Propagation characteristic estimation device, propagation characteristic estimation method, and propagation characteristic estimation program

Abstract

This propagation characteristic estimation device estimates a radio wave propagation characteristic between a transmission point and a reception point. Environmental information indicates an arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point. The propagation characteristic estimation device uses the environmental information as a basis for extracting a structural surface that is visible by line of sight from both the transmission point and the reception points as a structural surface of interest. The propagation characteristic estimation device estimates the radio wave propagation characteristic of a propagation path between the transmission point and the reception point by way of the structural surface of interest on the basis of a first area, which is the area of the structural surface of interest visible from the transmission point, and a second area, which is the area of the structural surface of interest visible from the reception point. If the structural surface of interest is a reflective surface of a dynamic reflector, the propagation characteristic estimation device estimates the radio wave propagation characteristic on the basis of the first and second areas for the case of hypothetically correcting the tilt of the reflective surface of the dynamic reflector so as to achieve a state of specular reflection.

Description

Propagation characteristic estimation device, propagation characteristic estimation method, and propagation characteristic estimation program

[0001] The present invention relates to a technique for estimating radio wave propagation characteristics between a transmitting point and a receiving point.

[0002] Non-Patent Document 1 discloses a ray tracing method, which is a method for estimating radio wave propagation characteristics in a wireless communication system.

[0003] T. Imai, "Mobile Propagation Simulation Using Ray Tracing Method," IEICE Transactions on Wireless Communication (B), Vol. J92-B, No. 9, pp. 1333-1347, Sept. 2009.

[0004] The color image method is a method for estimating radio wave propagation characteristics in wireless communication systems. According to the color image method, color images of the surface of a structure as seen from the transmitting and receiving points are created. Furthermore, the propagation paths of scattered waves are simultaneously searched based on the color images. This allows radio wave propagation characteristics such as propagation loss and received power to be estimated quickly and accurately.

[0005] However, existing color image methods only consider the scattering characteristics of structural surfaces. Existing color image methods do not consider the characteristics of dynamic reflectors (RIS: Reconfigurable Intelligent Surfaces), which can "intentionally" control the reflection direction. A technology that can estimate radio wave propagation characteristics while also considering the characteristics of dynamic reflectors is desired.

[0006] A first aspect relates to a propagation characteristic estimation device that estimates radio wave propagation characteristics between a transmission point and a reception point. The propagation characteristic estimation device includes one or more processors and one or more storage devices that store environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point. The one or more processors extract, based on the environmental information, structural surfaces that are visible from both the transmission point and the reception point as target structural surfaces. The one or more processors estimate radio wave propagation characteristics of a propagation path between the transmission point and the reception point that passes through the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point. When the target structural surface is a reflecting surface of a dynamic reflector, the one or more processors estimate the radio wave propagation characteristics based on the first area and the second area when the tilt of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.

[0007] A second aspect relates to a propagation characteristic estimation method for estimating radio wave propagation characteristics between a transmission point and a reception point, the propagation characteristic estimation method including: acquiring environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point; extracting, based on the environmental information, structural surfaces that are visible from both the transmission point and the reception point as target structural surfaces; and estimating radio wave propagation characteristics of a propagation path between the transmission point and the reception point via the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point. When the target structural surface is a reflecting surface of a dynamic reflector, estimating the radio wave propagation characteristics includes estimating the radio wave propagation characteristics based on the first area and the second area when the tilt of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.

[0008] A third aspect relates to a propagation characteristic estimation program for estimating radio wave propagation characteristics between a transmission point and a reception point. The propagation characteristic estimation program is executed by a computer. The propagation characteristic estimation program causes the computer to: acquire environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point; extract, based on the environmental information, structural surfaces that are visible from both the transmission point and the reception point as target structural surfaces; and estimate radio wave propagation characteristics of a propagation path between the transmission point and the reception point via the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point. When the target structural surface is the reflecting surface of a dynamic reflector, estimating the radio wave propagation characteristics includes estimating the radio wave propagation characteristics based on the first area and the second area when the inclination of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.

[0009] According to the present invention, it is possible to estimate radio wave propagation characteristics taking into consideration the characteristics of a dynamic reflector whose reflection direction is intentionally controlled.

[0010] 1 is a schematic diagram showing a wireless communication system; FIG. 2 is a block diagram showing an example of the configuration of a propagation characteristic estimation device; FIG. 3 is a block diagram showing an example of the functional configuration related to the color image method; FIG. 4 is a flowchart showing the propagation characteristic estimation process using the color image method; FIG. 5 is a conceptual diagram for explaining the creation of a color image; FIG. 6 is a diagram showing an example of a color image; FIG. 7 is a diagram for explaining a transmission point, a reception point, and a target structure surface; FIG. 8 is a conceptual diagram for explaining the path gain calculation process in the case of a dynamic reflector; and FIG. 9 is a flowchart showing the path gain calculation process (step S140).

[0011] An embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] 1. Overview of the Propagation Characteristics Estimation Device Fig. 1 is a schematic diagram showing a wireless communication system 1. The wireless communication system 1 includes a transmission point Tx that transmits radio waves and a reception point Rx that receives radio waves. Because radio waves are reflected and scattered by buildings and the like, multiple propagation paths exist between the transmission point Tx and the reception point Rx.

[0013] An object that affects radio wave propagation from a transmitting point Tx to a receiving point Rx will be referred to hereinafter as a "structure 10." Examples of the structure 10 include a building, a wall, and the like. Typically, a large number of structures 10 exist in a radio wave transmission area that includes the transmitting point Tx and the receiving point Rx. Radio waves are reflected and scattered by the surfaces of the structures 10. A surface of the structure 10 that reflects and scatters radio waves will be referred to hereinafter as a "structure surface 11." For example, the structure surface 11 is the wall surface of a building. When one structure 10 has multiple structure surfaces 11 (e.g., 11a to 11d), these multiple structure surfaces 11 are distinguished from one another.

[0014] According to this embodiment, radio wave propagation characteristics are estimated in the wireless communication system 1, i.e., radio wave propagation characteristics between a transmitting point Tx and a receiving point Rx. In particular, the radio wave propagation characteristics between the transmitting point Tx and the receiving point Rx are estimated taking into consideration reflection and scattering of radio waves on the structure surface 11. Examples of radio wave propagation characteristics include propagation loss, radio wave intensity of the received wave, received power, and delay time.

[0015] 2 is a block diagram showing an example configuration of a propagation characteristic estimation device 100 that estimates radio wave propagation characteristics between a transmission point Tx and a reception point Rx. The propagation characteristic estimation device 100 is a computer including one or more processors 101 (hereinafter simply referred to as "processors 101") and one or more storage devices 102 (hereinafter simply referred to as "storage devices 102"). The processor 101 executes various processes. Examples of the processor 101 include a central processing unit (CPU), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA). The storage device 102 stores various information. Examples of the storage device 102 include a hard disk drive (HDD), a solid state drive (SSD), a volatile memory, and a nonvolatile memory.

[0016] The propagation characteristics estimation program 103 is a computer program (software) executed by the processor 101. The functions of the propagation characteristics estimation apparatus 100 may be realized by cooperation between the processor 101 executing the propagation characteristics estimation program 103 and the storage device 102. The propagation characteristics estimation program 103 is stored in the storage device 102. The propagation characteristics estimation program 103 may be recorded on a computer-readable recording medium. The propagation characteristics estimation program 103 may be provided via a network.

[0017] The environmental information 104 is information necessary for estimating radio wave propagation characteristics in the wireless communication system 1. For example, the environmental information 104 includes position information of a transmission point Tx and position information of a reception point Rx. The environmental information 104 also includes structure information indicating the arrangement of structures 10 that affect radio wave propagation from the transmission point Tx to the reception point Rx. The structure information includes the arrangement (position, orientation, size), reflection coefficient, etc. of each structure surface 11 of each structure 10. The structure information may be provided in the form of three-dimensional computer-aided design (CAD) data, building information modeling (BIM) data, etc. The environmental information 104 may also include information on the wavelength of radio waves used in the wireless communication system 1. The environmental information 104 is stored in the storage device 102.

[0018] The propagation characteristics estimation apparatus 100 may further include a communication interface 105 for communicating with the outside. The environment information 104 may be provided to the propagation characteristics estimation apparatus 100 via the communication interface 105.

[0019] The propagation characteristics estimation apparatus 100 may further include a user interface 106 that accepts input from a user and presents various information to the user. The user interface 106 includes an input device and a display device. Examples of the input device include a keyboard, a mouse, and a touch panel. The user can operate the propagation characteristics estimation apparatus 100 by using the input device. The estimated results of the radio wave propagation characteristics are displayed on the display device.

[0020] The "color image method" is one method for estimating radio wave propagation characteristics in the wireless communication system 1. The color image method can estimate radio wave propagation characteristics quickly and with high accuracy. The color image method will be described in detail below.

[0021] Fig. 3 is a block diagram showing an example of a functional configuration related to the color image method. The propagation characteristics estimation apparatus 100 includes, as functional blocks, a structure surface information creation unit 110, a color image creation unit 120, a structure surface extraction unit 130, a path gain calculation unit 140, and a received power calculation unit 150. These functional blocks may be realized by cooperation between a processor 101 that executes a propagation characteristics estimation program 103 and a storage device 102. Fig. 4 is a flowchart showing a propagation characteristics estimation process using the color image method.

[0022] 1-1. Structure surface information creation process (step S110) In step S110, the structure surface information creation unit 110 recognizes each structure surface 11 of each structure 10 based on the environmental information 104. When one structure 10 has multiple structure surfaces 11 (e.g., 11a to 11d), these multiple structure surfaces 11 are distinguished from one another (see FIG. 1). Then, the structure surface information creation unit 110 assigns identification information to each structure surface 11. The identification information is different for each structure surface 11.

[0023] For example, the identification information of the structure surface 11 is "color." In this case, the structure surface information creation unit 110 assigns a different color to each structure surface 11. The color is expressed, for example, by RGB values. For example, the RGB values ​​assigned to the structure surface 11 are (R, G, B) = (10 to 249, 10 to 249, 10 to 249). Special colors (0, 0, 0) and (255, 255, 255) are assigned to the background and the ground.

[0024] The structure surface information is information relating to each structure surface 11. Specifically, the structure surface information includes identification information (color), arrangement (position, orientation, size), reflection coefficient, etc. of each structure surface 11. The position, orientation, size, reflection coefficient, etc. of each structure surface 11 are registered in advance in the environment information 104. The structure surface information creation unit 110 creates the structure surface information and adds the structure surface information to the environment information 104.

[0025] The identification information of the structure surface 11 may be an identification number. In the following description, a case will be described in which the identification information of the structure surface 11 is a color. The color representation format is not limited to RGB.

[0026] 1-2. Color Image Creation Process (Step S120) In step S120, the color image creation unit 120 creates a two-dimensional image of the structure surface 11 as seen from each of the transmission point Tx and the reception point Rx. If a unique color is assigned to each structure surface 11, the two-dimensional image becomes a two-dimensional color image. Hereinafter, this two-dimensional color image will be simply referred to as a "color image."

[0027] FIG. 5 is a conceptual diagram for explaining the creation of a color image. In FIG. 5, the viewpoint is the transmitting point Tx or the receiving point Rx. The line of sight direction is the direction from the viewpoint to the structure surface 11. For example, the line of sight direction is the direction from the viewpoint to the center point of the structure surface 11. The angle θ is the angle between the line of sight direction and the normal direction of the structure surface 11. It can also be said that the angle θ is the direction of the viewpoint (transmitting point Tx or receiving point Rx) as seen from the structure surface 11. The distance d is the distance between the viewpoint and the structure surface 11 along the line of sight direction. The color image creation unit 120 projects the structure surface 11 onto a unit sphere centered on the viewpoint. If the area of ​​the original structure surface 11 is S, the area S' of the structure surface 11 projected onto the unit sphere is S·cos θ / d ２ It is expressed as:

[0028] The color image creation unit 120 projects all of the structure surfaces 11 seen from the viewpoint onto the same unit sphere. Although the line of sight direction and distance d may differ for each structure surface 11, all of the structure surfaces 11 are projected onto the same unit sphere. The color image creation unit 120 then unfolds the unit sphere onto a plane. This allows a color image of the structure surface 11 seen from the viewpoint to be obtained.

[0029] 6 shows an example of a color image viewed from a transmitting point Tx and a color image viewed from a receiving point Rx. In the color image, each structure surface 11 is represented by a unique color assigned to each structure surface 11. The color image is generated taking occlusion into consideration.

[0030] As described above, the environment information 104 includes the position information of the transmission point Tx, the position information of the reception point Rx, and the structure surface information (the color, position, orientation, and size of each structure surface 11). Therefore, the color image creation unit 120 can create a color image seen from the transmission point Tx and a color image seen from the reception point Rx based on the environment information 104. The created color images are stored in the storage device 102.

[0031] 1-3. Structural Surface Extraction Process (Step S130) In the color image method, a propagation path that reaches the receiving point Rx from the transmitting point Tx with only one scattering and reflection is considered. In other words, the dominant single-scattered wave (reflected wave) is considered. For this reason, the structural surface 11 that is visible from both the transmitting point Tx and the receiving point Rx is extracted.

[0032] In step S130, the structure surface extraction unit 130 extracts structure surfaces 11 that are visible from both the transmission point Tx and the reception point Rx. Specifically, the structure surface extraction unit 130 compares the color image seen from the transmission point Tx with the color image seen from the reception point Rx, and extracts structure surfaces 11 that have the same color in the two color images. The structure surfaces 11 that have the same color in the two color images are structure surfaces 11 that are visible from both the transmission point Tx and the reception point Rx. The structure surfaces 11 that are visible from both the transmission point Tx and the reception point Rx will be referred to as the "target structure surface 11X" hereinafter.

[0033] By comparing the color image seen from the transmitting point Tx with the color image seen from the receiving point Rx, it is possible to simultaneously search for one or more target structure surfaces 11X. In other words, it is possible to simultaneously search for one or more propagation paths from the transmitting point Tx to the receiving point Rx. The ability to simultaneously search for propagation paths in this way contributes to speeding up the radio wave propagation characteristics.

[0034] 1-4. Path Gain Calculation Process (Step S140) In step S140, the path gain calculation unit 140 calculates the path gain of the propagation path between the transmission point Tx and the reception point Rx that passes through the target structure surface 11X. That is, the path gain calculation unit 140 calculates the path gain of the propagation path that is reflected and scattered at the target structure surface 11X.

[0035] 7 shows the transmission point Tx, the reception point Rx, and the target structure surface 11X. Ｔ is an angle θ that represents the direction of the transmission point Tx as seen from the target structure surface 11X. The first distance d1 is the distance d between the transmission point Tx and the target structure surface 11X. The second angle θ Ｒ is the angle θ representing the direction of the receiving point Rx as seen from the target structure surface 11X. The second distance d2 is the distance d between the receiving point Rx and the target structure surface 11X. The area of ​​the target structure surface 11X is S. The first area S1 is the area of ​​the target structure surface 11X seen from the transmitting point Tx. The second area S2 is the area of ​​the target structure surface 11X seen from the receiving point Rx. As shown in FIG. 5, the area S' of the structure surface 11 projected onto the unit sphere is S·cos θ / d ２ Therefore, the first area S1′ and the second area S2′ of the target structure surface 11X projected onto the unit sphere are respectively expressed by the following formulas (1) and (2).

[0036]

[0037]

[0038] The path gain PG of the propagation path that is reflected and scattered by the target structure surface 11X depends on the first area S1' and the second area S2'. Specifically, the path gain PG of the propagation path that is reflected and scattered by the target structure surface 11X is expressed by the following equations (3) to (5). Note that "i" in the equations is an identifier of the target structure surface 11X and is different for each target structure surface 11X.

[0039]

[0040]

[0041]

[0042] C represented by formula (4) Γ is a parameter corresponding to the reflection loss Γ of the target structure surface 11X. ｂ is a reflection pattern that indicates the level of the reflected wave (scattered wave) by the target structure surface 11X. FIG. 7 also shows the formula for the bistatic scattering cross section σ of the flat plate. Reflection pattern C ｂ is also included in the formula for the bistatic scattering cross section σ, and the first angle θ Ｔ and the second angle θ Ｒ It is expressed as a sinc function with the parameter

[0043] In this way, the path gain PG depends on the multiplication of the first area S1′ and the second area S2′. Also, the path gain PG depends on the reflection pattern C of the target structure surface 11X. ｂ Depends on.

[0044] The first area S1' and the second area S2' can also be replaced with the number of pixels on the color image. Ｐ，Ｔ is the number of pixels on the color image of the target structure surface 11X as seen from the transmission point Tx. Ｐ，Ｒ is the number of pixels on the color image of the target structure surface 11X as seen from the receiving point Rx. In this case, equation (3) is replaced by the following equations (6) and (7).

[0045]

[0046]

[0047] 4π / (H × W) in equation (7) is the area per pixel. The color image creation unit 120 develops the unit sphere onto a plane, and H × W represents the total number of pixels on the plane.

[0048] As described above, the environment information 104 includes the position information of the transmission point Tx, the position information of the reception point Rx, and the structure surface information (the color, position, orientation, and size of each structure surface 11). Therefore, the path gain calculation unit 140 can calculate the path gain PG based on the environment information 104 and the above formula. When formula (6) is used, the path gain calculation unit 140 calculates the first number of pixels N in the color image. Ｐ，Ｔand the second pixel number N Ｐ，Ｒ The path gain calculation unit 140 calculates the path gain PG for all the target structure surfaces 11X (propagation paths).

[0049] 1-5. Received Power Calculation Process (Step S150) In step S150, the received power calculation unit 150 calculates the received power (strength of the received radio wave) at the reception point Rx. Specifically, the received power calculation unit 150 calculates the sum of the path gains for all the target structure surfaces 11X to calculate the received power. In other words, the received power calculation unit 150 combines the path gains for all the target structure surfaces 11X to calculate the received power.

[0050] 2. Color image method taking into account dynamic reflectors Dynamic reflectors (RIS: Reconfigurable Intelligent Surface) are known for use in wireless communications. Dynamic reflectors are composed of numerous reflective elements and reflect incident radio waves. The reflection characteristics of a dynamic reflector, such as the reflection direction, can be dynamically controlled. For example, a dynamic reflector is a metasurface reflector. By using a dynamic reflector, it is possible to form a propagation path that bypasses obstacles or form multiple propagation paths for a single terminal device. This makes it possible to improve communication performance, such as communication quality and spatial multiplexing number.

[0051] The existing color image method only considers the scattering characteristics of the structure surface 11. The existing color image method does not consider the characteristics of dynamic reflectors whose reflection direction can be "intentionally" controlled. Therefore, this embodiment proposes a technology for estimating radio wave propagation characteristics using the color image method while also considering the characteristics of dynamic reflectors.

[0052] 8 is a conceptual diagram for explaining the path gain calculation process (step S140) in the case of the dynamic reflector 20. The target structure surface 11X is the reflecting surface 21 of the dynamic reflector 20. The first angle θ Ｔ represents the direction of the transmission point Tx as seen from the reflecting surface 21 of the dynamic reflector 20. Ｒ represents the direction of the receiving point Rx as seen from the reflecting surface 21 of the dynamic reflector 20.Ｒ represents the intended reflection direction. In order to take into account such intended reflection in the dynamic reflector 20 in the color image method, the above formula for calculating the path gain PG is corrected as follows:

[0053] Specifically, the radio wave is considered to be regularly reflected by the reflecting surface 21 of the dynamic reflector 20. Therefore, as shown in Fig. 8, the inclination of the reflecting surface 21 of the dynamic reflector 20 is virtually corrected so as to achieve a regularly reflected state. The corrected first angle θ Ｔ ' and the corrected second angle θ Ｒ ' are the first angles θ before correction. Ｔ and the second angle θ before correction Ｒ and is expressed by the following equation (8).

[0054]

[0055] Since the tilt of the reflecting surface 21 of the dynamic reflector 20 is virtually corrected, the area of ​​the target structure surface 11X visible from the transmitting point Tx and the receiving point Rx, i.e., the first area S1' and the second area S2', are also corrected. The corrected first area S1' and the corrected second area S2' are both the average of the pre-correction first area S1' and the pre-correction second area S2'. In the case of three dimensions, corrections are made for both the elevation angle and the azimuth angle. When considering the number of pixels equivalent to the area, the first pixel number N Ｐ，Ｔ and the second pixel number N Ｐ，Ｒ and the number of correction pixels N Ｐ，ＲＩＳ The number of corrected pixels is N Ｐ，ＲＩＳ is the first pixel number N Ｐ，Ｔ and the second pixel number N Ｐ，Ｒ is the average.

[0056]

[0057] This correction pixel number N Ｐ，ＲＩＳ By using the above equation, the path gain PG in the case of the dynamic reflector 20 is expressed by the following equation (10).

[0058]

[0059] As shown in equation (10), an additional loss η may be added to the path gain PG in the case of the dynamic reflector 20. The additional loss η may be predetermined.

[0060] When the target structure surface 11X is the reflecting surface 21 of the dynamic reflector 20, the path gain calculation unit 140 calculates the path gain PG based on the above formulas (9) and (10). More specifically, the environment information 104 also includes information about the dynamic reflector 20. The information about the dynamic reflector 20 includes a flag indicating that it is the dynamic reflector 20, the set reflection angle of the dynamic reflector 20, the reflection pattern C of the dynamic reflector 20, ｂ , additional loss η, etc. The path gain calculation unit 140 calculates the path gain PG when the target structural surface 11X is the reflecting surface 21 of the dynamic reflector 20 based on the environmental information 104.

[0061] 9 is a flowchart showing the path gain calculation process (step S140) according to this embodiment. In step S141, the path gain calculation unit 140 determines whether the target structure surface 11X is the reflecting surface 21 of the dynamic reflector 20 based on the environmental information 104.

[0062] If the target structural surface 11X is the reflecting surface 21 of the dynamic reflector 20 (step S141; Yes), the process proceeds to step S142. In step S142, the path gain calculation unit 140 calculates the path gain PG based on the above formula (10).

[0063] On the other hand, if the target structural surface 11X is not the reflecting surface 21 of the dynamic reflector 20 (step S141; No), the process proceeds to step S143. In step S143, the path gain calculation unit 140 calculates the path gain PG based on the above formula (6).

[0064] As described above, according to this embodiment, it is possible to calculate the path gain PG taking into consideration the characteristics of the dynamic reflector 20, the reflection direction of which is intentionally controlled. That is, it is possible to take into consideration the characteristics of the dynamic reflector 20 in the color image method. That is, it is possible to quickly estimate the radio wave propagation characteristics taking into consideration the characteristics of the dynamic reflector 20.

[0065] DESCRIPTION OF SYMBOLS 1... Wireless communication system, 10... Structure, 11... Structure surface, 11X... Target structure surface, 20... Dynamic reflector, 21... Reflecting surface, 100... Propagation characteristic estimation device, 101... Processor, 102... Storage device, 103... Propagation characteristic estimation program, 104... Environmental information, 105... Communication interface, 106... User interface, 110... Structure surface information creation unit, 120... Color image creation unit, 130... Structure surface extraction unit, 140... Path gain calculation unit, 150... Received power calculation unit

Claims

1. A propagation characteristic estimation device for estimating radio wave propagation characteristics between a transmission point and a reception point, comprising: one or more processors; and one or more storage devices for storing environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point, wherein the one or more processors are configured to: extract the structural surfaces that are visible from both the transmission point and the reception point as target structural surfaces based on the environmental information; and estimate the radio wave propagation characteristics of the propagation path between the transmission point and the reception point via the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point; and when the target structural surface is the reflecting surface of a dynamic reflector, the one or more processors estimate the radio wave propagation characteristics based on the first area and the second area when the inclination of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.

2. A propagation characteristics estimation device according to claim 1, wherein each of the first area after correction and the second area after correction is an average of the first area before correction and the second area before correction.

3. A propagation characteristic estimation device as described in claim 1, wherein the one or more processors estimate the radio wave propagation characteristics of the propagation path between the transmitting point and the receiving point passing through the target structure surface based on the multiplication of the first area and the second area.

4. A propagation characteristic estimation device according to any one of claims 1 to 3, wherein the one or more processors calculate a path gain of the propagation path between the transmitting point and the receiving point passing through the target structure surface based on the first area and the second area, and estimate the radio wave propagation characteristics based on the path gain.

5. A propagation characteristic estimation device according to claim 4, wherein, when the target structure surface is the reflecting surface of the dynamic reflector, the one or more processors add an additional loss to the path gain.

6. A propagation characteristic estimation method for estimating radio wave propagation characteristics between a transmission point and a reception point, comprising: acquiring environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point; extracting the structural surfaces that are visible from both the transmission point and the reception point in a line of sight as target structural surfaces based on the environmental information; estimating the radio wave propagation characteristics of a propagation path between the transmission point and the reception point via the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point; and estimating the radio wave propagation characteristics, when the target structural surface is the reflecting surface of a dynamic reflector, estimating the radio wave propagation characteristics based on the first area and the second area when the inclination of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.

7. A propagation characteristic estimation program for estimating radio wave propagation characteristics between a transmission point and a reception point, the propagation characteristic estimation program being executed by a computer and causing the computer to execute the following: acquire environmental information indicating the arrangement of structural surfaces that reflect and scatter radio waves from the transmission point to the reception point; extract the structural surfaces that are visible from both the transmission point and the reception point in a line of sight based on the environmental information as target structural surfaces; and estimate the radio wave propagation characteristics of the propagation path between the transmission point and the reception point via the target structural surface based on a first area that is the area of ​​the target structural surface visible from the transmission point and a second area that is the area of ​​the target structural surface visible from the reception point; and estimating the radio wave propagation characteristics includes, when the target structural surface is the reflecting surface of a dynamic reflector, estimating the radio wave propagation characteristics based on the first area and the second area when the inclination of the reflecting surface of the dynamic reflector is virtually corrected to achieve a specular reflection state.