Relay device, method and program for controlling relay device

Abstract

This relay device comprises the following configuration for rapidly and easily acquiring highly-accurate terminal location information, and for controlling a dynamic reflector. The dynamic reflector dynamically changes the reflection direction of radio waves. An image sensor images a usage range of a terminal device composed of a plurality of regions partitioned into a grid pattern. A control device controls the dynamic reflector. In particular, the control device acquires image data of the usage range of the terminal device imaged by the image sensor. The control device retrieves, from the image data, a region, from among the plurality of regions, where the terminal device is present. The control device directs the reflection direction of the dynamic reflector toward the region where the terminal device is present.

Description

[Technical field]

[0001] The present disclosure relates to a relay device, a control method and a program for the relay device, and in particular to a relay device that uses a reconfigurable intelligent surface (RIS), a control method and a program for the relay device. [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, it is necessary to acquire terminal position information in order to control the reflection angle of the dynamic reflector in the direction of the target terminal device.

[0004] As a technique for acquiring terminal location information, Non-Patent Document 1 discloses a technique for locating a terminal associated with a wireless LAN access point using distributed antennas by measuring the RTT (Round Trip Time) between the access point and the terminal. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Masamichi Hosoda and 8 others, "Wireless LAN Terminal Location Estimation Method Using Access Points with Distributed Antennas", Transactions of Information Processing Society of Japan, Vol.61, No.1, pp.3-15, (Jan. 2020). Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method of transmitting terminal position information to a dynamic reflector via a network requires an information transmission device and has a problem of large overhead. Also, when terminal position information is required to be accurate to the meter, the positioning method of Non-Patent Document 1 is not sufficiently accurate.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a relay device that can quickly and easily obtain highly accurate terminal position information and control a dynamic reflector, as well as a control method and program for the relay device. [Means for solving the problem]

[0008] The first aspect relates to a relay device. The relay device relays radio waves between the base station and the terminal device. The relay device includes a dynamic reflector, an image sensor, and a control device. The dynamic reflector dynamically changes the direction in which the radio waves are reflected. The image sensor captures an image of the usable range of the terminal device, which is made up of a plurality of areas divided into a grid pattern. The control device controls the dynamic reflector. The control device acquires image data of the utilization area captured by the image sensor. The control device searches the image data for an area among the plurality of areas in which the terminal device is present. The control device directs the reflection direction of the dynamic reflector toward the area where the terminal device is located.

[0009] The second aspect relates to a method for controlling a relay device. The relay device relays radio waves between the base station and the terminal device. The relay device includes a dynamic reflector and an image sensor. The dynamic reflector dynamically changes the direction in which the radio waves are reflected. The image sensor captures an image of the usable range of the terminal device, which is made up of a plurality of areas divided into a grid pattern. The control method includes a step of acquiring image data of the utilization area captured by the image sensor. The control method includes a step of searching for an area in which the terminal device is present from the image data, among the plurality of areas. The control method includes a step of directing the reflection direction of the dynamic reflector toward the area in which the terminal device is located.

[0010] A third aspect relates to a program for causing a computer to function as the relay device described above. Effect of the Invention

[0011] According to the present disclosure, the relay device can directly measure the position of the terminal device using an image sensor. Therefore, an information transmission device for acquiring terminal location information via a network is not required, and overhead is small. In addition, highly accurate terminal location information can be acquired from image data. Therefore, according to the present disclosure, highly accurate terminal location information can be acquired quickly and easily, and a dynamic reflector can be controlled. [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 example of an outline of functions of a relay device according to a first embodiment of the present invention. [Diagram 3] 10 is a diagram illustrating an example of area information stored in an information storage unit according to an embodiment of the present invention. FIG. [Figure 4] 5 is a flowchart illustrating a process executed by a control device of a relay device according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control 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 1, a terminal device 2, and a relay device 3. The base station 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 1 if it belongs to the communication area of ​​the base station 1 and there is no obstacle between them.

[0015] The relay device 3 includes a dynamic reflector 4 (FIG. 2), that is, a RIS (Reconfigurable Intelligent Surface). The relay device 3 is disposed to relay radio waves (radio frequency signals) between the base station 1 and the terminal device 2. Even if the terminal device 2 cannot directly communicate with the base station 1, it may be possible for the terminal device 2 to communicate with the base station 1 via the relay device 3.

[0016] (2) Repeater In order to perform communication using the dynamic reflector 4, terminal position information is necessary to control the reflection angle of the dynamic reflector 4 toward the target terminal device 2. It is desirable to be able to quickly obtain highly accurate terminal position information about the moving terminal device 2. Therefore, the relay device 3 of this embodiment is equipped with an image sensor 5 and measures the position of the terminal device 2 from image data.

[0017] 2 is a block diagram for explaining the configuration of the relay device 3 according to the embodiment. As shown in FIG. 2, the relay device 3 includes a dynamic reflector 4, an image sensor 5, and a control device 6.

[0018] The dynamic reflector 4 can change the reflection angle of the reflection element in response to a control signal from the control device 6, and reflects radio waves (radio frequency signals).

[0019] The image sensor 5 is a semiconductor sensor used in digital cameras, which converts the light incident from the camera lens into an electrical signal and outputs it as image data. The image sensor 5 captures the usable range of the terminal device 2, which consists of multiple areas divided into a grid pattern. 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.

[0020] The image sensor 5 captures an image of a usable area partitioned by tiles on a floor surface as shown in Fig. 1, for example. The image sensor 5 captures an image of a usable area partitioned by lines in a grid pattern, for example. If an object carrying 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 mobile object) is present within the usable area of ​​the terminal device 2, the object is captured together with the usable area. Image data generated by capturing the image is output to the control device 6.

[0021] The control device 6 includes an image acquisition unit 61 , an information storage unit 62 , an object position search unit 63 , and a reflector control unit 64 .

[0022] The image acquisition unit 61 acquires image data of the usable range of the terminal device 2 captured by the image sensor 5 .

[0023] 3 is a diagram illustrating an example of area information stored in the information storage unit 62. The information storage unit 62 stores in advance 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. The distance between the centers of adjacent areas is, for example, about several tens of centimeters to several meters.

[0024] The object position search unit 63 recognizes the image data as a plurality of regions divided into a grid pattern. The object position search unit 63 searches the image data for an area in which the terminal device 2 (object) exists among the plurality of areas. The object position search unit 63 acquires from the information storage unit 62 the center coordinates (center coordinates of the tile) of the area in which the terminal device 2 (object) exists.

[0025] The reflector control unit 64 directs the reflection direction of the dynamic reflector 4 toward the center of the area where the terminal device 2 exists, based on the central coordinates of the area where the terminal device 2 exists. In other words, the reflector control unit 64 outputs a control signal that controls the reflection angle of the dynamic reflector 4 so that the reflection direction of the radio wave is toward the area where the object having the terminal device 2 exists.

[0026] 4 is a flowchart illustrating a process executed by the control device 6 of the relay device 3 according to the embodiment. This control routine is repeatedly executed at a predetermined cycle. The initial value of the variable i is 1.

[0027] In step S100 , the image acquisition unit 61 acquires image data from the image sensor 5 .

[0028] In step S110, the object position search unit 63 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.

[0029] In step S120, the object position search unit 63 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. 1. If an object exists in the part of the image data corresponding to region i, the process of step S130 is executed. On the other hand, if an object does not exist, the process of step S140 is executed.

[0030] In step S130, the reflector control unit 64 outputs a control signal to the dynamic reflector 4 to orient the reflection direction of the dynamic reflector 4 toward the center of the area i in which the object exists. After that, this routine ends.

[0031] In step S140, 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 no object exists in any region of the image data, 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 S150, and processing is resumed from step S110 for the new region i.

[0032] (3) Effects As described above, according to the relay device 3 of this embodiment, the relay device 3 can directly measure the position of the terminal device 2 using an image sensor. Therefore, the wireless communication system does not require an information transmission device for acquiring terminal position information via a network, and overhead is small. In addition, highly accurate terminal position information can be acquired from image data. Therefore, according to the relay device 3 of this embodiment, highly accurate terminal position information can be acquired quickly and easily, and the dynamic reflector can be controlled. In addition, by using existing floor tiles, it is possible to easily perform position estimation without time and effort or spoiling the aesthetic appearance.

[0033] (4) Hardware configuration example 5 is a block diagram showing an example of a hardware configuration of the control device 6 of the relay device 3 according to this embodiment. Each of the above-mentioned functions is realized by a processing circuit. In one aspect, the processing circuit includes at least one processor 91 and at least one memory 92. In another aspect, the processing circuit includes at least one dedicated hardware 93.

[0034] When the processing circuit includes a processor 91 and a memory 92, each function is realized by software, firmware, or a combination of software and firmware. At least one of the software and firmware is written as a program. At least one of the software and firmware is stored in the memory 92. The processor 91 realizes each function by reading and executing the program stored in the memory 92.

[0035] Where the processing circuitry comprises dedicated hardware 93, the processing circuitry may be, for example, a single circuit, multiple circuits, a programmed processor, or a combination thereof. Each function is implemented by the processing circuitry.

[0036] Each function of the control device 6 may be partially or entirely configured by hardware, or may be configured as a program executed by a processor. That is, the control device 6 can be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network.

[0037] 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]

[0038] 1 base station 2 Terminal Device 3. Repeater 4 Dynamic reflector 5. Image Sensor 6. Control device 61 Image acquisition unit 62 Information storage section 63 Object position search unit 64 Reflector control section 91 Processor 92 Memory 93 Hardware

Claims

1. A relay device that relays radio waves between a base station and a terminal device, A dynamic reflector that dynamically changes the reflection direction of the radio wave; an image sensor that captures an image of a usable range of the terminal device, the usable range being made up of a plurality of areas divided into a grid pattern; A control device for controlling the dynamic reflector, The control device includes: Acquire image data of the utilization range captured by the image sensor; identifying an area in which the terminal device is present among the plurality of areas by sequentially searching the image data divided into the plurality of areas according to a predetermined search order; directing the reflection direction of the dynamic reflector toward the area where the terminal device is located; A relay device comprising:

2. the usable range of the terminal device is an area partitioned by a plurality of tiles arranged on a floor surface, each of the plurality of regions corresponds to a respective one of the plurality of tiles; 2. The relay device according to claim 1,

3. A method for controlling a relay device that relays radio waves between a base station and a terminal device, comprising the steps of: The relay device is A dynamic reflector that dynamically changes the reflection direction of the radio wave; an image sensor that captures an image of a usable range of the terminal device, the image sensor comprising a plurality of areas divided into a grid pattern; The control method includes: acquiring image data of the utilization area captured by the image sensor; a step of sequentially searching the image data divided into the plurality of regions according to a predetermined search order, thereby identifying an area in which the terminal device is present among the plurality of regions; directing the reflection direction of the dynamic reflector toward the area where the terminal device is present; A method for controlling a relay device comprising the steps of:

4. the usable range of the terminal device is defined by a plurality of tiles arranged on a floor surface, each of the plurality of regions corresponds to a respective one of the plurality of tiles; 4. The method for controlling a relay device according to claim 3.

5. A program that, when executed by a computer, causes the computer to function as the relay device according to claim 1.

Images