Location determination system, location determination device, location determination method, and location determination program

Abstract

A station-placement-determining system according to one embodiment determines the station placement of a RIS reflector in cases where an electromagnetic wave transmitted from a transmission point is relayed, by reflection, to a reception point in a reception region that is shielded and unobstructed, wherein the station-placement-determining system: executes ray tracing from the transmission point to a region that includes a station placement candidate region for the RIS reflector where the electromagnetic wave can be propagated to the reception region without obstruction after one round of reflection from the transmission point; calculates, on the basis of the results of ray tracing, a propagation path electric power and a reflection point position for each of propagation paths via which the electromagnetic wave is propagated from the transmission point to the reception region without obstruction after one round of reflection in the station placement candidate region; determines the reflection point position of the propagation path for which the calculated propagation path electric power is greatest as the station placement position of the RIS reflector; calculates an incident angle of the propagation path to the determined station placement position and a reflection angle from the determined station placement position to the reception region; and outputs values that respectively indicate the station placement position, the incident angle, and the reflection angle.

Description

Technical Field

[0001] The present invention relates to a location determination system, a location determination device, a location determination method, and a location determination program.

Background Art

[0002] In order to achieve high-speed and large-capacity wireless access, attention has been paid to utilizing high-frequency bands capable of securing a wide bandwidth. For example, in the fifth-generation mobile communication system, the 28 GHz band is used, and in the IEEE 802.11ad (millimeter-wave wireless LAN system), which is a wireless LAN standard, the 60 GHz band is used to achieve high-speed and large-capacity.

[0003] Radio waves in high-frequency bands are more likely to attenuate and are less diffractive than those in low-frequency bands. Therefore, when utilizing high-frequency bands, there are problems such as short transmission distances and significant degradation of reception quality due to shielding.

[0004] For example, in order to relay electromagnetic waves to a receiving point that is blocked in sight from a transmitting point, there exists a repeater device called a RIS (Reconfigurable Intelligent Surface) reflector that can electrically change element characteristics and dynamically control the reflection characteristics of electromagnetic waves.

[0005] Also, a method for calculating the location of a radio base station that relays electromagnetic waves is known (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] To enhance the effectiveness of repeaters such as RIS reflectors, it is necessary to place the RIS reflectors in a location where they can receive sufficient power from the transmitting station.

[0008] However, conventional technology could only calculate the location of wireless base stations that emit radio waves themselves, and it was difficult to calculate and determine the appropriate location for repeaters such as RIS reflectors.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a location determination system, location determination device, location determination method, and location determination program that can determine a suitable location for an RIS reflector that does not emit electromagnetic waves itself in order to increase the relay power. [Means for solving the problem]

[0010] A location determination system according to one aspect of the present invention is a location determination system for determining the location of an RIS reflector when electromagnetic waves transmitted from a transmitting point are relayed by reflection to a receiving point within a line-of-sight shielded receiving area, and includes a ray tracing unit that performs ray tracing from the transmitting point to an area including a candidate location area for the RIS reflector where electromagnetic waves can propagate in line of sight to the receiving area after one reflection from the transmitting point, and based on the ray tracing results performed by the ray tracing unit, the system determines the location of the RIS reflector where electromagnetic waves can propagate in line of sight to the receiving area after one reflection within the candidate location area from the transmitting point. The system is characterized by comprising: a first calculation unit that calculates the propagation path power and reflection point position for each propagation path that propagates electromagnetic waves into the region; a location determination unit that determines the reflection point position of the propagation path with the maximum propagation path power calculated by the first calculation unit as the location of the RIS reflector; a second calculation unit that calculates the incidence angle of the propagation path to the location determined by the location determination unit and the reflection angle from the location determined by the location determination unit to the receiving region; and an output unit that outputs the location determined by the location determination unit, as well as values ​​indicating the incidence angle and reflection angle calculated by the second calculation unit.

[0011] Furthermore, in a location determination device according to one aspect of the present invention, when electromagnetic waves transmitted from a transmission point are relayed by reflection to a receiving point within a receiving area shielded in the line of sight, the location determination device determines the location of an RIS reflector, and based on the ray tracing results obtained by performing ray tracing from the transmission point on an area including a candidate location area of ​​the RIS reflector where electromagnetic waves can propagate in the line of sight to the receiving area after one reflection from the transmission point, a propagation path is determined for the electromagnetic waves to propagate in the line of sight to the receiving area after one reflection from the transmission point within the candidate location area. The system is characterized by comprising: a first calculation unit that calculates the propagation path power and reflection point position for each propagation path; a location determination unit that determines the reflection point position of the propagation path with the maximum propagation path power calculated by the first calculation unit as the location of the RIS reflector; a second calculation unit that calculates the incidence angle of the propagation path to the location determined by the location determination unit and the reflection angle from the location determined by the location determination unit to the receiving area; and an output unit that outputs the location determined by the location determination unit, as well as values ​​indicating the incidence angle and reflection angle calculated by the second calculation unit.

[0012] Furthermore, in a location determination method according to one aspect of the present invention, when electromagnetic waves transmitted from a transmitting point are relayed by reflection to a receiving point within a receiving area shielded by line of sight, the location determination method for determining the location of an RIS reflector includes a ray tracing step of performing ray tracing from the transmitting point to a region including a candidate location area for the RIS reflector where electromagnetic waves can be propagated by line of sight to the receiving area after one reflection from the transmitting point, and based on the ray tracing results performed in the ray tracing step, the electromagnetic waves are propagated by line of sight to the receiving area after one reflection within the candidate location area from the transmitting point. The system is characterized by including: a first calculation step of calculating the propagation path power and reflection point position for each propagation path to be carried; a location determination step of determining the reflection point position of the propagation path with the maximum propagation path power calculated in the first calculation step as the location of the RIS reflector; a second calculation step of calculating the incidence angle of the propagation path to the location determined in the location determination step and the reflection angle from the location determined in the location determination step to the receiving area; and an output step of outputting the location determined in the location determination step, as well as values ​​indicating the incidence angle and reflection angle calculated in the second calculation step. [Effects of the Invention]

[0013] According to the present invention, it is possible to determine an optimal placement location for an RIS reflector that does not emit electromagnetic waves itself, in order to increase the relayed power. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram schematically shows the environment in which the placement position of an RIS reflector should be determined by a placement determination system according to one embodiment. [Figure 2] This figure shows an example configuration of a location determination system according to one embodiment. [Figure 3] This flowchart shows an example of the operation of a location determination system according to one embodiment. [Figure 4] This figure shows an example of the hardware configuration of a location determination device according to one embodiment.

Embodiment for Carrying out the Invention

[0015] When explaining the placement decision system according to an embodiment, first, regarding the environment that is the target for determining the placement position of the RIS reflector by the placement decision system, it will be described using FIG. 1.

[0016] FIG. 1 is a diagram schematically showing the environment that is the target for determining the placement position of the RIS reflector by the placement decision system according to an embodiment.

[0017] Note that the RIS reflector for which the placement (position) is to be determined is assumed to be a repeater for relaying the electromagnetic wave transmitted from the transmission point to the reception point in the reception area that is blocked in direct line of sight by reflecting it. However, when using the placement decision system, the reception area does not necessarily have to be blocked in direct line of sight from the transmission point.

[0018] As shown in FIG. 1, in the environment that is the target for determining the placement position of the RIS reflector, a plurality of obstacles W such as walls are arranged. The transmission point Tx where the transmission device for transmitting electromagnetic waves (radio waves) is arranged and the reception area Rx where the reception device receives the electromagnetic waves are blocked by the obstacle W in direct line of sight.

[0019] Also, the wall surface 100 is a structure on which the RIS reflector can be installed. The wall surface 100 includes the placement candidate area A of the RIS reflector.

[0020] The placement candidate area A of the RIS reflector is an area that can form a propagation path for propagating the electromagnetic wave to the reception area Rx in direct line of sight after one reflection within the placement candidate area A from the transmission point Tx, as illustrated in FIG. 1.

[0021] Next, a specific configuration example of the placement decision system 1 according to an embodiment will be described. FIG. 2 is a diagram showing a configuration example of the placement decision system 1 according to an embodiment. As shown in FIG. 2, the placement decision system 1 has, for example, a ray tracing unit 2 and a placement decision device 3.

[0022] The ray tracing unit 2 performs ray tracing from the transmission point Tx on a region including the placement candidate region A of the RIS reflector plate that enables electromagnetic waves to propagate in a line-of-sight manner to the reception region Rx after one reflection from the transmission point Tx, and outputs the result of the ray tracing to the placement determination device 3.

[0023] The placement determination device 3 has, for example, a storage unit 31, a first calculation unit 32, a placement position determination unit 33, a second calculation unit 34, and an output unit 35.

[0024] The storage unit 31 is a storage device having, for example, a result storage unit 311, a candidate region storage unit 312, and a reception region storage unit 313.

[0025] The result storage unit 311 stores the result of the ray tracing executed by the ray tracing unit 2. The candidate region storage unit 312 stores information indicating the position of the wall surface 100, information indicating the position (range) of the placement candidate region A, and the like. The reception region storage unit 313 stores information indicating the position (range) of the reception region Rx and the like.

[0026] The first calculation unit 32 accesses the storage unit 31, and based on the ray tracing result executed by the ray tracing unit 2, calculates the propagation path power and the reflection point position of each propagation path that propagates electromagnetic waves from the transmission point Tx to the reception region Rx in a line-of-sight manner after one reflection within the placement candidate region A, and outputs the calculated results to the placement position determination unit 33 and the second calculation unit 34.

[0027] The placement position determination unit 33 accesses the storage unit 31, determines the reflection point position C of the propagation path with the maximum propagation path power calculated by the first calculation unit 32 as the placement position (placement point) of the RIS reflector plate, and outputs the determined result to the second calculation unit 34 and the output unit 35.

[0028] The second calculation unit 34 calculates the incident angle of the propagation path to the placement position determined by the placement position determination unit 33 and the reflection angle from the placement position determined by the placement position determination unit 33 to the reception region Rx, and outputs the calculated results to the output unit 35.

[0029] Furthermore, the second calculation unit 34 may calculate the reflection angle to the centroid of the receiving region Rx, or the reflection angle to any receiving point within the receiving region Rx. Here, the second calculation unit 34 uses, for example, the geometric center, or a geometric center weighted according to the propagation path power, as the centroid.

[0030] The output unit 35 outputs the station location determined by the station location determination unit 33, as well as the values ​​indicating the incident angle and reflection angle calculated by the second calculation unit 34.

[0031] Next, an example of the operation of the location determination system 1 will be described. Figure 3 is a flowchart of an example of the operation of the location determination system 1 according to one embodiment. As shown in Figure 3, the location determination system 1 calculates the propagation path power and reflection point position from the transmission point Tx to the reception area Rx (receiving point) by ray tracing (S100).

[0032] Next, the station location determination system 1 determines the reflection point position C of the propagation path with the maximum calculated propagation path power from among the candidate station location areas A that have a line of sight to the receiving area Rx (receiving point) as the station location (station location point) of the RIS reflector (S102).

[0033] Subsequently, the station location determination system 1 calculates the incidence angle of the propagation path to the determined station location and the reflection angle from the station location to the receiving area Rx (S104).

[0034] The station location determination system 1 then outputs values ​​indicating the station location, the angle of incidence, and the angle of reflection (S106).

[0035] In this way, the station location determination system 1 calculates the propagation path power and reflection point position for each propagation path that propagates electromagnetic waves from the transmission point Tx to the receiving area Rx in line of sight after one reflection within the candidate station location area A. The system determines the reflection point position of the propagation path with the maximum calculated propagation path power as the station location for the RIS reflector. The system then calculates the incidence angle of the propagation path to the determined station location and the reflection angle from the station location to the receiving area Rx. Thus, it can determine a station location suitable for increasing the relay power for an RIS reflector that does not emit electromagnetic waves itself.

[0036] In other words, the station location determination system 1 can maximize the incoming power to the RIS reflector and maximize the relay power to the receiving point.

[0037] Furthermore, each function of the station location determination device 3 may be partially or entirely composed of hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array), or it may be composed of a program executed by a processor such as a CPU.

[0038] For example, the location determination device 3 according to the present invention can be implemented using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

[0039] Figure 4 shows an example of the hardware configuration of a location determination device 3 according to one embodiment. As shown in Figure 4, for example, the location determination device 3 has an input unit 50, an output unit 51, a communication unit 52, a CPU 53, a memory 54, and an HDD 55 connected via a bus 56, and is equipped with computer functions. The location determination device 3 is also configured to be able to input and output data to and from a computer-readable storage medium 57.

[0040] The input unit 50 is, for example, a keyboard and mouse. The output unit 51 is, for example, a display device such as a display, and corresponds to the output unit 35 described above. The communication unit 52 is a wired or wireless network interface.

[0041] The CPU 53 controls each component of the location determination device 3 and performs predetermined processing. The memory 54 and HDD 55 are storage units that store data, etc., and correspond to the storage unit 31 described above.

[0042] The storage medium 57 is capable of storing programs and the like that which execute the functions of the location determination device 3. Note that the architecture of the location determination device 3 is not limited to the example shown in Figure 4.

[0043] Here, "computer" includes hardware such as the operating system and peripheral devices. Furthermore, "computer-readable storage medium" refers to storage devices such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and other portable media.

[0044] Furthermore, "computer-readable storage medium" may include devices that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs over networks such as the Internet or communication lines such as telephone lines, as well as devices that hold programs for a certain period of time, such as volatile memory inside computers that act as servers or clients in such cases.

[0045] While embodiments of the present invention have been described above with reference to the drawings, it is clear that the above-described embodiments are merely illustrative examples of the present invention, and the present invention is not limited to the above-described embodiments. Therefore, additions, omissions, substitutions, and other modifications of components may be made without departing from the technical concept and scope of the present invention. [Explanation of Symbols]

[0046] 1...Location determination system, 2...Ray tracing unit, 3...Location determination device, 31...Storage unit, 32...First calculation unit, 33...Location location determination unit, 34...Second calculation unit, 35...Output unit, 50...Input unit, 51...Output unit, 52...Communication unit, 53...CPU, 54...Memory, 55...HDD, 56...Bus, 57...Storage medium, 100...Wall surface, 311...Result storage unit, 312...Candidate area storage unit, 313...Received area storage unit

Claims

1. In a system for determining the placement of RIS reflectors when electromagnetic waves transmitted from a transmission point are relayed by reflection to a receiving point within a receiving area shielded by line of sight, A ray tracing unit performs ray tracing from the transmission point on a region including a candidate area for the placement of a RIS reflector that allows electromagnetic waves to propagate from the transmission point to the receiving area in line of sight after one reflection, A first calculation unit calculates the propagation path power and reflection point position for each propagation path that propagates electromagnetic waves from the transmission point to the reception area in line of sight after one reflection within the candidate station area, based on the ray tracing results performed by the ray tracing unit, A location determination unit determines the location of the RIS reflector as the location of the reflection point of the propagation path where the propagation path power calculated by the first calculation unit is maximum, A second calculation unit calculates the incidence angle of the propagation path to the station location determined by the station location determination unit and the reflection angle from the station location determined by the station location determination unit to the receiving area. An output unit that outputs the location determined by the location determination unit and the values ​​indicating the angle of incidence and the angle of reflection calculated by the second calculation unit. A location determination system characterized by having the following features.

2. The second calculation unit is, Calculating the angle of reflection to the centroid of the receiving area, or to any receiving point within the receiving area. The location determination system according to claim 1, characterized by the following:

3. The second calculation unit is, The centroid is the geometric center, or a geometric center weighted according to the propagation path power. A location determination system according to claim 1 or 2, characterized by the above.

4. In a case where electromagnetic waves transmitted from a transmission point are relayed by reflection to a receiving point within a receiving area shielded by line of sight, in a location determination device that determines the location of the RIS reflector, A first calculation unit calculates the propagation path power and reflection point position for each propagation path that propagates electromagnetic waves from the transmission point to the reception area in line of sight after one reflection within the candidate location area, based on the ray tracing results obtained by performing ray tracing from the transmission point to the region including a candidate location area for a RIS reflector that can propagate electromagnetic waves from the transmission point to the reception area in line of sight after one reflection, A location determination unit determines the location of the RIS reflector as the location of the reflection point of the propagation path where the propagation path power calculated by the first calculation unit is maximum, A second calculation unit calculates the incidence angle of the propagation path to the station location determined by the station location determination unit and the reflection angle from the station location determined by the station location determination unit to the receiving area. An output unit that outputs the location determined by the location determination unit and the values ​​indicating the angle of incidence and the angle of reflection calculated by the second calculation unit. A location determination device characterized by having the following features.

5. The second calculation unit is, Calculating the angle of reflection to the centroid of the receiving area, or to any receiving point within the receiving area. The location determination device according to claim 4, characterized by the following:

6. The second calculation unit is, The centroid is the geometric center, or a geometric center weighted according to the propagation path power. A location determination device according to claim 4 or 5, characterized by the above.

7. In a method for determining the placement of an RIS reflector when electromagnetic waves transmitted from a transmission point are relayed by reflection to a receiving point within a receiving area shielded by line of sight, A ray tracing step is performed on a region including a candidate area for the placement of a RIS reflector that allows electromagnetic waves to propagate from the transmission point to the receiving area in line of sight after one reflection, A first calculation step calculates the propagation path power and reflection point position for each propagation path that propagates electromagnetic waves from the transmission point to the reception area in line of sight after one reflection within the candidate station area, based on the ray tracing results performed by the ray tracing step described above. A location determination step in which the reflection point position of the propagation path with the maximum propagation path power calculated in the first calculation step is determined as the location of the RIS reflector, A second calculation step that calculates the incidence angle of the propagation path to the station location determined in the station location determination step and the reflection angle from the station location determined in the station location determination step to the receiving area, An output step that outputs the location determined by the location determination step, and the values ​​indicating the angle of incidence and the angle of reflection calculated by the second calculation step. A method for determining a location, characterized by including the following:

8. A location determination program for causing a computer to function as a component of the location determination device described in claim 4 or 5.

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