Method, device, and program for determining antenna arrangement, and object detection system

Abstract

To determine an antenna arrangement that enables highly accurate object detection with a small load.SOLUTION: A method disclosed herein is a method for determining the arrangement of antennas in a system that detects an object using an AP (first wireless device) having multiple antennas 4 and a STA (second wireless device) 6. According to the method of the present disclosure, first, a target area for object detection is virtually divided into a number of small areas. Next, a combination of candidate positions for the antenna 4 is selected from among positions where the antenna 4 can be placed. Then, a score is calculated based on the number of small areas on the radio wave path between the position of the STA 6 and the candidate positions of the antenna 4. Finally, the combination of candidate positions for the antenna 4 that results in the maximum score is determined as the combination of positions for placing the antenna 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a technique for determining the arrangement of antennas in a system for detecting an object using radio waves. [Background technology]

[0002] As a method for estimating the position of an object using radio waves such as Wi-Fi, a method is known in which the object is detected based on the state of multipath waves (CSI: Channel State Information) that changes due to an object in a detection area. For example, Patent Document 1 proposes a method in which the object position is used as a label to create training data together with the corresponding CSI, a learning model is generated by machine learning using the training data, and the CSI is input into the learning model to detect an object in a target area.

[0003] 10 and 11 show an application example of the conventional method disclosed in Patent Document 1. In this application example, the target area for object detection is divided vertically into eight and horizontally into four, resulting in a total of 32 small areas. Then, using the conventional method described above, it is estimated in which small area from 1 to 32 an object exists. Note that in this application example, a wireless LAN conforming to the IEEE802.11ac or later standard (ac / ax / be, etc.) is used as the wireless system. Also, the CSI between one access point (AP) and one terminal (STA) is used for object detection. The AP has four antennas. The STA has one antenna.

[0004] In this application example, twelve candidate positions for antenna placement are set around the target area, indicated by circled numbers from 1 to 12. Antennas are placed at four positions selected from behind these twelve positions. The accuracy of object detection varies depending on the combination of the four antenna positions. In this application example, the detection accuracy was calculated by computer simulation for a total of 495 combinations of the four antenna positions. Figure 10 shows the top 10 antenna placements with the highest detection accuracy, and Figure 11 shows the bottom 10 antenna placements with the lowest detection accuracy.

[0005] According to the above application example, the detection accuracy is compared between all combinations of antenna position candidates, so that an antenna arrangement capable of detecting an object with high accuracy can be determined. However, if simulations such as ray tracing or experiments using real objects are performed for all of the huge number of antenna arrangement patterns, the load required for this becomes extremely large. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-034878 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure has been made in view of the above-mentioned problems, and has an object to provide a technique for determining, with a small load, an antenna arrangement that enables object detection with high accuracy. [Means for solving the problem]

[0008] The present disclosure provides a method for achieving the above object. The method of the present disclosure is a method for determining the arrangement of antennas in a system for detecting an object using a first wireless device having a plurality of antennas and a second wireless device that performs wireless communication with the first wireless device. The method of the present disclosure includes the following first to fourth steps. The first step is a step of virtually dividing a target area in which object detection is performed into a plurality of small areas. The second step is a step of selecting a combination of antenna position candidates from among positions where antennas can be arranged. The third step is a step of calculating a score based on the number of small areas on the radio wave path between the position of the second wireless device and each antenna position candidate. The fourth step is a step of determining the combination of antenna position candidates that maximizes the score as the combination of antenna arrangement positions.

[0009] The present disclosure provides a device for achieving the above object. The device of the present disclosure is a device for determining the arrangement of antennas in a system for detecting an object using a first wireless device having a plurality of antennas and a second wireless device that performs wireless communication with the first wireless device. The device of the present disclosure is configured to execute the following first to fourth processes. The first process is a process for virtually dividing a target area in which object detection is performed into a plurality of small areas. The second process is a process for selecting a combination of antenna position candidates from among positions where antennas can be arranged. The third process is a process for calculating a score based on the number of small areas on the radio wave path between the position of the second wireless device and each antenna position candidate. The fourth process is a process for determining the combination of antenna position candidates that maximizes the score as the combination of antenna arrangement positions.

[0010] The present disclosure also provides a program for achieving the above object. The program of the present disclosure is a program for determining the arrangement of antennas in a system for detecting an object using a first wireless device having a plurality of antennas and a second wireless device that wirelessly communicates with the first wireless device. The program of the present disclosure is configured to cause a computer to execute the following first to fourth processes. The first process is a process for virtually dividing a target area in which object detection is performed into a plurality of small areas. The second process is a process for selecting a combination of antenna position candidates from among positions where antennas can be arranged. The third process is a process for calculating a score based on the number of small areas on the radio wave path between the position of the second wireless device and each antenna position candidate. The fourth process is a process for determining the combination of antenna position candidates that maximizes the score as the combination of antenna arrangement positions.

[0011] The present disclosure further provides a system using the above antenna location determination device. The system of the present disclosure is a system for detecting an object within a target area. The system of the present disclosure includes a first wireless device having a plurality of antennas, a second wireless device that performs wireless communication with the first wireless device, and the above antenna location determination device. In the system of the present disclosure, the antennas are located at positions determined by the above antenna location determination device relative to the position of the second wireless device. Effect of the Invention

[0012] In the technology disclosed herein, the number of small areas on the radio wave path between the position of the second wireless device and each antenna position candidate is counted. Then, the combination of antenna position candidates that maximizes the score calculated based on the number of small areas is determined as the combination of antenna placement positions. According to this method, it is possible to determine an antenna placement that enables object detection with high accuracy with a small load. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an embodiment of an antenna arrangement determination device. [Diagram 2] FIG. 1 is a diagram for explaining an overview of a first embodiment of an antenna arrangement determination method. [Diagram 3] The effects of the first embodiment of the antenna arrangement determination method will now be described. [Figure 4] FIG. 4 is a flow chart showing details of a first embodiment of an antenna arrangement determination method. [Diagram 5] FIG. 13 is a diagram for explaining an overview of a second embodiment of an antenna arrangement determination method. [Figure 6] The effects of the second embodiment of the antenna arrangement determining method will now be described. [Figure 7] FIG. 11 is a flow chart showing details of a second embodiment of an antenna arrangement determination method. [Figure 8] FIG. 13 is a diagram for explaining an overview of a third embodiment of an antenna arrangement determining method. [Figure 9] FIG. 11 is a flow chart showing details of a third embodiment of an antenna arrangement determination method. [Figure 10] FIG. 13 is a diagram illustrating an evaluation of a detection rate by simulation. [Figure 11] FIG. 13 is a diagram illustrating an evaluation of a detection rate by simulation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1. Antenna layout determination device First, an embodiment of an antenna arrangement determination device will be described with reference to Fig. 1. The antenna arrangement determination device 10 constitutes an object detection system together with an access point (AP) 2 as a first wireless device and a terminal (STA) 6 as a second wireless device that performs wireless communication with the AP2. Object detection is performed, for example, based on CSI, which indicates the state of radio waves within a target area TA where object detection is performed. Multiple antennas 4 of the AP2 are arranged at positions determined by the antenna arrangement determination device 10 with respect to the position of the STA6.

[0015] The antenna arrangement determination device 10 is a computer including an input / output interface 11, a processor 12, a program memory 13, and an information memory 15. The number of each of the processor 12, the program memory 13, and the information memory 15 may be plural.

[0016] The processor 12 may be a CPU, RISC, DSP, FPGA, ASIC, PLD, or another processing unit, or may be a combination of two or more thereof, or may be a dedicated processor for the antenna placement determination apparatus 10. The processor 12 may also be communicatively coupled to a program memory 13 and an information memory 15, or may include the program memory 13 and the information memory 15.

[0017] The program memory 13 stores a plurality of instructions 14 executable by the processor 12. A program consisting of the plurality of instructions 14 may be stored in a computer-readable non-transitory storage medium, or may be provided via a network. The instructions 14 are executed by the processor 12, causing the antenna arrangement determination device 10 to implement the antenna arrangement determination method. The information memory 15 stores various information required to implement the antenna arrangement determination method.

[0018] Conditions for determining antenna placement are input to the input / output interface 11. The conditions to be input include the shape of the target area TA and the number of divisions into small areas, the number of antennas 4 of the AP2, positions where the antennas 4 can be placed, and the placement position of the STA6. In the example shown in Fig. 1, the target area TA is virtually divided vertically into 32 small areas numbered 1 to 32. The number of antennas 4 of the AP2 is four, and 12 position candidates for the antennas 4, numbered 1 to 12, indicated by circled numbers, are set. The STA6 is placed outside the target area TA, between the small areas numbered 16 and 17.

[0019] The instructions 14 cause the processor 12 to execute a process for determining an antenna arrangement based on the conditions input to the input / output interface 11. There are several preferred embodiments of the antenna arrangement determination method implemented by the antenna arrangement determination device 10. The following describes in detail the embodiments of the antenna arrangement determination method.

[0020] 2. Antenna placement method 2-1. First embodiment 2 is a diagram for explaining an overview of a first embodiment of the antenna arrangement determining method. In the example shown in Fig. 2, antenna 4 is arranged at position candidates 5 to 8.

[0021] In the first embodiment, the number of small areas through which the direct wave of the radio wave between the antenna 4 and the STA 6 has passed is counted. Specifically, each antenna 4 and the STA 6 are connected by a straight line, and the number of small areas through which the straight line passes is counted. In the example shown in FIG. 2, a small area with the number "0" is an area through which the direct wave does not pass, and a small area with the number "1" is an area through which the direct wave passes. The sum of the numerical values ​​of all the small areas constituting the target area is calculated as the score S1 of the corresponding combination of position candidates of the antenna 4 (also called the arrangement pattern of the antenna 4). In the example shown in FIG. 2, the score S1 of the combination of position candidates No. 5, No. 6, No. 7, and No. 8 is 22 points.

[0022] In the first embodiment, the above process is performed to calculate the score S1 for all 495 combinations of position candidates for the antenna 4. Then, among the 495 combinations of position candidates for the antenna 4, the combination of position candidates with the maximum score S1 is determined as the combination of positions for actually placing the antenna 4.

[0023] Figure 3 is a graph showing the relationship between the score S1 value and the object detection rate. The object detection rate is the result of an actual experiment. From this graph, it can be seen that, overall, the detection rate tends to improve as the score S1 value increases. In other words, there is a correlation between the score S1 value and the detection accuracy, as shown by the arrow line in Figure 3. Based on this correlation, the combination of location candidates that maximizes the score S1 is selected. According to this method, it is possible to determine an antenna arrangement that can detect objects with high accuracy, with much less load than when performing simulations or experiments.

[0024] Fig. 4 is a flow diagram showing details of a first embodiment of an antenna arrangement determination method. In the first embodiment, the antenna arrangement determination device 10 executes processing according to this flow diagram. In the flow diagram, Narea indicates the number of small areas, and Np indicates the number of arrangement patterns of the antenna 4. In the example shown in Fig. 2, Narea = 32, and Np = 495.

[0025] Step S101 is a repetitive process including steps S102 to S103. The processes from step S102 to S103 are repeatedly executed for each of the arrangement patterns of the first to Np antennas 4.

[0026] In step S102, all antennas 4 and STAs 6 are connected by straight lines.

[0027] Step S103 is a repetitive process including steps S104 to S105. The processes from step S104 to S105 are repeatedly executed for each of the small areas No. 1 to No. Narea.

[0028] In step S104, it is determined whether or not a straight line passes through the small region focused on in step S103. If a straight line does not pass through the small region, the process of step S105 is skipped, and if a straight line passes through the small region, the process of step S105 is executed.

[0029] In step S105, the score S1(i) is incremented by 1. The score S1(i) means the score of the i-th arrangement pattern from No. 1 to No. Narea, and its initial value is zero.

[0030] Step S106 is executed when the condition in step S101 is satisfied. In this step, the antenna arrangement pattern that maximizes the score S1(i) is selected. If there are multiple such antenna arrangement patterns, all of the antenna arrangement patterns are selected.

[0031] In step S107, the antenna arrangement pattern selected in step S106 is output, whereby the antenna arrangement determination method by the antenna arrangement determination device 10 is completed.

[0032] 2-2. Second embodiment 5 is a diagram for explaining an overview of the second embodiment of the antenna arrangement determining method. In the example shown in Fig. 5, antenna 4 is arranged at position candidates 5 to 8.

[0033] In the second embodiment, the total number of small areas on the path counted for each path of the direct wave between the antenna 4 and the STA6 is calculated. Specifically, each antenna 4 and the STA6 are connected by a straight line, and the total number of small areas through which the straight line passes is calculated. In the example shown in FIG. 5, the small areas with the number "0" are areas where no direct wave passes. The small areas with the number "1" are areas where one direct wave passes, and the small areas with the number "2" are areas where two direct waves pass. The total value of the numerical values ​​of all the small areas constituting the target area is calculated as the score S2 of the combination of the corresponding position candidates of the antenna 4, that is, the arrangement pattern of the antenna 4. In the example shown in FIG. 5, the score S2 of the combination of the position candidates No. 5, No. 6, No. 7, and No. 8 is 34 points.

[0034] In the first embodiment, the above process is performed to calculate the score S2 for all 495 combinations of position candidates for the antenna 4. Then, among the 495 combinations of position candidates for the antenna 4, the combination of position candidates with the maximum score S2 is determined as the combination of positions for actually placing the antenna 4.

[0035] Figure 6 is a graph showing the relationship between the score S2 value and the object detection rate. The object detection rate is the result of an actual experiment. From this graph, it can be seen that, overall, the detection rate tends to improve as the score S2 value increases. In other words, there is a correlation between the score S2 value and the detection accuracy, as shown by the arrow line in Figure 6. Based on this correlation, the combination of position candidates that maximizes the score S2 is selected. According to this method, it is possible to determine an antenna arrangement that can detect objects with high accuracy, with much less load than when performing simulations or experiments.

[0036] Fig. 7 is a flow diagram showing details of a second embodiment of the antenna arrangement determination method. In the second embodiment, the antenna arrangement determination device 10 executes processing according to this flow diagram. In the flow diagram, Narea indicates the number of small areas, Np indicates the number of arrangement patterns of the antennas 4, and Nant indicates the number of antennas 4. In the example shown in Fig. 7, Narea = 32, Np = 495, and Nant = 4.

[0037] Step S201 is a repetitive process for repeating the process of step S202. The process of step S202 is repeatedly executed for each of the arrangement patterns of the antennas 4 from No. 1 to No. Np.

[0038] Step S202 is a repetitive process including steps S203 and S204. The processes from step S203 to step S204 are repeatedly executed for each of antennas 4 from No. 1 to No. Nant.

[0039] In step S203, the j-th antenna 4 among the antennas 1 to Nant is connected to the STA 6 by a straight line.

[0040] Step S204 is a repetitive process including steps S205 to S206. The processes from step S205 to S206 are repeatedly executed for each of the small areas No. 1 to No. Narea.

[0041] In step S205, it is determined whether or not a straight line passes through the small region focused on in step S204. If a straight line does not pass through the small region, the process of step S206 is skipped, and if a straight line passes through the small region, the process of step S206 is executed.

[0042] In step S206, the score S2(i) is incremented by 1. The score S2(i) means the score of the i-th arrangement pattern from No. 1 to No. Narea, and its initial value is zero.

[0043] Step S207 is executed when the condition in step S201 is satisfied. In this step, the antenna arrangement pattern that maximizes the score S2(i) is selected. If there are multiple such antenna arrangement patterns, all of the antenna arrangement patterns are selected.

[0044] In step S208, the antenna arrangement pattern selected in step S207 is output, whereby the antenna arrangement determination method by the antenna arrangement determination device 10 is completed.

[0045] 2-3.Third embodiment 8 is a diagram for explaining an overview of a third embodiment of the antenna arrangement determination method. In the third embodiment, not only direct waves but also reflected waves are considered as radio waves that affect object detection. Here, assuming a maximum of two reflections, a method is described for determining an area through which radio waves pass by an imaging method in each of the cases of direct waves (k=1), one-reflected waves (k=2), and two-reflected waves (k=3).

[0046] In the imaging method, the target area for the single reflected wave is written on the left and right of the central target area for the direct wave. In this case, the arrangement of the small areas (arrangement of the numbers of the small areas) is reversed left and right. In addition, the target area for the double reflected wave is written to the right or left of the target area for the single reflected wave. In this case, the arrangement of the small areas is further reversed left and right. Then, the STA corresponding to each target area is written, and a straight line is drawn from the antenna position candidate set in the central target area to the STA of each target area. As an example, in Figure 8, a straight line is drawn connecting the position candidate number 5 and the STA of each target area. The solid line is the direct wave, the dotted line is the single reflected wave, and the dashed line is the double reflected wave. In the example shown in Figure 8, the target area is expanded left and right because the radio wave is reflected by the left and right walls, but if the radio wave is reversed by the top and bottom walls, the target areas are arranged up and down and reversed up and down.

[0047] In the third embodiment, the number of small areas through which each straight line passes is counted. In the example shown in Fig. 8, the direct wave (k = 1) passes through a total of nine small areas, namely, No. 25, No. 26, No. 27, No. 22, No. 21, No. 20, No. 19, No. 18, and No. 17. In calculating the score S3, a value obtained by multiplying the number of small areas through which the direct wave passed by the coefficient A1 for the direct wave is added to the score S3. The value of the coefficient A1 for the direct wave may be set to 1.

[0048] The left single reflected wave (k=2) passes through a total of eight small areas, numbered 25, 26, 27, 28, 29, 19, 18, and 17. The right single reflected wave (k=2) passes through a total of twelve small areas, numbered 25, 24, 23, 22, 11, 12, 5, 4, 3, 2, 15, and 16. In calculating the score S3, the value obtained by multiplying the number of small areas passed by the single reflected wave by the coefficient A2 for the single reflected wave is added to the score S3. The value of the coefficient A2 for the single reflected wave is smaller than the value of the coefficient A1 for the direct wave.

[0049] The left double-reflected wave (k=3) passes through a total of twelve small areas, including 25, 26, 23, 22, 21, 12, 13, 4, 3, 2, 15, and 16. The right double-reflected wave (k=3) passes through a total of fourteen small areas, including 25, 24, 23, 10, 6, 5, 12, 13, 20, 19, 30, 31, 32, and 17. In the calculation of the score S3, the value obtained by multiplying the number of small areas passed by the double-reflected wave by the coefficient A3 for the double-reflected wave is added to the score S3. The value of the coefficient A3 for the double-reflected wave is smaller than the value of the coefficient A2 for the single-reflected wave.

[0050] The above calculation is also performed for the other three position candidates for antenna 4 to calculate the combination of position candidates for antenna 4, i.e., the score S3 of the arrangement pattern of antenna 4. Then, among the 495 combinations of position candidates for antenna 4, the combination of position candidates with the maximum score S3 is determined as the combination of positions for actually arranging antenna 4. According to the method of the third embodiment, by taking into account not only direct waves but also reflected waves, it is possible to determine an antenna arrangement that can detect an object with higher accuracy.

[0051] In the example shown in FIG. 8, the first reflected wave and the second reflected wave are considered, but it is also possible to consider only the first reflected wave, or to consider more reflected waves including the third reflected wave. k The value of may be determined according to the material of the wall, for example. The same value may be used for the left and right, or different values ​​may be used when the materials of the walls on the left and right are different. When reflected waves pass through the same small area multiple times, they may be counted as one pass rather than being counted as multiple passes. For example, in the example shown in FIG. 8, the single reflected waves on the left and right pass through small area number 25, but this may be counted as one pass rather than two passes.

[0052] 9 is a flow diagram showing details of a third embodiment of the antenna arrangement determination method. In the third embodiment, the antenna arrangement determination device 10 executes processing according to this flow diagram. In the flow diagram, Narea indicates the number of small areas, Np indicates the number of arrangement patterns of the antennas 4, Nant indicates the number of antennas 4, and N k In the example shown in Figure 9, Narea = 32, Np = 495, Nant = 4, N k =3.

[0053] Step S301 is a repetitive process for repeating the process of step S302. The process of step S302 is repeatedly executed for each of the arrangement patterns of the antennas 4 from No. 1 to No. Np.

[0054] Step S302 is a repetitive process for repeating the process of step S303. The process of step S303 is repeatedly executed for each of antennas 4 from No. 1 to No. Nant.

[0055] Step S303 is a repetitive process including steps S304 to S305. k The process is repeated multiple times.

[0056] In step S304, the j-th antenna 4 among the antennas 1 to Nant and the STA 6 are connected by a straight line indicating the radio waves reflected (k-1) times by the wall.

[0057] Step S305 is a repetitive process for repeating the process of step S306. The process of step S306 is repeatedly executed for each of the J straight lines drawn in step S304.

[0058] Step S306 is a repetitive process including steps S307 to S308. The processes from step S307 to S308 are repeatedly executed for each of the small areas No. 1 to No. Narea.

[0059] In step S307, it is determined whether or not a straight line passes through the small region focused on in step S306. If a straight line does not pass through the small region, the process of step S308 is skipped, and if a straight line passes through the small region, the process of step S308 is executed.

[0060] In step S308, 1×A is added to the score S3(i). k The score S3(i) means the score of the i-th arrangement pattern from 1 to Narea, and its initial value is zero.

[0061] Step S309 is executed when the condition in step S301 is satisfied. In this step, the antenna arrangement pattern that maximizes the score S3(i) is selected. If there are multiple such antenna arrangement patterns, all of the antenna arrangement patterns are selected.

[0062] In step S310, the antenna arrangement pattern selected in step S309 is output, whereby the antenna arrangement determination method by the antenna arrangement determination device 10 is completed. [Explanation of symbols]

[0063] 2 AP (first wireless device) 4 Antennas 6 STA (Secondary Wireless Device) 10 Antenna layout determination device

Claims

1. 1. An antenna arrangement determination method for determining an arrangement of a plurality of antennas in a system for detecting an object using a first wireless device having a plurality of antennas and a second wireless device that performs wireless communication with the first wireless device, comprising: virtually dividing a target area in which the object is to be detected into a plurality of small areas; selecting a combination of candidate positions for the plurality of antennas from among positions where the plurality of antennas can be arranged; calculating a score based on the number of small areas on a radio wave path between the location of the second wireless device and the candidate locations of the plurality of antennas; determining a combination of the candidate positions of the plurality of antennas that maximizes the score as a combination of positions for arranging the plurality of antennas.

4. A method for determining an antenna arrangement comprising:

2. 2. The antenna arrangement determination method according to claim 1, Calculating the score includes calculating a score based on a total number of small areas counted for each path of radio waves between the location of the second wireless device and the candidate locations of the plurality of antennas.

4. A method for determining an antenna arrangement comprising:

3. 3. The antenna arrangement determination method according to claim 1, further comprising: Calculating the score includes calculating a score based on a number of small areas on a direct wave path between the second wireless device location and the candidate locations of the plurality of antennas.

4. A method for determining an antenna arrangement comprising:

4. 3. The antenna arrangement determination method according to claim 1, further comprising: Calculating the score includes calculating a score based on a number of small areas on a path of a direct wave between a position of the second wireless device and the candidate positions of the plurality of antennas and a number of small areas on a path of a reflected wave between a position of the second wireless device and the candidate positions of the plurality of antennas.

4. A method for determining an antenna arrangement comprising:

5. 5. The antenna arrangement determining method according to claim 4, and correcting the score according to the number of times the reflected wave is reflected between the position of the second wireless device and the candidate positions of the plurality of antennas.

4. A method for determining an antenna arrangement comprising:

6. 1. An antenna arrangement determination device for determining an arrangement of a first wireless device having a plurality of antennas in a system for detecting an object using a second wireless device that wirelessly communicates with the first wireless device, the antenna arrangement determination device comprising: A process of virtually dividing a target area in which the object is to be detected into a plurality of small areas; A process of selecting a combination of candidate positions of the plurality of antennas from among positions where the plurality of antennas can be arranged; A process of calculating a score based on the number of small areas on a radio wave path between the position of the second wireless device and the candidate positions of the plurality of antennas; and determining a combination of the candidate positions of the plurality of antennas that maximizes the score as a combination of positions for arranging the plurality of antennas. An antenna arrangement determination device comprising:

7. 1. A program for determining an arrangement of a plurality of antennas in a system for detecting an object using a first wireless device having a plurality of antennas and a second wireless device that wirelessly communicates with the first wireless device, the program comprising: A process of virtually dividing a target area in which the object is to be detected into a plurality of small areas; A process of selecting a combination of candidate positions of the plurality of antennas from among positions where the plurality of antennas can be arranged; A process of calculating a score based on the number of small areas on a radio wave path between the position of the second wireless device and the candidate positions of the plurality of antennas; determining a combination of the candidate positions of the plurality of antennas that maximizes the score as a combination of positions at which the plurality of antennas are to be disposed.

4. An antenna arrangement determination program comprising:

8. 1. An object detection system for detecting an object within a region of interest, comprising: a first wireless device having a plurality of antennas; a second wireless device that wirelessly communicates with the first wireless device; The antenna arrangement determination device according to claim 6, the plurality of antennas are arranged at positions determined by the antenna arrangement determination device relative to the position of the second wireless device; 1. An object detection system comprising:

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