Wireless communication system, wireless communication method, and base station device

Abstract

In this wireless communication system, a base station device communicates with a terminal device via any of relay devices (dynamic reflection plates). The base station device accumulates via-relay-device CSI in association with object arrangement information. When present-time object arrangement information is similar to accumulated past object arrangement information, the base station device determines the relay device to be used at the present time on the basis of each piece of CSI stored in association with the past object arrangement information. With the above configuration, overhead for CSI acquisition can be reduced by reusing CSI, and usage assessment for a plurality of dynamic reflection plates can be simultaneously executed.

Description

[Technical field]

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, and a base station device, and more particularly to a wireless communication system, a wireless communication method, and a base station device that use a dynamic reflector (RIS: Reconfigurable Intelligent Surface). [Background technology]

[0002] Dynamic reflectors used in wireless communication are known. A dynamic reflector is composed of a number of reflecting elements and reflects incident radio waves. The reflection characteristics of the dynamic reflector, such as the reflection direction, can be dynamically controlled. By using such a dynamic reflector, it is possible to form a propagation path that bypasses an obstacle or to form multiple propagation paths for a single terminal device. This makes it possible to improve communication performance, such as communication quality and spatial multiplexing number.

[0003] In order to communicate using a dynamic reflector, a base station device needs to acquire channel state information (CSI) indicating the state of the channel passing through the dynamic reflector and determine whether to use the dynamic reflector.

[0004] Non-Patent Document 1 discloses that an access point transmits a training signal to a terminal device and estimates channel state information from the response (CSI feedback). Non-Patent Document 2 discloses that channel state information via RIS is estimated using CSI feedback. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] N. Jindal, "MIMO Broadcast Channels With Finite-Rate Feedback," in IEEE Transactions on Information Theory, vol. 52, no. 11, pp. 5045-5060, Nov. 2006, doi: 10.1109 / TIT.2006.883550. [Non-Patent Document 2] Q. Wu, and R. Zhang, “Intelligent reflecting surface enhanced wireless network via joint active and passive beamforming,” IEEE transaction on wireless communications, vol.18, no.11, Nov. 2019. Summary of the Invention [Problem to be solved by the invention]

[0006] However, it takes a certain amount of time (overhead) to acquire channel state information (CSI). In addition, since the acquisition of CSI must be performed sequentially for each of multiple dynamic reflectors, the overhead increases as the number of channels passing through the dynamic reflector increases. If the overhead increases, there is a problem that the decision to use the dynamic reflector is delayed.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a wireless communication system, a wireless communication method, and a base station device that can reduce the overhead for acquiring CSI and simultaneously determine the use of multiple dynamic reflectors. [Means for solving the problem]

[0008] The first aspect relates to a wireless communication system. The wireless communication system includes a base station apparatus, a terminal apparatus, and at least a first relay apparatus and a second relay apparatus. The first relay device and the second relay device each have a dynamic reflector that reflects radio waves. The wireless communication system is capable of using a first channel for the base station device to communicate with the terminal device via the dynamic reflector of the first relay device, and a second channel for the base station device to communicate with the terminal device via the dynamic reflector of the second relay device. The base station device includes a sensor unit, a radio unit, an information storage unit, a similarity determination unit, and a relay device determination unit. The sensor unit acquires object position information including the positions of an obstacle and the terminal device. The radio unit obtains first channel state information of the first channel and second channel state information of the second channel. The information accumulation unit accumulates past object position information acquired by the sensor unit, and the first channel state information and the second channel state information acquired by the wireless unit regarding the past object position information in association with each other. The similarity determination unit determines whether or not the current object position information acquired by the sensor unit is similar to the past object position information stored in the information storage unit. When it is determined that the current object position information is similar to the past object position information, the relay device determination unit determines which of the first relay device and the second relay device is to be currently used based on the first channel state information and the second channel state information associated with the past object position information that is similar to the current object position information.

[0009] The second aspect relates to a wireless relay method. The wireless communication method enables a base station device to use a first channel for communicating with a terminal device via a dynamic reflector of a first relay device, and a second channel for communicating with the terminal device via a dynamic reflector of a second relay device. The wireless communication method includes an environmental information acquisition step, a CSI acquisition step, an information accumulation step, a similarity determination step, and a relay device determination step. The environmental information acquisition step acquires object position information including the positions of obstacles and the terminal device. The CSI acquisition step acquires first channel state information for the first channel and second channel state information for the second channel. The information accumulation process associates and accumulates past object position information acquired by the environmental information acquisition process with the first channel state information and the second channel state information acquired by the CSI acquisition process regarding the past object position information. The similarity determining step determines whether or not the current object position information acquired in the environment information acquiring step is similar to the past object position information stored in the information storing step. The relay device determination process, when it is determined that the current object position information is similar to the past object position information, determines which of the first relay device and the second relay device is to be currently used based on the first channel state information and the second channel state information associated with the past object position information that is similar to the current object position information.

[0010] The third aspect relates to a base station apparatus. A base station device can use a first channel for the base station device to communicate with a terminal device via a dynamic reflector of a first relay device, and a second channel for the base station device to communicate with the terminal device via a dynamic reflector of a second relay device. The base station device includes a sensor unit, a radio unit, an information storage unit, a similarity determination unit, and a relay device determination unit. The sensor unit acquires object position information including the positions of an obstacle and the terminal device. The radio unit obtains first channel state information of the first channel and second channel state information of the second channel. The information accumulation unit accumulates past object position information acquired by the sensor unit, and the first channel state information and the second channel state information acquired by the wireless unit regarding the past object position information in association with each other. The similarity determination unit determines whether or not the current object position information acquired by the sensor unit is similar to the past object position information stored in the information storage unit. When it is determined that the current object position information is similar to the past object position information, the relay device determination unit determines which of the first relay device and the second relay device is to be currently used based on the first channel state information and the second channel state information associated with the past object position information that is similar to the current object position information. Effect of the Invention

[0011] According to the present disclosure, when the current environment is similar to the past environment, the base station device can reuse the channel state information (CSI) accumulated in the past to determine the relay device to be used at the present time. Therefore, according to the present disclosure, the overhead for acquiring the CSI can be reduced and the use decision of multiple dynamic reflectors can be performed simultaneously. [Brief description of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram for explaining an overview of a wireless communication system according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram illustrating an overview of functions of a base station device according to an embodiment of the present invention. [Diagram 3] 5A to 5C are diagrams for explaining an object search process of a sensor unit according to an embodiment of the present invention. [Figure 4] 4 is a table illustrating area information stored in an information storage unit according to the embodiment of the present invention. [Diagram 5] 4 is a flowchart illustrating a process executed by a base station device according to an embodiment of the present invention. [Figure 6] 10 is a flowchart illustrating a process of a sensor unit according to an embodiment of the present invention. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a base station device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that elements common to the various drawings are designated by the same reference numerals and duplicated explanations will be omitted.

[0014] Embodiment (1) Wireless communication system Fig. 1 is a conceptual diagram for explaining an overview of a wireless communication system according to an embodiment. The wireless communication system shown in Fig. 1 includes a base station device 1, a terminal device 2, and a plurality of relay devices 3. The base station device 1 is, for example, a wireless base station under the management of a telecommunications carrier. The terminal device 2 is a user terminal such as a smartphone. The terminal device 2 can directly communicate with the base station device 1 if it belongs to the communication area of ​​the base station device 1 and there is no obstacle between them.

[0015] The relay device 3 includes a dynamic reflector 30, i.e., a Reconfigurable Intelligent Surface (RIS). The dynamic reflector 30 is composed of a number of reflecting elements and reflects incident radio waves (radio frequency signals). The dynamic reflector 30 of the relay device 3 is disposed to relay radio waves between the base station device 1 and the terminal device 2. Even if the terminal device 2 cannot directly communicate with the base station device 1, it may be possible for the terminal device 2 to communicate with the base station device 1 via the dynamic reflector 30 of the relay device 3.

[0016] 1 illustrates n relay devices 3 (first relay device 31, second relay device 32, ..., nth relay device 3n). In the environment (A) and environment (B) illustrated in Fig. 1, the positions of the base station device 1 and the multiple relay devices 3 are the same, and the positions of the terminal device 2a and the terminal device 2b, and the positions of the obstacles 4a and the obstacles 4b are approximately the same. In other words, the environment (A) and the environment (B) are similar.

[0017] In environment (A), the first channel transmits radio waves between the base station device 1 and the terminal device 2a via the dynamic reflector 30 of the first relay device 31. The second channel transmits radio waves between the base station device 1 and the terminal device 2a via the dynamic reflector 30 of the second relay device 32. The nth channel transmits radio waves between the base station device 1 and the terminal device 2a via the dynamic reflector 30 of the nth relay device 3n.

[0018] In environment (B), the first channel transmits radio waves between the base station device 1 and the terminal device 2b via the dynamic reflector 30 of the first relay device 31. The second channel transmits radio waves between the base station device 1 and the terminal device 2b via the dynamic reflector 30 of the second relay device 32. The nth channel transmits radio waves between the base station device 1 and the terminal device 2b via the dynamic reflector 30 of the nth relay device 3n.

[0019] (2)Base station equipment In order to perform communication utilizing the dynamic reflector 30 of the relay device 3, the base station device 1 needs to acquire channel state information (CSI) indicating the state of the channel passing through the dynamic reflector 30 and determine whether to use the relay device 3 (dynamic reflector 30). However, since acquisition of CSI needs to be performed sequentially for the dynamic reflector 30 of each relay device 3, overhead is large.

[0020] Therefore, in order to reduce the effect of overhead, the base station device 1 of this embodiment reuses channel state information (CSI) acquired in the past when the current environment is similar to a past environment, such as environment (A) and environment (B) illustrated in Figure 1, to determine the relay device 3 (dynamic reflector 30) to be currently used.

[0021] 2 is a block diagram illustrating an outline of functions of the base station device 1 according to the embodiment of the present invention. As shown in FIG. 2, the base station device 1 includes a sensor unit 10, a wireless unit 13, an information storage unit 16, a similarity determination unit 17, and a relay device determination unit 18.

[0022] The sensor unit 10 acquires object position information including the positions of the obstacle 4 and the terminal device 2. For example, the sensor unit 10 includes an image sensor 11 and an environmental information acquisition unit 12.

[0023] The image sensor 11 of the sensor unit 10 captures an image of the usable range of the terminal device 2, which is made up of a number of regions (FIG. 3) periodically divided into a grid pattern, and outputs the image data. The image sensor 11 is a semiconductor sensor used in digital cameras, which converts light incident from the camera lens into an electrical signal and outputs the signal as image data. The camera's angle of view is fixed, and the correspondence between each position in the usable range of the terminal device 2 (in real space) and each position in the image data is determined in advance.

[0024] For example, the usable range of the terminal device 2 is an area divided by tiles on the floor surface, and each of the multiple areas divided in a grid pattern corresponds to each of the multiple tiles arranged on the floor surface. If an obstacle 4 or an object such as the terminal device 2 (a "person" if the terminal device 2 is carried by a person, or a "mobile object" if the terminal device 2 is carried by a moving object) is present in the usable range of the terminal device 2, the object is photographed together with the usable range. Image data generated by photographing is output to the environmental information acquisition unit 12.

[0025] The environmental information acquisition unit 12 of the sensor unit 10 searches image data of multiple areas captured by the image sensor 11, and acquires the position of the area where the obstacle 4 exists and the position of the area where the terminal device 2 exists as object position information.

[0026] Specifically, first, the environmental information acquisition unit 12 acquires image data of the usable range of the terminal device 2 captured by the image sensor 11. The environmental information acquisition unit 12 recognizes the image data as a plurality of regions divided into a grid pattern. The environmental information acquisition unit 12 searches the image data to find a region among the plurality of regions in which an object (terminal device 2, obstacle 4) exists. The environmental information acquisition unit 12 acquires the center coordinates (center coordinates of the tile) of the region in which the object exists from the region information stored in the information accumulation unit 16.

[0027] 4 is a diagram illustrating an example of area information stored in the information storage unit 16. The information storage unit 16 stores in advance area information that defines the numbers, central X coordinates, and central Y coordinates of a plurality of areas (tile 1, tile 2, ...) partitioned in a lattice shape with respect to the usable range of the terminal device 2. For example, the distance between the centers of adjacent areas is approximately several tens of centimeters to several meters.

[0028] 2, the description will be continued. The wireless unit 13 performs wireless communication with the terminal device 2. For example, the wireless unit 13 performs wireless communication with the terminal device 2 via the dynamic reflector 30 of the relay device 3 determined by the relay device determination unit 18.

[0029] Moreover, the radio unit 13 acquires channel state information (CSI) for each of the multiple channels. That is, the radio unit 13 acquires first channel state information for a first channel, second channel state information for a second channel, ..., n-th channel state information for an n-th channel.

[0030] For example, the radio unit 13 includes a wireless communication circuit 14 and a CSI acquisition unit 15. The wireless communication circuit 14 includes an antenna and a transmission / reception circuit. The CSI acquisition unit 15 periodically transmits a known signal used for estimating CSI via the wireless communication circuit 14. The terminal device 2 feeds back the CSI estimated based on the received signal to the base station device 1 (CSI feedback, IEEE 802.11ac). That is, the CSI is periodically acquired.

[0031] The information storage unit 16 stores the object position information acquired by the sensor unit 10 in association with a plurality of pieces of channel state information (first channel state information, second channel state information, . . . , nth channel state information) acquired by the wireless unit 13 in relation to the object position information. The various pieces of information stored in the information storage unit 16 are stored in a storage device 92 (FIG. 7).

[0032] The similarity determination unit 17 determines whether or not the current object position information acquired by the sensor unit 10 is similar to the past object position information stored in the information storage unit 16. Specifically, the similarity determination unit 17 determines that the current object position information is similar to the past object position information when the area in which the obstacle 4 exists and the area in which the terminal device 2 exists in the current object position information are the same as the area in which the obstacle 4 exists and the area in which the terminal device 2 exists in the past object position information.

[0033] When it is determined that the current object position information is similar to the past object position information, the relay device determination unit 18 reads out from the information storage unit 16 a plurality of pieces of channel state information associated with the past object position information similar to the current object position information. The relay device determination unit 18 determines at least one relay device 3 (dynamic reflector 30) to be used at present among the plurality of relay devices 3 (first relay device 31, second relay device 32, ..., n-th relay device 3n) based on the plurality of pieces of channel state information. The base station device 1 executes control so that the wireless unit 13 communicates with the terminal device 2 using the dynamic reflector 30 of the determined relay device 3. In this way, the base station device 1 can determine the relay device to be used at present without waiting for the acquisition of the latest channel state information (CSI) for the current object position information.

[0034] After the latest channel state information (CSI) is acquired by the CSI acquisition unit 15, the relay device determination unit 18 determines a relay device to be used based on the latest channel state information. This allows the base station device 1 to re-determine the optimal relay device after the latest channel state information is acquired.

[0035] FIG. 5 is a flowchart illustrating a process executed by the base station device 1 according to the embodiment when acquiring environmental information.

[0036] In step S100, the environment information acquisition unit 12 acquires object position information of the obstacle 4 and the terminal device 2 from the image data acquired by the image sensor 11. A specific description will be given with reference to Fig. 6. Fig. 6 is a flowchart illustrating a process of acquiring object position information executed by the environment information acquisition unit 12. The initial value of the variable i is 1.

[0037] In step S101 , the environmental information acquisition unit 12 acquires image data from the image sensor 11 .

[0038] Next, in step S102, the environment information acquisition unit 12 acquires the state of the area i from the image data. For example, when i=1, an image corresponding to the tile 1 portion in FIG.

[0039] Next, in step S103, the environment information acquisition unit 12 judges whether or not an object exists on the image corresponding to region i. For example, when i=1, it judges whether or not an object is reflected in the image corresponding to tile 1 in FIG. 3. If an object exists in the part of the image data corresponding to region i, the process of step S104 is executed. On the other hand, if an object does not exist, the process of step S105 is executed.

[0040] In step S104, the environment information acquisition unit 12 adds the center coordinates of the region i to the object position information. The center coordinates of each region are stored in advance in the information storage unit 16 as region information.

[0041] In step S105, it is determined whether the variable i is equal to or greater than the total number of regions N. If the determination condition is met, it is determined that the object search has been completed for all regions of the image data. The object position information is output to the CSI acquisition unit 15 and the similarity determination unit 17, and this routine is terminated. On the other hand, if the determination condition is not met, the variable i is incremented by 1 in step S106, and the process is resumed from step S102 for the new region i.

[0042] As described above, according to the process of FIG. 6, the sensor unit outputs object position information based on image data.

[0043] Returning to Fig. 5, the description will be continued. In step S110, the similarity determination unit 17 determines whether or not the current object position information acquired by the sensor unit 10 is similar to past object position information stored in the information storage unit 16. If the determination condition is met, the process of step S120 is executed. On the other hand, if the determination condition is not met, the process of step S130 is executed.

[0044] In step S120, when it is determined that the current object position information is similar to the past object position information, the relay device determination unit 18 reads out a plurality of pieces of channel state information (CSI) associated with the past object position information similar to the current object position information from the information storage unit 16. Then, the process of step S150 is executed.

[0045] In step S150, the relay device determination unit 18 determines at least one relay device 3 (dynamic reflector 30) to be currently used from among the multiple relay devices 3 (first relay device 31, second relay device 32, ..., nth relay device 3n) based on multiple channel state information.

[0046] On the other hand, if it is determined in step S110 that there is no past object position information similar to the current object position information, it is necessary to acquire the latest channel state information (CSI). Therefore, in step S130, the wireless unit 13 acquires the channel state information (CSI) of each channel in the current object position information. Acquiring the channel state information requires a certain time (overhead).

[0047] Next, in step S140, the information accumulation unit 16 associates and accumulates the current object position information acquired by the sensor unit 10 and the latest multiple channel state information (first channel state information, second channel state information, ..., nth channel state information) acquired by the radio unit 13 regarding the object position information.

[0048] Next, in step S150, based on the latest channel state information of each channel, at least one relay device 3 (dynamic reflector 30) to be currently used among the multiple relay devices 3 (first relay device 31, second relay device 32, ..., nth relay device 3n) is determined.

[0049] (3) Effects As described above, according to the base station device 1 of the present embodiment, when the current environment is similar to the past environment, it is possible to determine the relay device 3 (dynamic reflector 30) to be used at the present time by reusing the previously stored channel state information (CSI) without waiting for the acquisition of the latest CSI for the current object position information. Therefore, according to the present disclosure, it is possible to reduce the overhead for acquiring CSI and simultaneously execute the use determination of multiple dynamic reflectors. In addition, after the latest channel state information is acquired, the base station device 1 can re-determine the optimal relay device 3 (dynamic reflector 30) based on the latest channel state information.

[0050] (4) Hardware configuration example 7 is a block diagram showing an example of a hardware configuration of the base station device 1 according to the present embodiment. The base station device 1 includes a control device 90, a sensor 80, and a wireless communication circuit 14 (FIG. 2).

[0051] The control device 90 controls the base station device 1. For example, the control device 90 includes one or more processors 91 (hereinafter simply referred to as "processor 91") and one or more storage devices 92 (hereinafter simply referred to as "storage device 92"). The processor 91 performs various information processing (including processing of each unit shown in FIG. 2). The processor 91 includes, for example, a CPU. The storage device 92 stores various information required for processing by the processor 91. Examples of the storage device 92 include a volatile memory, a non-volatile memory, a HDD, and an SSD. The processor 91 executes a control program, which is a computer program, to realize the functions of the control device 90. The control program is stored in the storage device 92. The control program may be recorded in a computer-readable recording medium.

[0052] Each function of the control device 90 may be partially or entirely configured by hardware, or may be configured as a program executed by a processor. That is, the control device 90 can be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network.

[0053] The sensor 80 is a sensor for acquiring information regarding the positions of the obstacle 4 and the terminal device 2. The sensor 80 is, for example, an image sensor 11 (FIG. 2). The wireless communication circuit 14 performs wireless communication with the terminal device 2 and the relay device 3. For example, the wireless communication circuit 14 includes an antenna and a transmitting / receiving circuit. The wireless communication circuit 14 is controlled by a control device 90 (processor 91).

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the present invention. In the above-mentioned embodiments, when the number, quantity, amount, range, etc. of each element is mentioned, the present invention is not limited to the mentioned numbers, unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the above-mentioned embodiments are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle. [Explanation of symbols]

[0055] 1 Base station equipment 2, 2a, 2b Terminal equipment 3, 31, 32, 3n relay device, 1st relay device, 2nd relay device, nth relay device 4,4a,4b Obstacles 10 Sensor section 11 Image Sensor 12 Environmental Information Acquisition Department 13 Radio Section 14 Wireless communication circuits 15 CSI Acquisition Department 16 Information Storage Unit 17 Similarity determination section 18 Relay device determination unit 30 Dynamic reflector 80 Sensors 90 Control device 91 Processor 92 Storage device

Claims

1. A wireless communication system comprising a base station device, a terminal device, and at least a first relay device and a second relay device, each of the first relay device and the second relay device having a dynamic reflector that reflects radio waves, the base station device being able to use a first channel for communicating with the terminal device via the dynamic reflector of the first relay device, and the base station device being able to use a second channel for communicating with the terminal device via the dynamic reflector of the second relay device, The base station device, A sensor unit for acquiring object position information including the positions of an obstacle and the terminal device; a radio unit that acquires first channel state information of the first channel and second channel state information of the second channel; an information storage unit that stores past object position information acquired by the sensor unit, and the first channel state information and the second channel state information acquired by the wireless unit regarding the past object position information in association with each other; a similarity determination unit that determines whether or not the current object position information acquired by the sensor unit is similar to the past object position information stored in the information storage unit; a relay device determination unit that, when it is determined that the current object location information is similar to the past object location information, determines which of the first relay device and the second relay device is to be currently used based on the first channel state information and the second channel state information associated with the past object location information similar to the current object location information; A wireless communication system comprising:

2. The sensor unit includes: An image sensor that captures images of a plurality of areas divided into a grid pattern; an environmental information acquisition unit that searches image data of the plurality of areas captured by the image sensor and acquires a position of the area where the obstacle exists and a position of the area where the terminal device exists as the object position information; the similarity determination unit determines that the current object position information is similar to the past object position information when an area in which the obstacle exists and an area in which the terminal device exists in the current object position information are the same as an area in which the obstacle exists and an area in which the terminal device exists in the past object position information; 2. The wireless communication system according to claim 1,

3. each of the plurality of regions corresponds to a respective one of a plurality of tiles arranged on a floor surface; 3. The wireless communication system according to claim 2,

4. A wireless communication method in which a base station device can use a first channel for communicating with a terminal device via a dynamic reflector of a first relay device, and a second channel for communicating with the terminal device via a dynamic reflector of a second relay device, comprising: an environmental information acquisition step of acquiring object position information including the positions of obstacles and the terminal device; acquiring first channel state information of the first channel and second channel state information of the second channel; an information storage step of storing past object position information acquired by the environment information acquisition step, and the first channel state information and the second channel state information acquired by the CSI acquisition step regarding the past object position information in association with each other; a similarity determination step of determining whether or not the current object position information acquired by the environment information acquisition step is similar to the past object position information stored by the information storage step; a relay device determination step of determining a relay device to be currently used from among the first relay device and the second relay device, based on the first channel state information and the second channel state information associated with the past object position information similar to the current object position information, when the current object position information is determined to be similar to the past object position information; A wireless communication method comprising:

5. the base station device includes an image sensor that captures an image of a plurality of areas divided into a grid pattern; The environmental information acquisition step includes searching image data of the plurality of areas photographed by the image sensor, and acquiring a position of an area where the obstacle exists and a position of an area where the terminal device exists as the object position information; the similarity determination step determines that the current object position information is similar to the past object position information when an area in which the obstacle exists and an area in which the terminal device exists in the current object position information are the same as an area in which the obstacle exists and an area in which the terminal device exists in the past object position information; 5. The wireless communication method according to claim 4,

6. each of the plurality of regions corresponds to a respective one of a plurality of tiles arranged on a floor surface; 6. The wireless communication method according to claim 5,

7. A base station device capable of using a first channel for communicating with a terminal device via a dynamic reflector of a first relay device, and a second channel for communicating with the terminal device via a dynamic reflector of a second relay device, A sensor unit for acquiring object position information including the positions of an obstacle and the terminal device; a radio unit that acquires first channel state information of the first channel and second channel state information of the second channel; an information storage unit that stores past object position information acquired by the sensor unit, and the first channel state information and the second channel state information acquired by the wireless unit regarding the past object position information in association with each other; a similarity determination unit that determines whether or not the current object position information acquired by the sensor unit is similar to the past object position information stored in the information storage unit; a relay device determination unit that determines a relay device to be currently used from the first relay device and the second relay device based on the first channel state information and the second channel state information associated with the past object position information similar to the current object position information when the current object position information is determined to be similar to the past object position information; and A base station device comprising:

8. The sensor unit includes: An image sensor that captures images of a plurality of areas divided into a grid pattern; an environmental information acquisition unit that searches image data of the plurality of areas captured by the image sensor and acquires a position of the area where the obstacle exists and a position of the area where the terminal device exists as the object position information; the similarity determination unit determines that the current object position information is similar to the past object position information when an area in which the obstacle exists and an area in which the terminal device exists in the current object position information are the same as an area in which the obstacle exists and an area in which the terminal device exists in the past object position information; The base station apparatus according to claim 7 .

Images