JP7699474B2 - Wireless communication characteristic prediction system and IoT wireless monitoring system - Google Patents

Description

The present invention relates to a wireless communication characteristic prediction system that analyzes the radio wave environment within a service area using structures that scatter radio waves.

Due to the worldwide spread of portable wireless information terminals, there is an increasing demand for wireless communication services such as wireless calls and wireless data transfers regardless of the surrounding environment. If there is a radio wave scatterer (structure) in a communication service area, the electromagnetic waves of the wireless communication medium are scattered by the scatterer, and the power of the electromagnetic waves emitted from the transmitter and reaching the receiver fluctuates, and in many cases the received power decreases, resulting in an area in which good quality wireless communication is difficult. Such weak electric field areas are generated by the arrangement relationship of the electromagnetic wave scatterers in the communication service area and the positional relationship of the wireless transmitter and receiver. Therefore, when forming a wireless communication network in a communication service area, it is important to predict the communication situation based on the arrangement of various transmitters and receivers. In order to know the communication situation in a specific transmitter and receiver arrangement in a communication service area, it is necessary to actually arrange the transmitter and receiver in the area and measure the received power at multiple points. However, since wireless communication is affected by radio wave scatterers around the transmitter and receiver, it is necessary to prohibit entry into the measurement area to minimize the fluctuating factors during measurement, and it is costly to secure personnel and time for measurement in the first place.

To solve this problem, a technology has been proposed that creates an electromagnetic field model in a computer to analyze wireless communication characteristics within a communication service area, and virtually realizes the electromagnetic field distribution in the location of transmitters and receivers within the communication service area.

The following prior art is included as background technology in this technical field. For example, Patent Document 1 (JP 2015-800616 A) describes a wireless network station design method in which a target area is photographed from multiple directions with a digital camera to generate image data. An image processing device extracts the characteristics of structures in the target area from the image data and shooting conditions to obtain structure characteristic data. An analytical numerical model creation device generates numerical model data from the structure characteristic data. A reception power analysis device performs electromagnetic field analysis on the numerical model data based on wireless device conditions, outputs the wireless device reception power as a calculation result, and a display displays this (see abstract).

Patent document 2 (JP Patent Publication 2010-74729A) describes a radio wave propagation characteristic estimation device that includes a ray launching method calculation unit 6 that uses planar data to calculate first radio wave propagation characteristic estimation data from the transmission point to the building where the reception point is located by the ray launching method, an imaging method calculation unit 7 that uses vertical cross-sectional data to calculate second radio wave propagation characteristic estimation data from the transmission point to the building where the reception point is located by the imaging method, and a synthesis unit 8 that calculates indoor penetration data up to the radio wave reception point inside the building for each of the first radio wave propagation characteristic estimation data and the second radio wave propagation characteristic estimation data, and synthesizes the indoor penetration data (see abstract).

In addition, in Patent Document 3 (JP Patent Publication 9-33584A), the start and end points of roads through which radio waves can pass, and information on the walls of buildings near the roads are stored as element information 60. Information on the positions of intersections through which radio waves can pass, the positions of roads relative to the intersections, and diffraction points caused by buildings near the intersections are stored as node information 50. A route of roads and intersections from a transmitting point to a receiving point is searched for using the start and end points stored as element information 60, and the positions of intersections and the positional relationship of roads to the intersections stored as node information 50. The element information of the roads included in the searched route and the node information of the intersections are used to configure the walls and diffraction points near the route. A field strength calculation device is described that uses the walls and diffraction points to ray trace radio waves from the transmitting point, and calculates the field strength by adding up the power of the rays that reach the receiving point (see abstract).

In addition, Patent Document 4 (JP Patent Publication 3-235013A) describes a scattering cross section calculation device that calculates the scattering cross section of a target, which includes a polyhedron approximation means that sets imaginary lines dividing the target into a number of individual pieces on the surface of the target, sets points on the circumference of the cross section of each individual piece when the target is divided by the imaginary lines at intervals of approximately the wavelength of the radio wave to be used, connects the points set on each individual piece with straight lines, forms a number of triangles for each of the surfaces of the target divided into each individual piece by the imaginary lines, forms a number of triangles on the surface of the target, and approximates the target with a polyhedron; and A scattering cross section calculation device is described that includes an edge search means for searching for edges, a unit vector calculation means for calculating a unit vector that is equal in angle with the incident direction and the observation direction that exist in each of the two faces that share the edge searched by the edge search means, an equivalent wave source calculation means for calculating an equivalent wave source having the direction of the unit vector to be hypothesized on each edge, a diffraction wave calculation means for calculating a diffracted wave emitted from the equivalent wave source in the observation direction, and a scattering cross section calculation means for calculating a scattering cross section from the sum of the diffracted waves (see claim 1).

JP 2015-800616 A JP 2010-74729 A Japanese Patent Application Publication No. 9-33584 Japanese Patent Application Publication No. 3-235013

The above-mentioned prior art reproduces the distribution of radio wave scatterers in a communication service area on computer resources using the actual measured values of the exact physical dimensions of the radio wave scatterers and the specifications of the radio wave scatterers, determines the electrical characteristics of the reproduced electromagnetic wave scatterers, and estimates the electromagnetic field distribution in the communication service area by ray tracing calculations in which the electromagnetic waves used for communication are rays that approximate light rays, using the electromagnetic wave scatterers virtually constructed on the computer resources as the subject of electromagnetic field calculations. This prior art method has the problem that it requires a huge amount of work to reproduce the distribution of electromagnetic wave scatterers with accurate physical dimensions on computer resources, and that in the ray tracing calculation, a separate calculation process that requires more computer resources is required to calculate the electromagnetic wave distribution in areas where rays are blocked by electromagnetic wave scatterers, compared to the calculation process for areas where rays are not blocked.

A representative example of the invention disclosed in the present application is as follows: That is, a wireless communication characteristic prediction system includes a model generation device, an electromagnetic field calculation device, and an output device , the model generation device calculates dimensional information of a structure from point cloud data representing the position of a surface of the structure within a communication service provision area and the wavelength of radio waves used for communication, the electromagnetic field calculation device has an arithmetic unit that executes predetermined processing and a storage device accessible by the arithmetic unit, and estimates an electromagnetic field distribution by repeatedly executing a ray tracing calculation, changes the generation state of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation using the position data of the structure and the calculated dimensional information of the structure, transmits the estimated electromagnetic field distribution to the output device, and the output device outputs the estimated electromagnetic field distribution.

According to one aspect of the present invention, the amount of work required to estimate the electromagnetic field strength within a communication service area can be reduced. Problems, configurations, and effects other than those described above will be made clear through the description of the following examples.

FIG. 1 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a first embodiment. FIG. 11 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a second embodiment. FIG. 11 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a third embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a fourth embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a fifth embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a sixth embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a seventh embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to an eighth embodiment. FIG. 13 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a ninth embodiment. FIG. 16 is a diagram illustrating a configuration of a wireless communication characteristic prediction system according to a tenth embodiment. 3A to 3C are diagrams illustrating data structures of various tables used by the wireless communication characteristic prediction system of the first embodiment. FIG. 2 is a diagram illustrating an operation flow of the wireless communication characteristic prediction system according to the first embodiment. FIG. 2 is a diagram illustrating an operation flow of the wireless communication characteristic prediction system according to the first embodiment. FIG. 2 is a diagram illustrating an operation flow of the wireless communication characteristic prediction system according to the first embodiment. 1A to 1C are diagrams illustrating radiation of diffracted waves and scattered waves other than reflected waves in the first embodiment. 1A to 1C are diagrams illustrating radiation of diffracted waves and scattered waves other than reflected waves in the first embodiment. 10A to 10C are diagrams illustrating an example of a process for creating a polygon group from point cloud data according to the first embodiment. 10A to 10C are diagrams illustrating an example of a process for creating a polygon group from point cloud data according to the first embodiment. 10A to 10C are diagrams illustrating an example of a process for creating a polygon group from point cloud data according to the first embodiment. 10A to 10C are diagrams illustrating an example of a process for creating a polygon group from point cloud data according to the first embodiment. FIG. 1 is a diagram showing an example of engineering using an IoT wireless monitoring system that uses the wireless communication characteristic prediction system of the present invention. FIG. 11 is a diagram showing another example of engineering by an IoT wireless monitoring system using the wireless communication characteristic prediction system of the present invention.

The following describes the examples with reference to the drawings.

Example 1
An example of a wireless communication characteristic prediction system according to an embodiment of the present invention will be described with reference to Fig. 1 and Fig. 11 to Fig. 20. The wireless communication characteristic prediction system according to the embodiment reduces the realization cost of a wireless system that provides a communication service.

Figure 1 shows the configuration of a wireless communication characteristic prediction system 101 of the first embodiment, Figure 11 shows the data structures of various tables used by the wireless communication characteristic prediction system, Figures 12 to 14 show the operation flow of the wireless communication characteristic prediction system, Figures 15 and 16 show the radiation of diffracted waves and scattered waves other than reflected waves, and Figures 17 to 20 show an example of the process of creating polygon groups from point cloud data.

The wireless communication characteristic prediction system 100 shown in FIG. 1 is composed of a measurement radio 1, a communication radio 4, a calculation model generation device 110 that receives data from each of the measurement radio 1 and the communication radio 4, a structure data storage device 140 that transfers data to and from the calculation model generation device 110, an electromagnetic field calculation device 150 that receives data from the structure data storage device 140, and a display device 180 that receives data from the electromagnetic field calculation device 150.

The measurement radio 1 is a distance measuring device having a measurement high-frequency signal source 2 and a measurement antenna 3, and transmits and receives high-frequency electromagnetic waves generated by the measurement high-frequency signal source 2 from the measurement antenna 3. The distance from the measurement radio 1 to each point on the surface of an electromagnetic wave scatterer present within the communication service area and the direction from the measurement radio 1 to each point are converted into vector data, and information regarding the measurement location within the communication service area is added, and the data is sent to the calculation model generating device 110.

The communication radio 4 has a communication high-frequency signal source 5 and a communication antenna 6, transmits and receives high-frequency electromagnetic waves generated by the communication high-frequency signal source 5 from the communication antenna 6, and adds spatial coordinates of a measurement location within the communication service area to information about the received electromagnetic waves, and sends the information to the calculation model generation device 110. If the frequency of the radio waves used by the communication radio 4 for communication is set to be less than one-quarter (preferably less than one-tenth) of the frequency of the radio waves used by the measurement radio 1 for measurement, the detailed shape of electromagnetic wave scatterers within the communication service area can be obtained, and the calculation accuracy of the electromagnetic field distribution can be improved.

The calculation model generating device 110 stores the data received from the measurement radio 1 and the communication radio 4 in the point cloud storage circuit 111. The point cloud coordinate generating circuit 112 calculates the coordinates of a plurality of points on the electromagnetic wave scatterer measured using the data related to the electromagnetic wave scatterer stored in the point cloud storage circuit 111. The point cloud filter circuit 113 uses the coordinates calculated by the point cloud coordinate generating circuit 112 to determine an isolated point from all points and deletes the data related to the determined point. The polygon generating circuit 114 generates polygons, which are polygonal elements, using the data related to the points determined by the point cloud filter circuit 113. The polygon group forming circuit 115 classifies the plurality of polygons generated by the polygon generating circuit 114 into a plurality of polygon groups using the positional relationship with adjacent polygons. The adjacent polygon connection state data generating circuit 116 calculates the connection relationship of each polygon group generated by the polygon group forming circuit 115 using the connection relationship with adjacent polygons. The polygon attribute determination circuit 117 uses the connection relationship between the polygon groups calculated by the adjacent polygon joint state data generation circuit 116 and the communication wavelengths of the communication wavelength data 143 stored in the structure data storage device 140 to add attributes to each polygon in the polygon group, and sends point cloud data on the determined multiple points, data on the polygon group, information on the electromagnetic field of the measurement location to which the spatial coordinates of the measurement location within the communication service provision area have been added, and polygon data to which the attributes have been added to the structure data storage device 140.

In the structure data storage device 140, the point cloud table 141 stores point cloud data on the determined points sent by the calculation model generation device 110. The communication area data 142 stores data on polygon groups and information on the electromagnetic field of the measurement location to which spatial coordinates of the measurement location within the communication service area are added. The contents stored in the communication area data 142 are output to the communication area storage circuit 160 of the electromagnetic field calculation device 150. The communication wavelength data 143 stores the wavelength used for wireless communication. The polygon table 144 stores data on polygons to which attributes are added. The electrical characteristic table 145 stores information on electrical constants such as dielectric constant, magnetic permeability, and conductivity. The data stored in the polygon table 144 is added with information on the electrical constants stored in the electrical characteristic table 145, and is output to the polygon table storage circuit 161 of the electromagnetic field calculation device 150. As shown in FIG. 11, the data structures of the point cloud table 141, communication area data 142, and polygon table 144 are arrays of spatial coordinates.

In the electromagnetic field calculation device 150, the iteration condition setting circuit 151 sets the iteration condition that controls the number of times rays are emitted. The transmission point generation circuit 152 generates a transmission point within the communication service provision area using the contents of the communication area storage circuit 160. The reception point generation circuit 153 generates multiple reception points within the communication service provision area using the contents of the communication area storage circuit 160. The ray emission circuit 154 uses information on the transmission point generated by the transmission point generation circuit 152 and the reception point generated by the reception point generation circuit 153 to generate multiple rays in different directions from the transmission point according to the contents of the iteration condition setting circuit 151 that the electromagnetic field calculation device 150 has in advance. The receiver arrival power integration circuit 155 uses the contents of the communication area storage circuit 160 to determine whether the ray generated by the ray emission circuit 154 passes through a predetermined finite area around the reception point, and if it does pass, integrates the energy of the ray at the point where the ray collides with the finite area taking into account the phase, and sets the ray arrival flag for the reception point. A ray/polygon collision determination circuit 156 determines whether or not the ray generated by the ray emission circuit 154 collides with each polygon present within the communication service area by using the contents of the polygon table storage circuit 161. A re-emission ray selection circuit 157 compares the polygon information from the ray/polygon collision determination circuit 156 with the contents of the polygon table storage circuit 161 to select the type of ray to be re-emitted. A re-emission ray generation circuit 158 re-emissions rays by using the information of the re-emission ray selection circuit 157. An iteration condition determination circuit 159 monitors the number of re-generations of the re-emission ray generation circuit 158, and continues the operation of the ray emission circuit 154 if the number of re-generations is within the number of times predetermined by the iteration condition setting circuit 151, and ends the operation of the ray emission circuit 154 if the number of re-generations exceeds the number of times. The electromagnetic field calculation device 150 then transmits to the display device 180 the results of integration taking into account the contents of the communication area storage circuit 160, the contents of the polygon table storage circuit 161, information on all rays generated by the ray emission circuit 154, and the energy and phase of the rays at the points of collision with each finite area of the receiver arrival power integration circuit 155.

The aforementioned computational model generating device 110, structural data storage device 140, and electromagnetic field calculation device 150 are configured by a computer having a processor (CPU), memory, auxiliary storage device, and a communication interface.

The processor is a computing device that executes programs stored in memory. The processor executes various programs to realize the functions of each device. Note that some of the processing performed by the processor by executing the programs may be executed by another computing device (e.g., hardware such as an ASIC or FPGA).

Memory includes ROM, which is a non-volatile storage element, and RAM, which is a volatile storage element. ROM stores unchanging programs (e.g., BIOS), etc. RAM is a high-speed, volatile storage element such as DRAM (Dynamic Random Access Memory), and temporarily stores programs executed by the processor and data used when executing the programs.

The auxiliary storage device is, for example, a large-capacity, non-volatile storage device such as a magnetic storage device (HDD) or a flash memory (SSD). The auxiliary storage device also stores data used by the processor when it executes a program, and the program executed by the processor. In other words, the program is read from the auxiliary storage device, loaded into memory, and executed by the processor to realize the functions of each device.

A communication interface is a network interface device that controls communications with other devices according to a specific protocol.

The computer may have an input interface and an output interface. The input interface is an interface to which input devices such as a keyboard or mouse are connected and which receives input from a user. The output interface is an interface to which output devices such as a display device 180 (described below) or a printer are connected and which outputs the results of program execution in a format that can be viewed by the user.

The programs executed by the processor are provided to each device via removable media (CD-ROM, flash memory, etc.) or a network, and are stored in a non-volatile auxiliary storage device, which is a non-transitory storage medium. For this reason, the computer should have an interface for reading data from removable media.

Each device is a computer system that is configured on one physical computer, or on multiple computers that are configured logically or physically, and may operate on a virtual computer constructed on multiple physical computer resources. The functional parts of each device may operate on separate physical or logical computers, or multiple devices may be combined to operate on a single physical or logical computer.

The display device 180 has a structure display circuit 181, a ray display circuit 182, an electromagnetic field display circuit 183, and a polygon display circuit 184. The structure display circuit 181 displays the contents stored in the communication area memory circuit 160 input from the electromagnetic field calculation device 150 on a display. The ray display circuit 182 displays information about all rays generated by the ray emission circuit 154. The electromagnetic field display circuit 183 displays the results of integrating the energy of rays at the points of collision with each finite area of the receiver arrival power integration circuit 155, taking into account the phase. The polygon display circuit 184 displays the contents of the polygon table memory circuit 161.

The display device 180 may be a terminal connected to the electromagnetic field calculation device 150 via a network. In this case, the electromagnetic field calculation device 150 has a web server function, the display device 180 accesses the electromagnetic field calculation device 150 using a predetermined protocol (e.g., http), and the web browser of the display device 180 realizes the display function. The display device 180 may also execute a dedicated application to realize the display function. In addition to or instead of the display device 180, an interface may be provided that outputs the wireless communication characteristic prediction results to another computer system. In this way, various forms can be adopted for the output device that outputs the wireless communication characteristic prediction results.

Figure 12 is a flowchart of an example of a computation model generation process executed by the computation model generation device 110.

After giving spatial coordinates to points representing each point on the surface of an electromagnetic wave scatterer within the communication service area, the maximum value l _max and minimum value l _min of the inter-point distance are set as thresholds (200), a first wavelength for calculating the electromagnetic wave characteristics of the electromagnetic wave scatterer and a second wavelength of the electromagnetic wave used for communication are set (201), the resolution of the spatial coordinates of the points is reset with the first wavelength shorter than the second wavelength, and the distance between the two closest points in the point cloud having the reset spatial coordinates is calculated (203). If the distance between the two points is smaller than the set minimum value l _min of the inter-point distance (no in 204), these two points are replaced with a single point having intermediate coordinates between both points (205). Then, the points in the point cloud are transformed so that all inter-point distances in the point cloud are equal to or greater than the minimum value, a triangular polygon is generated from the three closest points d1, d2, d3 of the transformed point cloud (206), and when adjacent polygons are considered to exist consecutively on the same plane within a predetermined error range using the positional relationship information and connection relationship information of the generated polygons, the polygons are grouped into the same group (207). The multiple polygon groups formed after grouping are classified (208), and the same electrical characteristics are given to the polygons belonging to each group, thus terminating the computational model generation process (209).

Figure 13 is a flowchart of an example of polygon group generation process 206 in the process of Figure 12.

A threshold value for the external dimensions of a polygon group consisting of a plurality of continuous polygons, a threshold value L for the connection angle permitted for adjacent polygons in the polygon group, and a threshold value δ for the curvature are set (210, 211). A central polygon _P0 is selected from all polygons (212), and up to three polygons _P1 , _P2 , and _P3 adjacent to the central polygon _P0 are extracted (213). Connection angles _q1 , _q2 , and _q3 between the central polygon P0 and a maximum of _three adjacent polygons are calculated (214), and if the connection angles _q1 , _q2 , and _q3 are smaller than the threshold value δ (yes in 216), these four polygons are grouped together (217). If the external shape G _i of the polygon group formed is larger than the threshold value L (yes in 218), this group is classified into a polygon group G ^R that generates a reflected wave (219). After the above process is completed for all polygons (yes in 220), one polygon is selected as a new center polygon _P0 from among all polygons (221), and polygons _P1 , _P2 , and _P3 adjacent to the center polygon are extracted (222). If the center polygon and adjacent polygons belong to the same group (yes in 223), these groups are classified into a polygon group G ^R that generates reflected waves (225). If the center polygon and adjacent polygons belong to different groups and both groups are not polygon groups that form reflected waves (no in 223, no in 224), these groups are classified into a polygon group G ^S that generates scattered waves (226). If the center polygon and adjacent polygons belong to different groups and only one group is not a polygon group that forms reflected waves (no in 223, yes in 225), these groups are classified into a polygon group G ^D that generates diffracted waves (227). After the processing relating to the classification of polygon groups has been completed for all polygons (yes in 223), electrical characteristics are given to each polygon (229), and the polygon group generation processing is completed.

Figure 14 is a flowchart of an example of the electromagnetic field calculation process performed by the electromagnetic field calculation device.

The thresholds l _min and l _max of the maximum propagation path of the ray used in the ray tracing calculation are set (230). A transmitting point and a receiving point are set within the communication service area (231), and a ray accumulation space is set around the receiving point (232). The maximum recurrence value N _max of the ray in the ray tracing calculation is set (233). Rays are emitted in all directions three-dimensionally with a set resolution from the transmitting point (234). Polygons that collide with each ray emitted from the transmitting point are searched for (235), and rays of reflected waves are generated from the searched polygons and re-emitted (236).

If the searched polygon belongs to a polygon group that generates diffracted waves (yes in 237), a ray of diffracted waves is generated from the polygon and re-radiated (238). As an example of the radiation direction of the diffracted waves, as shown in FIG. 15, the side corresponding to the outer shape of the polygon that forms the outer shape of each polygon group is taken as an edge line, and the re-radiation direction of the ray of the diffracted waves is determined so as to be linearly symmetrical with respect to the ray that collides with the polygon and the vector that is perpendicular to the edge line, which bisects the connection angle of two polygons that belong to other adjacent polygon groups that share the same edge line, in a virtual plane formed by the ray that collides with the polygon.

If the searched polygon belongs to a polygon group that generates scattered waves (yes in 239), a ray of scattered waves is generated from the polygon and re-radiated (240). As an example of the radiation direction of the scattered waves, as shown in FIG. 16, the side corresponding to the outer shape of the polygon forming the outer shape of each polygon group is set as an edge line, which bisects the connection angle of two polygons belonging to other adjacent polygon groups that share the same edge line, and the re-radiation direction of the scattered wave ray is determined so that it is in the opposite direction to the ray that collides in the virtual plane formed by the ray that collides with the polygon and the vector that is perpendicular to the edge line. Therefore, unlike the ray of the diffracted wave, the ray of the scattered wave has a degree of freedom in the re-radiation direction, and as an example, multiple rays may be re-radiated at regular intervals. In addition, the re-radiation of the ray of the scattered wave that has been re-radiated multiple times may be canceled depending on the situation in which the ray collides with the polygon again. The number of re-radiations of the ray is monitored, and if the number of re-radiations exceeds a threshold, the emission of the ray is terminated (no in 241). For all rays formed within the communication service area, the power of all rays that have passed through one of the ray accumulation spaces is added up, taking into account the phase (242).

Figures 17 to 20 show the process in which multiple polygons are generated from a large number of points on the surfaces of multiple electromagnetic wave scatterers present within a communication service area, and these multiple polygons are classified into various polygon groups with different attributes. A point cloud as shown in Figure 18 can be obtained for objects located in the communication service area, which is the space for calculating electromagnetic field characteristics as shown in Figure 17. The polygons shown in Figure 19 are generated using the obtained point cloud, and the generated polygons are classified to form attribute groups as shown in Figure 20.

According to this embodiment, the spatial coordinates of each point on the surface of an electromagnetic wave scatterer within a communication service area are obtained by measurement using electromagnetic waves with a frequency higher than the communication frequency, and the obtained spatial coordinates are used to perform ray tracing calculations of the electromagnetic field distribution within the communication service area on computer resources. In addition, since the ray tracing calculations can be performed simply by verifying the collision of a ray with a polygon that models the electromagnetic wave scatterer and re-emitting the ray at the time of collision, it is possible to quickly construct a model for calculating the electromagnetic field distribution within the communication service area and perform electromagnetic field calculations using the constructed model. In addition, the labor and time required to construct a wireless communication system within a communication service area can be reduced, and the cost required to construct a wireless communication system can be reduced.

Example 2
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 2. Example 2 differs from Example 1 in that an electromagnetic field calculation device 170 having a reflected ray generation circuit 162, a secondary ray determination circuit 163, and a secondary ray generation circuit 164 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 2, differences from Example 1 will be mainly described, and the same components as those in Example 1 will be assigned the same reference numerals and their description will be omitted.

Figure 2 is a diagram showing the configuration of a wireless communication characteristic prediction system 101 according to the second embodiment.

In the electromagnetic field calculation device 170 of this embodiment, the ray/polygon collision judgment circuit 156 judges whether the ray generated by the ray emission circuit 154 collides with a polygon in the communication service area by referring to the polygon table storage circuit 161. The reflected ray generation circuit 162 generates reflected waves that are re-radiated from all polygons with which the ray collides. The secondary ray judgment circuit 163 uses the information of the polygon table storage circuit 161 to judge whether the polygon with which the ray collides re-radiates a secondary ray of a diffracted wave or scattered wave different from the reflection. The secondary ray generation circuit 164 generates a secondary ray that is re-radiated from the polygon based on the judgment result of the secondary ray judgment circuit 163. The reflected wave generated by the ray being reflected by the polygon reflects the macro characteristics of the structure, while the diffracted wave generated by the ray going around the polygon at the corner of the structure and the scattered wave generated by the ray being scattered by the polygon reflect the micro characteristics of the structure. The secondary ray generating circuit 164 of the second embodiment generates secondary rays by taking into account both the microscopic and macroscopic characteristics of such structures. Therefore, the electromagnetic field characteristics can be calculated accurately regardless of the size of the structure or the range to which the structure is irradiated with radio waves (i.e., whether the entire structure is irradiated with radio waves or only a portion of it).

The repetition condition judgment circuit 159 monitors the number of times rays are regenerated by the re-radiation ray generation circuit 158, and if the number of regenerations is within a predetermined number, it continues the operation of the ray emission circuit 154, and if the number of regenerations exceeds the predetermined number, it ends the operation of the ray emission circuit 154. Then, the electromagnetic field calculation device 170 sends to the display device 180 the results of integration taking into account the contents of the communication area storage circuit 160, the contents of the polygon table storage circuit 161, information on all rays generated by the ray emission circuit 154, and the energy and phase of the rays at the points of collision with each finite area of the receiver arrival power integration circuit 155.

According to this embodiment, in the process of re-emitting a ray from a polygon with which the ray has collided, the generation of reflected waves, diffracted waves, and scattered waves is realized by different elements, so that the calculation of the generation of reflected waves, which can be accelerated in ray tracing calculations, can be executed by a dedicated routine, and the electromagnetic field analysis by ray tracing calculations can be accelerated. As a result, the labor and time required to build a wireless communication system within a communication service provision area can be reduced, and the cost required to build a wireless communication system can be reduced.

Example 3
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 3. The third embodiment differs from the second embodiment in that an electromagnetic field calculation device 171 further having a secondary ray tentative generation circuit 176 and a second ray/polygon collision determination circuit 177 is used instead of the electromagnetic field calculation device 170 of the second embodiment. In the third embodiment, differences from the second embodiment will be mainly described, and the same components as those of the second embodiment will be denoted by the same reference numerals and their description will be omitted.

Figure 3 is a diagram showing the configuration of a wireless communication characteristic prediction system 102 in Example 3.

In the electromagnetic field calculation device 171 of this embodiment, the secondary ray judgment circuit 163 uses the information of the polygon table storage circuit 161 to judge whether the polygon with which the ray collided re-radiates a secondary ray different from the reflection. The secondary ray provisional generation circuit 176 generates a secondary ray provisionally emitted from the polygon based on the judgment result of the secondary ray judgment circuit 163. The second ray/polygon collision judgment circuit 177 uses the information of the polygon table storage circuit 161 to judge which polygon group the provisionally emitted ray will collide with. The secondary ray generation circuit 164 re-radiates a secondary ray from the polygon based on the judgment result of the second ray/polygon collision judgment circuit 177 if the provisionally emitted ray does not collide with a polygon of the polygon group that generates a secondary ray again. The repetition condition judgment circuit 159 monitors the number of regenerations of the re-radiation ray generation circuit 158, and if the number of regenerations is within a predetermined number, it continues the operation of the ray emission circuit 154, and if the number of regenerations exceeds the predetermined number, it ends the operation of the ray emission circuit 154. The number of regenerations may be set to a different upper limit depending on the cause of the generation of the secondary ray. For example, since reflected waves are stronger than diffracted waves and scattered waves, it is advisable to increase the upper limit. Then, the electromagnetic field calculation device 171 transmits to the display device 180 the results of integration taking into account the contents of the communication area storage circuit 160, the contents of the polygon table storage circuit 161, information on all rays generated by the ray emission circuit 154, and the energy and phase of the rays at the points of collision with each finite area of the receiver arrival power integration circuit 155.

According to this embodiment, in order to prohibit secondary rays that are not reflected waves from re-radiating secondary rays again, it is possible to omit processing of rays that are even weaker due to reflected waves with an order of magnitude weaker intensity for reflected waves whose influence can be ignored in the electromagnetic field calculation results, thereby speeding up electromagnetic field analysis using ray tracing calculations. As a result, it is possible to reduce the labor and time required to build a wireless communication system within a communication service provision area, and to reduce the cost required to build a wireless communication system.

Example 4
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 4. Example 4 differs from Example 1 in that a camera 8 is used as a distance measuring device instead of the measurement wireless device 1, and an image data conversion device 7 is provided that acquires image data from the camera 8. In Example 4, differences from Example 1 will be mainly described, and the same components as those in Example 1 will be assigned the same reference numerals, and descriptions thereof will be omitted.

Figure 4 is a diagram showing the configuration of a wireless communication characteristic prediction system 103 in Example 4.

The video data conversion device 7 uses image diagnosis technology to calculate the coordinates of each point on the surface of the electromagnetic wave scatterer within the communication service area from the video data acquired by the camera 8, and outputs the calculation results to the computational model generation device 110.

According to this embodiment, the electromagnetic waves emitted by this system to obtain the data required by the computational model generating device 110 are only emitted by the communication radio 4, and the amount of electromagnetic waves emitted by this system can be reduced compared to the embodiment of Figure 1, thereby reducing the electromagnetic interference caused by this system to other systems.

Example 5
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 5. Example 5 differs from Example 1 in that a computation model generating device 130 having a polygon combining circuit 118 is used instead of the computation model generating device 110. In Example 5, differences from Example 1 will be mainly described, and the same components as those in Example 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

Figure 5 is a diagram showing the configuration of a wireless communication characteristic prediction system 104 in Example 5.

In the computational model generating device 130 of this embodiment, the polygon group forming circuit 115 classifies the multiple polygons generated by the polygon generating circuit 114 into multiple polygon groups using the positional relationship with adjacent polygons. The polygon combining circuit 118 replaces multiple adjacent polygons for each of the multiple polygon groups by grouping them into one polygon using the positional relationship with adjacent polygons of the multiple polygons generated by the polygon generating circuit 114. The polygon combining circuit 118 may combine polygons with reference to the communication wavelength data 143. For example, they may be combined into polygons that are one-quarter or less in size to the wavelength of the electromagnetic wave for communication. In addition, the polygons may be made larger in the center of the electromagnetic wave scatterer and smaller in the corners of the electromagnetic wave scatterer. Secondary rays are mainly generated by reflection in the center of the electromagnetic wave scatterer, and secondary rays generated by scattering and diffraction in the corners of the electromagnetic wave scatterer must be considered. For this reason, it is advisable to make the polygons larger in the center of the electromagnetic wave scatterer to take into account macroscopic characteristics, and to make the polygons smaller in the corners of the electromagnetic wave scatterer to take into account microscopic characteristics. The adjacent polygon connection state data generation circuit 116 calculates the connection relationship of each polygon group generated by the polygon group formation circuit 115 using the connection relationship between multiple polygons and adjacent polygons.

According to this embodiment, the total number of polygons in the calculation model used by the electromagnetic field calculation device 150 can be reduced, so that collision determination between rays and polygons, which is frequently repeated in ray tracing calculations, can be reduced, and electromagnetic field analysis by ray tracing calculations can be accelerated. As a result, the labor and time required to build a wireless communication system within a communication service area can be reduced, and the cost required to build a wireless communication system can be reduced.

Example 6
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 6. Example 6 differs from Example 1 in that a calculation model generating device 131 having an adjacent polygon junction state determination/data generating circuit 119 is used instead of the adjacent polygon junction state data generating circuit 116. In Example 6, differences from Example 1 will be mainly described, and the same components as those in Example 1 will be assigned the same reference numerals and their description will be omitted.

Figure 6 is a diagram showing the configuration of a wireless communication characteristic prediction system 105 in Example 6.

In the computational model generating device 131 of this embodiment, the adjacent polygon connection state determination/data generation circuit 119 calculates the connection relationship of each polygon group generated by the polygon group forming circuit 115 using the connection relationship between multiple polygons and adjacent polygons. If the polygon is connected to another polygon, the polygon attribute determination circuit 117 adds an attribute to each polygon in the polygon group using the connection relationship between the polygon groups calculated by the adjacent polygon connection state determination/data generation circuit 119, and if the polygon is not connected to another polygon, the process returns to the point cloud filter circuit 113 to remove each point in the point cloud that formed the polygon.

According to this embodiment, polygons that do not affect the results of the electromagnetic field analysis in the ray tracing calculation performed by the electromagnetic field calculation device 150, that is, polygons that are smaller than the wavelength of the electromagnetic waves for communication, can be removed from the calculation target, and the electromagnetic field analysis by the ray tracing calculation can be accelerated. As a result, the labor and time required to build a wireless communication system within a communication service area can be reduced, and the cost required to build a wireless communication system can be reduced.

Example 7
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 7. Example 7 differs from Example 1 in that a structure data storage device 190 having structure physical property data 146 is used instead of the structure data storage device 140 of Example 1. In Example 7, differences from Example 1 will be mainly described, and the same components as those of Example 1 will be denoted by the same reference numerals, and description thereof will be omitted.

Figure 7 is a diagram showing the configuration of a wireless communication characteristic prediction system 106 in Example 7.

The structural property data 146 of the structural data storage device 190 provides the electrical characteristics of the electromagnetic wave scatterers in the communication service area to the polygon attribute determination circuit 117 of the computational model generation device 110. The polygon attribute determination circuit 117 changes the electrical properties in accordance with the scatterer structure determined from the structure of the polygon group.

According to this embodiment, the properties of the ray re-radiated when the ray collides with a polygon can be changed according to the differences in the electrical properties of the electromagnetic wave scatterer, so that the accuracy of the electromagnetic field analysis by ray tracing calculation can be improved, and the electromagnetic field distribution within the communication service area estimated by this system can be made closer to reality. As a result, the labor and time required to build a wireless communication system within the communication service area can be reduced, and the cost required to build the wireless communication system can be reduced.

Example 8
Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 8. Example 8 differs from Example 1 in that an electromagnetic field calculation device 172 having a reflected ray generation circuit 162, a secondary ray determination circuit 163, a diffracted ray generation circuit 167, and a scattered ray generation circuit 166 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 8, differences from Example 1 will be mainly described, and the same components as those of Example 1 will be assigned the same reference numerals and their description will be omitted.

Figure 8 is a diagram showing the configuration of a wireless communication characteristic prediction system 107 in Example 8.

In the electromagnetic field calculation device 172 of this embodiment, the ray/polygon collision judgment circuit 156 judges whether the ray generated by the ray emission circuit 154 collides with a polygon in the communication service area by referring to the polygon table storage circuit 161. The reflected ray generation circuit 162 generates reflected waves that are re-radiated from all polygons with which the ray collides. The secondary ray judgment circuit 163 uses the information of the polygon table storage circuit 161 to judge whether the polygon with which the ray collides re-radiates a secondary ray of a diffracted wave or scattered wave different from the reflection. The diffraction ray generation circuit 167 generates a diffraction ray that is re-radiated from the polygon based on the judgment result of the secondary ray judgment circuit 163. The scattered ray generation circuit 166 generates a scattered ray that is re-radiated from the polygon based on the judgment result of the secondary ray judgment circuit 163. The repetition condition judgment circuit 159 monitors the number of times rays are regenerated by the diffraction ray generation circuit 167 and the scattering ray generation circuit 166, and if the number of times of regeneration is within a predetermined number, it continues the operation of the ray emission circuit 154, and if the number of times of regeneration exceeds the predetermined number, it ends the operation of the ray emission circuit 154.Then, the electromagnetic field calculation device 172 sends to the display device 180 the results of integration taking into account the contents of the communication area storage circuit 160, the contents of the polygon table storage circuit 161, information on all rays generated by the ray emission circuit 154, and the energy and phase of the rays at the points of collision with each finite area of the receiver arrival power integration circuit 155.

According to this embodiment, in the process of re-emitting a ray from a polygon with which the ray has collided, the generation of reflected waves, diffracted waves, and scattered waves is realized by different elements, so that the calculation of the generation of reflected waves, which can be accelerated in ray tracing calculations, can be executed by a dedicated routine, and the electromagnetic field analysis by ray tracing calculations can be accelerated. In addition, since the calculation process for scattered waves and the calculation process for diffracted waves can be executed independently in the same calculation process as the reflected waves, the electromagnetic field analysis by ray tracing calculations can be further accelerated. As a result, the labor and time required to build a wireless communication system within a communication service provision area can be reduced, and the cost required to build a wireless communication system can be reduced.

<Example 9>
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 9. Example 9 differs from Example 8 in that an electromagnetic field calculation device 173 having a polygon table history circuit 168 is used instead of the electromagnetic field calculation device 172 of Example 8. In Example 9, differences from Example 8 will be mainly described, and the same components as those in Example 8 will be denoted by the same reference numerals and their description will be omitted.

Figure 9 shows the configuration of a wireless communication characteristic prediction system in Example 9.

In the electromagnetic field calculation device 173 of this embodiment, the polygon table history circuit 168 sequentially stores the contents of the polygon table storage circuit 161, and sends data to the ray-polygon collision determination circuit 156, the reflected ray generation circuit 162, the secondary ray determination circuit 163, and the polygon display circuit 184 of the display device 180, instead of the polygon table storage circuit 161.

According to this embodiment, past polygon data can be used in ray tracing calculations and polygon display when the spatial arrangement of electromagnetic wave scatterers within a communication service area changes, making it possible to evaluate dynamic fluctuations in the electromagnetic field distribution when a mobile object is included within the communication service area, thereby expanding the applications of the wireless communication characteristics prediction system of the present invention.

Example 10
Another example of a wireless communication characteristic prediction system according to the present invention will be described with reference to Fig. 10. Example 10 differs from Example 1 in that an electromagnetic field calculation device 174 having a received power determination circuit 169 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 10, differences from Example 1 will be mainly described, and the same components as those in Example 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

Figure 10 is a diagram showing the configuration of a wireless communication characteristic prediction system of Example 10.

In the electromagnetic field calculation device 174 of this embodiment, the repetition condition judgment circuit 159 monitors the number of regenerations of the re-radiation ray generation circuit 158, and if the number of regenerations is within a predetermined number, the operation of the ray emission circuit 154 is continued, and if the number of regenerations exceeds the predetermined number, the operation of the ray emission circuit 154 is terminated. The reception power judgment circuit 169 checks the ray arrival flags for all reception points of the receiver arrival power integration circuit 155, and if there is a reception point for which the flag is not set, changes the contents of the repetition condition setting circuit 151 and repeats a series of processes starting from the transmission point generation circuit 152. On the other hand, if the flag is set for all reception points, the electromagnetic field calculation device 174 sends to the display device 180 the results of integration taking into account the contents of the communication area storage circuit 160, the contents of the polygon table storage circuit 161, information on all rays generated by the ray emission circuit 154, and the energy and phase of the rays at the points of collision with each finite area of the receiver arrival power integration circuit 155.

According to this embodiment, the processing of the electromagnetic field calculation device 174 can be optimized according to the display resolution of the electromagnetic field distribution, and the electromagnetic field distribution can be displayed in the minimum calculation time for the required resolution of the electromagnetic field distribution. As a result, the labor and time required to build a wireless communication system within a communication service area can be reduced, and the cost required to build a wireless communication system can be reduced.

Example 11
In this embodiment, an example of engineering using a wireless monitoring system that estimates an electromagnetic field environment in a communication service providing area and predicts communication quality in the area using the wireless communication characteristic prediction system of any of the above-mentioned embodiments will be described with reference to Fig. 21. Since the wireless communication characteristic prediction system of any of the above-mentioned embodiments can be used for the wireless monitoring system, a description thereof will be omitted.

Figure 21 is a diagram showing an example of engineering using an IoT wireless monitoring system 1101 that uses the wireless communication characteristic prediction system of the present invention.

In the IoT wireless monitoring system 1101, a plurality of fixed structures 1012 and a movable structure 1013 exist inside a building 1011, which is a communication service provision area, and a plurality of wireless communication devices 1021 are installed. A mobile environment measuring device 1003 having a communication wireless device 4 and a measurement wireless device 1 moves inside the building 1011 along a measurement route 1004, and at each point on the measurement route 1004, the measurement wireless device 1 acquires the coordinates of each point on the surface of the plurality of fixed structures 1012 and the movable structure 1013, which are electromagnetic wave scatterers in the building 1011, which is a communication service provision area, and the communication wireless device 4 receives transmitted radio waves from the plurality of wireless communication devices 1021. The spatial positional relationship between the building 1011 and the measurement route 1004 is acquired in advance. The wireless communication characteristic prediction system uses electromagnetic field analysis using computer resources to estimate the electromagnetic field distribution at each required point within the communication service area, that is, within the building 1011, using the electromagnetic field intensity within the communication service area obtained from the acquired positional relationship and the acquired spatial coordinates of the electromagnetic wave scatterers.

According to this embodiment, a model is generated at the site of the communication service area where the wireless communication system is to be constructed, for calculating the radio wave environment for the electromagnetic waves used by the wireless communication system, and the various characteristics of the wireless communication system within the area can be predicted using this model, so that an appropriate wireless communication environment can be constructed within the communication service area, and various wireless communication performances in the appropriate environment can be displayed. This makes it possible to reduce the number of personnel and work hours required for wireless engineering to construct a wireless communication system, and to reduce the cost of wireless engineering.

<Example 12>
In this embodiment, another example of engineering using a wireless monitoring system that estimates an electromagnetic field environment in a communication service area by using the wireless communication characteristic prediction system of any of the above-mentioned embodiments and predicts communication quality in the area will be described with reference to Fig. 22. The twelfth embodiment differs from the eleventh embodiment in that, instead of a movable structure 1013, a plurality of mobile objects 1015 serving as electromagnetic wave scatterers are present in a building 1011, and a plurality of measurement wireless devices 1 are fixedly distributed in the building 1011 instead of being disposed in a mobile environment measuring device 1003. In the twelfth embodiment, differences from the eleventh embodiment will be mainly described, and the same components as those in the eleventh embodiment will be assigned the same reference numerals and their description will be omitted. In addition, since the wireless communication characteristic prediction system of any of the above-mentioned embodiments 1 to 10 can be used for the wireless monitoring system, its description will be omitted.

Figure 22 is a diagram showing an example of engineering using an IoT wireless monitoring system 1101 that uses the wireless communication characteristic prediction system of the present invention.

The position of the measurement radio 1 within the building 1001 can be obtained in advance. In Example 12, similar to Example 11, the coordinates of each point on the surface of the multiple fixed structures 1012 and the moving body 1015 that serve as electromagnetic wave scatterers can be obtained. In particular, even if the spatial arrangement of the electromagnetic wave scatterers within the building 1011 changes, the coordinates of each point on the surface of the electromagnetic wave scatterers can be obtained in real time without moving the mobile environment measuring device 1003.

According to this embodiment, even if there is an electromagnetic wave scatterer moving within the communication service area, as in embodiment 11, the electromagnetic field distribution at each required point within the building 1011 within the communication service area can be estimated by electromagnetic field analysis using computer resources, and a model is generated to calculate the radio wave environment for the electromagnetic waves used by the wireless communication system at the site of the communication service area where the wireless communication system is to be constructed, and various characteristics of the wireless communication system within the area can be predicted using this model, making it possible to construct an appropriate wireless communication environment within the communication service area and display various wireless communication performances in the appropriate environment. This makes it possible to reduce the number of personnel and work time required for wireless engineering to construct a wireless communication system, and reduce the cost of wireless engineering.

The present invention is not limited to the above-described embodiments, but includes various modified examples and equivalent configurations within the spirit of the appended claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to having all of the configurations described. Furthermore, part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Furthermore, the configuration of another embodiment may be added to the configuration of one embodiment. Furthermore, part of the configuration of each embodiment may be added, deleted, or replaced with other configurations.

Furthermore, each of the configurations, functions, processing units, processing means, etc. described above may be realized in part or in whole in hardware, for example by designing them as integrated circuits, or may be realized in software by a processor interpreting and executing a program that realizes each function.

Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory, hard disk, or SSD (Solid State Drive), or in a recording medium such as an IC card, SD card, or DVD.

In addition, the control lines and information lines shown are those considered necessary for explanation, and do not necessarily represent all control lines and information lines necessary for implementation. In reality, it is safe to assume that almost all components are interconnected.

1 Measurement radio 2 Measurement high frequency signal source 3 Measurement antenna 4 Communication radio 5 Communication high frequency signal source 6 Communication antenna 7 Video data conversion device 8 Camera 100 to 107 Wireless communication characteristic prediction system 110 Calculation model generation device 111 Point cloud storage circuit 112 Point cloud coordinate generation circuit 113 Point cloud filter circuit 114 Polygon generation circuit 115 Polygon group formation circuit 116 Adjacent polygon joint state data generation circuit 117 Polygon attribute determination circuit 118 Polygon connection circuit 119 Data generation circuit 130 Calculation model generation device 131 Calculation model generation device 140 Structure data storage device 141 Point cloud table 142 Communication area data 143 Communication wavelength data 144 Polygon table 145 Electrical characteristic table 146 Structure physical property data 150 Electromagnetic field calculation device 151 Iteration condition setting circuit 152 Transmission point generation circuit 153 Reception point generation circuit 154 Ray emission circuit 155, receiver incoming power integration circuit 156, polygon collision judgment circuit 157, re-radiation ray selection circuit 158, re-radiation ray generation circuit 159, iteration condition judgment circuit 160, communication area storage circuit 161, polygon table storage circuit 162, reflected ray generation circuit 163, secondary ray judgment circuit 164, secondary ray generation circuit 166, scattered ray generation circuit 167, diffraction ray generation circuit 168, polygon table history circuit 169, received power judgment circuit 170, 171, 172, 173, 174, electromagnetic field calculation device 176, secondary ray temporary generation circuit 177, polygon collision judgment circuit 180, display device 181, structure display circuit 182, ray display circuit 183, electromagnetic field display circuit 184, polygon display circuit 190, structure data storage device 1001, 1011, building 1003, moving environment measurement device 1004, measurement route 1006 Polygon group generation process 1012, 1013 Structure 1015 Mobile object 1021 Wireless communication device 1101 IoT wireless monitoring system

Claims (11)

A wireless communication characteristic prediction system,
A model generating device, an electromagnetic field calculating device, and an output device,
the model generating device calculates dimensional information of the structure from point cloud data representing the positions of the surfaces of the structure within the communication service providing area and the wavelength of the radio waves used for communication;
The electromagnetic field calculation device is
A computing device that executes a predetermined process and a storage device that can be accessed by the computing device,
Iterative ray tracing calculations are performed to estimate the electromagnetic field distribution,
Using the position data of the structure and the calculated dimensional information of the structure, a generation state of a reflected wave, a diffracted wave, and a scattered wave in the ray tracing calculation is changed;
transmitting the estimated electromagnetic field distribution to the output device;
The wireless communication characteristic prediction system is characterized in that the output device outputs the estimated electromagnetic field distribution. A wireless communication characteristic prediction system,
A measuring device, an electromagnetic field calculation device, and an output device are provided,
The measuring device measures a distance and a direction to a point on a surface of a structure within a communication service area by using electromagnetic waves;
The electromagnetic field calculation device is
A computing device that executes a predetermined process and a storage device that can be accessed by the computing device,
Iterative ray tracing calculations are performed to estimate the electromagnetic field distribution,
changing the generation state of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation based on the position data of the structure;
transmitting the estimated electromagnetic field distribution to the output device;
The output device outputs the estimated electromagnetic field distribution,
A wireless communication characteristic prediction system, characterized in that the frequency of electromagnetic waves used for communication by wireless communication devices located within the communication service area is less than one-tenth the frequency of electromagnetic waves used for measurement by the measurement device. A wireless communication characteristic prediction system,
The system includes a mobile measurement device, a model generation device, a structure data storage device, an electromagnetic field calculation device, and an output device,
the mobile measurement device is equipped with a measurement device that measures a distance and a direction to a point on a surface of an electromagnetic wave scatterer that exists within a communication service area, and an electromagnetic field measurement device that measures an electromagnetic field intensity at a communication frequency;
the model generation device generates polygons representing structures within the communication service provision area from the data measured by the measurement device;
The structure data storage device stores data necessary for ray tracing calculations;
The electromagnetic field calculation device is
A computing device that executes a predetermined process and a storage device that can be accessed by the computing device,
Repeating the ray tracing calculation to estimate an electromagnetic field distribution;
changing the generation state of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation based on the position data of the structure;
transmitting the estimated electromagnetic field distribution to the output device;
The wireless communication characteristic prediction system is characterized in that the output device outputs the estimated electromagnetic field distribution. A wireless communication characteristic prediction system,
The system includes a measurement device, a mobile measurement device, a model generation device, a structure data storage device, an electromagnetic field calculation device, and an output device;
The measuring device measures a distance and a direction to a point on a surface of an electromagnetic wave scatterer present within a communication service providing area;
The mobile measurement device is equipped with an electromagnetic field measuring device that measures electromagnetic field strength at a communication frequency;
the model generation device generates polygons representing structures within the communication service provision area from the data measured by the measurement device;
The structure data storage device stores data necessary for ray tracing calculations;
The electromagnetic field calculation device is
A computing device that executes a predetermined process and a storage device that can be accessed by the computing device,
Repeating the ray tracing calculation to estimate an electromagnetic field distribution;
changing the generation state of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation based on the position data of the structure;
transmitting the estimated electromagnetic field distribution to the output device;
The wireless communication characteristic prediction system is characterized in that the output device outputs the estimated electromagnetic field distribution. The wireless communication characteristic prediction system according to claim 1 ,
The point cloud data is generated from actual measurement data of distances to a surface of the structure,
The electromagnetic field calculation device acquires the point cloud data as position data of the structure. The wireless communication characteristic prediction system according to claim 1 ,
the model generating device groups the polygons generated from the point cloud data according to their positional relationships with adjacent polygons;
The wireless communication characteristic prediction system, wherein the electromagnetic field calculation device uses information of the grouped polygons to determine whether a diffracted wave will occur in the ray tracing calculation. The wireless communication characteristic prediction system according to claim 1 ,
the model generating device groups the polygons generated from the point cloud data according to their positional relationships with adjacent polygons and communication wavelengths;
The wireless communication characteristic prediction system is characterized in that the electromagnetic field calculation device uses information of the grouped polygons to determine whether diffracted waves and scattered waves will occur in the ray tracing calculation. The wireless communication characteristic prediction system according to claim 1 ,
an electromagnetic field measuring device for measuring electromagnetic field strengths at a plurality of locations within a communication service area in which a wireless communication device is located;
The electromagnetic field calculation device re-executes the ray tracing calculation by changing the position and orientation of a polygon generated from the point cloud data so as to reduce the difference between the electromagnetic field distribution within the area obtained by the ray tracing calculation and the measured electromagnetic field intensity. The wireless communication characteristic prediction system according to claim 6 or 7,
The electromagnetic field calculation device is
storing data in which information regarding electrical characteristics is added to the generated polygon;
A wireless communication characteristic prediction system characterized by determining the radiation direction and initial intensity of a ray that is re-radiated when a ray collides with a polygon in the ray tracing calculation by referring to information about the electrical characteristics. The wireless communication characteristic prediction system according to claim 1 ,
The output device generates display data to display the results of electromagnetic field calculations using polygons within a communication service area and information regarding groups of polygons used in the electromagnetic field calculations. An IoT wireless monitoring system using the wireless communication characteristic prediction system according to claim 3 or 4 .

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