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

Abstract

A relay station installation position calculation apparatus according to one embodiment of the present invention comprises: a first specification unit for specifying the position of a station placement candidate point where an LOS region from a relay station becomes maximum; a next candidate point extraction unit that uses the position having been specified by the first specification unit as a radio wave transmission point and extracts the second or lower order next station placement candidate points where the LOS region for the next relay station becomes maximum; a correction unit for correcting, on the basis of a Fresnel zone for the next relay station, each of the positions of the next station placement candidate points extracted by the next candidate point extraction unit; and a second specification unit for specifying, as a next relay station installation position, the position of a next station placement candidate point where the reflection angle of a radio wave toward a next station placement candidate point becomes minimum, among the next station placement candidate points of which the positions have been corrected by the correction unit and the next station placement candidate points extracted by the next candidate position extraction unit.

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) that relays radio waves.

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

[0004] In addition, a method for calculating the location of a base station is known in order to construct a wireless communication system that relays 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 an RIS reflector, it is necessary to locate the relay station at a position where there is a line-of-sight (LOS) propagation from the transmitting station.

[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 a relay station.

[0008] In addition, for example, a relay station composed of a reflector or the like is preferably installed so as to suppress a decrease (loss) in the propagation efficiency of the radio waves to be relayed. Here, the area that is LOS is referred to as the LOS area, and the area that is out of sight propagation (NLOS: Non-Line Of Sight) is referred to as the NLOS area for distinction.

[0009] 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 prevent a decrease in the propagation efficiency of the radio waves to be relayed.

Means for Solving the Problems

[0010] A relay station installation position calculation device 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 station location candidate points predetermined as candidate installation positions of the relay station, a first specifying unit that specifies, based on the relaying possible range of radio waves by the relay station, the position of a station location candidate point that maximizes the LOS area from the relay station as the installation position of the first relay station; a next candidate point extraction unit that regards the installation position of the first relay station specified by the first specifying unit as a radio wave transmission point, and extracts, based on the relaying possible range of radio waves by the next relay station, up to two or less upper-ranked station location sub-candidate points that maximize the LOS area for the next relay station; a correction unit that corrects the position of each of the station location sub-candidate points extracted by the next candidate point extraction unit based on the Fresnel zone for the next relay station; a second specifying unit that specifies, as the installation position of the next relay station, the position of a station location sub-candidate point for which the reflection angle of the radio wave directed to the station location sub-candidate point extracted by the next candidate point extraction unit or the station location sub-candidate point whose position has been corrected by the correction unit is minimized; and a control unit that controls so that the total number of the installation positions of the relay stations specified by the first specifying unit and the second specifying unit becomes a predetermined number.

[0011] Further, a relay station installation position calculation method according to an embodiment of the present invention is to maximize the LOS area from the relay station based on the relayable range of radio waves by the relay station, within the station location candidate range where a relay station for relaying radio waves can be installed, or among a plurality of predetermined station location candidate points as candidate positions for the installation position of the relay station. A first specifying step of specifying the position of the station location candidate point as the installation position of the first relay station; regarding the specified installation position of the first relay station as a radio wave transmission point, and based on the relayable range of radio waves by the next relay station, a next candidate point extraction step of extracting up to two next station location candidate points where the next relay station maximizes the LOS area; a correction step of correcting the position of each of the extracted next station location candidate points based on the Fresnel zone for the next relay station; and a second specifying step of specifying the position of the next station location candidate point where the reflection angle of the radio wave toward the extracted next station location candidate point or the next station location candidate point with the corrected position is minimized as the installation position of the next relay station; and a control step of controlling so that the total number of the installation positions of the relay stations specified by the first specifying step and the second specifying step becomes a predetermined number.

Advantages of the Invention

[0012] According to the present invention, it is possible to calculate the installation position of a relay station so as to prevent a decrease in the propagation efficiency of the relayed radio wave.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, a configuration example of the installation position calculation device 1 of the relay station according to an embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of the installation position calculation device 1 of the relay station according to an embodiment.

[0015] As shown in FIG. 1, the installation position calculation device 1 of the relay station 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 a wireless communication system using, for example, a high frequency band.

[0016] 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, for example, a RIS reflector.

[0017] The storage unit 2 includes, for example, a repeater information storage unit 21, a station placement candidate range storage unit 22, a total number of stations storage unit 23, a transmission point storage unit 24, a LOS region storage unit 25, a station placement candidate point storage unit 26, and a station placement point storage unit 27.

[0018] The relay information storage unit 21 stores the characteristics of the relays for constructing the wireless communication system. For example, the relay information storage unit 21 stores in advance information indicating a dynamically controllable relay range (relay coverage area: reflectable angle) in which the RIS reflector serving as the relay reflects radio waves.

[0019] The installation candidate range storage unit 22 stores in advance the range where the relay can be installed as the installation 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 installation candidate range of the relay that reflects the radio waves transmitted by the transmitting station S.

[0020] The total number of installed relays storage unit 23 stores in advance the total number of relays (total number of installed relays) that the operator plans to install to configure the wireless communication system.

[0021] The transmission point storage unit 24 stores the position of the transmission point. For example, the transmission point storage unit 24 stores in advance the position of the transmission station S shown in FIG. 2 etc. as the transmission point.

[0022] The LOS area storage unit 25 stores the LOS areas from all the transmission points stored in the transmission point storage unit 24.

[0023] The installation candidate point storage unit 26 stores the position that has become a candidate point for installing the relay as the installation candidate point by the processing of the processing unit 3. Further, the installation candidate point storage unit 26 may store a plurality of installation candidate points predetermined as candidate positions for the installation position of the relay.

[0024] The installation point storage unit 27 stores the position of the relay as the installation point when the installation position of the relay is determined. For example, the installation point storage unit 27 stores the position of the installation candidate point specified by the first specifying unit 32 described later, or the position of the installation candidate point specified by the second specifying unit 36 described later as the installation position (installation point) of the relay. Further, when the installation position of the relay is determined, the installation point storage unit 27 also stores the position of the relay as a new transmission point.

[0025] The processing unit 3 includes a LOS area calculation unit 30, a candidate point extraction unit 31, a first specification unit 32, a next candidate point extraction unit 33, a Fresnel zone calculation unit 34, a correction unit 35, and a second specification unit 36.

[0026] The LOS area calculation unit 30 calculates the LOS area from the transmission point stored in the storage unit 2. For example, the LOS area calculation unit 30 calculates, as the LOS area, the range surrounded by the wall 10 shown in FIG. 3 and the line connecting the boundary point A and the boundary point 11 on the straight line L1 passing through the boundary point 11, which is the vertex of the wall 10, and the transmission station S.

[0027] The candidate point extraction unit 31 extracts one or more placement candidate points from the placement candidate range stored in the placement candidate range storage unit 22 based on the straight line passing through the transmission point that transmits radio waves and orthogonal to the surface facing the transmission point (the reflection surface within the placement candidate range), and outputs them to the first specification unit 32.

[0028] For example, as shown in FIG. 4, the candidate point extraction unit 31 extracts the placement candidate points B1 and B2 on the straight line L2 passing through the transmission station S and orthogonal to the wall 10, and the placement candidate points B3 and B4 on the straight line L3 passing through the transmission station S and orthogonal to the wall 10, and outputs them to the first specification unit 32.

[0029] The first specification unit 32 specifies, from within the placement candidate range stored in the placement candidate range storage unit 22 or among the placement candidate points stored in the placement candidate point storage unit 26, the position of the placement candidate point that maximizes the LOS area from the repeater as the installation position of the first repeater based on the relaying possible range stored in the repeater information storage unit 21.

[0030] For example, the first specification unit 32 specifies the position of any one of the placement candidate points extracted by the candidate point extraction unit 31 or the placement candidate points stored in the placement candidate point storage unit 26 as the installation position of the first repeater. In the example shown in FIG. 4, the first specification unit 32 specifies the position of the placement candidate point B4 as the installation position of the first repeater (see FIG. 5).

[0031] The secondary candidate point extraction unit 33 regards the installation position of the first repeater specified by the first specifying unit 32 as the radio wave transmission point, and extracts the top two or fewer candidate installation secondary points where the next repeater maximizes the LOS area based on the radio wave relay range by the next repeater.

[0032] For example, as shown in FIG. 5, the secondary candidate point extraction unit 33 regards the installation position B4 of the repeater as the radio wave transmission point, and extracts the top candidate installation secondary points C1 and C2 where the next repeater maximizes the LOS area. At this time, the radio wave relay range by the repeater installed at the installation position B4 is the straight line a 11 and the straight line a 12 and the range sandwiched between them.

[0033] The candidate installation secondary point C1 is on the straight line L4 passing through the installation position B4 and the boundary point 12 which is the vertex of the wall 10, and is one of the top two candidate installation secondary points that maximize the LOS area. The candidate installation secondary point C2 is on the straight line a 12 extending from the installation position B4 to the wall 10, and is one of the top two candidate installation secondary points that maximize the LOS area.

[0034] The Fresnel zone calculation unit 34 calculates the Fresnel zone between the transmission point and the candidate installation point (repeater). For example, the Fresnel zone calculation unit 34 calculates the Fresnel zone (see the Fresnel zone Z1 shown in FIG. 5) between the transmission point and the candidate installation secondary point.

[0035] The correction unit 35 corrects the position of each candidate installation secondary point extracted by the secondary candidate point extraction unit 33 based on the Fresnel zone for the next repeater (candidate installation secondary point) calculated by the Fresnel zone calculation unit 34. For example, the correction unit 35 corrects the position of each candidate installation secondary point extracted by the secondary candidate point extraction unit 33 so that there is no object that blocks the radio wave within the Fresnel zone for the next repeater.

[0036] Specifically, as shown in FIG. 5, the correction unit 35 adjusts the position of the candidate installation secondary point C1 to the candidate installation secondary point C so that the boundary point 12 which is the vertex of the wall 10 does not enter the Fresnel zone Z1. m1Perform correction to move it. Further, since there is no object that blocks radio waves within the Fresnel zone (not shown) with respect to the next candidate placement point C2 in the correction unit 35, the position of the next candidate placement point C2 is not corrected.

[0037] The second specifying unit 36 specifies the position of the next relay device installation position as the position of the next candidate placement point where the reflection angle of the radio wave toward the next candidate placement point extracted by the next candidate point extraction unit 33 or the next candidate placement point whose position has been corrected by the correction unit 35 is minimized.

[0038] Here, let the reflection angle at which the relay device installed at the installation position B4 reflects the radio wave transmitted by the transmitting station S toward the next candidate placement point C be X. Also, let the reflection angle at which the relay device installed at the installation position B4 reflects the radio wave transmitted by the transmitting station S toward the next candidate placement point C2 be Y. m1 For example, as shown in FIG. 6, since the reflection angle X is smaller than the reflection angle Y, the second specifying unit 36 specifies the position of the next candidate placement point C as the installation position of the next relay device.

[0039] m1 as the installation position of the next relay device.

[0040] FIG. 7 is a diagram illustrating the incident angle of radio waves reflected by a reflector. FIG. 7(a) is a diagram showing the effective area where radio waves incident on the reflector can be reflected when the incident angle is small (0 degrees). FIG. 7(b) is a diagram showing the effective area where radio waves incident on the reflector can be reflected when the incident angle is large.

[0041] As shown in FIG. 7, the effective area where radio waves incident on the reflector can be reflected is larger when the incident angle with respect to the reflector is small than when the incident angle with respect to the reflector is large.

[0042] That is, when the relay device installed at the installation position B4 reflects radio waves, the second specifying unit 36 determines that the position of the next candidate placement point C is more suitable as the position for installing the next relay device than the next candidate placement point C2 because the propagation efficiency of radio waves at the installation position B4 is better. m1 m1 m1 m1 as the installation position of the next relay device.

[0043] At this time, the relayable range of radio waves by the repeater installed at the candidate placement point C m1 is the range sandwiched between the straight line a 21 and the straight line a 22 and becomes the range sandwiched between them.

[0044] Then, the control unit 4 controls so that the total number of installation positions of the repeaters specified by the first specifying unit 32 and the second specifying unit 36 (the total number of placement points stored in the placement point storage unit 27) becomes a predetermined number (for example, the total number of repeaters stored in the total placement number storage unit 23).

[0045] For example, when the placement position of one hop is determined, the control unit 4 controls to sequentially calculate the placement candidate points of two hops and the placement candidate points of three hops.

[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 candidate point extraction unit 31 extracts placement candidate points based on a straight line passing through the transmission point (transmission station S) and orthogonal to the surface of the wall 10 facing the transmission point.

[0048] In step 102 (S102), the first specifying unit 32 specifies the installation position of the first repeater that maximizes the LOS area based on the relayable range by the repeater.

[0049] In step 104 (S104), the next candidate point extraction unit 33 regards the installation position of the first repeater specified by the first specifying unit 32 as the radio wave transmission point, and based on the relayable range of radio waves by the next repeater, extracts the top two or less candidate placement points for the next repeater to maximize the LOS area.

[0050] In step 106 (S106), the correction unit 35 corrects the positions of the relay next candidate points extracted by the next candidate point extraction unit 33 based on the Fresnel zone calculated by the Fresnel zone calculation unit 34.

[0051] In step 108 (S108), the control unit 4 determines whether the number of relay installation positions calculated by the installation position calculation device 1 is less than the total number of installations stored in the total installation number storage unit 23. If it is less (S108: Yes), the process proceeds to the process of S110, and in other cases (S108: No), the process ends.

[0052] In step 110 (S110), the second specifying unit 36 specifies the position of the relay next candidate point with the minimum radio wave reflection angle toward the relay next candidate point extracted by the next candidate point extraction unit 33 or the relay next candidate point whose position is corrected by the correction unit 35 as the installation position of the next relay.

[0053] As described above, the installation position calculation device 1 according to an embodiment specifies the position of the relay next candidate point with the minimum radio wave reflection angle toward the relay next candidate point as the installation position of the next relay station, so that the installation position of the relay station can be calculated to prevent the propagation efficiency of the relayed radio wave from decreasing.

[0054] Note that 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.

[0055] 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.

[0056] 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 can input and output data to and from a computer-readable storage medium 57.

[0057] 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.

[0058] The CPU 53 controls each part 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.

[0059] The storage medium 57 can 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

[0060] 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 number of installations 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, 31... Candidate point extraction unit, 32... First specific unit, 33... Next candidate point extraction unit, 34... Fresnel zone calculation unit, 35... Correction unit, 36... Second specific unit, 50... Input unit, 51... Output unit, 52... Communication unit, 53... CPU, 54... Memory, 55... HDD, 56... Bus, 57... Storage medium

Claims

1. A first specifying unit that specifies, from within a station location candidate range where a relay station for relaying radio waves can be installed, or from among a plurality of predetermined station location candidate points as candidate installation positions of the relay station, the position of a station location candidate point that maximizes the LOS area from the relay station based on the radio wave relaying range by the relay station, as the installation position of the first relay station; A next candidate point extraction unit that regards the installation position of the first relay station specified by the first specifying unit as a radio wave transmission point, and extracts up to two next station location candidate points that maximize the LOS area by the next relay station based on the radio wave relaying range by the next relay station; A correction unit that corrects the position of each of the next station location candidate points extracted by the next candidate point extraction unit based on the Fresnel zone for the next relay station; A second specifying unit that specifies, as the installation position of the next relay station, the position of a next station location candidate point where the reflection angle of the radio wave directed at the next station location candidate point extracted by the next candidate point extraction unit or the next station location candidate point whose position has been corrected by the correction unit is minimized; A control unit that controls so that the total number of installation positions of the relay stations specified by the first specifying unit and the second specifying unit becomes a predetermined number A relay station installation position calculation device, characterized by comprising the above.

2. A candidate point extraction unit that extracts one or more station location candidate points based on a straight line passing through a transmission point that transmits radio waves and orthogonal to the plane facing the transmission point, with respect to the station location candidate range further comprising, The first specifying unit specifies, as the installation position of the first relay station, the position of any one of the station location candidate points extracted by the candidate point extraction unit or among a plurality of predetermined station location candidate points as candidate installation positions of the relay station The relay station installation position calculation device according to claim 1, characterized by the above.

3. The correction unit corrects the position of each of the next station location candidate points extracted by the next candidate point extraction unit so that nothing that blocks radio waves is located within the Fresnel zone for 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 first specifying step of specifying, from within a station location candidate range where a relay station for relaying radio waves can be installed, or from among a plurality of predetermined station location candidate points as candidate installation positions of the relay station, the position of a station location candidate point that maximizes the LOS area from the relay station based on the radio wave relaying range by the relay station, as the installation position of the first relay station; Regarding the installation position of a specific first relay station as the radio wave transmission point, based on the relay range of radio waves by the next relay station, a next candidate point extraction step of extracting up to two candidate placement points where the next relay station maximizes the LOS area; A correction step of correcting the position of each of the extracted candidate placement points based on the Fresnel zone for the next relay station; A second specifying step of specifying the position of the candidate placement point where the reflection angle of the radio wave toward the extracted candidate placement point or the candidate placement point with the corrected position is minimized as the installation position of the next relay station; A control step of controlling so that the total number of the installation positions of the relay stations specified by the first specifying step and the second specifying step becomes a predetermined number; A method for calculating the installation position of a relay station, characterized by including the above.

6. A candidate point extraction step of extracting one or more candidate placement points based on a straight line passing through the transmission point that transmits radio waves and perpendicular to the plane facing the transmission point with respect to the placement candidate range. Further including: In the first specifying step: Specifying the position of any one of the candidate placement points extracted by the candidate point extraction step or a plurality of candidate placement points predetermined as candidate installation positions of the relay station as the installation position of the first relay station. The method for calculating the installation position of a relay station according to claim 5, characterized by the above.

7. In the correction step: Correcting the position of each of the candidate placement points extracted by the next candidate point extraction step so that there is no object that blocks radio waves within the Fresnel zone for the relay station. The method for calculating the installation position of a relay station according to claim 5 or 6, characterized by the above.

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

Images