Received power prediction method and received power prediction system

Abstract

In this reception power predicting method, a reception power predicting system executes: an acquisition process of acquiring dynamic environment information of an object present in a predetermined area; a process of acquiring the position of a communication terminal present in the predetermined area; a process of predicting a predicted position of the communication terminal after the elapse of a predetermined time; a process of predicting the dynamic environment information after the elapse of the predetermined time; and a prediction process of predicting a reception power of the communication terminal after the elapse of the predetermined time on the basis of path information of radio wave propagation that has previously been calculated at the predicted position of the communication terminal or at an evaluation point in the periphery of the predicted position, and path information of a path that is blocked according to the dynamic environment information after the elapse of the predetermined time.

Description

[Technical Field]

[0001] The present invention relates to a received power prediction method and a received power prediction system. [Background technology]

[0002] There are known techniques for predicting wireless communication quality in wireless communication systems. For example, there is a known technique for predicting the received power of a communication terminal based on past measured values ​​of received power at a given position, assuming a static environment with obstacles such as buildings and trees whose position and size do not change on a second-by-second basis. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Keisuke Wakao, Kenichi Kawamura, Takatsune Moriyama, "Quality Prediction Technology for Optimal Use of Multiple Wireless Access Points," NTT Technical Journal, April 2020, pp. 11-13 [Non-patent document 2] "How do we determine the location of people and objects indoors? A summary of indoor positioning methods," [online], Techfirm Blog, [Retrieved October 7, 1991], Internet<URL: https: / / www.techfirm.co.jp / blog / indoor-localization> Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional technology, it is difficult to predict the received power of a communication terminal in a dynamic environment where moving objects such as people, vehicles, and robots are present, taking into account the blocking of radio waves by moving objects.

[0005] An embodiment of the present invention has been made in consideration of the above-mentioned problems, and provides a received power prediction method that can predict the received power of a communication terminal in a dynamic environment where mobile objects are present, taking into account the blocking of radio waves by mobile objects. [Means for solving the problem]

[0006] In order to solve the above problem, a received power prediction method according to an embodiment of the present invention is a method for predicting received power in a predetermined area. Contains information indicating the location of a mobile object An acquisition process for acquiring dynamic environmental information of an object, a process for acquiring a position of a communication terminal in the predetermined area, a process for predicting a predicted position of the communication terminal after a predetermined time has elapsed, a process for predicting the dynamic environmental information after the predetermined time has elapsed, and path information of radio wave propagation calculated in advance at the predicted position of the communication terminal or an evaluation point around the predicted position. From all paths contained in the dynamic environmental information after the predetermined time has elapsed, The position of the moving object included Paths blocked by Delete and a prediction process for predicting the received power of the communication terminal after the predetermined time has elapsed. [Effects of the Invention]

[0007] According to an embodiment of the present invention, it is possible to provide a received power prediction method that can predict the received power of a communication terminal in a dynamic environment where moving objects exist, taking into account the blocking of radio waves by moving objects. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of a system configuration of a received power prediction system according to an embodiment of the present invention. [Figure 2] 10A and 10B are diagrams for explaining a prediction process of received power according to the present embodiment. [Figure 3] FIG. 10 is a diagram for explaining a pre-processing according to the present embodiment. [Figure 4] FIG. 10 is a diagram illustrating another example of the system configuration of the received power prediction system according to the present embodiment. [Figure 5] 10 is a flowchart illustrating an example of a process for predicting received power according to the first embodiment. [Figure 6]10 is a flowchart illustrating an example of a process of predicting received power according to the second embodiment. [Figure 7] FIG. 10 is a diagram (1) for explaining a process of predicting received power according to the second embodiment. [Figure 8] FIG. 10 is a diagram (2) for explaining the prediction process of the received power according to the second embodiment. [Figure 9] 10 is a flowchart illustrating an example of pre-processing according to the present embodiment. [Figure 10] FIG. 2 is a diagram illustrating an example of a hardware configuration of a prediction device according to the present embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a hardware configuration of a communication terminal according to the present embodiment. [Figure 12] FIG. 1 is a diagram (1) for explaining a problem of the present embodiment. [Figure 13] FIG. 2 is a diagram (2) for explaining the problem of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0010] <System configuration> The received power prediction system 1 according to this embodiment is a system that predicts the received power that a communication terminal receives from a wireless base station in a wireless communication network.

[0011] A conventional quality prediction system such as that shown in Non-Patent Document 1 predicts wireless communication quality from actual measurement values ​​of communication quality at evaluation points acquired in advance, the current position of the communication terminal, movement information of the communication terminal, etc. With this conventional technology, for example, as shown in Fig. 12, in a static environment 1200 with only stationary objects such as buildings 1203, it is possible to predict the received power that a communication terminal 902 receives from a wireless base station 901 based on actual measurement values ​​of received power acquired in advance.

[0012] However, with this method, for example, in a dynamic environment 1300 containing moving objects such as a vehicle 1301, a person 1302, and a robot 1303, as shown in FIG. 13, radio waves are blocked by the moving objects, making it difficult to predict the received power that a communication terminal 1202 will receive from a wireless base station 1201.

[0013] Therefore, the received power prediction system 1 of this embodiment has a system configuration shown in, for example, FIG. 1 or FIG. 4 so that the received power received by the communication terminal 1202 can be predicted in a dynamic environment 1300 where mobile objects exist, taking into account the blocking of radio waves by the mobile objects.

[0014] (System Configuration 1) 1 is a diagram showing an example of the system configuration of a received power prediction system according to this embodiment. In the example of FIG.

[0015] The prediction device 100 is an information processing device having a computer configuration, or a system including multiple computers. The prediction device 100 realizes functional configurations such as an environmental information acquisition unit 101, a terminal position acquisition unit 102, a terminal position prediction unit 103, an environmental information prediction unit 104, a received power prediction unit 105, and a communication unit 106 by executing a predetermined program on the computer included in the prediction device 100. Note that at least a part of the above functional configurations may be realized by hardware.

[0016] Furthermore, the prediction device 100 implements an environment information storage unit 111, a terminal position storage unit 112, an estimation result storage unit 113, and the like, using a storage device, memory, and the like provided in the prediction device 100.

[0017] The environmental information acquisition unit 101 executes an acquisition process to acquire dynamic environmental information of objects in a predetermined area. For example, as shown in Fig. 2, the environmental information acquisition unit 101 acquires dynamic environmental information within a building 201, which is an example of the predetermined area, using a three-dimensional sensor such as a LiDAR 211, a stereo camera 212, a depth camera 213, a camera 214, or a wireless sensing device 215. This dynamic environmental information includes, for example, information indicating the positions of moving objects 202a, 202b, and 202c within the building 201.

[0018] The LiDAR (Light Detection and Ranging, or Laser Imaging Detection and Ranging) 211 is a device that measures the distance to an object by irradiating the object with light such as laser light and detecting the reflected light with an optical sensor or the like. The environmental information acquisition unit 101 may use the LiDAR 211 to sense a predetermined area, such as the inside of a building 201, to acquire three-dimensional point cloud data, and may use the acquired three-dimensional point cloud data as dynamic environmental information.

[0019] The stereo camera 212 is a camera that can measure the distance to an object along with an image of the object by simultaneously capturing images of the object from two different directions. The environment information acquisition unit 101 may use the stereo camera 212 to sense a predetermined area, such as the inside of the building 201, to acquire three-dimensional point cloud data, and use the acquired three-dimensional point cloud data as dynamic environment information.

[0020] The depth camera 213 is a camera that captures a depth image including depth data indicating the distance to the object by capturing an image of the object. The environment information acquisition unit 101 may use the depth camera 213 to capture an image of a predetermined area, such as the inside of the building 201, to acquire depth data, and use the acquired depth data as dynamic environment information.

[0021] The camera 214 is, for example, a monocular camera that captures normal camera images that do not include depth data. A technology for estimating a depth image from a monocular camera image that does not include depth data is realized by deep learning. The environment information acquisition unit 101 may generate depth data from the camera image captured by the camera 214 by deep learning, and use the generated depth data as dynamic environment information.

[0022] The wireless sensing device 215 is a device that measures the position, etc., of an object using wireless communication or radio wave reflection. For example, a technology has been developed that acquires the position, etc., of an object by using multiple subcarriers such as wireless local area network (LAN) communication to acquire channel state information (CSI) of each subcarrier and inputting the acquired CSI into a trained machine learning model. The wireless sensing device 215 may also be a millimeter-wave radar or the like that can measure the distance, angle, speed, etc., of the object. The environmental information acquisition unit 101 may use the wireless sensing device 215 to sense a predetermined area, such as inside the building 201, to acquire position data, etc. of objects in the predetermined area, and use the acquired position data, etc. as dynamic environmental information.

[0023] Furthermore, the environmental information acquisition unit 101 may acquire dynamic environmental information of objects in a predetermined area using other positioning methods. In this way, the dynamic environmental information acquired by the environmental information acquisition unit 101 may include three-dimensional point cloud data, depth data, position data, or the like of objects acquired by a three-dimensional sensor, and may be data that can identify the position of a moving object in a predetermined area. Furthermore, the positioning method for acquiring the dynamic environmental information may be any positioning method.

[0024] The terminal position acquisition unit 102 executes a process of acquiring the position of a communication terminal in a predetermined area. For example, the communication terminal adds position information (coordinate information) indicating the position of the terminal itself and transmits request information to the prediction device 100, requesting acquisition of a predicted value of received power. The terminal position acquisition unit 102 may acquire the position of the communication terminal from the request information received from the communication terminal by the communication unit 106, for example. However, the present invention is not limited to this, and the terminal position acquisition unit 102 may acquire the position of the communication terminal using various three-dimensional sensors, similar to the environment information acquisition unit 101.

[0025] Terminal position prediction unit 103 executes a process of predicting the predicted position of the communication terminal after a predetermined time (t seconds) has elapsed from the present time. For example, terminal position acquisition unit 102 stores the acquired position of the communication terminal in terminal position storage unit 112. Furthermore, terminal position prediction unit 103 may predict the position of the communication terminal after a predetermined time has elapsed, for example, by linear prediction or the like, based on the position history of the communication terminal stored in terminal position storage unit 112.

[0026] As another example, the communication terminal may have the terminal position prediction unit 103. In this case, the terminal position prediction unit 103 of the communication terminal calculates a predicted position of the communication terminal after a predetermined time (t seconds) has elapsed, based on the current position of the communication terminal and the movement of the communication terminal (movement direction, movement speed, etc.) measured by a sensor such as an acceleration sensor or an angle sensor. Furthermore, the communication terminal adds the position of the communication terminal and the predicted position of the communication terminal after the predetermined time has elapsed, and transmits request information to the prediction device 100 requesting acquisition of a predicted value of received power.

[0027] The environmental information prediction unit 104 executes a process of predicting dynamic environmental information after a predetermined time (t seconds) has elapsed from the present time. For example, the environmental information acquisition unit 101 stores the acquired dynamic environmental information in the environmental information storage unit 111. Furthermore, the environmental information prediction unit 104 predicts the dynamic environmental information after the predetermined time has elapsed, for example, by linear prediction, based on the history of the dynamic environmental information stored in the environmental information storage unit 111.

[0028] For example, the environmental information prediction unit 104 acquires the positions of the moving objects 202a, 202b, and 202c shown in FIG. 2 from dynamic environmental information, and stores the acquired position histories of the moving objects 202a, 202b, and 202c in the environmental information storage unit 111 or the like. Furthermore, the environmental information prediction unit 104 may calculate the movement of the moving object (movement direction, movement speed, etc.) from the position history of the moving object stored in the environmental information storage unit 111 or the like, and predict the position of the moving object after a predetermined time has elapsed from the current position of the moving object and the movement of the moving object. Alternatively, the environmental information prediction unit 104 may predict the position of the moving object after a predetermined time has elapsed by inputting the movement history of the moving object into a prediction model that has been machine-learned in advance to predict the position of the moving object after a predetermined time has elapsed from the movement history of the moving object.

[0029] The received power prediction unit 105 predicts the received power of the communication terminal after a predetermined time has elapsed, based on path information 206 of radio wave propagation generated in advance by ray tracing or the like, at the predicted position of the communication terminal or an evaluation point around the predicted position, and the position of the mobile body after a predetermined time has elapsed.

[0030] 2, path information 206 is information on a plurality of radio wave propagation paths through which radio waves transmitted from a radio base station (BS) 204 are received at evaluation point 205, and preferably includes information on the received power received on each path. Received power prediction unit 105 predicts the received power of communication terminal 203 after a predetermined time has elapsed by deleting paths in the direction of mobile bodies 202a and 202b after a predetermined time has elapsed from path information 206 of radio wave propagation generated in advance at evaluation points around the predicted position of communication terminal 203.

[0031] The prediction device 100 stores in advance in the estimation result storage unit 113 path information 206 of radio wave propagation at a plurality of evaluation points, which information has been acquired in advance by pre-processing such as that shown in FIG.

[0032] 3 is a diagram illustrating the pre-processing according to this embodiment. This pre-processing is performed, for example, by an information processing device having a computer configuration using a program for radio wave propagation simulation such as ray tracing. Note that the information processing device used for the pre-processing may be the same information processing device as the prediction device 100, or may be an information processing device different from the prediction device 100.

[0033] The information processing device acquires static environmental information from a building DB (Database) (or map DB) 311 representing the structure of the building 201, CAD (Computer Aided Design) data 312, or BIM (Building Information Modeling) data 313 (step S11).

[0034] The information processing device also sets multiple evaluation points 205 within a building 201, which is an example of a predetermined area, and generates (calculates) path information 206 of radio wave propagation at each of the set evaluation points 205 by ray tracing or the like (step S12).

[0035] This provides, for example, radio wave propagation path information 206 generated in advance at a plurality of evaluation points 205 within the building 201. The prediction device 100 stores the radio wave propagation path information 206 obtained by this pre-processing in the estimation result storage unit 113 in advance.

[0036] 1, the functional configuration of the prediction device 100 will be further described. The communication unit 106 executes communication processing for communicating with the communication terminal 203 and the like via a communication network.

[0037] The environmental information storage unit 111 stores dynamic environmental information etc. acquired by the environmental information acquisition unit 101. The terminal position storage unit 112 stores the position of the communication terminal 203 acquired by the terminal position acquisition unit 102. The estimation result storage unit 113 stores in advance path information 206 of radio wave propagation generated in advance at multiple evaluation points acquired in pre-processing.

[0038] With the above-described functional configuration, the environmental information acquisition unit 101 of the prediction device 100 acquires dynamic environmental information using various three-dimensional sensors, for example, as shown in Fig. 2 (step S1). This dynamic environmental information includes, for example, information indicating the positions of mobile objects 202a, 202b, and 202c within a predetermined area. Furthermore, the terminal position acquisition unit 102 of the prediction device 100 acquires the position of the communication terminal 203 (step S2).

[0039] Next, the terminal position prediction unit 103 of the prediction device 100 predicts the predicted position of the communication terminal 203 after a predetermined time (t seconds) has passed, and the environmental information prediction unit 104 predicts dynamic environmental information after the predetermined time has passed (step S3).

[0040] Furthermore, the received power prediction unit 105 of the prediction device 100 acquires path information 206 of radio wave propagation generated in advance at the predicted position of the communication terminal 203 after a predetermined time has elapsed or at an evaluation point in the vicinity of the predicted position from the estimation result storage unit 113. Furthermore, the received power prediction unit 105 deletes paths in the direction in which the mobile bodies 202a and 202b are located after a predetermined time has elapsed from the acquired path information 206 of radio wave propagation, and predicts the received power of the communication terminal 203 after a predetermined time has elapsed.

[0041] Through the above processing, the received power prediction system 1 can predict the received power of the communication terminal 203 in a dynamic environment where mobile objects exist, taking into consideration the blocking of radio waves by mobile objects.

[0042] 1 is an example. At least some of the functional components of the prediction device 100 may be included in the communication terminal 203.

[0043] (System Configuration 2) Fig. 4 shows another example of the system configuration of the received power prediction system according to this embodiment. In the example of Fig. 4, the received power prediction system 1 includes a prediction device 100 and a communication terminal 203 that can communicate with the prediction device 100 via a communication network 2.

[0044] In the received power prediction system 1 shown in FIG. 4, the terminal position acquisition unit 102 and the terminal position prediction unit 103 described in FIG.

[0045] The communication terminal 203 is a wireless communication device having a computer configuration. The communication terminal 203 realizes functional configurations such as a terminal location acquisition unit 102, a terminal location prediction unit 103, and a communication unit 401 by executing a predetermined program on the computer included in the communication terminal 203. Note that at least a part of the above functional configurations may be realized by hardware.

[0046] The terminal position acquisition unit 102 acquires the current position of the communication terminal 203 on the communication terminal 203 side, for example, by positioning using a GPS (Global Positioning System) device and autonomous navigation using sensors such as an acceleration sensor and an angle sensor.

[0047] The terminal position prediction unit 103 executes a process of predicting the predicted position of the communication terminal after a predetermined time (t seconds) has elapsed from the present time on the communication terminal 203 side. For example, the terminal position prediction unit 103 may predict the position of the communication terminal 203 after a predetermined time has elapsed by, for example, linear prediction, based on the history of the position of the communication terminal 203 acquired by the terminal position acquisition unit 102.

[0048] Alternatively, the terminal position prediction unit 103 may calculate the predicted position of the communication terminal 203 after a predetermined time (t seconds) has elapsed from the current position of the communication terminal 203 and the movement of the communication terminal (movement direction, movement speed, etc.) measured by sensors such as an acceleration sensor or an angle sensor.

[0049] The communication unit 401 connects to the communication network 2 by predetermined wireless communication such as 5G (5th Generation) or LTE (Long Term Evolution), and executes communication processing to communicate with the prediction device 100, etc. For example, the communication unit 401 adds information about the communication terminal, the position of the communication terminal 203, the predicted position of the communication terminal 203, etc. to request information requesting the prediction device 100 to predict received power, and transmits the request information to the prediction device 100. The communication unit 401 also receives the prediction result of the received power transmitted by the prediction device 100.

[0050] 4, in the prediction device 100, the request information received by the communication unit 106 from the communication terminal 203 includes the position of the communication terminal 203, a predicted position of the communication terminal 203 after a predetermined time has elapsed, etc. Therefore, the prediction device 100 does not need to include the terminal position acquisition unit 102, the terminal position prediction unit 103, etc.

[0051] In this way, the received power prediction system 1 only needs to have each of the functional components provided in the prediction device 100 described in FIG. 1, and any device in the system may have these components.

[0052] <Processing flow> Next, the processing flow of the received power prediction method according to this embodiment will be described.

[0053] <Prediction of received power> [Example 1] Fig. 5 is a flowchart showing an example of a received power prediction process according to the first embodiment. This process shows an example of a received power prediction process in which the received power prediction system 1 having the functional configuration shown in Fig. 1 or 4 predicts the received power of the communication terminal 203 after a predetermined time has elapsed. It is assumed that, at the start of the process shown in Fig. 5, the estimation result storage unit 113 stores path information 206 of radio wave propagation measured in advance at a plurality of evaluation points within a predetermined area.

[0054] In step S501, the environment information acquisition unit 101 acquires dynamic environment information of objects in a predetermined area. For example, the environment information acquisition unit 101 acquires the dynamic environment information using the LiDAR 211, the stereo camera 212, the depth camera 213, the camera 214, or the wireless sensing device 215 installed in the predetermined area. This dynamic environment information includes information indicating the positions of moving objects in the predetermined area.

[0055] In step S502, the terminal position acquisition unit 102 acquires the position of the communication terminal 203 in a predetermined area. This process may be executed by the prediction device 100 or the communication terminal 203.

[0056] In step S503, the terminal position prediction unit 103 predicts the predicted position of the communication terminal 203 after t seconds (after a predetermined time has elapsed). This process may be executed by the prediction device 100 or the communication terminal 203.

[0057] In step S504, the environment information prediction unit 104 predicts dynamic environment information after t seconds (after a predetermined time has elapsed). The predicted dynamic environment information includes information indicating the predicted positions of moving objects in a predetermined area after t seconds.

[0058] In step S505, the received power predicting unit 105 predicts paths (radio wave propagation paths) that will be blocked by the predicted position of the mobile object after t seconds at the predicted position of the communication terminal 203 after t seconds.

[0059] For example, the received power prediction unit 105 acquires path information 206 of radio wave propagation measured in advance at the predicted position of the communication terminal 203 after t seconds or at an evaluation point around the predicted position. Furthermore, the received power prediction unit 105 predicts paths that will be blocked by the predicted position of the mobile object after t seconds from the acquired path information 206 of radio wave propagation.

[0060] In step S506, the received power predicting unit 105 subtracts the received power of the blocked paths from all paths included in the acquired radio wave propagation path information 206, and predicts (calculates) the communication terminal 203 after t seconds.

[0061] For example, as shown in step S4 of Figure 2, the received power prediction unit 105 removes paths that will be blocked by moving bodies 202a and 202b after t seconds from the acquired radio wave propagation path information 206, and calculates the received power of communication terminal 203 after t seconds.

[0062] By the process of FIG. 5, the received power prediction system 1 can predict the received power of the communication terminal 203 in a dynamic environment where moving objects exist, taking into consideration the blocking of radio waves by moving objects.

[0063] [Example 2] Fig. 6 is a flowchart showing an example of a received power prediction process according to the second embodiment. This process shows another example of a received power prediction process in which the received power prediction system 1 having the functional configuration shown in Fig. 1 or 4 predicts the received power of the communication terminal 203 after a predetermined time has elapsed. Among the processes shown in Fig. 6, the processes of steps S501 to S505 are the same as the received power prediction process according to the first embodiment described with reference to Fig. 5, and therefore, description thereof will be omitted here.

[0064] In step S601, the received power prediction unit 105 predicts the received power of the communication terminal t seconds later based on the proportion of the first Fresnel zone of each path in the acquired radio wave propagation path information 206 that will be blocked by the predicted position of the moving body t seconds later.

[0065] 7 and 8 are diagrams for explaining the received power prediction process according to Example 2. A method for calculating the electric field at the reception point from the blocking ratio of a blocking object in the radius of the first Fresnel zone is known (for example, see Patent Document: JP 2020-31366 A).

[0066] 7, the propagation path of radio waves transmitted from radio base station (BS) 204 to communication terminal (UE) 203 is a three-dimensional space (spheroid) centered on shortest path 702, which connects radio base station 204 and communication terminal 203 with a line segment. This three-dimensional propagation path of radio waves is called a Fresnel zone. Furthermore, the innermost region of the Fresnel zone, where most of the radio wave energy exists, is called first Fresnel zone 701.

[0067] According to the above-mentioned patent document, if the reception electric field of the communication terminal 203 when the mobile object 202a is not present is E0(i), the reception electric field E1(i) of the communication terminal 203 when the mobile object 202a is present is: It can be calculated using the following (Equation 1) and (Equation 2).

[0068] (In the case of direct waves) As shown in FIG. 7, the propagation path of radio waves from the wireless base station 204 to the communication terminal 203 is a direct wave. In this case, the received electric field E1(i) is calculated by the following (Equation 1). |E1(i)| 2 =|E0(i)| 2 ×r(i) ... (Equation 1) Here, r(i) is the blocking ratio of the moving body 202a to the first Fresnel zone 701. For example, if the area indicated by the moving body 202a is 70% of the area of ​​the first Fresnel zone 701 at the position of the moving body 202a, the blocking ratio is 70% (0.7).

[0069] (In the case of reflected waves) As shown in FIG. 8, when the propagation path from the radio base station (BS) 204 to the communication terminal (UE) 203 is a reflected wave, the received electric field E1(i) is calculated by the following (Equation 2). |E1(i)| 2 =|E0(i)| 2 ×r(i) / La …(Equation 2) Here, La is the reflection loss, and an approximate value determined by the material of the reflecting surface 801, etc., is used.

[0070] In addition, when there are N paths from the wireless base station 204 to the communication terminal 203, the reception electric field E1(i) obtained for each path is summed up to obtain the transmission / reception electric field E1(i) received by the communication terminal 203. total can be calculated (Equation 3).

[0071]

number

[0072] According to the second embodiment, the received power prediction system 1 can calculate the blocking rate by a moving object for the first Fresnel zone of each path in the radio wave propagation path information 206, thereby more quickly calculating the received power (or attenuation) of the communication terminal 203.

[0073] <Pre-processing> 9 is a flowchart showing an example of pre-processing according to this embodiment. This processing shows an example of processing in which an information processing device having a computer configuration acquires path information of radio wave propagation at multiple evaluation points within a predetermined area.

[0074] In step S901, the information processing device acquires static environmental information of a predetermined area from the building DB (or map DB) 311, the CAD data 312, the BIM data 313, or the like. This static environmental information includes, for example, information indicating the positions of objects that do not generally move, such as buildings, walls, and floors.

[0075] In step S902, the information processing device sets the position of the wireless base station in the static environment information of the predetermined area.

[0076] In step S903, the information processing device sets a plurality of evaluation points in a planar manner in the static environmental information of a predetermined area.

[0077] In step S904, the information processing device generates (calculates) path information between the wireless base station and each evaluation point by radio wave propagation estimation such as ray tracing.

[0078] By the processing of FIG. 9, the information processing device can generate path information 206 of radio wave propagation generated at a plurality of evaluation points to be stored in the estimation result storage unit 113.

[0079] <Hardware configuration example> (Hardware configuration of the prediction device) Fig. 10 is a diagram showing an example of the hardware configuration of a prediction device according to this embodiment. The prediction device 100 has, for example, the configuration of a computer 1000 as shown in Fig. 10. In the example of Fig. 10, the computer 1000 has a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus B, etc.

[0080] The processor 1001 is, for example, an arithmetic device such as a CPU (Central Processing Unit) that executes a predetermined program to realize various functions. The memory 1002 is a storage medium readable by the computer 1000, and includes, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage device 1003 is a computer-readable storage medium, and may include, for example, a HDD (Hard Disk Drive), an SSD (Solid State Drive), various optical disks, and magneto-optical disks.

[0081] The communication device 1004 includes one or more pieces of hardware (communication devices) for communicating with other devices via a wireless or wired network. The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., an input / output device such as a touch panel display).

[0082] The bus B is commonly connected to the above components and transmits, for example, address signals, data signals, and various control signals. The processor 1001 is not limited to a CPU, and may be, for example, a DSP (Digital Signal Processor), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0083] (Hardware configuration of communication terminal) 11 is a diagram showing an example of the hardware configuration of a communication terminal according to this embodiment. The communication terminal 203 includes, for example, a GPS device 1101, a sensor 1102, and the like in addition to the hardware configuration of the computer 1000 described in FIG.

[0084] The GPS device 1101 is a positioning device that receives positioning signals transmitted by GPS satellites and outputs position information indicating the current position of the communication terminal 203. The sensor 1102 is a detection device that detects the movement of the communication terminal 203, such as an acceleration sensor or angle sensor.

[0085] (supplement) The prediction device 100 in this embodiment is not limited to being realized by a dedicated device, but may also be realized by a general-purpose computer. In this case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize the function. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0086] Additionally, "computer-readable recording media" includes various storage devices such as portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as hard disks built into computer systems. Furthermore, "computer-readable recording media" may also include devices that dynamically store programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and devices that store programs for a certain period of time, such as volatile memory within computer systems that serve as servers or clients in such cases.

[0087] Furthermore, the above program may be one that realizes part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in a computer system, or may be one that is realized using hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

[0088] <Effects of the embodiment> According to this embodiment, it is possible to provide a received power prediction method that can predict the received power of a communication terminal in a dynamic environment where moving objects exist, taking into account the blocking of radio waves by moving objects.

[0089] In addition, the above effects enable stable use of wireless communication or applications in wireless communication systems, such as switching the location (wireless base station) where a communication terminal is accommodated due to deterioration of communication quality, controlling communication parameters, or changing the driving route of an autonomous vehicle.

[0090] <Summary of the embodiment> This specification discloses at least the following wireless communication methods and wireless communication systems. (Section 1) The received power prediction system an acquisition process for acquiring dynamic environmental information of objects in a predetermined area; A process of acquiring the location of a communication terminal in the predetermined area; predicting a predicted location of the communication terminal after a predetermined time has elapsed; a process of predicting the dynamic environmental information after the predetermined time has elapsed; a prediction process for predicting the received power of the communication terminal after the predetermined time has elapsed, based on path information of radio wave propagation calculated in advance at the predicted position of the communication terminal or at an evaluation point around the predicted position, and path information of paths blocked by the dynamic environmental information after the predetermined time has elapsed; A received power prediction method that performs the above. (Section 2) The reception power prediction method according to claim 1, wherein the dynamic environmental information acquired in the acquisition process includes three-dimensional point cloud data, depth data, or position data of the object acquired by a three-dimensional sensor. (Section 3) The received power prediction method described in claim 1, wherein the path information of radio wave propagation includes path information at the evaluation point calculated by ray tracing radio wave propagation characteristic estimation using static environmental information of the specified area. (Section 4) 4. The received power prediction method according to claim 3, wherein the received power prediction system has path information of the radio wave propagation calculated in advance at a plurality of evaluation points within the predetermined area. (Section 5) the dynamic environmental information after the predetermined time has elapsed includes information indicating a position of a moving object in the predetermined area after the predetermined time has elapsed; The received power prediction method described in paragraph 3, wherein the prediction process subtracts paths that will be blocked by moving objects in the specified area after the specified time has elapsed from the path information of radio wave propagation calculated in advance at the evaluation point, and predicts the received power of the communication terminal after the specified time has elapsed. (Section 6) the dynamic environmental information after the predetermined time has elapsed includes information indicating a position of a moving object in the predetermined area after the predetermined time has elapsed; The received power prediction method described in paragraph 3, wherein the prediction process predicts the received power of the communication terminal after the specified time has elapsed based on the blocking rate by moving objects in the specified area for a first Fresnel zone of each path from path information of the radio wave propagation calculated in advance at the evaluation point. (Section 7) an environment information acquisition unit configured to acquire dynamic environment information of objects in a predetermined area; a terminal location acquisition unit configured to acquire the location of a communication terminal in the predetermined area; a terminal location predictor configured to predict a predicted location of the communication terminal after a predetermined time has elapsed; an environmental information prediction unit configured to predict the dynamic environmental information after the predetermined time has elapsed; a reception power prediction unit configured to predict reception power of the communication terminal after the predetermined time has elapsed, based on path information of radio wave propagation calculated in advance at a predicted position of the communication terminal or an evaluation point around the predicted position, and path information of paths blocked by the dynamic environmental information after the predetermined time has elapsed; A received power prediction system comprising:

[0091] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0092] 1. Received power prediction system 101 Environmental Information Acquisition Department 102 Terminal location acquisition unit 103 Terminal location prediction unit 104 Environmental Information Forecasting Department 105 Received power prediction unit 113 Estimation result storage unit 113 206 Radio wave propagation path information 211 LiDAR 212 Stereo Camera 213 Depth Camera 214 Camera 215 Wireless Sensing Devices 205 evaluation points 701 First Fresnel Zone

Claims

1. The received power prediction system an acquisition process for acquiring dynamic environmental information of an object, including information indicating the position of a moving object in a predetermined area; A process of acquiring the location of a communication terminal in the predetermined area; predicting a predicted location of the communication terminal after a predetermined time has elapsed; a process of predicting the dynamic environmental information after the predetermined time has elapsed; a prediction process for predicting the received power of the communication terminal after the predetermined time has elapsed by deleting paths that are blocked by the position of the moving body included in the dynamic environment information from all paths included in path information of radio wave propagation that is calculated in advance at the predicted position of the communication terminal or an evaluation point around the predicted position; A received power prediction method that performs the above.

2. The received power prediction method according to claim 1 , wherein the dynamic environmental information acquired in the acquisition process includes three-dimensional point cloud data, depth data, or position data of the object acquired by a three-dimensional sensor.

3. The reception power prediction method according to claim 1 , wherein the path information of radio wave propagation includes path information at the evaluation point that is generated in advance by estimating radio wave propagation characteristics using static environmental information of the predetermined area.

4. The received power prediction method according to claim 3 , wherein the received power prediction system has path information of the radio wave propagation generated in advance at a plurality of evaluation points within the predetermined area.

5. the dynamic environmental information after the predetermined time has elapsed includes information indicating a position of a moving object in the predetermined area after the predetermined time has elapsed; 4. The received power prediction method according to claim 3, wherein the prediction process predicts the received power of the communication terminal after the predetermined time has elapsed by deleting paths that are blocked by a moving object in the predetermined area from all paths included in the path information of radio wave propagation calculated in advance at the evaluation point.

6. an environment information acquisition unit configured to acquire dynamic environment information of an object, including information indicating the position of a moving object in a predetermined area; a terminal location acquisition unit configured to acquire the location of a communication terminal in the predetermined area; a terminal location predictor configured to predict a predicted location of the communication terminal after a predetermined time has elapsed; an environmental information prediction unit configured to predict the dynamic environmental information after the predetermined time has elapsed; a reception power prediction unit configured to predict reception power of the communication terminal after the predetermined time has elapsed by deleting paths that are blocked by the position of the moving object included in the dynamic environment information from all paths included in path information of radio wave propagation that is calculated in advance at the predicted position of the communication terminal or an evaluation point around the predicted position; A received power prediction system comprising:

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