radio base station, on the basis of propagation channel information H_PT between the radio base station and the phase control reflector and propagation channel information H_RP between the phase control reflector and the terminal.

Description

Wireless communication system, phase control reflector and wireless communication method

The present invention relates to a wireless communication system, a phase control reflector and a wireless communication method, and more particularly to a phase control of a wireless signal.

The 3rd Generation Partnership Project (3GPP) has specified Long Term Evolution (LTE), and aims to further speed up LTE with LTE-Advanced (hereinafter referred to as LTE including LTE-Advanced), and the 5th generation mobile communication system. Specifications (also called 5G, New Radio (NR) or Next Generation (NG)) are also underway.

In particular, in order to cope with the explosively increasing traffic volume of mobile communication, 3GPP has a small cell (small cell) using a high frequency band exceeding 52.6 GHz and a large scale (massive) having a large number of antenna elements. ) Massive MIMO (Multiple-Input Multiple-Output) using an antenna is being studied.

By using such a high frequency band, it is possible to widen the bandwidth. In addition, beamforming using a large number of antenna elements makes it possible to compensate for propagation loss that is remarkable in a high frequency band, and Massive MIMO enables spatial multiplexing of a large number of streams.

On the other hand, in such a high frequency band, there is a problem that a dead zone is likely to occur due to the strong straightness of radio waves. Therefore, a method of improving MIMO performance in a multipath environment using a passive repeater has been tried (see Non-Patent Document 1).

When the high frequency band as described above is used and the carrier frequency is high, an increase in phase noise becomes a problem. When a passive repeater as described in Non-Patent Document 1 is used, a certain effect can be expected for eliminating dead zones.

However, the phase of the radio signal received by the terminal (User Equipment, UE) via the repeater may have rotated significantly from the reference value, and may not always be optimal. In 3GPP, PTRS: Phase Tracking RS is specified in order to deal with such phase noise, but appropriate processing on the terminal side is required.

Therefore, the present invention has been made in view of such a situation, and when a high frequency band is used, a wireless communication system, a phase control reflector, and a phase control reflector that can greatly reduce phase noise while eliminating dead zones. The purpose is to provide a wireless communication method.

One aspect of the present disclosure is a radio communication system (wireless communication system 10) including a phase control reflector (phase control reflector 300) that reflects a radio signal from a radio base station (for example, radio base station 150A) or a terminal (UE200). The first propagation channel information acquisition unit (H _PT acquisition unit 310) for acquiring the first propagation channel information (H _PT ) between the radio base station and the phase control reflector, and the phase control reflector. And a second propagation channel information acquisition unit (H _RP acquisition unit 320) for acquiring the second propagation channel information (H _RP ) with the terminal, and the phase control reflector is the first propagation channel information. The phase of the radio signal reflected toward the terminal or the radio base station is controlled based on (H _PT ) and the second propagation channel information (H _RP ).

One aspect of the present disclosure is a phase control reflector (phase control reflector 300) that reflects a radio signal from a radio base station (eg, radio base station 150A) or terminal (UE200), wherein the radio base station and the above. Based on the first propagation channel information ( _HPT ) between the phase control reflector and the second propagation channel information (H _RP ) between the phase control reflector and the terminal, the terminal or the radio base station. The phase of the radio signal reflected toward is controlled.

One aspect of the present disclosure is a step of estimating the first propagation channel information between the radio base station and the phase control reflector, and a step of estimating the second propagation channel information between the phase control reflector and the terminal. And the step of controlling the phase of the radio signal reflected by the phase control reflector toward the terminal or the radio base station based on the first propagation channel information and the second propagation channel information. The method.

FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10. FIG. 2 is a basic configuration diagram of a network using the phase control reflector 300. FIG. 3 is a functional block configuration diagram of the phase control reflector 300. FIG. 4A is a diagram showing an example of forming an antenna beam by a conventional radio base station. FIG. 4B is a diagram showing an example of forming an antenna beam by a radio base station corresponding to Massive MIMO. FIG. 5 is an explanatory diagram of a typical problem when a high frequency band is used. FIG. 6 is a diagram showing a phase optimization operation flow of a radio signal using a phase control reflector. FIG. 7 is a diagram showing an estimation example of propagation channel information (H _PT , H _RP ) according to the first embodiment. FIG. 8 is a diagram showing an estimation example of propagation channel information ( _HPT , _HRP ) according to the second embodiment. FIG. 9 is a diagram showing an estimation example of propagation channel information (H _PT , H _RP ) according to the third embodiment. FIG. 10 is a diagram showing an example of the hardware configuration of the UE 200 and the phase control reflector 300.

Hereinafter, embodiments will be described based on the drawings. The same functions and configurations are designated by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

(1) Overall Schematic Configuration of Wireless Communication System FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10 according to the present embodiment. The wireless communication system 10 is a wireless communication system according to 5G New Radio (NR), and is composed of a plurality of radio base stations and a plurality of terminals.

Specifically, the wireless communication system 10 includes a wireless base station 100, a wireless base station 150A to a wireless base station 150D, and a user terminal 200 (hereinafter, UE200, User Equipment).

Radio base station 100 is a radio base station according to 5G and forms cell C1. Note that cell C1 is a relatively large cell and is called a macro cell.

Radio base stations 150A to 150D are also radio base stations according to 5G, but they form cells C11 to C14, which are relatively small in size, respectively. Cell C11 to cell C14 may be referred to as a small cell, a semi-macro cell, or the like. As shown in FIG. 1, cells C11 to C14 may be formed so as to be included (overlaid) in cell C1 (macro cell).

A macro cell is generally interpreted as a communicable area with a radius of several hundred meters to several tens of kilometers covered by one radio base station. In addition, a small cell is interpreted as a general term for cells that have a small transmission power and cover a small area as compared with a macro cell.

The radio base station 100 and the radio base station 150A to the radio base station 150D may be described as gNodeB (gNB) or BS. In addition, UE200 may be described as MS or the like. Further, the specific configuration of the wireless communication system 10 including the number of wireless base stations and terminals is not limited to the example shown in FIG.

Further, the wireless communication system 10 is not necessarily limited to the wireless communication system according to 5G. For example, the wireless communication system 10 may be a 5G next-generation wireless communication system (may be called Beyond 5G or the like) or a wireless communication system according to Long Term Evolution (LTE).

Radio base station 100 and radio base station 150A to radio base station 150D execute wireless communication according to UE200 and 5G. Radio base station 100 and radio base station 150A to radio base station 150D and UE200 are Massive MIMO, multiple components that generate more directional beam BM by controlling radio signals transmitted from multiple antenna elements. It can support carrier aggregation (CA), which uses carriers (CC) in a bundle, and dual connectivity (DC), which communicates simultaneously between the UE and each of the two NG-RAN Nodes.

In addition, the wireless communication system 10 can also support a high frequency band higher than the following frequency range (FR) specified in 3GPP Release 15.

・ FR1: 410 MHz to 7.125 GHz
・ FR2: 24.25 GHz to 52.6 GHz
Specifically, the wireless communication system 10 supports a frequency band exceeding 52.6 GHz and up to 114.25 GHz. Here, such a high frequency band is referred to as "FR4" for convenience. FR4 belongs to the so-called EHF (extremely high frequency, also called millimeter wave). FR4 is a tentative name and may be called by another name.

Further, the wireless communication system 10 includes a phase control reflector 300. The phase control reflector 300 reflects (may be called a relay or the like) a radio signal transmitted from a radio base station (for example, radio base station 150A). The UE 200 can receive the radio signal reflected by the phase control reflector 300. Further, the phase control reflector 300 reflects the radio signal transmitted to the UE 200. That is, the phase control reflector 300 reflects the radio signal from the radio base station or terminal.

The phase control reflector 300 can change the phase of the radio signal reflected toward the UE 200. From this point of view, the phase control reflector 300 may be referred to as a phase variable reflector. As will be described later, the phase control reflector 300 has a function of changing the phase of the radio signal and relaying the signal, and the name of the reflector does not necessarily have to be used. For example, it may be called a repeater, a repeater, a reflect array, a transmit array, or the like.

(2) Basic Configuration of Network Using Phase Control Reflector Next, the basic configuration of the network using the phase control reflector 300 will be described. FIG. 2 is a basic configuration diagram of a network using the phase control reflector 300.

As shown in FIG. 2, the phase control reflector 300 is interposed between the radio base station 150A (may be another radio base station) and the UE 200, and the radio transmitted / received between the radio base stations 150A and the UE 200. Reflects (relays) the signal.

Specifically, when the radio quality is good, the radio base stations 150A and UE200 directly transmit and receive radio signals without going through the phase control reflector 300.

When the UE 200 detects the deterioration of the radio quality, it transmits a reference signal (RS) to the phase control reflector 300.

Phase control reflector 300, based on the propagation channel information between the radio base stations 150A ~ phase control reflector 300 (H _PT), the propagation channel information between the UE 200 ~ phase control reflector 300 (H _RP), the radio base station 150A Controls the phase of the radio signal transmitted by and reflected towards the UE200. Similarly, the phase control reflector 300, based on the H _PT and H _RP, sent by the UE 200, and controls the phase of the radio signal reflected toward the radio base station 150A.

The propagation channel is an individual communication path for wireless communication, and here, it is a communication path between each transmission / reception antenna (BS ant. And MS ant. In the figure).

The phase control reflector 300 includes a compact multi-element antenna 301 compatible with Massive MIMO, a phase shifter 303 that changes the phase of a radio signal, substantially a radio wave, to a specific phase, and uses the phase shifter 303. , UE200 or radio base station 150A controls the phase of the radio waves reflected (relayed). The specific method of controlling the phase by the phase control reflector 300 will be described later.

(3) Functional Block Configuration of Phase Control Reflector FIG. 3 is a functional block configuration diagram of the phase control reflector 300. As shown in FIG. 3, the phase control reflector 300 includes an _HPT acquisition unit 310, an H _RP acquisition unit 320, a phase control unit 330, and a reflector unit 340.

The H _PT acquisition unit 310 acquires the propagation channel information (H _PT ) between the radio base station 150A (may be another radio base station, the same applies hereinafter) and the phase control reflector 300. In the present embodiment, the _HPT acquisition unit 310 constitutes a first propagation channel information acquisition unit that acquires the first propagation channel information.

Specifically, the _HPT acquisition unit 310 estimates the _HPT based on the reference signal (RS) included in the radio signal transmitted from the radio base station 150A. As the reference signal, for example, Channel State Information-Reference Signal (CSI-RS) can be used. However, other reference signals (for example, Demodulation reference signal (DMRS)) or signals that can serve as a reference signal may be used.

The H _PT acquisition unit 310 may directly estimate the H _PT using the reference signal, or wirelessly (or or) estimate the HP _PT estimated by another node (for example, the radio base station 150A) in the wireless communication system 10. It may be acquired via communication (which may be wired).

The H _RP acquisition unit 320 acquires the propagation channel information (H _RP ) between the phase control reflector 300 and the UE 200. In the present embodiment, the H _RP acquisition unit 320 constitutes a second propagation channel information acquisition unit that acquires the second propagation channel information.

Specifically, the H _RP acquisition unit 320 estimates the H _RP based on the reference signal (RS) included in the radio signal transmitted from the UE 200. For the reference signal, like the H _PT, or the like can be used DMRS or Sounding Reference Signal (SRS).

H _PT and H _RP can be expressed as follows.

M is the number of antennas of the terminal (reception), N is the number of antennas of the wireless base station (transmission), and K is the number of reflectors.

The phase control unit 330 controls the phase of a radio signal (which may be called a radio wave) reflected by the reflector unit 340. Specifically, the phase control unit 330, based on the H _PT and H _RP, to control the phase of the radio signal reflected toward the UE200 or the radio base station 150A.

In the present embodiment, the phase control unit 330, by maximizing the predetermined eigenvalue of H _PT, the combination of the predetermined eigenvalue of H _RP, to control the phase of the radio signal. The predetermined eigenvalue, H _PT, m or n-th eigenvalue included in the H _RP (the m eigenvalues, the n eigenvalues) corresponding to. The specific phase optimization algorithm will be described later.

The reflector unit 340 is composed of functional parts that reflect radio signals (radio waves). Specifically, the reflector unit 340 is composed of a small multi-element antenna 301 corresponding to Massive MIMO and a plurality of phase shifters 303 (see FIG. 2).

In the present embodiment, the phase control reflector 300 can adopt a configuration in which the phase shifter 303 is sub-arrayed. That is, the phase control reflector 300 has a plurality of sub-arrays. Therefore, a different sub-array may be assigned to each terminal, and the phase control unit 330 may control the phase of the radio signal for each terminal by using the sub-array.

Note that instead of the physical phase control reflector 300 sub-array, a digital pseudo-sub-array may be configured, the pseudo-sub-array may be assigned to each terminal, and the phase of the radio signal may be controlled for each terminal. Specifically, the phase control unit 330 controls the phase for each sub-array (that is, a pseudo-sub-array for the terminal) corresponding to one propagation channel selected in MultiUser-MIMO (MU-MIMO).

Alternatively, a plurality of reflector elements constituting the phase control reflector 300 are sequentially assigned according to the communication quality with the terminals (the reflector elements may be assigned to the plurality of terminals so that the quality is equal, or assigned. By doing so, a pseudo sub-array may be constructed and controlled.

Further, the phase control unit 330 may convert the radio signal received from the radio base station 150A or UE200 into a baseband signal (equivalent low frequency system) and control the phase in the equivalent low frequency system. The equivalent low frequency system can be expressed as a virtual system in which only the digital region represented by the phase and amplitude of the radio signal (radio wave) is extracted.

Alternatively, the phase control unit 330 may control the phase of the radio signal in the radio frequency (RF) band without converting to the equivalent low frequency system.

In the present embodiment, the phase control reflector 300 controls (changes) only the phase of the radio signal (radio wave) by the phase control unit 330, and amplifies the power of the reflected (relayed) radio signal. There is no power supply.

(4) Operation of the wireless communication system Next, the operation of the wireless communication system 10 will be described. Specifically, the basic operation of a wireless base station that supports Massive MIMO and the problems when using a high frequency band of several GHz to several tens of GHz or more will be explained, and phase control that can solve the problems will be explained. The operation of transmitting and receiving a radio signal using a reflector will be described.

(4.1) Massive MIMO Transmission FIGS. 4A and 4B show an example of forming an antenna beam by a conventional radio base station and an example of forming an antenna beam by a radio base station corresponding to Massive MIMO, respectively.

As shown in FIG. 4A, the conventional radio base station 100P that does not support Massive MIMO forms a beam BM11 with a wide beam width.

On the other hand, as shown in FIG. 4B, the radio base station 150A corresponding to Massive MIMO can transmit the beam BM21 or the beam BM22 having a beam width narrower than that of the beam BM11.

Massive MIMO generally means MIMO communication using an antenna having 100 or more antenna elements, and wireless communication at a higher speed than before is possible due to the multiplexing effect of multiple streams.

In addition, as shown in FIG. 4B, more advanced beamforming (BF) than before is possible. The beam width can be dynamically changed depending on the frequency band used or the state of UE200, such as beam BM21 or narrower beam BM22. In addition, it is possible to increase the received signal power due to the beamforming (BF) gain by using a narrow beam. Furthermore, effects such as reduction of interference and effective use of wireless resources can be expected.

In particular, when a high frequency band of several GHz to several tens of GHz or more as described above is used, it is possible to secure radio resources in a wider bandwidth than in a low frequency band. Further, since the size of the antenna element is proportional to the wavelength of the radio frequency used, if the number of antenna elements is the same, the antenna can be miniaturized as the frequency increases. That is, even with the same antenna size, a large number of antenna elements can be accommodated. In other words, the decrease in received signal strength due to the increase in propagation loss in the high frequency band can be recovered by the BF gain.

When using a low frequency band, the radio signal (radio wave) transmitted by the radio base station 100P reaches a long distance even if the beam width is wide as in the beam BM11 (see FIG. 4A).

On the other hand, when using the high frequency band as described above, if the beam width is wide like the beam BM21, it will not reach far. By narrowing the beam width like the beam BM22, it will reach far.

(4.2) Problems in Using the High Frequency Band FIG. 5 is an explanatory diagram of typical problems in the case of using the high frequency band. In addition to the problem of the reach of radio waves as described above, when a high frequency band of several GHz to several tens of GHz or more is used, a dead zone is likely to occur due to the strong straightness of radio waves.

As shown in FIG. 5, when the radio base station 150A and UE200 can be seen, there is no effect on the wireless communication between the radio base stations 150A and UE200 even when the high frequency band is used.

If the line of sight between the radio base station 150A and UE200 is obstructed by an obstacle OB such as a building or a tree, the radio quality will be significantly deteriorated. In other words, if the UE200 moves to a dead zone shielded by an obstacle OB, communication may be interrupted.

Considering the existence of applications (remote control, etc.) that take advantage of the high-speed, large-capacity and low-latency characteristics of 5G, dead zones are eliminated and communication within the wireless communication system 10 is not interrupted. It is important that and continue to be connected.

(4.3) Example Next, an example of a radio signal transmission / reception operation using a phase control reflector will be described.

(4.3.1) Outline of operation In this embodiment, a procedure for improving radio quality is executed by using the phase control reflector 300 (see FIGS. 1 and 2).

The outline of the procedure is as follows.

-(Procedure 1): Estimate the propagation channel information ( _HPT ) between the radio base station and the phase control reflector based on the reference signal (or assume that the positions of the radio base station and the phase control reflector are unchanged. , The phase control reflector may be acquired in advance)
- (Step 2): when detecting a radio quality degradation in the terminal transmits a reference signal to the phase control reflector, estimates the propagation channel information between terminals - phase control reflector (H _RP) (or H _PT is Based on the reference signal (RS) included in the radio signal transmitted from UE200, assuming that the radio base station 150A is known and the propagation channel does not fluctuate, the radio base station 150A has radio base stations 150A and UE200. The propagation channel H _RT between them may be obtained and estimated by H _RP = H _RT · H _PT ^-1 or by using the least square method).
-(Procedure 3): Determine the phase combination of the radio signal in the phase control reflector based on the estimated propagation channel information ( _HPT , H _RP ).-(Procedure 4): The radio base station and the terminal are phase control reflectors. FIG. 6 is a flow diagram showing more specifically the operation according to the above-mentioned procedures 1 to 4, in which data is transmitted and received via the above. Specifically, FIG. 6 shows a phase optimization operation flow of a radio signal using a phase control reflector.

As shown in FIG. 6, the radio base station (for example, the radio base station 150A) transmits a reference signal to the phase control reflector 300 (S10). As described above, the type of the reference signal (RS) is not particularly limited, and CSI-RS, DM-RS and the like can be appropriately used.

Phase control reflector 300, based on the reference signal from the radio base station, estimates the H _PT (S20). Specifically, the phase control reflector 300 sets the propagation channel of the radio base station to the phase control reflector 300, that is, the individual communication paths of radio communication between the radio base station and the phase control reflector 300, based on the reference signal. Estimate and generate propagation channel information.

Next, the UE200 (terminal) transmits a reference signal to the phase control reflector 300 (S30). As described above, the type of the reference signal (RS) is not particularly limited, and DM-RS, SRS, or the like can be appropriately used.

Note that the timing at which the UE 200 transmits a reference signal to the phase control reflector 300 is typically when a deterioration in radio quality is detected as described above, but the timing is not necessarily limited to such timing. For example, the UE 200 may send a reference signal to the phase control reflector 300 based on explicit or implicit instructions from the network.

The phase control reflector 300 estimates the H _RP based on the reference signal from the terminal (S40). Specifically, the phase control reflector 300 estimates and propagates the propagation channel of the terminal to the phase control reflector 300, that is, the individual communication path of the wireless communication between the terminal and the phase control reflector 300 based on the reference signal. Generate channel information.

Phase control reflector 300, based on the estimated H _PT and H _RP, reflecting derives the optimum phase combination to be applied to radio signal (relay) (S50). Specifically, the phase control reflector 300 determines the optimum phase combination based on the phase optimization algorithm described later.

The radio base station transmits a radio signal to the phase control reflector 300, and the radio signal is reflected by the phase control reflector 300 toward the terminal. As a result, data is transmitted from the radio base station to the terminal via the phase control reflector 300 (S60).

Similarly, regarding the direction from the terminal to the wireless base station (upward direction), data is transmitted from the terminal to the wireless base station via the phase control reflector 300.

Further, in the flow shown in FIG. 6, the phase control reflector 300 estimates _HPT and H _RP and derives the optimum phase combination applied to the radio signal. However, the estimation of _HPT and H _RP and the phase are derived. Either or both of the derivation of the combination may be performed by the radio base station or the terminal, and the result may be notified (feedback) to the phase control reflector 300.

(4.3.2) Example 1
FIG. 7 shows an estimation example of propagation channel information (H _PT , H _RP ) according to the first embodiment. This embodiment can be applied to a static environment in which the UE200 (terminal) does not move much.

Specifically, the radio base stations 150A and UE200 transmit a reference signal for channel estimation toward the phase control reflector 300. As a result, the phase control reflector 300 estimates the propagation channel information ( _HPT , H _RP ) and derives the optimum phase combination.

When the UE200 detects deterioration of radio quality due to changes in the surrounding propagation environment, the UE200 retransmits the reference signal to the phase control reflector 300 and updates the propagation channel information.

(4.3.3) Example 2
FIG. 8 shows an estimation example of propagation channel information (H _PT , H _RP ) according to the second embodiment. This embodiment can be applied to a dynamic environment in which the UE200 (terminal) moves.

Specifically, when the UE 200 continues to move at a certain speed or higher, such as when the UE 200 is placed in an automobile, the propagation channel information (H _RP ) between the UE 200 and the phase control reflector 300 fluctuates.
Therefore, it is necessary to update the H _RP according to the degree of the fluctuation.

More specifically, the UE 200 updates the H _RP held by the phase control reflector 300 by appropriately transmitting a reference signal to the phase control reflector 300 based on the radio quality (for example, shown in the figure). As such, _H'RP to H " _RP ). The phase control reflector 300 derives the optimum phase combination based on the updated H" _RP .

If it is assumed in advance that the UE 200 will continue to move at a certain speed or higher, the H _RP may be updated at appropriate time intervals regardless of the radio quality.

(4.3.4) Example 3
FIG. 9 shows an estimation example of propagation channel information (H _PT , H _RP ) according to the third embodiment. This embodiment can be applied to a multi-user environment.

In this embodiment, a plurality of phase control reflectors are installed, and one phase control reflector is assigned to each user (Fig.) To realize multi-user communication.

Specifically, FIG. 9 shows an example of 2MU-MIMO. In the example shown in FIG. 9, the phase control reflector 300A is assigned for the UE 200A, and the phase control reflector 300B is assigned for the UE 200B.

The phase control reflector 300A estimates (or acquires) the H ¹ _PT and H ¹ _RP for the UE 200A. In addition, the phase control reflector 300B estimates (or acquires) H ² _PT and H ² _RP for UE 200B.

(4.3.5) Phase Optimization Algorithm The following describes an example of the phase optimization algorithm applied to the above-mentioned phase control reflector.

As described above, if the propagation channel between the transmission antenna and the phase control reflector and H _PT, the propagation channel between the phase control reflector and receiving antennas and H _RP,

The entire channel row example H _RT including the phase component is

Can be expressed as. In the present embodiment, a method for uniquely determining the optimum combination of the phase components is proposed.

Propagation channel information When H _PT and H _RP are decomposed into singular values,

here,

And. W becomes the power component. Also, since U _RP and V_PT ^ H are unitary matrices,

Next,

Then, it can be expressed as follows.

D _RP and D _PT are power components, and χ is a weight component. In the phase optimization algorithm of the present embodiment, W is taken into consideration and the phase combination is derived so as to increase the signal-to-noise ratio (SN ratio).

Here, assuming that the number of antennas M of the terminal (reception) and the number of antennas N of the radio base station (transmission) are less than the number K of the reflectors.

Next,

It can be expressed as. For example, the upper left of the matrix (ψ _RP1 , ψ _PT1 ) corresponds to the first eigenvalue component. Below that ((ψ _RP2 , ψ _PT1 ) corresponds to the second eigenvalue component of H _RP and the first eigenvalue component of H _PT .

In other words, the first m eigenvalues of H _RP, (the power component maximum) maximize the combination of the first n eigenvalues of H _PT If you want to, can be achieved by maximizing the coefficient of xi] _mn.

Specifically, ξ _mn is

It can be expressed as. To maximize ξ _mn ,

Derivation of the optimal combination β _opt of the values of.

For example, when it is desired to increase the first eigenvalue component, the component of ξ11 may be increased. In the phase optimization algorithm in this embodiment, the weight components contained in ξ _mn are in-phased.

For example, assuming a simple 1-bit phase shifter, the phase value will be either 0 or π (or π / 2, 3π / 2), but the weight component contained in ξ _mn will be any of them. It will be aligned to the phase (0, π) or (π / 2, 3π / 2). When the phase (0, π) is used, the imaginary part is discarded and the real part is adjusted to the positive or negative direction. On the other hand, when (π / 2, 3π / 2) is used, the real part is discarded and the imaginary part is adjusted to the positive or negative direction.

In practice, as described above, it is typical to have a phase value of 4 values (2 ² ) or 8 values (2 ³ ).

(5) Action / Effect According to the above-described embodiment, the following action / effect can be obtained. Specifically, the phase control reflector 300, based on the propagation channel information (H _PT and H _RP), can control the phase of the radio signal reflected toward the UE200 or the radio base station 150A.

Therefore, the phase noise included in the radio signal on the receiving side can be greatly reduced. In particular, when a high frequency band of several GHz to several tens of GHz or more is used, it can exert a great effect in reducing phase noise.

Further, since the phase control reflector 300 reflects (relays) the radio signal between the radio base station and the terminal, it can contribute to the elimination of the dead zone even when a high frequency band having high straightness of radio waves is used.

That is, according to the wireless communication system 10, when the high frequency band is used, the phase noise can be greatly reduced while eliminating the dead zone.

In the present embodiment, the phase control reflector 300, by controlling the phase of the radio signal reflected toward the UE200 or radio base station 150A, optimization and predetermined eigenvalues of H _PT, the combination of the predetermined eigenvalue of H _RP To do. Specifically, the phase control reflector 300, based on the phase optimization algorithm described above, the eigenvalues ingredients in the specified H _PT and H _RP, that is, to select the best combination of phase components. As a result, the phase noise can be significantly reduced while using the phase control reflector 300.

In the present embodiment, in the phase control reflector 300, a different sub-array is assigned to each terminal, and the phase of the radio signal can be controlled by using the sub-array. Therefore, appropriate phase control for each terminal can be realized without increasing the number of phase control reflectors 300.

In the present embodiment, the phase control reflector 300 can convert the radio signal received from the radio base station 150A or UE200 into an equivalent low frequency system and control the phase in the equivalent low frequency system. Alternatively, the phase control reflector 300 can control the phase of the radio signal in the radio frequency (RF) band without converting to the equivalent low frequency system. When the phase is controlled in the RF band, the signal conversion to the equivalent low frequency system does not occur, so that the phase control processing can be performed without delay.

Therefore, appropriate phase control of the radio signal can be realized according to the performance or installation conditions required for the phase control reflector 300.

(6) Other Embodiments Although the contents of the present invention have been described above with reference to Examples, the present invention is not limited to these descriptions, and various modifications and improvements are possible. It is self-evident to the trader.

For example, in the above-described embodiment, the direction from the radio base station to the terminal (downward direction) is mainly described, but as appropriately described in the above-described embodiment, the radio from the terminal to the radio base station direction (upward direction) is mainly described. The phase of the signal may also be controlled.

Further, the block configuration diagram (FIG. 3) used in the description of the above-described embodiment shows a block for each functional unit. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or two or more physically or logically separated devices may be directly or indirectly (eg, for example). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. There are broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but only these. I can't. For example, a functional block (constituent unit) that makes transmission function is called a transmitting unit or a transmitter. As described above, the method of realizing each is not particularly limited.

Further, the above-mentioned UE200 (including UE200A and 200B) and the phase control reflector 300 (including the phase control reflectors 300A and 300B) may function as a computer for processing the wireless communication method of the present disclosure. FIG. 10 is a diagram showing an example of the hardware configuration of the UE 200 and the phase control reflector 300. As shown in FIG. 10, the UE 200 and the phase control reflector 300 may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In the following explanation, the word "device" can be read as a circuit, device, unit, etc. The hardware configuration of the device may be configured to include one or more of the devices shown in the figure, or may be configured not to include some of the devices.

Each functional block of the phase control reflector 300 (see FIG. 3) is realized by any hardware element of the computer device or a combination of the hardware elements.

Further, each function or a part of the functions in the phase control reflector 300 is calculated by the processor 1001 by loading predetermined software (program) on the hardware such as the processor 1001 and the memory 1002, and is performed by the communication device 1004. It may be realized by controlling communication or controlling at least one of reading and writing of data in the memory 1002 and the storage 1003.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, and the like.

Further, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. Further, the various processes described above may be executed by one processor 1001 or may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one such as ReadOnlyMemory (ROM), ErasableProgrammableROM (EPROM), Electrically ErasableProgrammableROM (EEPROM), and RandomAccessMemory (RAM). May be done. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can execute the method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, for example, an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, an optical magnetic disk (for example, a compact disk, a digital versatile disk, or a Blu-ray). It may consist of at least one (registered trademark) disk), smart card, flash memory (eg, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. Storage 1003 may be referred to as auxiliary storage. The recording medium described above may be, for example, a database, server or other suitable medium containing at least one of memory 1002 and storage 1003.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like.

Communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be composed of.

The input device 1005 is an input device (for example, keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

In addition, each device such as the processor 1001 and the memory 1002 is connected by the bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

Further, the device includes hardware such as a microprocessor, a digital signal processor (Digital Signal Processor: DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), and a Field Programmable Gate Array (FPGA). The hardware may implement some or all of each functional block. For example, processor 1001 may be implemented using at least one of these hardware.

Further, the notification of information is not limited to the mode / embodiment described in the present disclosure, and may be performed by using another method. For example, information notification includes physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI), upper layer signaling (eg, RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block)). (MIB), System Information Block (SIB)), other signals or combinations thereof. RRC signaling may also be referred to as an RRC message, for example, RRC Connection Setup. ) Message, RRC Connection Reconfiguration message, etc. may be used.

Each aspect / embodiment described in the present disclosure includes LongTermEvolution (LTE), LTE-Advanced (LTE-A), SUPER3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system ( 5G), FutureRadioAccess (FRA), NewRadio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UltraMobile Broadband (UMB), IEEE802.11 (Wi-Fi (registered trademark)) , IEEE802.16 (WiMAX®), IEEE802.20, Ultra-WideBand (UWB), Bluetooth®, and other systems that utilize appropriate systems and at least one of the next generation systems extended based on them. It may be applied to one. Also, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

The order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

In some cases, the specific operation performed by the base station in the present disclosure may be performed by its upper node (upper node). In a network consisting of one or more network nodes having a base station, various operations performed for communication with the terminal are performed by the base station and other network nodes other than the base station (for example, MME or). It is clear that it can be done by at least one of (but not limited to, S-GW, etc.). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

Information and signals (information, etc.) can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

The input / output information may be stored in a specific location (for example, memory) or may be managed using a management table. The input / output information can be overwritten, updated, or added. The output information may be deleted. The input information may be transmitted to another device.

The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Software is an instruction, instruction set, code, code segment, program code, program, subprogram, software module, whether called software, firmware, middleware, microcode, hardware description language, or another name. , Applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, procedures, features, etc. should be broadly interpreted.

In addition, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, a website, where the software uses at least one of wired technology (coaxial cable, fiber optic cable, twist pair, Digital Subscriber Line (DSL), etc.) and wireless technology (infrared, microwave, etc.). When transmitted from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

Note that the terms explained in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms "system" and "network" used in this disclosure are used interchangeably.

In addition, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or using other corresponding information. It may be represented. For example, the radio resource may be one indicated by an index.

The names used for the above parameters are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (eg PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are in any respect limited names. is not it.

In this disclosure, "Base Station (BS)", "Wireless Base Station", "Fixed Station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", " "Access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "cell group" Terms such as "carrier" and "component carrier" can be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (for example, three) cells (also called sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (Remote Radio)). Communication services can also be provided by Head: RRH).

The term "cell" or "sector" refers to a base station that provides communication services in this coverage, and part or all of the coverage area of at least one of the base station subsystems.

In the present disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" may be used interchangeably. ..

Mobile stations can be subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless, depending on the trader. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned or unmanned). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor.

Further, the base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, communication between a base station and a mobile station has been replaced with communication between a plurality of mobile stations (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the mobile station may have the function of the base station. In addition, words such as "up" and "down" may be read as words corresponding to communication between terminals (for example, "side"). For example, the uplink, downlink, and the like may be read as side channels.

Similarly, the mobile station in the present disclosure may be read as a base station. In this case, the base station may have the functions of the mobile station.
The radio frame may be composed of one or more frames in the time domain.
Each one or more frames in the time domain may be referred to as a subframe.
Subframes may further consist of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that is independent of numerology.

The numerology may be a communication parameter that applies to at least one of the transmission and reception of a signal or channel. Numerology includes, for example, SubCarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame configuration, transmission / reception. At least one of a specific filtering process performed by the machine in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like may be indicated.

The slot may be composed of one or more symbols (Orthogonal Frequency Division Multiple Access (OFDM) symbol, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. Slots may be unit of time based on numerology.

The slot may include a plurality of mini slots. Each minislot may consist of one or more symbols in the time domain. Further, the mini slot may be called a sub slot. A minislot may consist of a smaller number of symbols than the slot. PDSCH (or PUSCH) transmitted in time units larger than the minislot may be referred to as PDSCH (or PUSCH) mapping type A. PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (or PUSCH) mapping type B.

The wireless frame, subframe, slot, mini slot and symbol all represent the time unit when transmitting a signal. The radio frame, subframe, slot, minislot and symbol may have different names corresponding to each.

For example, one subframe may be referred to as a transmission time interval (TTI), a plurality of consecutive subframes may be referred to as TTI, and one slot or one minislot may be referred to as TTI. That is, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (eg, 1-13 symbols), or a period longer than 1ms. It may be. The unit representing TTI may be called a slot, a mini slot, or the like instead of a subframe.

Here, TTI refers to, for example, the minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station schedules each user terminal to allocate wireless resources (frequency bandwidth that can be used in each user terminal, transmission power, etc.) in TTI units. The definition of TTI is not limited to this.

The TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling or link adaptation. When a TTI is given, the time interval (for example, the number of symbols) to which the transport block, code block, code word, etc. are actually mapped may be shorter than the TTI.

When one slot or one mini slot is called TTI, one or more TTIs (that is, one or more slots or one or more mini slots) may be the minimum time unit for scheduling. Further, the number of slots (number of mini-slots) constituting the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, or the like. TTIs shorter than normal TTIs may also be referred to as shortened TTIs, short TTIs, partial TTIs (partial or fractional TTIs), shortened subframes, short subframes, minislots, subslots, slots, and the like.

Note that long TTIs (eg, normal TTIs, subframes, etc.) may be read as TTIs with a time length of more than 1 ms, and short TTIs (eg, shortened TTIs, etc.) are less than the TTI length of long TTIs and 1 ms. It may be read as a TTI having the above TTI length.

A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain.
The number of subcarriers contained in the RB may be the same regardless of the numerology, and may be, for example, 12. The number of subcarriers contained in the RB may be determined based on numerology.

Further, the time domain of RB may include one or more symbols, and may have a length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

One or more RBs include a physical resource block (Physical RB: PRB), a sub-carrier group (Sub-Carrier Group: SCG), a resource element group (Resource Element Group: REG), a PRB pair, an RB pair, etc. May be called.

Further, the resource block may be composed of one or a plurality of resource elements (ResourceElement: RE). For example, 1RE may be a radio resource area of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (which may also be called partial bandwidth, etc.) can also represent a subset of consecutive common resource blocks (RBs) for a neurology in a carrier. Good. Here, the common RB may be specified by the index of the RB with respect to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWP may include BWP for UL (UL BWP) and BWP for DL (DL BWP). One or more BWPs may be set in one carrier for the UE.

At least one of the configured BWPs may be active, and the UE may not expect to send or receive a given signal / channel outside the active BWP. In addition, "cell", "carrier" and the like in this disclosure may be read as "BWP".

The above-mentioned structures such as wireless frames, subframes, slots, mini slots and symbols are merely examples. For example, the number of subframes contained in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots contained within a slot, the number of symbols and RBs contained in a slot or minislot, included in RB. The number of subcarriers, the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements, and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and, as some non-limiting and non-comprehensive examples, the radio frequency domain. , Electromagnetic energies with wavelengths in the microwave and light (both visible and invisible) regions can be considered to be "connected" or "coupled" to each other.

The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot (Pilot) depending on the applicable standard.

The phrase "based on" as used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

The "means" in the configuration of each of the above devices may be replaced with "part", "circuit", "device" and the like.

Any reference to elements using designations such as "first", "second" as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Thus, references to the first and second elements do not mean that only two elements can be adopted there, or that the first element must somehow precede the second element.

When "include", "including" and variations thereof are used in the present disclosure, these terms are as comprehensive as the term "comprising". Is intended. Moreover, the term "or" used in the present disclosure is intended not to be an exclusive OR.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include that the nouns following these articles are in the plural.

The terms "determining" and "determining" used in this disclosure may include a wide variety of actions. "Judgment" and "decision" are, for example, judgment (judging), calculation (calculating), calculation (computing), processing (processing), derivation (deriving), investigation (investigating), search (looking up, search, inquiry). It may include (eg, searching in a table, database or another data structure), ascertaining as "judgment" or "decision". Also, "judgment" and "decision" are receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (Accessing) (for example, accessing data in memory) may be regarded as "judgment" or "decision". In addition, "judgment" and "decision" mean that "resolving", "selecting", "choosing", "establishing", "comparing", etc. are regarded as "judgment" and "decision". Can include. That is, "judgment" and "decision" may include that some action is regarded as "judgment" and "decision". Further, "judgment (decision)" may be read as "assuming", "expecting", "considering" and the like.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may mean that "A and B are different from C".
Terms such as "separate" and "combined" may be interpreted in the same way as "different".

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure may be implemented as an amendment or modification without departing from the purpose and scope of the present disclosure, which is determined by the description of the scope of claims. Therefore, the description of this disclosure is for purposes of illustration only and does not have any restrictive meaning to this disclosure.

10 Wireless communication system 100, 100P Wireless base station 150A-150D Wireless base station 200, 200A, 200B UE
300, 300A, 300B Phase control reflector 301 Small multi-element antenna 303 Phase shifter 310 H _PT acquisition unit 320 H _RP acquisition unit 330 Phase control unit 340 Reflector unit BM11, BM21, BM22 Beam C1, C11 to C14 Cell OB Obstacle 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims (7)

1. A radio communication system that includes a phase control reflector that reflects radio signals from a radio base station or terminal.
   A first propagation channel information acquisition unit that acquires first propagation channel information between the radio base station and the phase control reflector, and a first propagation channel information acquisition unit.
   A second propagation channel information acquisition unit that acquires second propagation channel information between the phase control reflector and the terminal is provided.
   The phase control reflector is a radio communication system that controls the phase of the radio signal reflected toward the terminal or the radio base station based on the first propagation channel information and the second propagation channel information.
2. A phase control reflector that reflects radio signals from a radio base station or terminal.
   Based on the first propagation channel information between the radio base station and the phase control reflector and the second propagation channel information between the phase control reflector and the terminal, the terminal or the radio base station A phase control reflector that controls the phase of the radio signal that is directed and reflected.
3. The phase control reflector according to claim 2, wherein the phase control reflector controls the phase by maximizing a combination of a predetermined eigenvalue of the first propagation channel information and a predetermined eigenvalue of the second propagation channel information. ..
4. The phase control reflector has a plurality of subarrays and has a plurality of subarrays.
   The phase control reflector according to claim 2 or 3, wherein a different sub-array is assigned to each terminal, and the phase is controlled by using the sub-array.
5. The phase control reflector according to any one of claims 2 to 4, wherein the phase control reflector converts the radio signal into an equivalent low frequency system and controls the phase in the equivalent low frequency system.
6. The phase control reflector according to any one of claims 2 to 4, wherein the phase control reflector controls the phase of the radio signal in a radio frequency band.
7. The step of estimating the first propagation channel information between the radio base station and the phase control reflector,
   A step of estimating the second propagation channel information between the phase control reflector and the terminal,
   A wireless communication method including a step in which the phase control reflector controls the phase of a radio signal reflected toward the terminal or the radio base station based on the first propagation channel information and the second propagation channel information.

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