Method for relaying communication to multiple user terminals, device for controlling relay of communication to multiple user terminals, and program

Abstract

To suppress interference between user terminals while effectively utilizing in each user terminal the merit of performing a communication using a plurality of relay devices when performing the communication to the plurality of user terminals via the relay devices.SOLUTION: A control device creates a group of user terminals satisfying a predetermined spatial condition suppressing share of a relay device between user terminals in a plurality of user terminals. A plurality of relay devices is allocated to each of the plurality of user terminals according to a predetermined allocation rule. To user terminals (space multiplex users) belonging to the group, a radio resource of the same frequency and the same time is allocated and to user terminals (time / frequency multiplex users) not belonging to the group, a radio resource of a frequency and a time different from the other user terminals is allocated.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a technique for relaying communications to a plurality of user terminals. [Background technology]

[0002] The use of high frequency bands is essential to realize a high-speed, large-capacity, and low-latency wireless network. However, radio waves in high frequency bands are easily attenuated and have high linearity, so communication coverage cannot be formed in areas beyond the line of sight due to obstructions, and there is also a problem in improving the spatial multiplexing gain to user terminals. In this regard, Non-Patent Document 1 discloses a method for improving spatial multiplexing gain in high frequency bands using a large number of relay devices. By using relay devices, communication coverage beyond the line of sight can be formed at low cost without installing a new base station. Furthermore, by deploying a large number of relay devices to secure new communication paths and widen the angle of arrival of radio waves, the spatial multiplexing gain can be improved. However, the conventional technology disclosed in Non-Patent Document 1 is based on the premise of a single user terminal, and does not take into account interference between users that may occur when multiple user terminals are accommodated. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] K. Sakaguchi, et al., "Mmwave massive analog relay MIMO", ITU Journal on Future and Evolving Technologies, Vol.2, Issue6, Sept. 2021 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been made in consideration of the above-mentioned problems, and aims to suppress interference between multiple user terminals when communicating with multiple user terminals via a relay device, while allowing each user terminal to enjoy the benefits of communicating using multiple relay devices. [Means for solving the problem]

[0005] The present disclosure provides a method for achieving the above object. The method of the present disclosure is a method for relaying communication to a plurality of user terminals. The method of the present disclosure includes the following first to fourth steps. The first step is a step of creating a group of user terminals (hereinafter referred to as a spatial multiplexing group) that satisfies a predetermined spatial condition that suppresses sharing of a relay device between the user terminals among the plurality of user terminals. The second step is a step of allocating a plurality of relay devices to each of the plurality of user terminals according to a predetermined allocation rule. However, the execution order of the second step and the execution order of the first step may be reversed. The third step is a step of allocating radio resources of the same frequency and time to user terminals that belong to the spatial multiplexing group. The fourth step is a step of allocating radio resources of different frequency and time from other user terminals to user terminals that do not belong to the spatial multiplexing group.

[0006] The present disclosure also provides an apparatus for achieving the above object. The apparatus of the present disclosure is an apparatus for controlling relay of communication for a plurality of user terminals. The apparatus of the present disclosure is configured to execute the following first to fourth processes. The first process is a process of creating the above spatial multiplexing group among a plurality of user terminals. The second process is a process of allocating a plurality of relay devices to each of a plurality of user terminals according to a predetermined allocation rule. However, the execution order of the second process and the execution order of the first step may be reversed. The third process is a process of allocating radio resources of the same frequency and time to user terminals belonging to the spatial multiplexing group. The fourth process is a process of allocating radio resources of different frequency and time from other user terminals to user terminals not belonging to the spatial multiplexing group.

[0007] Furthermore, the present disclosure provides a program for achieving the above object. The program of the present disclosure is a program including a plurality of instructions executable by at least one processor provided in a system that relays communications to a plurality of user terminals. The plurality of instructions included in the program of the present disclosure are configured to cause the at least one processor to execute the first to fourth processes described above. The program of the present disclosure may be stored in a computer-readable non-transitory storage medium, or may be provided via a network. Effect of the Invention

[0008] In the technology of the present disclosure, multiple relay devices are assigned to each of multiple user terminals according to a predetermined rule. In addition, in the technology of the present disclosure, the wireless resource allocation method is switched depending on whether the user terminal belongs to a group that satisfies a predetermined spatial condition, so that wireless resources are assigned in a manner suitable for the situation in which each user terminal is placed. As a result, according to the technology of the present disclosure, it is possible to suppress interference between user terminals while enjoying the benefits of communication using multiple relay devices in each user terminal. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an overview of a wireless relay method according to the present disclosure. [Diagram 2] 1A to 1C are diagrams illustrating a first embodiment of a method for determining spatial multiplexing users. [Diagram 3] 1A to 1C are diagrams illustrating a first embodiment of a method for determining spatial multiplexing users. [Figure 4] FIG. 11 is a diagram for explaining a second embodiment of a method for determining spatial multiplexing users. [Diagram 5] FIG. 11 is a diagram for explaining a second embodiment of a method for determining spatial multiplexing users. [Figure 6] FIG. 11 is a diagram for explaining a third embodiment of a method for determining spatial multiplexing users. [Figure 7]FIG. 11 is a diagram for explaining a third embodiment of a method for determining spatial multiplexing users. [Figure 8] FIG. 2 is a diagram illustrating an embodiment of a method for allocating a relay device to a user terminal. [Figure 9] FIG. 1 is a diagram illustrating an overview of a wireless relay system according to the present disclosure. [Figure 10] FIG. 4 is a flow chart showing one embodiment of a process performed by a control device of the present disclosure. [Figure 11] FIG. 11 is a flow diagram illustrating one embodiment of the coordination of operations between devices related to relay device allocation. [Figure 12] 1 is a block diagram showing an embodiment of a configuration of a wireless relay system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 1. Overview of wireless relay methods Fig. 1 is a diagram for explaining an outline of the wireless relay method of the present disclosure. As shown in Fig. 1, there are cases where a large number of shields 50 exist between a base station device 30 and a user terminal 10. Even in such cases, it is possible to form communication coverage up to an area beyond the line of sight of the shields 50 by arranging a large number of analog relay devices (hereinafter simply referred to as relay devices) 20 in a space where wireless communication is performed.

[0011] 1 shows an ideal allocation of relay devices 20 to user terminals 10. In this example, relay devices 20 are allocated to the user terminals 10 of users #1, #2, and #3 without overlapping. If relay devices 20 can be allocated in this way, multi-user transmission by spatial multiplexing between all user terminals 10 becomes possible, and interference between user terminals 10 can be minimized.

[0012] However, if the relay device 20 is simply operated randomly, all relay devices 20 that have received location information from the user terminal 10 will operate. Therefore, the relay device 20 needs to actively assign to each user terminal 10 according to a certain rule. Also, depending on the location relationship between the user terminals 10, spatial multiplexing may not always be possible between all user terminals 10. In that case, it is necessary to select a user multiplexing method suitable for the situation in which each user terminal 10 is placed so that interference between the user terminals 10 can be suppressed as much as possible.

[0013] In addition to spatial multiplexing as shown in Fig. 1, time multiplexing and frequency multiplexing can be used as a method of user multiplexing between user terminals 10. Time multiplexing and frequency multiplexing can be used as alternatives when spatial multiplexing cannot be used. Hereinafter, when a certain user terminal 10 is taken as a reference, a user terminal 10 that can realize spatial multiplexing with the reference user terminal 10 is referred to as a spatial multiplexing user. Then, for a user terminal 10 that cannot realize spatial multiplexing with the reference user terminal 10, time multiplexing or frequency multiplexing is applied, and the user terminal 10 is referred to as a time / frequency multiplexing user.

[0014] Whether a certain user terminal 10 is set as a spatial multiplexing user or a time / frequency multiplexing user is determined based on whether the user terminal 10 satisfies a predetermined spatial condition. The predetermined spatial condition is a spatial condition that suppresses sharing of the relay device 20 between the user terminals 10. For a group of user terminals 10 that satisfies such a spatial condition, that is, for user terminals 10 that belong to a spatial multiplexing group, spatial multiplexing can be applied as a user multiplexing method. On the other hand, for user terminals 10 that do not belong to a spatial multiplexing group, time multiplexing or frequency multiplexing can be applied.

[0015] There are several preferred embodiments of the method for determining whether the user terminal 10 satisfies a predetermined spatial condition, i.e., the method for determining spatial multiplexing users. Hereinafter, the embodiments of the method for determining spatial multiplexing users will be specifically described.

[0016] 2. Method for determining spatially multiplexed users 2-1. First embodiment 2 and 3 are diagrams for explaining a first embodiment of a method for determining spatial multiplexing users. In the first embodiment, a reference user terminal 10-1 is first determined (hereinafter, when individual user terminals are not distinguished, it is written as user terminal 10, and when individual user terminals are distinguished, it is written as user terminal 10-X). Then, as shown in FIG. 2, a distance threshold is set for the reference user terminal 10-1. Whether a certain user terminal 10 is a spatial multiplexing user or a time / frequency multiplexing user is determined based on whether the distance from the user terminal 10-1 is greater than the threshold. This is because the greater the spatial distance between the user terminals 10, the more likely it is that multi-user transmission using spatial multiplexing will be effective. The distance threshold can be set to an arbitrary value. The distance between the user terminals 10 is calculated from location information obtained by positioning each user terminal 10.

[0017] In the example shown in FIG. 2, the user terminal 10-2 is determined to be a spatial multiplexing user because the distance from the user terminal 10-1 is greater than a threshold. The user terminals 10-1 and 10-2 can be considered to belong to a group made up of user terminals 10 whose spatial distances to other user terminals 10 are greater than a threshold. In the first embodiment, such a group is created as a spatial multiplexing group. On the other hand, the user terminal 10-3 is determined to be a time / frequency multiplexing user because the distance from the user terminal 10-1 is equal to or less than the threshold. The user terminal 10-3 is a user terminal that does not belong to a spatial multiplexing group.

[0018] The determination as to whether the user terminal 10 is a spatial multiplexing user is performed in order. The order of the determination may be determined according to a predetermined rule or may be random. In the example shown in FIG. 2, the determination may be performed for the user terminal 10-2 and then for the user terminal 10-3, or the determination may be performed for the user terminal 10-2 and then for the user terminal 10-3. In the example shown in FIG. 3, the determination is performed for the user terminal 10-4 after the user terminals 10-2 and 10-3. Whether the user terminal 10-4 is a spatial multiplexing user is determined based on whether it belongs to a spatial multiplexing group consisting of the user terminals 10-1 and 10-2. Specifically, if the distance of the user terminal 10-4 from the user terminal 10-1 is greater than a threshold value and the distance of the user terminal 10-4 from the user terminal 10-2 is greater than a threshold value, the user terminal 10-4 is determined to belong to the spatial multiplexing group.

[0019] 2-2. Second embodiment 4 and 5 are diagrams for explaining a second embodiment of a method for determining spatial multiplexing users. In the second embodiment, first, a relay device 20 is assigned to each user terminal 10 including a reference user terminal 10-1 according to a predetermined allocation rule. The method for assigning the relay device 20 will be described in detail later, but in the example shown in FIG. 4, five relay devices 20 are assigned to each user terminal 10 in order from the relay device 20 closest to the user terminal 10. Whether a certain user terminal 10 is a spatial multiplexing user or a time / frequency multiplexing user is determined based on whether the number of relay devices 20 shared with the user terminal 10-1 is equal to or less than a predetermined number. This is because the fewer the number of relay devices 20 shared with the user terminal 10-1, that is, the more the number of assigned relay devices 20 different from the user terminal 10-1, the more likely it is that multi-user transmission by spatial multiplexing will be effective. The predetermined number serving as a criterion for determination can be set to any value.

[0020] In the example shown in FIG. 4, the number of relay devices 20 shared by the user terminal 10-2 and the user terminal 10-1 is zero. If the number of relay devices 20 shared, which is the criterion for determining whether a user is a spatial multiplexing user or a time / frequency multiplexing user, is two, the user terminal 10-2 is determined to be a spatial multiplexing user. The user terminals 10-1 and 10-2 can be considered to belong to a group consisting of user terminals 10 that share the relay device 20 with each other and that share the relay device 20 in a number equal to or less than a predetermined number. In the second embodiment, such a group is created as a spatial multiplexing group. The user terminal 10-3 is a user terminal that does not belong to a spatial multiplexing group because the number of relay devices 20 shared between the user terminal 10-1 and the user terminal 10-3 is three. Therefore, the user terminal 10-3 is determined to be a time / frequency multiplexing user.

[0021] In the example shown in Fig. 5, the user terminal 10-4 is judged following the user terminals 10-2 and 10-3. Whether the user terminal 10-4 is a spatial multiplexing user is judged based on whether it belongs to a spatial multiplexing group consisting of the user terminals 10-1 and 10-2. Specifically, if the number of shared relay devices 20 between the user terminal 10-4 and the user terminal 10-1 is equal to or less than a predetermined number, and the number of shared relay devices 20 between the user terminal 10-4 and the user terminal 10-2 is equal to or less than a predetermined number, the user terminal 10-4 is judged to belong to the spatial multiplexing group.

[0022] 2-3.Third embodiment 6 and 7 are diagrams for explaining a third embodiment of a method for determining spatial multiplexing users. In the third embodiment, whether a certain user terminal 10 is a spatial multiplexing user or a time / frequency multiplexing user is determined based on whether or not there is an obstruction such as a building between the user terminal 10-1 and a reference user terminal. This is because there is a high possibility that multi-user transmission using spatial multiplexing will be effective when a space is divided by an obstruction. It is possible to determine whether or not there is an obstruction between the user terminals 10 by comparing the position information of each user terminal 10 with map information.

[0023] In the example shown in FIG. 6, a shield 50-1 exists between the user terminal 10-2 and the user terminal 10-1. Therefore, the user terminal 10-2 is determined to be a spatial multiplexing user. The user terminal 10-1 and the user terminal 10-2 can be considered to belong to a group consisting of user terminals 10 having shields between them and other user terminals 10. In the third embodiment, such a group is created as a spatial multiplexing group. The user terminal 10-3 is a user terminal that does not belong to a spatial multiplexing group because there is no shield between it and the user terminal 10-1. Therefore, the user terminal 10-3 is determined to be a time / frequency multiplexing user.

[0024] In the example shown in Fig. 7, a determination is made for user terminal 10-4 following user terminals 10-2 and 10-3. Whether user terminal 10-4 is a spatial multiplexing user is determined based on whether it belongs to a spatial multiplexing group consisting of user terminals 10-1 and 10-2. Shields 50-1 and 50-2 exist between user terminal 10-4 and user terminal 10-1, and a shield 50-2 exists between user terminal 10-4 and user terminal 10-2. For this reason, user terminal 10-4 is determined to belong to the spatial multiplexing group.

[0025] 3. Method of assigning relay devices Next, a method of allocating relay devices 20 to user terminals 10 will be described. The allocation of relay devices 20 to user terminals 10 is performed according to a predetermined allocation rule. Fig. 8 is a diagram illustrating one embodiment of a method of allocating relay devices 20 to user terminals 10. Here, it is assumed that multi-user transmission to user terminals 10-1 and 10-2 is performed via multiple relay devices 20.

[0026] When the relay devices 20 are assigned, first, the distances between the user terminals 10-1, 10-2 and each relay device 20 are calculated from the position information of the user terminals 10-1, 10-2 and each relay device 20. Then, a predetermined number of relay devices 20 are assigned to the user terminal 10-1 in order of proximity to the user terminal 10-1. Similarly, a predetermined number of relay devices 20 are assigned to the user terminal 10-2 in order of proximity to the user terminal 10-2. The number of relay devices 20 assigned to the user terminals 10-1, 10-2 can be set arbitrarily. In the example shown in FIG. 8, the number of assigned relay devices 20 is set to seven.

[0027] In the example shown in Fig. 8, the relay device 20x and the relay device 20y are assigned to both the user terminal 10-1 and the user terminal 10-2. When the relay devices 20x and 20y are shared between the user terminals 10-1 and 10-2 in this manner, the user scheduling information of the user terminals 10-1 and 10-2 is notified to each of the relay devices 20x and 20y. Each of the relay devices 20x and 20y executes beam control for each of the user terminals 10-1 and 10-2 according to the user scheduling information. At that time, the radio resources of each of the relay devices 20x and 20y are assigned to each of the user terminals 10-1 and 10-2 in a time-division manner.

[0028] 4. Overview of the wireless relay system The above-mentioned wireless relay method is executed in a wireless relay system. Fig. 9 is a diagram for explaining an outline of the wireless relay system of the present disclosure. In one embodiment shown in Fig. 9, the wireless relay system 2 includes a relay device 20, a base station device 30, and a control device 40.

[0029] The relay device 20 includes a processor 201, a memory 202, and a plurality of instructions 203 executable by the processor 201. The plurality of instructions 203 are stored in the memory 102. The number of each of the processors 201 and the memories 202 constituting the relay device 20 may be plural. One wireless relay system 2 includes a plurality of relay devices 20.

[0030] The base station device 30 includes a processor 301, a memory 302, and a plurality of instructions 303 executable by the processor 301. The plurality of instructions 303 are stored in the memory 302. The base station device 30 may include a plurality of processors 301 and a plurality of memories 302. One wireless relay system 2 includes one or a plurality of base station devices 30.

[0031] The control device 40 is a device that controls the operation of the wireless relay system 2. The control device 40 includes a processor 401, a memory 402, and a plurality of instructions 403 executable by the processor 401. The plurality of instructions 403 are stored in the memory 402. The memory 402 includes a RAM, a ROM, and a storage. Various thresholds and setting values ​​used in the above-mentioned determination of spatial multiplexing users may be stored in the memory 402. Furthermore, the memory 402 may store map information. The number of each of the processors 401 and memories 402 constituting the control device 40 may be multiple. A part or all of the functions of the control device 40 may be integrated with the relay device 20. Furthermore, a part or all of the functions of the control device 40 may be integrated with the base station device 30.

[0032] In addition, in one embodiment, the user terminal 10 may be included as a component of the wireless relay system 2. In that case, one wireless relay system 2 may include multiple user terminals 10. The user terminal 10 includes a processor 101, a memory 102, and multiple instructions 103 executable by the processor 101. The multiple instructions 103 are stored in the memory 102. The user terminal 10 may include multiple processors 101 and multiple memories 102.

[0033] As described above, the wireless relay system 2 includes a plurality of executable instructions. When these instructions are executed by at least one processor included in the wireless relay system 2, the wireless relay system 2 operates as described below, and multi-user transmission is performed using the wireless relay method described above. The processor included in the wireless relay system 2 may be a CPU, RISC, DSP, FPGA, ASIC, PLD, or another processing unit, or may be a combination of two or more of these, or may be a dedicated processor that operates according to the embodiments described below. The processor may be communicatively coupled to a memory, or may include a memory.

[0034] 5. Processing by the control device Next, the processing performed by the control device 40 will be described. Fig. 10 is a flow diagram showing one embodiment of the processing performed by the control device 40. The subject of the processing shown in the flow diagram is the control device 40, more specifically, at least one processor that executes instructions corresponding to those processing. Note that in the flow diagram, the user means the user terminal 10, and this term will be used in the following explanation of the flow diagram.

[0035] First, in step S01, the control device 40 determines a reference user #1 from among users who are targets of multi-user transmission. In one method of selecting user #1, a user randomly selected from all users or users who will communicate in the future is set as user #1. In another method of selecting user #1, a user who will have the largest transmission capacity when performing single-user transmission from among all users or users who will communicate in the future is selected as user #1.

[0036] Next, in step S02, the control device 40 determines the relay device 20 to be allocated to the user #1. The method of allocating the relay device 20 to the user #1 is as described in "3. Method of Allocating Relay Devices".

[0037] Next, in step S03, the control device 40 checks whether there are any users other than the currently selected user. If there are any other users, the process proceeds to step S04.

[0038] In step S04, the control device 40 selects the next user #n from among the users other than those already selected. n means that the user is the nth user selected. The next user #n may be selected according to a predetermined order or randomly.

[0039] Next, in step S05, the control device 40 judges whether spatial multiplexing can be applied to the user #n selected in step S04. To judge whether spatial multiplexing can be applied, the method described in "2. Method for judging spatial multiplexing user" is used. Any one of the first to third embodiments of the method for judging spatial multiplexing user may be used, or two or all of them may be used in combination. If spatial multiplexing can be applied, the process proceeds to step S07, and if spatial multiplexing cannot be applied, the process proceeds to step S08.

[0040] In step S07, the control device 40 sets the user #n as a spatial multiplexing user. The user #n set as a spatial multiplexing user forms a spatial multiplexing group together with the users previously set as spatial multiplexing users, including the user #1.

[0041] In step S08, the control device 40 sets the user #n as a time / frequency multiplexed user.

[0042] Next, in step S09, the control device 40 determines the relay device 20 to be allocated to the user #n. The method of allocating the relay device 20 to the user #n is as described in "3. Method of Allocating Relay Devices".

[0043] After step S09 is executed, step S03 is executed again. The control device 40 repeatedly executes the processes from step S03 to step S09 until there are no other selectable users. Then, when there are no other selectable users, the process proceeds to step S10.

[0044] In step S10, the control device 40 allocates frequency / time resources to each user. In detail, the spatial multiplexing users belonging to the spatial multiplexing group are allocated radio resources of the same frequency and time. The time / frequency multiplexing users not belonging to the spatial multiplexing group are allocated radio resources of different frequency and time from other users. The allocation of radio resources between the spatial multiplexing users and the time / frequency multiplexing users may be performed using a method of allocation that is fair among users, or may be performed using a method of allocation based on a proportional fairness standard.

[0045] 6. Coordination of operations between devices Next, a description will be given of the cooperation of operations between devices related to the allocation of relay device 20. Fig. 11 is a flow chart showing one embodiment of the cooperation of operations between devices.

[0046] The user terminal 10 performs its own positioning using a built-in positioning function. Positioning is performed for each user terminal 10. Next, the user terminal 10 transmits location information obtained by the positioning to the control device 40. The user terminal 10 may transmit the location information periodically, or may transmit the location information when a certain level of reception quality is not satisfied.

[0047] The control device 40 receives the location information transmitted from the user terminal 10, and assigns the relay device 20 to the user terminal 10 based on the location information. Information on the relay device 20 assigned by the control device 40 is notified from the control device 40 to the base station device 30 and the relay device 20. Note that, as a pre-processing, the control device 40 acquires the location information of the base station device 30 and the relay device 20 and stores it in the memory 402.

[0048] When the same relay device 20 is assigned to multiple user terminals 10, the control device 40 notifies each relay device 20 of user scheduling information. When the user scheduling information is generated by the base station device 30, the user scheduling information is notified from the base station device 30 to each relay device 20.

[0049] In order to enable the above-described cooperation between the devices, the base station device 30, the control device 40, and the relay device 20 have a communication function for exchanging information between the devices, and use the communication function to synchronize the devices.

[0050] 6. Wireless relay system configuration Next, a configuration of a wireless relay system 2 capable of executing the wireless relay method described above will be described. Fig. 12 is a block diagram showing one embodiment of the configuration of the wireless relay system 2. In this embodiment, the control device 40 is configured as a device independent of the base station device 30 and the relay device 20. However, the control device 40 may be incorporated into the base station device 30 or into the relay device 20. Note that the number of base station devices 30 and relay devices 20 is not limited to one each, and multiple devices may be used.

[0051] The control device 40 includes a processing unit 411, a storage unit 412, and a communication unit 413. When instructions 403 stored in the memory 402 are executed by the processor 401, the processor 401 functions as the processing unit 411, the storage unit 412, and the communication unit 413. However, the communication unit 413 may be configured as a communication circuit, and the storage unit 412 may be configured as a storage device.

[0052] The processing unit 411 performs the processing described in "5. Processing by the control device". Among the results of the processing, the control information related to the base station device 30 is notified to the control unit 311 of the base station device 30, and the control information related to the relay device 20 is notified to the control unit 214 of the relay device 20. The control information is notified through a management line laid between the control device 40 and the base station device 30 and between the control device 40 and the relay device 20. The communication through the management line may be wired or wireless. The storage unit 412 stores the information of the user terminal 10 acquired via the communication unit 413 and the information acquired in advance for executing the above-mentioned processing. The communication unit 413 performs wireless communication with the second communication unit 112 of the user terminal 10.

[0053] The base station device 30 includes a control unit 311, a processing unit 312, and a communication unit 313. When instructions 303 stored in the memory 302 are executed by the processor 301, the processor 301 functions as the processing unit 311, the storage unit 322, and the communication unit 313. However, the communication unit 313 may be configured as a communication circuit.

[0054] The communication unit 313 transmits and receives wireless signals to and from the relay device 20. The processing unit 312 processes signals transmitted and received using the communication unit 313. The control unit 311 controls the processing unit 312 in response to a notification from the control device 40.

[0055] The relay device 20 has a base station side antenna unit 211, an amplifier unit 213, a terminal side antenna unit 212, and a control unit 214. Of these, the base station side antenna unit 211 and the terminal side antenna unit 212 include physical devices described below. When instructions 203 stored in the memory 202 are executed by the processor 201, the processor 201 functions as the amplifier unit 213 and the control unit 214, and also functions as a part of the base station side antenna unit 211 and the terminal side antenna unit 212.

[0056] The base station side antenna unit 211 transmits and receives radio signals to and from the base station device 30. The base station side antenna unit 211 performs beamforming using multiple antenna elements. The terminal side antenna unit 212 transmits and receives radio signals to and from the user terminal 10. The terminal side antenna unit 212 performs beamforming using multiple antenna elements. The amplifier unit 213 amplifies a signal received by the base station side antenna unit 211 or the terminal side antenna unit 212. The controller 214 controls the base station side antenna unit 211 and the terminal side antenna unit 212, and selects a beam when performing beamforming. Note that a management line is laid between the controller 214 of the relay device 20 and the controller 311 of the base station device 30. Control information is transmitted and received using the management line. Communication via the management line may be wired or wireless.

[0057] The user terminal 10 includes a first communication unit 111, a second communication unit 112, a processing unit 113, a control unit 114, and a positioning unit 115. When instructions 103 stored in memory 102 are executed by the processor 101, the processor 101 functions as the first communication unit 111, the second communication unit 112, the processing unit 113, the control unit 114, and the positioning unit 115. However, the first communication unit 111 and the second communication unit 112 may be configured as communication circuits. The positioning unit 115 also includes physical devices.

[0058] The first communication unit 111 receives a wireless signal transmitted via the relay device 20. The second communication unit 112 receives the location information acquired by the positioning unit 115 as a wireless signal. The first communication unit 111 and the second communication unit 112 may be integrated into one communication unit. The positioning unit 115 has a function of acquiring the location of the user terminal 10. Any method may be used to acquire the location, and for example, positioning may be performed using a method such as GPS, LiDAR, cellular communication, or short-range wireless communication. The processing unit 113 processes signals transmitted and received using the first communication unit 111 and the second communication unit 112. The control unit 114 controls the positioning unit 115 and the processing unit 113. [Explanation of symbols]

[0059] 2 Radio relay system 10 User terminal 20 Relay Device 30 Base station equipment 40 Control device 50 Cover

Claims

1. A method for relaying communications to a plurality of user terminals, comprising: forming a group of user terminals among the plurality of user terminals that satisfies a predetermined spatial condition that limits sharing of a relay device between the user terminals; Allocating a plurality of relay devices to each of the plurality of user terminals in accordance with a predetermined allocation rule; Allocating radio resources of the same frequency and time to user terminals belonging to the group; and allocating radio resources of different frequencies and times to user terminals not belonging to the group, the radio resources being different from those of other user terminals. A method comprising:

2. 10. The method of claim 1 , Creating a group of user terminals that satisfy the predetermined spatial condition includes creating a group consisting of user terminals whose spatial distance from other user terminals is greater than a threshold. A method comprising:

3. 10. The method of claim 1 , Creating a group of user terminals that satisfy the predetermined spatial condition includes creating a group made up of user terminals that share a relay device with each other and that share a relay device with a predetermined number or less of user terminals. A method comprising:

4. 10. The method of claim 1 , Creating a group of user terminals that satisfy the predetermined spatial condition includes creating a group of user terminals that have obstructions between them and other user terminals. A method comprising:

5. The method according to any one of claims 1 to 4, Allocating a plurality of relay devices according to the predetermined allocation rule includes allocating a predetermined number of relay devices to each of the user terminals belonging to the group and the user terminals not belonging to the group in order of proximity to the target user terminal. A method comprising:

6. 6. The method of claim 5, The method further includes allocating wireless resources of the shared relay device in a time-division manner to a set of user terminals that share the relay device in the group. A method comprising:

7. An apparatus for controlling relay of communications for a plurality of user terminals, comprising: forming a group of user terminals among the plurality of user terminals that satisfies a predetermined spatial condition that limits sharing of a relay device between the user terminals; Allocating a plurality of relay devices to each of the plurality of user terminals in accordance with a predetermined allocation rule; Allocating radio resources of the same frequency and time to user terminals belonging to the group; and assigning to user terminals not belonging to the group radio resources of different frequencies and times to other user terminals. An apparatus comprising:

8. A program including a plurality of instructions executable by at least one processor provided in a system that relays communications to a plurality of user terminals, The instructions are provided to the at least one processor: forming a group of user terminals among the plurality of user terminals that satisfies a predetermined spatial condition that limits sharing of a relay device between the user terminals; Allocating a plurality of relay devices to each of the plurality of user terminals in accordance with a predetermined allocation rule; Allocating radio resources of the same frequency and time to user terminals belonging to the group; Allocating radio resources of different frequencies and times to user terminals not belonging to the group, the radio resources being different from those of other user terminals; It is configured to run A program characterized by:

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