Wireless communication environment evaluation method and system

Abstract

To estimate the position of a movable object and reflect it in a structural model built in a computer for evaluating a wireless communication environment without the need for the movable object to recognize and report its own position.SOLUTION: A wireless communication environment evaluation method is used by an information processing device that is equipped with a central processing unit, an output device, an input device, and a storage device and can provide computer resources, and the information processing device constructs a structural model of an electromagnetic wave scatterer within the computer resources, calculates the characteristics of the electromagnetic field using the structural model and a ray that simulates radio waves traveling in real space, and obtains position information regarding the position of the second object on the basis of the result of the calculation using the first structural model corresponding to the real space that includes the first object and does not include the second object, and electromagnetic wave vector measurement data in the real space that includes the first object and the second object.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a technology for evaluating wireless communication characteristics, and more particularly to wireless communication in which information is transmitted using electromagnetic waves in a radio wave environment in which movable radio wave scatterers exist in a service area, and to a wireless communication characteristics evaluation technology for predicting the wireless communication state within the area by measuring the electromagnetic field within the service area and numerically analyzing the electric field environment using computer resources. [Background technology]

[0002] With the worldwide spread of portable wireless information terminals, there is an increasing demand for stable wireless communication services, such as wireless calls and wireless data transfers, regardless of the surrounding environment. When radio wave scatterers exist within an area providing wireless communication services, the scatterers scatter the electromagnetic waves of the wireless communication medium, causing power fluctuations when the electromagnetic waves emitted from the transmitter reach the receiver. In many cases, this causes a decrease in received power, resulting in the formation of areas within the area where good-quality wireless communication is difficult. Furthermore, if the relative positions and attitudes of the scatterers and the communicating wireless devices change dynamically, the areas where good-quality wireless communication is possible change, causing the signal strength received by the receiver to fluctuate over time, which can lead to degradation of communication quality or even the inability to communicate.

[0003] The occurrence of such areas and times is determined by the relationship between the placement of electromagnetic wave scatterers within the service area and the positions of the transmitters and receivers that perform wireless communication. Therefore, when forming a wireless communication network within the same area, the relationship between the placement of the transmitters and receivers and the positions of electromagnetic wave scatterers within the area greatly affects the communication status of the wireless communication network.

[0004] To solve this problem, a technology has been proposed that constructs an electromagnetic field model in a computer to analyze wireless communication characteristics within a service area and virtually realizes the electromagnetic field distribution for all transmitter / receiver placements within that area. To construct an electromagnetic field calculation model within computer resources, it is necessary to construct a structural model of electromagnetic wave scatterers that affect the electromagnetic waves present within the wireless communication service area. In principle, data on structures within the service area can be obtained from building design data and catalog specifications for fixtures present within the area. However, if these are movable, the structural model constructed in the computer must be modified to suit the actual situation.

[0005] Several such correction techniques have been proposed, for example, Japanese Patent Application Laid-Open No. 2018-200526 describes a technique in which a mobile object itself checks landmarks attached to fixed structures and reports its own position, and Japanese Patent Application Laid-Open No. 2021-103108 describes a technique in which a mobile object receives signals transmitted from satellites outside the communication area, recognizes its own position, and reports it. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-200526 [Patent Document 2] Patent Publication No. 2021-103108 Summary of the Invention [Problem to be solved by the invention]

[0007] All of these prior art technologies are based on the principle that a movable body recognizes and reports its own position, but there is a problem in that if the movable body does not have a means for reporting, or if the communication means for reporting is unusable due to a malfunction or the like, the position of the movable body cannot be determined.

[0008] The object of the present invention is to estimate the position of a mobile body without the mobile body having to recognize and report its own position, and to reflect this in a structural model constructed in a computer for evaluating the wireless communication environment. [Means for solving the problem]

[0009] One aspect of the present invention is a method for evaluating a wireless communication environment, which uses an information processing device that has a central processing unit, an output device, an input device, and a storage device and is capable of providing computer resources, and the information processing device constructs a structural model of an electromagnetic wave scatterer within the computer resources, calculates the characteristics of the electromagnetic field using the structural model and a ray that simulates radio waves traveling in real space, and obtains location information regarding the position of the second object based on the result of the calculation using a first structural model corresponding to a real space that includes a first object but does not include a second object, and electromagnetic wave vector measurement data in the real space that includes the first object and the second object.

[0010] Another aspect of the present invention is a wireless communication environment evaluation system comprising an arrival wave information storage module that stores measurement data on the arrival direction of received waves within a wireless communication service area, an electromagnetic field analysis model storage module that stores a structural model of an electromagnetic wave scatterer, and an electromagnetic field calculation engine that performs electromagnetic field calculations, wherein the electromagnetic field calculation engine uses the measurement data and the structural model to estimate the position of a movable object within the wireless communication service area by electromagnetic field calculation. [Effects of the Invention]

[0011] According to the present invention, the position of a mobile body can be estimated and reflected in a structural model constructed in a computer for wireless communication environment evaluation without the mobile body having to recognize and report its own position. [Brief explanation of the drawings]

[0012] [Figure 1A] FIG. 1 is a diagram illustrating the configuration of a real space of an example of a wireless communication environment evaluation system. [Figure 1B] FIG. 1 is a diagram illustrating the configuration of a virtual space in an example of a wireless communication environment evaluation system. [Figure 1C]FIG. 1 is a diagram illustrating the configuration of a real space of an example of a wireless communication environment evaluation system. [Figure 1D] FIG. 1 is a diagram illustrating the configuration of a virtual space in an example of a wireless communication environment evaluation system. [Figure 2A] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 2B] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 3A] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 3B] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 4A] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 4B] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 5A] FIG. 10 is a diagram illustrating the configuration of a real space in another example of the wireless communication environment evaluation system. [Figure 5B] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 6A] FIG. 10 is a diagram illustrating the configuration of a real space in another example of the wireless communication environment evaluation system. [Figure 6B] FIG. 10 is a diagram illustrating the configuration of a virtual space in another example of the wireless communication environment evaluation system. [Figure 7] FIG. 1 is a block diagram of an example of a measurement radio device. [Figure 8] FIG. 2 is a block diagram of an example central radio station. [Figure 9] FIG. 10 is a block diagram of another example of a measurement radio device. [Figure 10] FIG. 10 is a block diagram of another example of a central radio station. [Figure 11] 4 is a flowchart illustrating an example of the operation of the wireless communication environment evaluation system. [Figure 12] 10 is a flowchart illustrating another example of the operation of the wireless communication environment evaluation system. [Figure 13] FIG. 10 is an image diagram showing an example of a display of a man-machine interface of the wireless communication environment evaluation system. [Figure 14]FIG. 10 is an image diagram showing another example of the display of the man-machine interface of the wireless communication environment evaluation system. [Figure 15] FIG. 10 is an image diagram showing another example of the display of the man-machine interface of the wireless communication environment evaluation system. [Figure 16] FIG. 10 is an image diagram showing another example of the display of the man-machine interface of the wireless communication environment evaluation system. DETAILED DESCRIPTION OF THE INVENTION

[0013] Examples will be described below with reference to the drawings. However, the present invention should not be construed as being limited to the description of the embodiments shown below. Those skilled in the art will readily understand that the specific configuration can be modified within the scope of the concept and spirit of the present invention.

[0014] In the configurations of the embodiments described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and redundant explanations may be omitted.

[0015] When there are multiple elements having the same or similar functions, they may be described using the same reference numeral with different subscripts. However, when there is no need to distinguish between multiple elements, the subscripts may be omitted.

[0016] The designations "first," "second," "third," etc. in this specification are used to identify components and do not necessarily limit the number, order, or content thereof. Furthermore, numbers used to identify components are used in different contexts, and numbers used in one context do not necessarily indicate the same configuration in another context. Furthermore, this does not prevent a component identified by a certain number from also serving the function of a component identified by another number.

[0017] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings etc. may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings etc.

[0018] All publications, patents, and patent applications cited herein are incorporated by reference in their entirety.

[0019] As used herein, elements referred to in the singular are intended to include the plural unless the context clearly indicates otherwise.

[0020] In one example embodiment, measurement radio devices are installed at multiple points within a wireless communication service area, each receiving electromagnetic waves used for communication with multiple antennas and measuring the direction of arrival of the waves, and the direction of arrival of the waves received by the communication radio devices installed within the service area is measured. A calculation model for electromagnetic field analysis is created within computer resources using shape data of fixed structures, and the position of a minute region on the surface of a movable body existing within the service area is identified by numerical calculation of the electromagnetic field using the electromagnetic wave propagation trajectories calculated from the calculation model and the directions of arrival of the electromagnetic waves obtained from the multiple measurement radio devices within the service area. The shape of the movable body is identified by grouping the multiple directions of arrival measured by the multiple measurement radio devices and the multiple minute regions obtained from the multiple propagation trajectories calculated within the computer resources using the calculation model for electromagnetic field analysis.

[0021] Here, computer resources refer to functions provided by an information processing device that includes, for example, a processing device, a storage device, an input device, and an output device, and can typically be realized by the processing device processing and utilizing software and data in the storage device. [Example]

[0022] An example of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described with reference to FIGS. 1A to 1D.

[0023] In Example 1, electromagnetic waves with propagation characteristics similar to those of the electromagnetic waves used in communication are transmitted in multiple directions from multiple points within a wireless communication service area in real space. Measurement wireless devices are deployed to receive the electromagnetic waves with multiple antennas and measure their directions of arrival. Using shape data of fixed structures, a computational model for electromagnetic field analysis is constructed in a virtual space within computer resources. The propagation trajectory of the electromagnetic waves calculated from the computational model and the directions of arrival of the electromagnetic waves obtained from multiple measurement wireless devices within the service area are used to estimate the position of a moving object within the service area through numerical calculation of the electromagnetic field.

[0024] Fig. 1A shows a hardware layout of a real space 10. Fig. 1B shows a calculation model of the real space 10 of Fig. 1A for electromagnetic field analysis constructed in a virtual space within a computer resource 100. As shown in FIG. 1A, a room 1 exists in the real space, which is composed of a ceiling, walls, and floor, and a shelf 2, a container 3, and a table 4 are arranged inside the room 1. A plurality of measurement radio devices 11 are arranged on the ceiling, walls, and floor of the room 1, and a central radio station 12 is arranged on the floor. Inside the room 1, there are floating movable bodies 6 (e.g., drones) that change location in the air and grounded movable bodies 5 (e.g., robots) that change location on the floor, which change location on a route 8 and a course 7, respectively. Note that the arrangement positions of each element are merely examples, and are not limited to these.

[0025] In such a real space 10, there may be a need to perform wireless communication between the grounded movable body 5 or the floating movable body 6 and the access point 9 to control a robot or a drone or to receive data collected by the robot or the drone. However, since the positions of the grounded movable body 5 and the floating movable body 6 change over time, the wireless environment changes over time, and the communication performance also changes accordingly.

[0026] 1B, a virtual room 101 exists in the computing resource 100 corresponding to the real space, and a virtual shelf 102, a virtual table 104, and a virtual container 103 are arranged inside the virtual room 101. A plurality of virtual measurement radio devices 111 are arranged on the ceiling, walls, and floor of the virtual room 101, and a virtual central radio station 112 is arranged on the floor. A virtual floating movable body 106 that changes location in the air and a virtual grounded movable body 105 that changes location on the floor are predicted inside the virtual room 101, and are presumed to change location on a virtual route 108 and a virtual course 107, respectively.

[0027] 1C and 1D are diagrams illustrating the operation of a wireless communication environment evaluation system that accurately predicts communication performance in a wireless communication environment including a moving object. Fig. 1C shows a real space 10, and Fig. 1D shows the state of a computer resource 100.

[0028] As shown in FIG. 1C, electromagnetic waves distributed and transmitted from measurement radio device 11b located on the left wall in real space 10 travel in multiple directions as wave packets. As indicated by the solid arrows, the wave packets that collide with floating movable body 6 are reflected by the floating movable body 6 and arrive at measurement radio device 11d as received waves. The wave packets that collide with grounded movable body 5 are reflected by the grounded movable body 5 and arrive at measurement radio device 11c as received waves. Each measurement radio device 11 reports the reception status of the arriving wave (e.g., reception strength and arrival direction) to central radio station 12 via wireless means (or wired means). Each measurement radio device 11 is equipped with an antenna with directivity in, for example, six orthogonal directions, and can measure the arrival direction and strength of the received radio wave based on each received signal.

[0029] As shown in Figure 1D, the central radio station 12 constructs a calculation model for electromagnetic field analysis that does not include floating movable bodies 6 and grounded movable bodies 5 in its computer resources 100 from the structural data of a virtual room 101, a virtual shelf 102, a virtual table 104, and a virtual container 103, and calculates rays (indicated by solid arrow A) corresponding to arriving waves in real space using electromagnetic field analysis using the ray tracing method.

[0030] Methods for creating calculation models for electromagnetic field analysis are known, and for example, structural data can be obtained from building design data and catalog specifications for fixtures present in the area. Alternatively, a point cloud measurement system using a measurement system that uses light waves such as visible light and infrared light called LIDAR (Light Detection and Ranging) can be used to obtain a set of three-dimensional coordinates (point cloud) of points that cause reflection, and structural data can be obtained from the point cloud.

[0031] A structural model for electromagnetic field calculation, represented by polygons created using point cloud data, is modified using physical quantities measurable within the service area (for example, reflectivity and absorption rate of radio waves), and a wireless communication environment in real space is reproduced (called an environment reproduction model). Because the strength and direction of radio waves emitted from measurement radio device 11 in real space are known, reproduction of the wireless communication environment is realized by ray tracing calculation, and the strength and direction of arrival of radio waves at any point can be estimated (for details of these technologies, see, for example, WO2012 / 172670 A1).

[0032] The central radio station 12 compares the information on the incoming waves obtained from the measurement radio device 11 with the ray calculation results in the computational resources, thereby identifying the location in the virtual room 101 where the transmitted waves from the measurement radio device 11b are reflected by ray tracing calculation. That is, the central radio station 12 compares the information on the incoming waves obtained from the measurement radio device 11 when the floating movable body 6 and the grounded movable body 5 are present (first information) with the information on the incoming waves obtained by the ray calculation in the computational resources when the floating movable body 6 and the grounded movable body 5 are not present (second information), and corrects the environment reproduction model so that the second information in the virtual space approaches the first information in the real space.

[0033] Here, the information on the arriving waves refers to, for example, the direction of arrival and strength of radio waves at multiple measurement points distributed in space, and in this embodiment, the direction of arrival and strength of radio waves that can be measured or estimated by the measurement wireless device 11 and the virtual measurement wireless device 111. In the example of Fig. 1D, an infinitesimal region 119 is added to the environment reproduction model so that the ray indicated by the solid arrow A estimated by the virtual measurement wireless device 111c and the virtual measurement wireless device 111d is changed to the ray indicated by the dotted arrow B measured in real space. The infinitesimal region 119 is, for example, a point or a surface with a finite area.

[0034] The simplest method for searching the above-mentioned infinitesimal region 119 is to set infinitesimal regions in various locations so as to cover the virtual space in the computer resource 100, and repeat ray tracing calculations to find the infinitesimal region 119 in which the second information is closest to the first information. Alternatively, if the movement paths of the floating movable body 6 and the grounded movable body 5 are determined in advance, the infinitesimal region may be set in a limited area around the path.

[0035] According to this embodiment, it is possible to identify the location where a movable object within a wireless communication service area scatters electromagnetic waves used for wireless communication. Therefore, it is possible to predict the location of the movable object within the service area, and it is possible to predict how the communication environment within the service area changes due to the presence of the movable object and how the communication quality changes as a result. Therefore, it is possible to grasp the dynamic communication performance of the wireless communication system, which is effective in controlling the wireless communication system to operate stably. [Example]

[0036] Another embodiment of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described with reference to FIGS. 2A and 2B.

[0037] In Example 2, based on Example 1, the position of a minute region on the surface of a moving object existing within a service area is identified by numerical calculation of the electromagnetic field. Using the arrival directions of multiple radio waves measured by multiple measurement radio devices and a calculation model for electromagnetic field analysis constructed within computer resources, the shape of the moving object is estimated by grouping multiple minute regions obtained from multiple calculated propagation trajectories.

[0038] Figure 2A is a diagram explaining a method for identifying multiple microscopic area positions within a computer resource 100 where the floating movable body 6 and the grounded movable body 5 reflect the transmitted wave from the measurement wireless device 11 using the direction of arrival of the wave measured by the measurement wireless device 11 in the real space 10.

[0039] FIG. 2B is a diagram for explaining a method for estimating the shapes of the floating movable body 6 and the grounded movable body 5 from a plurality of minute regions on the floating movable body 6 and the grounded movable body 5. In FIG.

[0040] In the real space corresponding to the computer resource 100 in FIG. 2A, similar to the first embodiment (FIG. 1C), the transmission wave from the measurement wireless device 11b is reflected by the floating movable body 6 and the grounded movable body 5 and arrives at the measurement wireless device 11d and the measurement wireless device 11c, respectively. The transmission wave from the measurement wireless device 11a is reflected by the grounded movable body 5 and arrives at the measurement wireless device 11d. The transmission wave from the measurement wireless device 11c is reflected by the grounded movable body 5 and arrives at the measurement wireless device 11a. The transmission wave from the measurement wireless device 11a is reflected by the floating movable body 6 and arrives at the measurement wireless device 11b. The transmission wave from the measurement wireless device 11d is reflected by the floating movable body 6 and arrives at the measurement wireless device 11b (see the ray indicated by the dotted arrow B).

[0041] As in Example 1, a minute region 119 is added to the environment reproduction model so that the ray indicated by the solid arrow A estimated by the virtual measurement radio device 111c and the virtual measurement radio device 111d is changed to the ray indicated by the dotted arrow B measured in the real space.

[0042] What is shown in the figure is an example of the reflection of the floating movable body 6 and the grounded movable body 5 to a specific wave packet of the transmitted wave from the measurement radio 11, and by performing a similar procedure on the reflection of the floating movable body 6 and the grounded movable body 5 to multiple (ideally all) wave packets of the transmitted wave from the measurement radio 11, multiple micro-regions 119 that contribute to the reflection of multiple wave packets of the transmitted wave from the measurement radio 11 can be obtained, as shown in Figure 2B.

[0043] Within the computer resources, the multiple infinitesimal regions 119 obtained in this way can be divided into groups of adjacent regions based on their relative positions. To do this, a threshold value can be set for the distance between the infinitesimal regions. Furthermore, by generating polygons with vertices at the centers of the multiple grouped infinitesimal regions and connecting adjacent polygons, virtual objects corresponding to the floating movable body 6 and the grounded movable body 5 can be generated within the computer resources.

[0044] In other words, by setting more micro-regions 119 than in Example 1 and connecting the micro-regions, the environmental reproduction model can be modified (specifically, by adding polygons and the physical quantities associated with them), and an environmental reproduction model including the virtual floating movable body 106 and the virtual grounded movable body 105 can be obtained.

[0045] 2A and 2B, multiple infinitesimal regions 119 in Fig. 2B are identified so that the ray indicated by the solid arrow A in Fig. 2A is changed to the ray indicated by the dotted arrow B, and the virtual floating movable body 106 and the virtual grounded movable body 105 (outline) are added by connecting the multiple infinitesimal regions. The more rays that are calculated, the more accurate the outline can be estimated.

[0046] According to this embodiment, movable bodies within a wireless communication service area can be reproduced within the computational resources, making it possible to predict how the communication environment within the service area will change and how the communication quality will change as a result, making it possible to grasp the dynamic communication performance of the wireless communication system, and providing an effect on control for stable operation of the wireless communication system. [Example]

[0047] Another embodiment of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described with reference to FIGS. 3A and 3B.

[0048] In addition to the configuration of Example 2, Example 3 estimates the movement trajectory of a movable body from information on the estimated shape and position of the movable body that changes over time. In Example 3, snapshots of the communication environment of the movable body that moves over time are constructed in a virtual space, and the trajectory of the movable body can be reproduced by linking these snapshots.

[0049] In Fig. 3A, the direction of arrival of the wave measured by the measurement radio 11 in the real space 10 is used to identify one or more positions of infinitesimal regions 119 in the computer resource 100 where the floating movable body 6 reflects the transmitted wave of the measurement radio 11. The shape of the floating movable body 6 is estimated in time series from the identified infinitesimal regions 119, and a virtual route 118 along which the floating movable body 6 changes its location is estimated. When there is only one infinitesimal region 119, the shape of the movable body cannot be estimated, but an approximate route can be estimated.

[0050] As in the second embodiment, a process is performed in which virtual floating movable bodies 106 corresponding to the floating movable bodies 6 are generated within the computer resources using the directions in which transmitted waves from multiple measurement wireless devices 11 are reflected by the floating movable bodies 6 and arrive as received waves at other measurement wireless devices 11. This process is repeated in time series to form a virtual floating movable body group 116 within the computer resources. The virtual floating movable body group 116 shown in Fig. 3A is composed of multiple virtual floating movable bodies 106 corresponding to the floating movable bodies 6 at different times.

[0051] The floating movable body 6 may be, for example, a remotely controlled drone, and its operation may be controlled by radio waves from an access point 9. When it is desired to ensure that radio waves from the access point 9 located in real space reach the floating movable body 6, whose position changes over time, stably, a virtual access point 109 corresponding to the access point 9 located in real space is set within the computer resources. A transmission wave is generated from the virtual access point 109 as multiple wave packets toward the virtual floating movable body group 116, and the path along which the wave packets reach the virtual floating movable body group 116 can be calculated.

[0052] Figure 3B is a diagram explaining a method for forming a virtual floating movable body group 116 according to the procedure of Figure 3A, and then changing the placement position of the virtual access point 109 within the virtual room 101 to determine a placement such that the transmitted wave from the virtual access point 109 reaches all of the virtual floating movable bodies 106 that make up the virtual floating movable body group 116.

[0053] In this example, in the computer resource 100 of Fig. 3A, it is found by ray tracing calculation that radio waves from the virtual access point 109 are blocked by the virtual table 104 for the virtual floating movable body 106X. Therefore, as shown in Fig. 3B, by performing ray tracing calculations with the position of the virtual access point 109 variously changed, it is possible to search for a position where radio waves from the virtual access point 109 can reach all of the virtual floating movable body group 116 including the virtual floating movable body 106X. If the route 8 is a fixed route, radio waves from the access point 9 placed in the real space corresponding to the virtual access point 109 can always reach the virtual floating movable body 106 stably.

[0054] According to this embodiment, it is possible to predict the optimal position of an access point 9 that can communicate with a mobile object within a wireless communication service area, which has the effect of realizing highly reliable and stable wireless communication with a mobile object located within the wireless communication service area. [Example]

[0055] Another embodiment of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a movable object will be described with reference to Figures 4A and 4B. In the third embodiment, the position of the access point 9 is changed to ensure communication with the movable object. In the fourth embodiment, the path of the movable object is changed instead of changing the position of the access point.

[0056] 4A shows a method for identifying, within computer resources, one or more infinitesimal regions where the floating movable body 6 reflects the transmitted waves from the measurement wireless device 11 using the direction of arrival waves measured by the measurement wireless device 11 in the real space 10, and estimating the route along which the floating movable body 6 will change its location from the results of time-series estimation of the shape of the floating movable body 6 from the multiple infinitesimal regions 119. This is a diagram explaining a method for extracting, by ray tracing calculation, places along the route where radio waves are difficult to reach, and generating a new route that avoids such places.

[0057] As in the third embodiment, the process of generating virtual floating movable bodies 106 corresponding to the floating movable bodies 6 at different times within the computer resources is repeated in time series using the directions in which transmitted waves from multiple measurement wireless devices 11 are reflected by the floating movable bodies 6 and arrive as received waves at other measurement wireless devices 11. A virtual floating movable body group 116 is formed within the computer resources from a collection of the virtual floating movable bodies 106. Trajectories of the virtual floating movable bodies that make up the obtained virtual floating movable body group 116 are generated, and portions of the trajectories that are difficult to reach with transmitted waves from any of multiple virtual access points 109 corresponding to multiple access points 9 in real space are found by ray tracing calculation. Then, those portions of the trajectories are replaced with locations that can be reached by transmitted waves from any of the virtual access points 109, and a new route along which the virtual floating movable body 106 may exist is generated.

[0058] In Fig. 4A, ray tracing calculations reveal that one of the virtual floating movable bodies 106 on the virtual route 118 is blocked by the virtual table 104, making it difficult for the transmitted waves from the virtual access point 109 to reach it. Therefore, the virtual route 118 is changed to a virtual detour route 120. To determine what virtual route to change to, multiple routes that can be traveled without being obstructed by fixed objects such as the virtual shelf 102, the virtual table 104, and the virtual container 103 can be assumed, and the radio wave conditions can be simulated.

[0059] Figure 4B is a diagram explaining a method for verifying, by ray tracing calculation, whether at least one (or all) of the virtual access points 109 installed in the virtual room 101 can communicate wirelessly with all the virtual floating movable bodies 106 in the group of virtual floating movable bodies when the virtual floating movable body 106 is on a newly generated route according to the procedure of Figure 4A, by changing the virtual route 118 to a virtual detour route 120.

[0060] According to this embodiment, the movement trajectory of a mobile object is estimated, and areas where communication is difficult along the estimated movement trajectory are identified. Then, by searching for a route that avoids the areas where communication is difficult, it is possible to find a route where the mobile object should be located, so that an access point 9 installed within a wireless communication service area can perform stable wireless communication with the mobile object. Therefore, it is possible to realize highly reliable and stable wireless communication with mobile objects located within the wireless communication service area. [Example]

[0061] Another example of a wireless communication environment evaluation system that accurately predicts communication performance in a wireless communication environment including a moving object will be described with reference to Figures 5A and 5B. In this example, radio waves from an access point 9 that is installed in real space and that communicates with a grounded moving object 5 or a floating moving object 6 are used to detect the position of the moving object.

[0062] FIG. 5A explains the operation of hardware placed in real space 10, and FIG. 5B explains a method for identifying a minute area on a movable body that scatters electromagnetic waves by electromagnetic field analysis within computer resources 100.

[0063] In Figure 5A, a real space 10 contains a room 1 consisting of a ceiling, walls, and floor, and a shelf 2, a container 3, and a table 4. Multiple measurement radio devices 11 are installed on the ceiling, walls, and floor of the room 1, and a central radio station 12 is installed on the floor. Inside the room 1, there are a floating movable body 6 that changes location in the air and a grounded movable body 5 that changes location on the floor, and they change location on a route 8 and a course 7, respectively. An access point 9 is installed inside the room 1, and the transmitted wave generated by the access point 9 is scattered by the floor, ceiling, and walls of the room 1, the shelf 2, the table 4, the container 3, the floating movable body 6, and the grounded movable body 5 to generate a reflected wave. The reflected wave reaches the multiple measurement radio devices 11 and is measured as a received wave, and the information is transmitted to the central radio station 12.

[0064] As in the previously described embodiments, the central radio station 12 estimates a virtual grounded movable body 105 or a virtual floating movable body 106 corresponding to the grounded movable body 5 or the floating movable body 6, or further estimates a virtual course 107 or a virtual route 108. In this embodiment, radio waves 500 from the access point 9 and rays 501 from the virtual access point 109 are also used in the estimation calculation.

[0065] 5B is a diagram illustrating the operation of the computer resource 100 of a wireless communication environment evaluation system that accurately predicts communication performance in a wireless communication environment including a moving object. Electromagnetic waves distributed and transmitted from a virtual access point 109 corresponding to access point 9 located on the left wall of FIG. 5A travel straight in multiple directions as a wave packet. The wave packet that collides with a virtual floating movable object 106 corresponding to the floating movable object 6 is reflected by the virtual floating movable object 106 and arrives at a virtual measurement wireless device 111d corresponding to the measurement wireless device 11d, where it becomes a received wave. The wave packet that collides with a virtual grounded movable object 105 corresponding to the grounded movable object 5 is reflected by the virtual grounded movable object 105 and arrives at a virtual measurement wireless device 111c corresponding to the measurement wireless device 11c, where it becomes a received wave.

[0066] The central radio station 12 constructs a calculation model for electromagnetic field analysis, including a virtual floating movable body 106 and a virtual grounded movable body 105, in its computer resources 100 from the structural data of a virtual room 101, a virtual shelf 102, a virtual table 104, and a virtual container 103, and can calculate rays corresponding to incoming waves in the real space 10 by electromagnetic field analysis using the ray tracing method, thereby simulating radio waves from the access point 9.

[0067] According to this embodiment, it is possible to identify the location where a mobile object within a wireless communication service area scatters electromagnetic waves used for wireless communication, also using radio waves from access point 9. This makes it possible to predict the location of a mobile object within the service area, and to predict how the presence of the mobile object will change the communication environment within the service area and how the communication quality will change as a result. This makes it possible to grasp the dynamic communication performance of the wireless communication system, which is effective in controlling the wireless communication system to operate stably. [Example]

[0068] Another embodiment of the wireless communication environment evaluation system for accurately predicting communication performance in a wireless communication environment including a mobile object will be described with reference to Figures 6A and 6B. In the sixth embodiment, a method for reducing the calculation load will be described.

[0069] 6A is a diagram illustrating the operation of hardware placed in real space 10. In real space 10, a transmitted wave from access point 9 travels in a straight line inside room 1 as a plurality of distributed wave packets 600, and is repeatedly reflected by the floor, ceiling, and walls of room 1, shelf 2, table 4, container 3, and grounded movable object 5.

[0070] The more rays corresponding to the wave packet 600 are reproduced and calculated in the virtual space, the more accurate the simulation becomes, but the calculation load naturally increases. Also, for example, when the grounded movable body 5 moves to the grounded movable body 5X, in order to track the moving movable object and estimate its position with high accuracy, it is necessary to perform ray tracing calculations repeatedly at short time intervals, which also increases the calculation load.

[0071] Figure 6B is a diagram illustrating a method for reducing the computational load by using ray tracing calculations to obtain rays corresponding to wave packets in real space arriving at a virtual grounded movable body 105 corresponding to the grounded movable body 5 in order to identify the location of the grounded movable body 5 within a wireless communication service area within the computing resources.

[0072] The rays in the computational resources 100 required to identify the location of the grounded moving body 5 in Fig. 6A are only rays that reach the virtual grounded moving body 105 in Fig. 6B. Since the location of the virtual grounded moving body 105 is continuous with the time-series location of the corresponding grounded moving body 5, it can be determined that the location of the virtual grounded moving body 105X at the next time of the virtual grounded moving body 105 is close to the previously estimated position.

[0073] In the ray tracing calculation performed in the computer resources, the rays distributed and emitted from the virtual access point 109 corresponding to the wave packet of the transmitted wave from the access point 9 in the real space are constant regardless of the location of the virtual ground movable body 105 or the virtual ground movable body 105X. Therefore, if an infinitesimal area that reflects on the virtual ground movable body 105 is identified in time series, it is possible to identify the infinitesimal area at the next time that reflects on the virtual ground movable body 115 using only the rays that arrive in the vicinity of the infinitesimal area at the next time. To do this, for example, it is sufficient to only target rays that pass within a predetermined range from the position coordinates of the infinitesimal area estimated last time.

[0074] In addition, if the virtual path 107 can be estimated, the minute area can be limited to coordinates along the virtual path 107, further reducing the amount of calculation required.

[0075] 6B is a diagram explaining a method for identifying minute regions that reflect on the virtual ground movable body in a time series manner using only rays that have the potential to reach the vicinity of the virtual ground movable body 115 among all rays generated by the virtual access point 109. Only the rays indicated by the thick arrow P need to be calculated, and calculations can be omitted for the rays indicated by the thin arrow N.

[0076] According to this embodiment, the number of steps required for electromagnetic field calculation using the ray tracing method to identify the presence of a moving object within a computer resource can be significantly reduced, thereby significantly reducing the time required to identify the position of a moving object present within a wireless communication service area and enabling real-time detection of a change in the position of a moving object within the service area.

[0077] Although the radio waves from the access point 9 have been described above, the radio waves from the measurement wireless device 11 can also be handled in the same manner. [Example]

[0078] An example of the configuration and operation of the measurement radio 11, which is a component of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, will be described.

[0079] 7 is an example of a circuit diagram of a measurement radio 11 used in a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object. The measurement radio 11 uses a changeover switch 39 to switch between a sine wave signal to be transmitted to other measurement radios 11 and a digital signal to be transmitted to the central wireless station 12. This measurement radio 11 uses a frequency different from the frequency used for wireless communication in the wireless communication service area.

[0080] A quadrature demodulator 31, to which a local signal ω1 is supplied by a local signal generator 32, is coupled to each of a plurality of receiving antennas 41 that receive sine wave signals from other measurement radio devices 11. The I / Q (In-Phase / Quadrature-Phase) outputs of the quadrature demodulator 31 are input to a central processing unit 34 via analog-to-digital converters 33, respectively.

[0081] The transmitting antenna 42 is connected to the transmitting mixer 36. The digital signal generated by the central processing unit 34 is input to the transmitting mixer 36 via the modulator 35. The transmitting mixer 36 switches between the measurement high-frequency signal generator 38 and the communication high-frequency signal generator 37 to generate a local signal using a changeover switch 39 operated by a control signal from the central processing unit 34, and up-converts the output signal of the modulator 35 before transmitting it from the transmitting antenna 42 to the central radio station 12.

[0082] During measurement, the transmitting mixer 36 transmits a sine wave signal from the measuring high frequency signal generator 38 from the transmitting antenna 42 by means of a changeover switch 39 which operates in response to a control signal from the central processing unit 34 .

[0083] The central processing unit 34 detects the relative phase difference in the high-frequency signal region of the signals received from the multiple receiving antennas 41 and measures the angle of arrival of the signal at the measurement radio device 11. The multiple receiving antennas 41 are required to have little spatial correlation, and it is desirable to arrange them uniformly in three dimensions at distances of at least half the wavelength of the high-frequency signal used for communication. The central processing unit 34 transmits the measured angle of arrival to the central radio station 12 via wireless communication using the high-frequency communication signal ω0.

[0084] During measurement, the measurement radio frequency signal ω1 is transmitted to generate an incoming wave that is received by the other measurement radio device 11.

[0085] According to this embodiment, the direction of arrival of electromagnetic waves present within a wireless communication area can be measured, and therefore, the hardware of the measurement wireless device of the wireless communication environment evaluation system of the embodiment can be realized. [Example]

[0086] An example of the configuration and operation of the central radio station 12, which is a component of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object, will be described.

[0087] FIG. 8 is an example of a block diagram of a central radio station 12 used in a radio communication environment evaluation system that predicts communication performance with high accuracy in a radio communication environment including a mobile object.

[0088] A receive mixer 51 is coupled to the receive antenna 43 and is supplied with a local signal ω0 by a local signal generator 52. The output of the receive mixer 51 is input to a central processing unit 54 via a demodulator 53.

[0089] The central processing unit 54 uses the received digital signals to perform numerical calculations to determine the individual phase differences of the multiple incoming waves arriving at the measurement radio. The incoming wave information from the measurement radio 11 obtained by the central processing unit 54 is transmitted to a computer resource unit 55. The computer resource unit 55 includes an incoming wave information storage module 56, an electromagnetic field calculation engine 57, and an electromagnetic field analysis model storage module 58.

[0090] The information on the incoming waves (direction and intensity) at each point in the real space obtained from the multiple measurement radio devices 11 reaches the central radio station 12 via wireless communication, where it is down-converted and demodulated. The demodulated information on the incoming waves is stored in the incoming wave information storage module 56 in the computer resource unit 55.

[0091] Information about structures not including movable bodies, which is necessary for electromagnetic field calculation within the wireless communication area, is stored in advance in the electromagnetic field analysis model storage module 58. The computer resource unit 55 uses the data in the arrival wave information storage module 56 and the electromagnetic field analysis model storage module 58 to perform the calculation shown in FIG. A ~ figure 6 B Electromagnetic field calculations are performed for each of the embodiments.

[0092] The central radio station 12 may be provided with an output device 81 and an input device 82 as a man-machine interface. The central processing unit 54, output device 81, input device 82, and computer resource unit 55 may be configured using a general computer. A general configuration such as a display can be used as the output device 81 and a keyboard can be used as the input device 82. The computer resource unit 55 can be realized by software, hardware, or a combination of these. In this embodiment, the computer resource unit 55 is configured by a storage device such as a hard disk or semiconductor memory.

[0093] The incoming wave information storage module 56 is a database containing data on the reception coordinates, intensity, and direction of incoming waves stored in a storage device.

[0094] The electromagnetic field calculation engine 57 is software (program) stored in a storage device, and ray tracing calculations and the like are executed by the central processing unit 54. The electromagnetic field calculation engine 57 may be dedicated hardware, and therefore the electromagnetic field calculation engine 57 may be the subject of the electromagnetic field calculation.

[0095] The electromagnetic field analysis model storage module 58 is a calculation model (environment reproduction model) stored in a storage device, and is either created by the electromagnetic field calculation engine 57 or created separately and stored in the storage device. The environment reproduction model is read and used when the electromagnetic field calculation engine 57 performs electromagnetic field calculation. In addition, the electromagnetic field calculation engine 57 modifies the calculation model to reflect information about movable objects in the real space.

[0096] According to this embodiment, the direction of arrival of electromagnetic waves present within a wireless communication area can be measured, so that the hardware of the central wireless station of the wireless communication environment evaluation system of the embodiment can be realized.

[0097] In the system of the embodiment, for example, a plurality of measurement radio devices 11 of the seventh embodiment are prepared, and one central radio station 12 of the eighth embodiment is prepared. Then, the measurement sine waves are simultaneously transmitted from the plurality of measurement radio devices 11, and simultaneously received by the plurality of measurement radio devices 11.

[0098] The geometric configuration of the measurement radio 11 may be, for example, a cube with a transmitting antenna 42 on one side and receiving antennas 41 for measuring incoming waves at the eight vertices of the cube, so that the receiving antennas 41 satisfy the condition of low spatial correlation mentioned above.

[0099] The measurement radio 11 simultaneously receives multiple signals with different phases obtained by multiple receiving antennas 41 at different locations in space. These signals are then compared with a signal of the same phase generated by the local signal generator 32 provided in the measurement radio 11. Specifically, the phase difference is detected from the change in amplitude of the signal obtained by multiplying the signal of the arriving wave by the signal of the oscillator (maximum amplitude results in the same phase, and zero amplitude results in a 90° phase difference). This allows the phase difference between each arriving wave to be detected.

[0100] Multiple signals (sine waves) with the same frequency but different phases arriving at multiple different locations simultaneously form a three-dimensional intensity distribution of the received signals in space called a "directional pattern." This distribution is specific to the phase deviation of the multiple arriving waves, and this directional pattern makes it possible to identify the direction of multiple radio waves arriving simultaneously. Incidentally, the technology that applies this principle to transmission is known as a beamforming antenna.

[0101] The directional pattern has a spatial distribution of peaks with maximum amplitude and nulls with minimum amplitude in polar coordinates, resembling an amoeba, with the maximum points coinciding with the direction of arrival of the electric field. The measurement radio 11 receives a mixture of multiple transmitted waves, but the above technology can identify rays that correspond to the arriving waves in real space.

[0102] However, instead of transmitting measurement sine waves simultaneously from multiple measurement radio devices 11 as described above, measurements may be performed by transmitting from only one measurement radio device 11 and repeating the transmission one by one. Although this requires measurement time, the receiver configuration and calculations are simplified because the rays to be tracked are independent one by one. [Example]

[0103] Another example of the configuration and operation of the measurement radio device 11, which is a component of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, will be described. The measurement radio device of this embodiment receives radio waves transmitted by the access point 9 and uses them for measurement.

[0104] FIG. 9 is another example of a circuit diagram of a measurement radio device 11-2 used in a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, and that is suitable for use in the fifth embodiment.

[0105] A carrier signal generator 45 outputs a local signal ω to a plurality of receiving antennas 41. C The quadrature demodulator 31 is coupled to the central radio station 12, and receives an I / Q signal from the quadrature demodulator 31. The I / Q outputs of the quadrature demodulator are input to the central processing unit 34 via an analog-to-digital converter 33. A transmitting antenna 42 is coupled to the transmitting mixer 36, and the digital signal generated by the central processing unit 34 is input to the transmitting mixer 36 via a modulator 35. The transmitting mixer up-converts the output signal of the modulator 35 using a communications high-frequency signal generator 37 as a local signal ω0, and transmits it from the transmitting antenna 42 to the central radio station 12.

[0106] This embodiment differs from the embodiment shown in FIG. 7 in that the signal received by the receiving antenna 41 of the measurement wireless device 11-2 is the communication radio wave transmitted by the access point 9.

[0107] According to this embodiment, the measurement radio device does not need to generate the measurement high-frequency signal ω1, which is effective in reducing the cost, size, and weight of the measurement radio device by simplifying the hardware configuration of the measurement radio device. [Example]

[0108] Another example of the configuration and operation of the central radio station 12, which is a component of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object, will be described.

[0109] Fig. 10 is an example of a circuit diagram of a central radio station 12-2 used in a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object. The difference from the central radio station 12 of the embodiment in Fig. 8 is that an incoming wave information storage module 56, an electromagnetic field calculation engine 57, and an electromagnetic field analysis model storage module 58 are arranged in a computer resource cloud 59 instead of the computer resource unit 55.

[0110] According to this embodiment, it is possible to develop a platform for a wireless communication environment evaluation system that uses the Internet environment to predict communication performance with high accuracy in a wireless communication environment including a mobile object. This has the effect of making the wireless communication environment evaluation system more versatile and reducing the size, weight, and cost of the hardware that constitutes the system. [Example]

[0111] An example of the operation flow of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0112] FIG. 11 corresponds to the second embodiment and is a diagram illustrating the flow of operations of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object.

[0113] First, structures within the wireless communication service area that do not include moving bodies (grounded moving bodies 5 and floating moving bodies 6) within the computer resources 100 are converted into structural data suitable for electromagnetic field calculations, and a static model is created for calculating the electric field of a communication environment that does not include moving bodies (S701).

[0114] Next, virtual measurement radios corresponding to the multiple measurement radios deployed in the real space are placed in the static model (S702). The static model created as described above is stored in the electromagnetic field analysis model storage module 58. The static model may be created by the electromagnetic field calculation engine 57, or may be created separately by another information processing device.

[0115] Next, the electromagnetic field calculation engine 57 uses the static model stored in the electromagnetic field analysis model storage module 58 and the placement information of the virtual measurement wireless device 111 to calculate within the computer resources rays corresponding to wave packets propagating within the wireless communication area (S703). Note that the creation of the static model and the ray tracing calculation may basically be performed using known techniques.

[0116] Next, the measurement radio 11 (or the access point 9) deployed in the real space transmits a measurement signal, and multiple measurement radios 11 deployed in the real space measure the direction of arrival of the received wave and obtain information about the arriving wave (S704). The arriving wave information is, for example, the direction of arrival of one or multiple arriving waves received by each measurement radio 11. The arriving wave information is output as a digital signal from the central processing unit 34 together with, for example, the identification information, location information, and measurement time of the measurement radio that received the arriving wave, and is modulated as described with reference to FIG. 7 etc. and transmitted from the measurement radio 11 to the central radio station 12. The central radio station 12 demodulates the information and stores it in the arriving wave information storage module 56.

[0117] The electromagnetic field calculation engine 57 compares the direction of the incoming wave obtained from the information of the measured incoming wave stored in the incoming wave information storage module 56 with the direction of arrival of the ray formed within the computer resources calculated by the electromagnetic field calculation engine 57 (S705).

[0118] The electromagnetic field calculation engine 57 determines for each ray in the computational resources whether or not the two match (S706). If a mismatch is detected (S706 yes), a ray is generated from the transmission wave generation point (virtual measurement wireless device 111 or virtual access point 109) in the computational resources. At the same time, a ray is generated from the virtual measurement wireless device 111 corresponding to the measurement wireless device 11 that measured the arrival wave direction that does not match the ray in the computational resources toward the arrival direction measured by the measurement wireless device 11 (S707).

[0119] The progress of each ray is calculated in order by ray tracing (S708), and the point where the two collide is searched for (709).

[0120] The above processing will be explained using the ray between the measurement wireless devices 11b and 11d in Figures 1C and 1D. For simplicity of explanation, it is assumed that the measurement signal is generated only from the measurement wireless device 11b. Since the direction and strength of the radio wave transmitted from the measurement wireless device 11b are known, it is possible to generate a ray A from the virtual measurement wireless device 111b to the virtual measurement wireless device 111d within the corresponding computer resources. Therefore, the arrival direction of the radio wave measured by the virtual measurement wireless device 111d is also determined from the ray A (see Figure 1D).

[0121] On the other hand, in the measurement wireless device 11d in the real space, the direction of arrival of the radio waves to be measured is determined by arrow K (see FIG. 1C). This direction of arrival does not match ray A in the computational resource 100. Ray B is generated from the virtual measurement wireless device 111d, which corresponds to the measurement wireless device 11d, in the direction of arrival of the radio waves in the real space (see FIG. 1D). The reason why the rays in the real space and the virtual space differ is the position where ray B collides with ray A in the computational resource. A minute region 119 is set at that position, assuming that a floating movable body 6 is located there (see FIG. 1D).

[0122] Furthermore, when the above processing is performed in a time series manner to track a moving object, the moving object can be tracked efficiently by limiting the search range of the minute area to the moving range of the moving object estimated from the speed of the moving object. To this end, the calculation target is limited to ray A passing through the above moving range, thereby enabling the moving object to be tracked efficiently.

[0123] The processes from S705 to S709 are repeatedly executed for all rays (S710), and after the process is completed for all rays (S710 yes), data on the collision points is accumulated to obtain point cloud data as a collection of minute areas that cause reflection of radio waves on the moving body (S711).

[0124] The obtained point cloud data can be used to obtain data on the virtual floating movable body 106 and the virtual grounded movable body 105. The electromagnetic field calculation engine 57 uses this data to modify the environment reproduction model (static model) in the electromagnetic field analysis model storage module 58, thereby obtaining an environment reproduction model including movable objects. Furthermore, by repeating this process in a time series and dynamically changing the environment reproduction model, a dynamic environment reproduction model (dynamic model) can be obtained.

[0125] According to this embodiment, the position and shape of a mobile object existing within a wireless communication service area are Special This has the effect of generating a point cloud within the computer resources for determining the location. [Example]

[0126] Another example of the operation flow of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0127] FIG. 12 corresponds to the fourth embodiment and is a diagram illustrating another operation flow of the wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object.

[0128] As in the eleventh embodiment, first, structures in a wireless communication service area that do not include moving objects within the computer resources are converted into structural data suitable for electromagnetic field calculations to create a static model for calculating the electric field of a communication environment that does not include moving objects (S701), and then virtual measurement wireless devices 111 corresponding to the multiple measurement wireless devices 11 deployed in real space are placed within the static model (S702).

[0129] Next, the electromagnetic field calculation engine 57 obtains point cloud data for identifying the position and shape of the movable body (S721) in the same procedure (S720) as in the embodiment of FIG. 11 (S703 to S710).

[0130] The above operations are repeated in time series, and the path along which the moving object exists is estimated from the obtained point cloud data (S722).

[0131] A ray is emitted from a transmission wave generation point set in the computer resources, for example, the virtual access point 109, and it is determined whether the ray reaches the obtained path. Then, parts of the path where the ray cannot reach and where wireless communication is difficult are extracted (S723).

[0132] A region where rays can reach and communication is possible in the vicinity of the extracted wireless communication difficult location is searched for by ray tracing calculation (S724).

[0133] Using the discovered communication area, a new route (virtual detour route 120) that bypasses the communication difficulty area is calculated by ray tracing (S725).

[0134] The newly obtained communication path is used to perform highly stable and reliable communication with a mobile object within the wireless communication service area (S726). For example, it becomes possible to control a mobile object, such as a robot, without interruption.

[0135] According to this embodiment, it is possible to realize highly reliable and stable communication with a mobile object existing within the wireless communication service area. [Example]

[0136] An example of a man-machine interface for a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0137] FIG. 13 is a diagram for explaining the man-machine interface of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, and shows elements displayed on an output device 81 such as a display.

[0138] The man-machine interface 800 of the wireless communication environment evaluation system suitable for application to Example 2 simultaneously displays a virtual room 801, a virtual shelf 802, a virtual table 804, and a virtual container 803, which are objects corresponding to non-movable static structures used to identify the position of movable bodies present within the wireless communication service area, as well as a virtual floating movable body group 806 and a virtual grounded movable body group 805 generated within the virtual room 101 and computer resources, and a central wireless station 812, if necessary.

[0139] According to this embodiment, the relative positional relationship between movable objects present within a wireless communication area and structures present within the same area becomes clear, which has the effect of facilitating wireless engineering, including the installation of access points, for building a highly stable and reliable wireless network. [Example]

[0140] Another example of a man-machine interface for a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0141] FIG. 14 is a diagram for explaining another man-machine interface of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, and shows elements displayed on an output device 81 such as a display.

[0142] The man-machine interface 800-2 of the wireless communication environment evaluation system, which is suitable for application to Example 3, etc., in addition to Example 13, uses the time-series existence information of each movable body included in the virtual floating movable body group 806 and the virtual grounded movable body group 805 to display the route 808 and course 807 on which the virtual floating movable body and the virtual grounded movable body exist.

[0143] According to this embodiment, the relative positional relationship between movable objects present within a wireless communication area and structures present within the same area becomes clear over time, which has the effect of facilitating wireless engineering, including the installation of access points, for dynamically building a highly stable and reliable wireless network. [Example]

[0144] Another example of a man-machine interface for a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0145] FIG. 15 is a diagram for explaining another man-machine interface of a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a moving object, and shows elements displayed on an output device 81 such as a display.

[0146] The man-machine interface 800-3 of the wireless communication environment evaluation system suitable for application to Example 3, etc., simultaneously displays a virtual room 801, a virtual shelf 802, a virtual table 804, and a virtual container 803 corresponding to non-movable static structures used to identify the position of movable objects present within the wireless communication service area, as well as a group of virtual floating movable objects 806 generated within the virtual room 101 and the computer resources.

[0147] Furthermore, by using the time-series presence information of the moving bodies included in the virtual floating moving body group 806, the position of the moving body at each time is interpolated or extrapolated if necessary to estimate and display the course 808 on which the virtual floating moving body exists. This can also be applied to the virtual grounded moving body group 805.

[0148] According to this embodiment, the relative positional relationship between moving objects present within a wireless communication area and structures present within the same area becomes clear in chronological order, which has the effect of facilitating wireless engineering, including the installation of access points, for dynamically constructing a highly reliable wireless network. [Example]

[0149] Another example of a man-machine interface for a wireless communication environment evaluation system that predicts communication performance with high accuracy in a wireless communication environment including a mobile object will be described.

[0150] FIG. 16 is a diagram for explaining another man-machine interface of the wireless communication environment evaluation system suitable for application to the fourth embodiment, and shows elements to be displayed on an output device 81 such as a display.

[0151] The man-machine interface 800-4 simultaneously displays a virtual room 101, a virtual shelf 102, a virtual table 104, and a virtual container 103, which correspond to non-movable static structures used to identify the position of movable objects within a wireless communication service area, as well as a group of virtual floating movable objects 806 generated within the virtual room 101 and computer resources.

[0152] Furthermore, by using time-series existence information of the movable bodies included in the virtual floating movable body group 806 and information on the area reached by rays emitted from the transmission point of the virtual access point 109 installed in the computer resource, the virtual floating movable body group 806 and the course 808 showing the existence positions of the floating movable bodies that can wirelessly communicate with the virtual access point 109 are estimated and displayed. The same can be applied to the virtual grounded movable body group 805.

[0153] According to this embodiment, the relative positional relationship between a moving object present within a wireless communication area and a structure present within the same area can be clarified in time series, which has the effect of facilitating wireless engineering, including the installation of access points, for building a dynamic, highly reliable, and highly stable wireless network that does not experience interruptions in wireless communication.

[0154] In the above embodiment, the floating movable body 6 is the main object of communication, but it goes without saying that the present invention can be similarly applied to the grounded movable body 5 and other movable objects.

[0155] According to the above embodiment, the communication quality within a service area providing wireless communication can be estimated by adding the structure of a movable body estimated using measured values ​​of the direction of arrival of electromagnetic waves in real space and the identified position of the movable body to the computational resources of an electromagnetic field calculation model for fixed structures constructed within the computational resources. Therefore, it is possible to accurately predict communication performance by reflecting the effects of all electromagnetic wave scatterers that affect wireless communication performance within a service area including the movable body through electromagnetic field calculation. Therefore, it is possible to determine the placement of transmitters and receivers to achieve highly stable and reliable wireless communication in a wireless communication environment including the movable body, which is effective in optimizing the communication performance of a wireless system.

[0156] Furthermore, since it is possible to simulate radio wave environments with high accuracy within computer resources, it is possible to reduce work in the real world, consume less energy, reduce carbon emissions, prevent global warming, and contribute to the realization of a sustainable society. [Explanation of symbols]

[0157] Room 1, shelf 2, container 3, table 4, grounded movable body 5, floating movable body 6, route 7, route 8, access point 9, real space 10, measurement radio 11, central radio station 12, computer resource unit 55, incoming wave information storage module 56, electromagnetic field calculation engine 57, electromagnetic field analysis model storage module 58, computer resource 100

Claims

1. An information processing device that is equipped with a central processing unit, an output device, an input device, and a storage device and is capable of providing computer resources is used, The information processing device includes: constructing a structural model of an electromagnetic wave scatterer within the computer resources, and calculating the characteristics of an electromagnetic field using the structural model and a ray simulating radio waves traveling in real space; obtaining position information regarding the position of the second object based on a result of the calculation using a first structural model corresponding to a real space including a first object but not a second object, and electromagnetic wave vector measurement data in the real space including the first object and the second object; Wireless communication environment evaluation method.

2. modifying the first structural model based on the position information to generate a second structural model including the first object and the second object; The method for evaluating a wireless communication environment according to claim 1.

3. the electromagnetic wave vector measurement data is a result of receiving, at a second position, a transmitted electromagnetic wave transmitted in a predetermined direction from a first position in a real space including the first object and the second object; a first step of generating a first ray simulating the transmitted electromagnetic wave transmitted from the first position in the predetermined direction to the second position using the first structural model; a second step of generating second rays from the electromagnetic wave vector measurement data using the first structural model; a third step of obtaining the position information based on the first ray and the second ray, generating a structural model of an electromagnetic wave scatterer corresponding to at least a part of a second object as an additional structural model based on the position information, and adding the additional structural model to a computer resource to generate the second structural model; The method for evaluating a wireless communication environment according to claim 2, wherein the method further comprises:

4. the additional structure model has as its component an area defined at a position where the first ray and the second ray collide; The method for evaluating a wireless communication environment according to claim 3.

5. estimating the shape of the second object by connecting the regions; The method for evaluating a wireless communication environment according to claim 4.

6. the first object is a stationary object whose position does not change over time, and the second object is a movable object whose position changes over time; The method for evaluating a wireless communication environment according to claim 3.

7. collecting the electromagnetic wave vector measurement data at a plurality of times, and generating a plurality of the additional structure models corresponding to the plurality of times by the first to third steps; performing a fourth step of estimating a path of the movable body based on a plurality of the additional structural models; The method for evaluating a wireless communication environment according to claim 6.

8. calculating electromagnetic field characteristics using the second structural model and rays simulating radio waves traveling from an access point placed in real space, and performing at least one of changing the position of the access point and changing the path so that radio waves from the access point reach the entire path of the movable body; The method for evaluating a wireless communication environment according to claim 7.

9. When the electromagnetic wave vector measurement data is collected at a first time and a second time, In the first step corresponding to the second time, only a ray passing within a predetermined range from the position of the first additional structure model generated corresponding to the first time is defined as the first ray; The method for evaluating a wireless communication environment according to claim 7.

10. The system includes an arrival wave information storage module that stores measurement data of the arrival direction of a received wave within a wireless communication service area, an electromagnetic field analysis model storage module that stores a structural model of an electromagnetic wave scatterer, and an electromagnetic field calculation engine that performs electromagnetic field calculations, the electromagnetic field calculation engine uses the measurement data and the structural model to estimate the position of a mobile object within the wireless communication service area by electromagnetic field calculation; Wireless communication environment evaluation system.

11. the measurement data includes directions of arrival of radio waves obtained by receiving radio waves transmitted from one or more transmitters present within the wireless communication service area by one or more receivers within the wireless communication service area, The wireless communication environment evaluation system according to claim 10.

12. the structural model is a structural model based on data of a structure that does not include the movable object and that exists within the wireless communication service area; The wireless communication environment evaluation system according to claim 11.

13. The measurement data is compared with a traveling trajectory of the radio waves calculated using a structural model based on data of a structure that does not include the movable body, and the position of the movable body is estimated using the arrival direction of the received wave and the traveling trajectory of the radio waves that are inconsistent with each other. The wireless communication environment evaluation system according to claim 12.

14. The transmitter uses radio waves of a frequency different from a frequency used for wireless communication in the wireless communication service area. The wireless communication environment evaluation system according to claim 11.

15. The transmitter uses radio waves of the same frequency as the frequency used for wireless communication in the wireless communication service area. The wireless communication environment evaluation system according to claim 11.

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