Relay Station Installation Location Calculation Device, Installation Location Calculation Method, and Installation Location Calculation Program

Abstract

A device for calculating the installation position of a relay station according to one embodiment of the present invention has: a specification unit for specifying, from among a plurality of station placement candidate points that are within a station placement candidate range or are predetermined as installation position candidates, a station placement candidate point for which a LOS region from a relay station is maximized; a correction unit for correcting the position of each specified station placement candidate point on the basis of a Fresnel zone with respect to the relay station; a storage unit for storing the position of a station placement candidate point for which the LOS region from the relay station is maximized, from among each of the specified station placement candidate points or the corrected station placement candidate points, as the installation position of the relay station; and a control unit for performing control such that the number of installation positions of the relay station that are stored by the storage unit is kept at a predetermined number.

Description

Technical Field

[0001] The present invention relates to a relay station installation position calculation device, an installation position calculation method, and an installation position calculation program.

Background Art

[0002] For example, in a wireless communication system using a high-frequency band, there is a system in which radio waves transmitted by a transmitting station are reflected by a reflector and relayed to a receiving station. That is, the reflector serves as a relay station (repeater) for relaying radio waves.

[0003] The reflectors for reflecting radio waves also include RIS (Reconfigurable Intelligent Surface) reflectors that are enabled to electrically change element characteristics and dynamically control the reflection characteristics of electromagnetic waves.

[0004] In addition, a method for calculating the installation position of a base station is known in order to construct a wireless communication system for relaying radio waves (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to enhance the effect of a relay station such as a RIS reflector, it is necessary to locate the relay station at a position where line-of-sight (LOS) propagation from the transmitting station is possible. That is, it is desirable to determine the location of the relay station such that the LOS area (LOS region) is maximized and the non-line-of-sight (NLOS) propagation area (NLOS region) is minimized.

[0007] However, in the prior art, it was only possible to calculate the location of a base station that emits radio waves by itself, and it was difficult to directly calculate the location of the relay station.

[0008] The present invention has been made in view of the above-described problems, and an object thereof is to provide a relay station installation position calculation device, an installation position calculation method, and an installation position calculation program that can calculate the installation position of a relay station so as to minimize the NLOS region.

Means for Solving the Problems

[0009] A relay station installation position calculation device according to an embodiment of the present invention includes a specifying unit that specifies one or more candidate placement points that maximize the LOS area from the relay station from within a placement candidate range where a relay station for relaying radio waves can be installed, or from among a plurality of candidate placement points predetermined as candidate installation positions of the relay station, based on the range in which the relay station can relay radio waves; a correcting unit that corrects the position of each of the candidate placement points specified by the specifying unit based on the Fresnel zone with respect to the relay station; a storage unit that stores the position of one or more candidate placement points that maximize the LOS area from the relay station as the installation position of the relay station, from among the candidate placement points specified by the specifying unit or the candidate placement points corrected by the correcting unit; and a control unit that controls such that the number of installation positions of the relay station stored in the storage unit becomes a predetermined number.

[0010] In addition, the relay station installation position calculation method according to an embodiment of the present invention includes, within a station location candidate range where a relay station for relaying radio waves can be installed, or among a plurality of pre-determined station location candidate points as candidate installation positions of the relay station, based on the relayable range of radio waves by the relay station, a specifying step of specifying one or more station location candidate points that maximize the LOS area from the relay station; a correcting step of correcting the positions of the specified station location candidate points based on the Fresnel zone with respect to the relay station; a storing step of storing, in a storage unit, the positions of one or more station location candidate points that maximize the LOS area from the relay station, from among the specified station location candidate points or the corrected station location candidate points; and a control step of controlling such that the number of the installation positions of the relay station stored in the storage unit becomes a pre-determined number.

Advantages of the Invention

[0011] According to the present invention, it is possible to calculate the installation position of a relay station so as to minimize the NLOS area.

Brief Description of the Drawings

[0012]

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Embodiment for Carrying Out the Invention

[0013] Hereinafter, a configuration example of a relay station installation position calculation device 1 according to an embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a relay station installation position calculation device 1 according to an embodiment.

[0014] As shown in FIG. 1, a relay station installation position calculation device 1 according to an embodiment includes a storage unit 2, a processing unit 3, and a control unit 4, and calculates the installation position of a repeater (relay station) for configuring, for example, a wireless communication system using a high-frequency band.

[0015] The control unit 4 controls each unit constituting the installation position calculation device 1. Note that the repeater is, for example, a reflector that reflects and relays radio waves. The reflector also includes an RIS reflector and the like.

[0016] The storage unit 2 includes, for example, a repeater information storage unit 21, a stationing candidate range storage unit 22, a total number of stations storage unit 23, a transmission point storage unit 24, a LOS area storage unit 25, a stationing candidate point storage unit 26, and a stationing point storage unit 27.

[0017] The repeater information storage unit 21 stores characteristics of repeaters for configuring a wireless communication system. For example, the repeater information storage unit 21 stores in advance information indicating a dynamically controllable relaying range (repeater coverage area: reflection possible angle) in which an RIS reflector serving as a repeater reflects radio waves.

[0018] The stationing candidate range storage unit 22 stores in advance the range where the repeater can be installed as the stationing candidate range. For example, in the example shown in FIG. 2, the entire range surrounded by the wall 10 (inside the wall 10) is the stationing candidate range of the repeater that reflects the radio waves transmitted by the transmitting station S.

[0019] The total number of relay stations memory unit 23 stores in advance the total number of relay stations (total number of installed stations) that an operator plans to install to configure a wireless communication system.

[0020] The transmission point memory unit 24 stores the position of the transmission point. For example, the transmission point memory unit 24 stores in advance the position of the transmission station S shown in FIG. 2 etc. as the transmission point.

[0021] The LOS area memory unit 25 stores the LOS areas from all the transmission points stored in the transmission point memory unit 24.

[0022] The installed station candidate point memory unit 26 stores, as installed station candidate points, the positions that have become candidate points for installing relay stations by the processing of the processing unit 3. Further, the installed station candidate point memory unit 26 may store a plurality of installed station candidate points predetermined as candidate installation positions of the relay stations.

[0023] The installed station point memory unit 27 stores, when the installation position of the relay station is determined, the position of the relay station as the installed station point. For example, the installed station point memory unit 27 stores, from among the installed station candidate points specified by the specifying unit 34 described later, or the installed station candidate points corrected by the correcting unit 38 described later, the positions of one or more installed station candidate points that maximize the LOS area from the relay station as the installation position (installed station point) of the relay station. Further, the installed station point memory unit 27 also stores, when the installation position of the relay station is determined, the position of the relay station as a new transmission point.

[0024] The processing unit 3 includes a LOS area calculation unit 30, an extraction unit 32, a specifying unit 34, a Fresnel zone calculation unit 36, and a correction unit 38.

[0025] The LOS area calculation unit 30 calculates the LOS area from the transmission points stored in the memory unit 2. For example, the LOS area calculation unit 30 calculates the LOS area shown in FIG. 3.

[0026] The extraction unit 32 extracts the boundary between the LOS area and the NLOS area with respect to the installed station candidate range stored in the installed station candidate range memory unit 22, and outputs information indicating the extracted boundary to the specifying unit 34.

[0027] For example, the extraction unit 32 extracts, as the boundary between the LOS region and the NLOS region, a line connecting a boundary point A1 on a straight line L1 passing through the boundary point 11, which is the vertex of the wall 10 shown in FIG. 3, and the boundary point 11, and the transmission station S.

[0028] The specifying unit 34 specifies one or more candidate placement points that maximize the LOS region from the repeater, based on the relaying possible range stored in the repeater information storage unit 21 and the boundary extracted by the extraction unit 32, within the candidate placement range stored in the candidate placement range storage unit 22 or among the candidate placement points stored in the candidate placement point storage unit 26.

[0029] For example, the specifying unit 34 deletes, from the candidate placement points stored in the candidate placement point storage unit 26, for example, the boundary point 11, which is the vertex of the wall 10 shown in FIG. 4, and the candidate placement points where the LOS region does not expand. Then, the specifying unit 34 specifies the boundary point A1 as the candidate placement point that maximizes the LOS region from the repeater.

[0030] The Fresnel zone calculation unit 36 calculates the Fresnel zone between the transmission point and the candidate placement point (repeater). For example, the Fresnel zone calculation unit 36 calculates the Fresnel zone (the same Fresnel radius as the Fresnel zone Z1 shown in FIG. 4) between the transmission station S (not shown in FIG. 4) and the boundary point A1.

[0031] The correction unit 38 corrects the position of each candidate placement point specified by the specifying unit 34 based on the Fresnel zone for the repeater calculated by the Fresnel zone calculation unit 36. More specifically, the correction unit 38 corrects the position of the candidate placement point specified by the specifying unit 34 so that there is no object that blocks the radio wave within the Fresnel zone between the transmission point and the candidate placement point.

[0032] For example, the correction unit 38 corrects the position of the candidate placement point from the boundary point A1 to the placement position A so that the boundary point 11, which is the vertex of the wall 10, does not enter the Fresnel zone Z1. Here, the number of candidate placement points for one hop is one. m1 to move.

[0033] In FIG. 4, when the installation position of the first (1-hop) repeater is set as the station location A m1 the relaying range of the repeater is the range sandwiched between the straight line a 11 and the straight line a 12 At this time, the boundary between the LOS region and the NLOS region is determined by the straight line a 12 and the straight line L2 passing through the boundary point 12 which is the vertex of the wall 10 and the station location A m1 .

[0034] Then, the control unit 4 controls so that the number of installation positions of the repeaters stored in the storage unit 2 (the number of station points stored in the station point storage unit 27) becomes a predetermined number (for example, the total number of repeaters stored in the total station number storage unit 23).

[0035] For example, when the 1-hop station location is determined, the control unit 4 controls to calculate the 2-hop station candidate points.

[0036] For example, the installation position calculation device 1 deletes the boundary point 12 which is the vertex of the wall 10 shown in FIG. 5 from the station candidate points. Then, the installation position calculation device 1 specifies the boundary point B1 as one of the 2-hop station candidate points that maximizes the LOS region from the repeater.

[0037] Then, the installation position calculation device 1 corrects the position of the station candidate point to move from the boundary point B1 to the station position B 21 so that the boundary point 12 which is the vertex of the wall 10 does not enter the Fresnel zone Z m1 . The station position B m1 has the largest LOS region among the installation positions of the 2-hop repeaters.

[0038] In FIG. 5, when one of the installation positions of the 2-hop repeaters is set as the station position B m1 the relaying range of the repeater is the range sandwiched between the straight line b 11 and the straight line b 12 At this time, the boundary between the LOS region and the NLOS region is the straight line a 12 , the straight line b 11, the straight line L2, and the straight line b 12 are determined by

[0039] Also, as shown in FIG. 6, the installation position calculation device 1 identifies the boundary point B2 as another two-hop placement candidate point that maximizes the LOS area from the relay.

[0040] Then, since there is nothing in the Fresnel zone Z 22 that blocks the radio wave, the installation position B2 is set as the boundary point B2 without correcting the position. The installation position B2 has the second largest LOS area among the installation positions of the two-hop relays after the installation position B1.

[0041] In FIG. 6, when another installation position of the two-hop relay is set as the installation position B2, the relay range of the relay is the range sandwiched between the straight line b 21 and the straight line b 22 . At this time, the boundary between the LOS area and the NLOS area is the straight line b 21 , the straight line L2, and the straight line b 12 are determined by

[0042] After that, as shown in FIG. 7, the installation position calculation device 1 identifies the three-hop placement candidate points C1 and C2 that maximize the LOS area from the relay.

[0043] Then, since there is nothing in the Fresnel zones Z 31 , Z 32 that blocks the radio wave, the installation positions C1 and C2 are set as the placement candidate points C1 and C2 without correcting the positions.

[0044] When one of the installation positions of the three-hop relay is set as the installation position C1, the relay range of the relay is the range sandwiched between the straight line C 11 and the straight line C 12 . Also, when the other installation position of the three-hop relay is set as the installation position C2, the relay range of the relay is the range sandwiched between the straight line C 21 and the straight line C 22 .

[0045] In addition, in FIG. 7, when the installation positions of the three-hop repeaters are set to the stationing positions C1 and C2, the boundary between the LOS region and the NLOS region is the straight line C 11 , the straight line L3 passing through the boundary point 13 which is the vertex of the wall 10, and the straight line C 21 is determined by.

[0046] Next, an operation example of the installation position calculation device 1 will be described with reference to FIG. 8. FIG. 8 is a flowchart showing an operation example of the installation position calculation device 1 according to an embodiment.

[0047] In step 100 (S100), the extraction unit 32 extracts the boundary between the LOS region and the NLOS region from the transmission point with respect to the stationing candidate range.

[0048] In step 102 (S102), the specifying unit 34 specifies one or more stationing candidate points that maximize the LOS region based on the relaying range of the repeater. At this time, the specifying unit 34 deletes, for example, the boundary point that is the vertex of the wall 10 and the stationing candidate points where the LOS region does not expand, as being outside the target of the stationing candidate points.

[0049] In step 104 (S104), the correction unit 38 corrects the position of each stationing candidate point based on the Fresnel zone calculated by the Fresnel zone calculation unit 36 to obtain the stationing position of the repeater.

[0050] In step 106 (S106), the control unit 4 determines whether the number of stationing positions of the repeater calculated by the installation position calculation device 1 is less than the total number of stationings stored in the total stationing number storage unit 23. If it is less (S106: Yes), the process proceeds to the process of S108, and in other cases (S106: No), the process ends.

[0051] In step 108 (S108), the stationing point storage unit 27 stores the stationing candidate point with the maximum LOS region as the stationing point. Note that the stationing candidate points where the LOS region is not maximized are deleted, for example, by the specifying unit 34.

[0052] In step 110 (S110), the control unit 4 determines whether the number of remaining placement candidate points of the hop count currently calculating the placement position is greater than 0. If it is greater (S110: Yes), the process returns to the process of S106, and in other cases (S110: No), the process proceeds to the process of S112.

[0053] In step 112 (S112), with the placement point as the transmission point, the process returns to the process of S100.

[0054] In addition, when the placement candidate points are predetermined, the installation position calculation device 1 sequentially sets the placement position from the placement candidate points that can most expand the LOS area among the plurality of placement candidate points in the LOS area.

[0055] Thus, the installation position calculation device 1 according to one embodiment sequentially sets the positions of one or more placement candidate points that maximize the LOS area as the installation positions of the relay stations, so that the installation positions of the relay stations can be calculated to minimize the NLOS area.

[0056] Each function of the installation position calculation device 1 may be partially or entirely configured by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

[0057] For example, the installation position calculation device 1 can be realized using a computer and a program, and it is also possible to record the program on a storage medium or provide it through a network.

[0058] FIG. 9 is a diagram showing a hardware configuration example of the installation position calculation device 1 according to an embodiment. As shown in FIG. 9, in the installation position calculation device 1, an input unit 50, an output unit 51, a communication unit 52, a CPU 53, a memory 54, and an HDD 55 are connected via a bus 56, and the device has functions as a computer. Further, the installation position calculation device 1 is enabled to input and output data to and from a computer-readable storage medium 57.

[0059] The input unit 50 is, for example, a keyboard and a mouse. The output unit 51 is, for example, a display device such as a display. The communication unit 52 is, for example, a network interface.

[0060] The CPU 53 controls each unit constituting the installation position calculation device 1 and performs predetermined processing and the like. The memory 54 and the HDD 55 correspond to the above-described storage unit 2 that stores data and the like.

[0061] The storage medium 57 is enabled to store a program and the like for executing the functions of the installation position calculation device 1. Note that the architecture constituting the installation position calculation device 1 is not limited to the example shown in FIG. 9.

Description of Reference Numerals

[0062] 1... Installation position calculation device, 2... Storage unit, 3... Processing unit, 4... Control unit, 10... Wall, 21... Repeater information storage unit, 22... Installation candidate range storage unit, 23... Total installation number storage unit, 24... Transmission point storage unit, 25... LOS area storage unit, 26... Installation candidate point storage unit, 27... Installation point storage unit, 30... LOS area calculation unit, 32... Extraction unit, 34... Specific unit, 36... Fresnel zone calculation unit, 38... Correction unit, 50... Input unit, 51... Output unit, 52... Communication unit, 53... CPU, 54... Memory, 55... HDD, 56... Bus, 57... Storage medium

Claims

1. A specifying unit that specifies one or more candidate placement points that maximize the LOS area from the relay station based on the relayable range of radio waves by the relay station, within a candidate placement range where a relay station for relaying radio waves can be installed, or among a plurality of candidate placement points predetermined as candidate installation positions of the relay station; A correction unit that corrects the position of each candidate placement point specified by the specifying unit based on the Fresnel zone with respect to the relay station; A storage unit that stores the positions of one or more candidate placement points that maximize the LOS area from the relay station as the installation position of the relay station, from among the candidate placement points specified by the specifying unit or the candidate placement points corrected by the correction unit; A control unit that controls such that the number of installation positions of the relay station stored in the storage unit becomes a predetermined number A relay station installation position calculation device, characterized by comprising the above.

2. An extraction unit that extracts the boundary between the LOS area and the NLOS area from the transmission point that transmits radio waves with respect to the candidate placement range; further comprising; The specifying unit specifies one or more candidate placement points that maximize the LOS area from the relay station based on the boundary extracted by the extraction unit. The relay station installation position calculation device according to claim 1, characterized by the above.

3. The correction unit corrects the position of the candidate placement point specified by the specifying unit so that there is no object that blocks radio waves within the Fresnel zone with respect to the relay station. The relay station installation position calculation device according to claim 1 or 2, characterized by the above.

4. The relay station is a reflector that reflects radio waves. The relay station installation position calculation device according to any one of claims 1 to 3, characterized by the above.

5. A specifying step of specifying one or more candidate placement points that maximize the LOS area from the relay station based on the relayable range of radio waves by the relay station, within a candidate placement range where a relay station for relaying radio waves can be installed, or among a plurality of candidate placement points predetermined as candidate installation positions of the relay station; A correction step of correcting the position of each specified candidate placement point based on the Fresnel zone with respect to the relay station; A storage step in which a storage unit stores the positions of one or more candidate placement points that maximize the LOS area from the relay station as the installation position of the relay station, from among the specified candidate placement points or the corrected candidate placement points; A control step of controlling such that the number of installation positions of the relay station stored in the storage unit becomes a predetermined number A method for calculating the installation position of a relay station, characterized by including

6. An extraction step of extracting a boundary between a LOS region and a NLOS region from a transmission point that transmits radio waves with respect to the candidate installation range further including In the specifying step, specifying one or more candidate installation points that maximize the LOS region from the relay station based on the boundary extracted by the extraction step The method for calculating the installation position of a relay station according to claim 5, characterized by

7. In the correction step, correcting the position of the candidate installation point specified by the specifying step so that there is no object that blocks radio waves within the Fresnel zone with respect to the relay station The method for calculating the installation position of a relay station according to claim 5 or 6, characterized by

8. A relay station installation position calculation program for causing a computer to function as each part of the relay station installation position calculation device according to any one of claims 1 to 4.

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