JP2021136545A - Information processing device, propagation loss calculation method and program - Google Patents

Abstract

To provide an information processing device capable of calculating a propagation loss of radio waves from an emission source to a reception point with high accuracy.SOLUTION: An information processing device 1 includes an environment specification part 2 and a calculation part 4. The environment specification part 2 specifies one or more environments in which a propagation path passes through between a radio wave emission source and a reception point. The calculation part 4 calculates a propagation loss of radio waves from the emission source to the reception point in accordance with a change in an environment when the radio waves propagate on the propagation path in the case that the propagation path passes through a plurality of environments. The calculation part 4 calculates a propagation loss of the radio waves from the emission source to the reception point by changing the degree of change of an attenuation amount to distance from the emission source in accordance with a change in an environment when the radio waves propagate on the propagation path.SELECTED DRAWING: Figure 1

Description

The present invention relates to an information processing device, a propagation loss calculation method and a program, and more particularly to an information processing device for calculating a radio wave propagation loss, a propagation loss calculation method and a program.

When the radio waves emitted from the source pass through the outdoor space and are received at the receiving point, the radio waves can be attenuated depending on the outdoor environment. Therefore, in the design of wireless circuits and the like, the propagation loss of radio waves from the emission source to the reception point is calculated. In relation to this technique, Patent Document 1 describes a stationing design method capable of calculating the position where the propagation loss is minimized without increasing the amount of calculation in the stationing design for determining the position where the base station is arranged. To disclose. In the technique of Patent Document 1, the propagation loss of radio waves for each mesh is calculated for each candidate at a higher position for the plurality of meshes in the region divided into a plurality of meshes.

Japanese Unexamined Patent Publication No. 2011-234091

In the technique according to Patent Document 1, based on the fact that the larger the line-of-sight area is, the smaller the propagation loss is, the calculation amount is reduced by narrowing down the station position candidates for which the propagation loss is to be calculated based on the line-of-sight area. The station position where the propagation loss is minimized is calculated without increasing it. However, in the technique according to Patent Document 1, for example, if there is a building or the like that shields radio waves in the vicinity of the emission source, there is a possibility that the propagation loss of the environment ahead of the building or the like cannot be taken into consideration when calculating the propagation loss. be. Therefore, the technique according to Patent Document 1 may not be able to accurately calculate the propagation loss of radio waves from the emission source to the reception point.

An object of the present disclosure is to solve such a problem, and an information processing device capable of accurately calculating the propagation loss of radio waves from a source to a receiving point, a propagation loss calculation method, and a method for calculating the propagation loss. To provide a program.

The information processing apparatus according to the present disclosure includes an environment specifying means for specifying one or more environments through which a propagation path between a radio wave emitting source and a receiving point passes, and a case where the propagation path passes through a plurality of environments. By changing the degree of change in the amount of attenuation with respect to the distance from the emission source in accordance with the change in the environment when the radio wave propagates in the propagation path, the propagation loss of the radio wave from the emission source to the reception point It has a calculation means for calculating.

Further, the propagation loss calculation method according to the present disclosure specifies one or more environments through which a propagation path between a radio wave emission source and a reception point passes, and when the propagation path passes through a plurality of environments, By changing the degree of change in the amount of attenuation with respect to the distance from the emission source in accordance with the change in the environment when the radio wave propagates in the propagation path, the propagation loss of the radio wave from the emission source to the reception point is reduced. calculate.

Further, the program according to the present disclosure includes a step of specifying one or more environments through which a propagation path between a radio wave emitting source and a receiving point passes, and a radio wave when the propagation path passes through a plurality of environments. Calculates the propagation loss of radio waves from the source to the receiving point by changing the degree of change in the amount of attenuation with respect to the distance from the source in response to changes in the environment when the computer propagates in the propagation path. Have your computer perform the steps you want to take.

According to the present disclosure, it is possible to provide an information processing device, a propagation loss calculation method, and a program capable of accurately calculating the propagation loss of a radio wave from a source to a receiving point.

It is a figure which shows the outline of the information processing apparatus which concerns on embodiment of this disclosure. It is a figure for demonstrating the operation of the information processing apparatus which concerns on this Embodiment. It is a figure for demonstrating the operation of the information processing apparatus which concerns on this Embodiment. It is a figure for demonstrating the propagation model of 2.5 power law. It is a figure for demonstrating the propagation model of 2.5 power law. It is a figure for demonstrating the propagation model of the cubic law. It is a figure for demonstrating the propagation model of the cubic law. It is a figure which shows the structure of the information processing apparatus which concerns on Embodiment 1. FIG. It is a flowchart which shows the propagation loss calculation method performed by the information processing apparatus which concerns on Embodiment 1. FIG. It is a figure which illustrates the environment table stored in the environment table storage part which concerns on Embodiment 1. FIG. It is a figure for demonstrating 1st specific example of the propagation loss calculation method which concerns on Embodiment 1. FIG. It is a figure which illustrates the propagation model in 1st specific example. It is a figure for demonstrating the 2nd specific example of the propagation loss calculation method which concerns on Embodiment 1. FIG. It is a figure which illustrates the propagation model in the 2nd specific example.

(Outline of Embodiments of the present disclosure)
Prior to the description of the embodiments of the present disclosure, an outline of the embodiments according to the present disclosure will be described. FIG. 1 is a diagram showing an outline of the information processing device 1 according to the embodiment of the present disclosure. The information processing device 1 has an environment specifying unit 2 and a calculation unit 4. The environment identification unit 2 has a function as an environment identification means. The calculation unit 4 has a function as a calculation means.

The environment specifying unit 2 identifies one or more environments through which the propagation path between the radio wave emitting source and the receiving point passes. When the propagation path passes through a plurality of environments, the calculation unit 4 calculates the propagation loss of the radio wave from the emission source to the reception point according to the change in the environment when the radio wave propagates in the propagation path. At this time, the calculation unit 4 changes the degree of change in the amount of attenuation with respect to the distance from the emission source according to the change in the environment when the radio wave propagates in the propagation path, so that the radio wave from the emission source to the reception point is changed. Calculate the propagation loss.

2 and 3 are diagrams for explaining the operation of the information processing device 1 according to the present embodiment. As shown in FIG. 2, consider that radio waves propagate in a space consisting of regions Ar1 to Ar9. At this time, the radio wave propagates along the propagation path Rt from the emission source Pt to the reception point Pr. Further, in the example of FIG. 2, the propagation path Rt passes through the regions Ar1, Ar2, Ar5, Ar6, Ar9. Here, the environment of the regions Ar1 to Ar4 and Ar6 to Ar8 is a "city", the environment of the region Ar5 is a "forest", and the environment of the region Ar9 is a "river". Therefore, the propagation path Rt passes through a plurality of environments (city, forest, river).

When calculating the propagation loss of radio waves from the emission source Pt to the reception point Pr, the radio wave propagation model described later is used. The propagation model is a function or attenuation curve that shows the relationship between the distance from the source and the amount of radio wave attenuation. Then, as will be described later, the propagation model used may differ depending on the visibility of the environment through which the propagation path Rt passes. Here, the visibility may depend on how many obstacles there are, such as whether there are many obstacles such as buildings or open areas. Therefore, in the example of FIG. 2, the propagation model may differ for each "city", "forest" and "river" environment. Here, for example, when the environment in which the propagation path Rt from the emission source Pt to the reception point Pr passes is only the "city", the propagation model corresponding to the "city" is used to use the propagation model from the emission source Pt to the reception point Pr. The propagation loss up to can be calculated.

On the other hand, as illustrated in FIG. 2, when the propagation path Rt passes through a plurality of environments, the propagation loss may be calculated using a propagation model corresponding to any one of the plurality of environments. .. For example, in the example of FIG. 2, the propagation loss of the radio wave from the emission source Pt to the reception point Pr may be calculated by using the propagation model corresponding to the “river” which is the environment of the reception point Pr. However, this method does not consider the influence on the radio waves of other environments "city" and "forest" through which the propagation path Rt passes. Therefore, with this method, there is a possibility that the propagation loss of radio waves from the emission source to the reception point cannot be calculated accurately.

On the other hand, in the present embodiment, as illustrated in FIG. 3, the propagation loss is calculated by classifying according to the environment passing through the propagation path Rt from the emission source Pt to the reception point Pr. In the example of FIG. 3, the division # 1 is defined from the emission source Pt in the “city” to the boundary A where the environment changes from the “city” to the “forest”. Therefore, the environment corresponding to Category # 1 is "city". Further, the boundary A to the boundary B where the environment changes from "forest" to "city" is defined as category # 2. Therefore, the environment corresponding to Category # 2 is "Forest". Further, the area from the boundary B to the boundary C where the environment changes from the "city" to the "river" is classified as Category # 3. Therefore, the environment corresponding to Category # 3 is "city". Further, the area from the boundary C to the receiving point Pr in the "river" is classified as Category # 4. Therefore, the environment of Category # 4 is "river".

In this case, the environment specifying unit 2 according to the present embodiment identifies a plurality of environments (city, forest, river) through which the propagation path Rt passes. In the propagation model, the calculation unit 4 calculates the propagation loss of the radio wave from the emission source Pt to the reception point Pr by changing the degree of change of the attenuation amount with respect to the distance from the emission source Pt at each boundary A to C in the propagation model. .. That is, as will be described later, the calculation unit 4 calculates the propagation loss of the radio wave from the emission source to the reception point by using the propagation model corresponding to each of the categories # 1 to # 4. Therefore, the information processing apparatus 1 according to the present embodiment can calculate the propagation loss in consideration of each of the plurality of environments.

As described above, the information processing device 1 according to the present embodiment is configured to calculate the propagation loss of the radio wave from the emission source to the reception point according to the change in the environment when the radio wave propagates along the propagation path. Has been done. Therefore, the information processing device 1 according to the present embodiment can accurately calculate the propagation loss of radio waves from the emission source to the reception point even when the propagation path passes through a plurality of environments. .. Even if the propagation loss calculation method and the program that executes the propagation loss calculation method executed by the information processing apparatus 1 are used, it is possible to accurately calculate the propagation loss of the radio wave from the emission source to the reception point.

(Propagation model)
Here, the propagation model will be described. _Let the transmission power of the emission source be _PT, and let it be the reception power PR at the receiving point. At this time, the transmission gain G _T, when the reception gain and G _R, the reception power P _R is represented by Formula 1 below.

Here, Loss (r) is a function (propagation model) indicating the propagation loss (attenuation amount). From the transmission formula of Frith, the function (propagation model) showing the propagation loss in free space is expressed by the following equation 2. Here, r [m] is the distance from the emission source. Further, λ is the wavelength [m] of the radio wave. In Equation 2, the exponent of the power of the distance r (hereinafter, simply referred to as "exponent") is "2", so Equation 2 is called the "square law".

Further, from the Okumura-Hata model, the function (propagation model) showing the propagation loss in the urban area is approximated as shown by the following equation 3. In Equation 3, the exponent of the distance r is "3", so Equation 3 is called the "3rd power law".

From the above equations 2 and 3, the index of the distance r in the propagation model differs depending on the environment (good visibility, etc.) from the emission source to the reception point. For example, if there are many obstacles between the emission source and the receiving point, the index of the distance r can be large, and if there are few obstacles, the index of the distance r can be small. In general, the propagation loss (attenuation) may vary in a range proportional to the distance r to the 2nd to 4th power depending on the environment. Therefore, as shown in Equation 4 below, the propagation model is defined so that the exponent of the distance r varies between 2 and 4 for each land environment. Here, 2 ≦ n ≦ 4. In Equation 4, the exponent of the distance r is "n", so Equation 4 is called the "Nth power law". Further, in the propagation model in the Nth power law of Equation 4, the exponent n of the distance r is referred to as a “propagation loss coefficient”.

The propagation model is defined for each environment using Equation 4, but the value of the propagation loss coefficient n may differ for each environment. For example, in an environment with good visibility such as a rice field, n is a value close to 2. Further, in an environment such as a city where there are relatively many buildings and the like, n can be a value close to 3. Then, for other environments, the propagation model is defined by appropriately setting the value of the propagation loss coefficient n. The value of the propagation loss coefficient n can be determined by an experiment, for example. Further, the type of environment can be set to correspond to, for example, 23 types of land divisions in the real estate registration law, but is not limited to this.

For example, in an environment between an environment where the state of obstacles is completely visible (n = 2) and an environment where there are relatively many obstacles such as urban areas (n = 3), the propagation model is defined by the following equation 5. Will be done. In Equation 5, the propagation loss coefficient n is “2.5”, so Equation 5 is called the “2.5 power law”.

4 and 5 are diagrams for explaining a propagation model of the 2.5th power law. As shown in FIG. 4, it is assumed that the distance from the emission source to the reception point is Da, and the section from the emission source to the reception point corresponds to the 2.5th power law. That is, in this example, it is assumed that there is a single environment in the section from the emission source to the reception point. FIG. 5 is a diagram illustrating a damping curve corresponding to a propagation model of the 2.5th power law. The attenuation curve shown by the broken line in FIG. 5 corresponds to Equation 5. The attenuation curve is a graph in which the vertical axis is the amount of attenuation [dB] and the horizontal axis is the distance from the emission source.

6 and 7 are diagrams for explaining the propagation model of the cube law. As shown in FIG. 6, it is assumed that the distance from the emission source to the reception point is Db, and the section from the emission source to the reception point corresponds to the cube law. That is, in this example, it is assumed that there is a single environment in the section from the emission source to the reception point. FIG. 7 is a diagram illustrating a damping curve corresponding to the propagation model of the cube law. The attenuation curve shown by the dotted line in FIG. 7 corresponds to Equation 3.

Here, as can be seen from FIGS. 5 and 7, in the attenuation curve, the amount of attenuation increases in the negative direction as the distance increases. Therefore, it can be said that the amount of attenuation increases as the distance from the emission source increases. Further, as can be seen from FIGS. 5 and 7, the larger the propagation loss coefficient n, the larger the slope of the attenuation curve, that is, the degree of change (change amount) of the attenuation amount with respect to the distance. For example, the degree of change in the amount of attenuation when the distance from the emission source is from 500 m to 1000 m is that of the attenuation curve of n = 3 (FIG. 7) as compared with the case of the attenuation curve of n = 2.5 (FIG. 5). The case is bigger.

When the environment from the emission source to the reception point is only the environment corresponding to the 2.5th power law, the propagation loss of the radio wave from the emission source to the reception point can be calculated by using the propagation model shown in FIG. Further, when the environment from the emission source to the reception point is only the environment corresponding to the cube law, the propagation loss of the radio wave from the emission source to the reception point can be calculated by using the propagation model shown in FIG. On the other hand, when there are a plurality of environments from the emission source to the reception point, if the propagation model shown in FIG. 5 or the propagation model shown in FIG. 7 is simply used, the propagation loss may not be calculated accurately as described above. be.

(Embodiment 1)
Hereinafter, embodiments will be described with reference to the drawings. In order to clarify the explanation, the following description and drawings have been omitted or simplified as appropriate. Further, in each drawing, the same elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary.

FIG. 8 is a diagram showing a configuration of the information processing device 100 according to the first embodiment. The information processing device 100 has a control unit 102, a storage unit 104, a communication unit 106, and an interface unit 108 (IF; Interface) as a main hardware configuration. The control unit 102, the storage unit 104, the communication unit 106, and the interface unit 108 are connected to each other via a data bus or the like.

The control unit 102 is, for example, a processor such as a CPU (Central Processing Unit). The control unit 102 has a function as an arithmetic unit that performs control processing, arithmetic processing, and the like. The storage unit 104 is a storage device such as a memory or a hard disk. The storage unit 104 is, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage unit 104 has a function for storing a control program, an arithmetic program, and the like executed by the control unit 102. In addition, the storage unit 104 has a function for temporarily storing processed data and the like. The storage unit 104 may include a database.

The communication unit 106 performs processing necessary for communicating with another device via a wired or wireless network or the like. The communication unit 106 may include a communication port, a router, a firewall, and the like. The interface unit 108 is, for example, a user interface (UI; User Interface). The interface unit 108 includes an input device such as a keyboard, a touch panel, or a mouse, and an output device such as a display or a speaker. The interface unit 108 accepts a data input operation by a user (operator or the like) and outputs information to the user.

Further, the information processing device 100 includes an environment information acquisition unit 110, an environment identification unit 112, a propagation loss calculation unit 114, an environment table storage unit 116, and a propagation loss output unit 118 (hereinafter, referred to as “each component”). .. The environment information acquisition unit 110, the environment identification unit 112, the propagation loss calculation unit 114, the environment table storage unit 116, and the propagation loss output unit 118 are the environment information acquisition means, the environment identification means, the propagation loss calculation means, and the environment table storage, respectively. It functions as a means and a propagation loss output means. The environment specifying unit 112 corresponds to the environment specifying unit 2 in FIG. The propagation loss calculation unit 114 corresponds to the calculation unit 4 in FIG.

Each component can be realized, for example, by executing a program under the control of the control unit 102. More specifically, each component can be realized by the control unit 102 executing the program stored in the storage unit 104. Further, each component may be realized by recording a necessary program on an arbitrary non-volatile recording medium and installing it as needed. Further, each component is not limited to being realized by software by a program, and may be realized by a combination of hardware, firmware, software, or the like. Further, each component may be realized by using a user-programmable integrated circuit such as an FPGA (field-programmable gate array) or a microcomputer. In this case, this integrated circuit may be used to realize a program composed of each of the above components.

The environment table storage unit 116 stores the environment table. The environment table associates each of the plurality of environments with the propagation model corresponding to the environment in advance. The environment table will be described later. The specific functions of the other components will be described later.

FIG. 9 is a flowchart showing a propagation loss calculation method performed by the information processing apparatus 100 according to the first embodiment. The environment information acquisition unit 110 acquires the environment information (step S102). Then, the environment information acquisition unit 110 outputs the acquired environment information to the environment identification unit 112. The environment information acquisition unit 110 may acquire the environment information input to the interface unit 108 by the user, or may acquire the environment information received from another device via the communication unit 106.

Here, the environmental information is information for specifying the environment from the emission source to the reception point. For example, environmental information may include location information of the source and the receiving point. Further, for example, the environmental information may include information indicating the environment of the region existing between the emission source and the receiving point and the size of the region corresponding to the environment. The region may be divided in advance in a mesh shape as illustrated in FIG. In this case, the environmental information may be information representing the space illustrated in FIG. Here, the region may be divided into a mesh shape according to, for example, latitude and longitude. In addition, the environmental information may include at least map information in the vicinity between the emission source and the receiving point, and information indicating the type of environment of the region indicated by the map information. Further, the environmental information may include position information (latitude, longitude, etc.) and information indicating the type of environment in the position information, at least in the vicinity between the emission source and the reception point. That is, it is possible to specify in which environment an arbitrary position in the vicinity between the emission source and the reception point exists by using the environment information.

The environment specifying unit 112 identifies one or more environments through which the propagation path between the radio wave emitting source and the receiving point passes (step S104). Specifically, the environment identification unit 112 identifies the propagation path between the emission source and the reception point by using the position information of the emission source and the reception point included in the environment information. In the examples of FIGS. 2 and 3, the environment identification unit 112 identifies the positions of the emission source Pt and the reception point Pr, and the propagation path Rt. In addition, the environment specifying unit 112 specifies the environment through which the specified propagation path passes by using the environment information. In the examples of FIGS. 2 and 3, the environment identification unit 112 has a propagation path Rt of the environment "city", the environment "forest", the environment "city", and the environment "river" from the emission source Pt toward the reception point Pr. Identify passing through.

Further, the environment specifying unit 112 specifies the length of each environment division by using the environment information. Specifically, the environment specifying unit 112 specifies the position of the boundary of each environment division and calculates the distance between the boundaries. In the example of FIG. 3, the environment specifying unit 112 specifies the positions of the boundary A, the boundary B, and the boundary C. Then, the environment specifying unit 112 specifies the length of the division # 1 in which the environment is a "city" by calculating the distance between the emission source Pt and the boundary A. Further, the environment specifying unit 112 specifies the length of the division # 2 in which the environment is a "forest" by calculating the distance between the boundary A and the boundary B. Further, the environment specifying unit 112 specifies the length of the division # 3 in which the environment is a "city" by calculating the distance between the boundary B and the boundary C. The environment specifying unit 112 specifies the length of the division # 4 in which the environment is a "river" by calculating the distance between the boundary C and the receiving point Pr.

The propagation loss calculation unit 114 calculates the propagation loss of the radio wave from the emission source to the reception point (step S106). Specifically, the propagation loss calculation unit 114 calculates the propagation loss by using the propagation model according to the environment specified by the environment identification unit 112. Here, when the propagation path passes through a plurality of environments, the propagation loss calculation unit 114 calculates the propagation loss of the radio wave from the emission source to the reception point according to the change in the environment when the radio wave propagates through the propagation path. calculate. At this time, the propagation loss calculation unit 114 changes the degree of change in the amount of attenuation with respect to the distance from the emission source according to the change in the environment when the radio wave propagates in the propagation path, thereby moving from the emission source to the reception point. Calculate the propagation loss of radio waves. In the example of FIG. 3, the propagation loss calculation unit 114 changes the degree of change in the amount of attenuation with respect to the distance from the emission source Pt in the propagation model at each boundary A to C from the emission source Pt to the reception point Pr. Calculate the propagation loss of radio waves. Details will be described later.

The propagation loss output unit 118 performs a process for outputting the propagation loss calculated in the process of S106 (step S108). For example, the propagation loss output unit 118 may perform a process for displaying the calculated propagation loss on the interface unit 108. Further, the propagation loss output unit 118 causes the communication unit 106 to transmit information indicating the propagation loss to another device in order to display the calculated propagation loss on another device different from the information processing device 100. Processing may be performed.

Here, the propagation loss calculation unit 114 calculates the propagation loss of the radio wave from the emission source to the receiving point by using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. May be good. Here, at the boundary A in FIG. 3, the environment before the change (category # 1) is “city”, and the environment after the change (category # 2) is “forest”. At the boundary B in FIG. 3, the environment before the change (Category # 2) is “forest”, and the environment after the change (Category # 3) is “city”. At the boundary C in FIG. 3, the environment before the change (Category # 3) is “city”, and the environment after the change (Category # 4) is “river”. Therefore, in the example of FIG. 3, the propagation loss calculation unit 114 calculates the propagation loss of the radio wave from the emission source to the reception point by using the propagation model corresponding to each environment of the categories # 1 to # 4. With such a configuration, the propagation loss calculation unit 114 can calculate the propagation loss of the radio wave from the emission source to the reception point in consideration of both the environment before the change and the environment after the change.

Further, the propagation loss calculation unit 114 corresponds to the degree of change in the amount of attenuation with respect to the distance from the emission source for the propagation path in the changed environment, and the degree of change in the attenuation curve indicating the propagation model corresponding to the changed environment. Thus, the propagation loss of radio waves may be calculated. In the example of FIG. 3, the propagation loss calculation unit 114 determines the degree of change in the amount of attenuation with respect to the distance from the emission source in the propagation path Rt in the division # 2 after the change in the environment for the boundary A, and the environment in the division # 2. Make it correspond to the degree of change of the attenuation curve showing the propagation model corresponding to "Forest". Further, with respect to the boundary B, the propagation loss calculation unit 114 corresponds to the degree of change in the amount of attenuation with respect to the distance from the emission source in the propagation path Rt in the category # 3 after the change in the environment, and corresponds to the environment “city” in the category # 3. Corresponds to the degree of change of the attenuation curve showing the propagation model. Further, with respect to the boundary C, the propagation loss calculation unit 114 corresponds to the degree of change in the amount of attenuation with respect to the distance from the emission source in the propagation path Rt in the category # 4 after the change in the environment, and corresponds to the environment “river” in the category # 4. Corresponds to the degree of change of the attenuation curve showing the propagation model. With such a configuration, the propagation loss calculation unit 114 can calculate the propagation loss of the radio wave from the emission source to the reception point in consideration of the degree of change of the attenuation curve showing the propagation model corresponding to the changed environment. can.

Further, the propagation loss calculation unit 114 may calculate the propagation loss of the radio wave from the emission source to the reception point as follows. The propagation loss calculation unit 114 calculates the amount of attenuation at the boundary using a propagation model corresponding to the environment before the change. The propagation loss calculation unit 114 calculates the amount of attenuation at the boundary using a propagation model corresponding to the changed environment. Then, the propagation loss calculation unit 114 sets the attenuation amount calculated by using the propagation model corresponding to the environment before the change and the attenuation amount calculated by using the propagation model corresponding to the environment after the change at the boundary. Calculate the difference. Further, the propagation loss calculation unit 114 calculates the amount of attenuation at the receiving point using a propagation model corresponding to the environment of the receiving point. Then, the propagation loss calculation unit 114 calculates the propagation loss of the radio wave from the emission source to the reception point by using the calculated difference and the attenuation amount calculated by using the propagation model corresponding to the environment of the reception point. do. With such a configuration, the propagation loss calculation unit 114 can easily calculate the propagation loss of the radio wave from the emission source to the reception point.

In the example of FIG. 3, for the boundary A, the propagation loss calculation unit 114 calculates the amount of attenuation at the boundary A using the propagation model corresponding to the environment “city” of the category # 1. The propagation loss calculation unit 114 calculates the amount of attenuation at the boundary A using the propagation model corresponding to the environment “forest” of category # 2. Then, the propagation loss calculation unit 114 sets the attenuation amount calculated by using the propagation model corresponding to the environment "city" and the attenuation amount calculated by using the propagation model corresponding to the environment "forest" for the boundary A. The difference ΔA of is calculated.

Further, with respect to the boundary B, the propagation loss calculation unit 114 calculates the amount of attenuation at the boundary B using the propagation model corresponding to the environment “forest” of the category # 2. The propagation loss calculation unit 114 calculates the amount of attenuation at the boundary B using the propagation model corresponding to the environment “city” of category # 3. Then, the propagation loss calculation unit 114 sets the attenuation amount calculated by using the propagation model corresponding to the environment "forest" and the attenuation amount calculated by using the propagation model corresponding to the environment "city" for the boundary B. The difference ΔB of is calculated.

Further, with respect to the boundary C, the propagation loss calculation unit 114 calculates the amount of attenuation at the boundary C using the propagation model corresponding to the environment “city” of the category # 3. The propagation loss calculation unit 114 calculates the amount of attenuation at the boundary C using the propagation model corresponding to the environment “river” of category # 4. Then, the propagation loss calculation unit 114 sets the attenuation amount calculated by using the propagation model corresponding to the environment "city" and the attenuation amount calculated by using the propagation model corresponding to the environment "river" for the boundary C. The difference ΔC of is calculated.

Further, for the reception point Pr, the propagation loss calculation unit 114 calculates the attenuation amount at the reception point Pr by using the propagation model corresponding to the environment “river” of the category # 4. Then, the propagation loss calculation unit 114 uses the differences ΔA, ΔB, and ΔC and the attenuation amount at the reception point Pr calculated by using the propagation model corresponding to the environment “river” from the emission source to the reception point. Calculate the propagation loss of radio waves.

Further, the propagation loss calculation unit 114 generates a propagation model corresponding to the section from the emission source to the reception point by using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. You may. That is, the propagation loss calculation unit 114 may generate a propagation model corresponding to the section from the emission source to the reception point by using the propagation model corresponding to a plurality of environments. Then, the propagation loss calculation unit 114 may calculate the propagation loss of the radio wave from the emission source to the reception point by using the generated propagation model. In the example of FIG. 3, the propagation loss calculation unit 114 generates a propagation model corresponding to the section from the emission source Pt to the reception point Pr by using the propagation model corresponding to each environment of the divisions # 1 to # 4. May be good. Then, the propagation loss output unit 118 may output an attenuation curve representing the generated propagation model. With such a configuration, the user can easily grasp the propagation loss to a point other than the receiving point.

Further, the propagation loss calculation unit 114 may calculate the propagation loss of the radio wave from the emission source to the reception point by referring to the environment table stored in the environment table storage unit 116. By referring to the environment table by the propagation loss calculation unit 114, the process of calculating the propagation loss of the radio wave by the propagation loss calculation unit 114 becomes easy.

FIG. 10 is a diagram illustrating an environment table stored in the environment table storage unit 116 according to the first embodiment. The environment table illustrated in FIG. 10 shows the relationship between the type of environment and the propagation loss coefficient n. Here, from Equation 4, if the propagation loss coefficient n is determined, the propagation model is determined. In the example of FIG. 10, for example, the propagation loss coefficient n corresponding to the environment A is n _A , so that the exponent of the distance r is n _A in the propagation model corresponding to the environment A. For example, if the environment A is a "city", then n _A = 3.

(Specific example of propagation loss calculation method)
FIG. 11 is a diagram for explaining a first specific example of the propagation loss calculation method according to the first embodiment. In the first embodiment, the propagation path passes through two environments. In the first specific example, as shown in FIG. 11, the division I from the emission source to the boundary a is an environment corresponding to the 2.5th power law, and the division II from the boundary a to the receiving point b is the third power law. It is an environment corresponding to. The distance A from the emission source to the boundary a is 500 [m], and the distance from the emission source to the reception point b is 1500 [m].

FIG. 12 is a diagram illustrating a propagation model in the first specific example. In FIG. 12, the dotted line represents a damping curve showing a propagation model corresponding to a 2.5 power law environment. Also, the alternate long and short dash line represents an attenuation curve showing a propagation model corresponding to the environment of the cube law. Further, the solid line represents an attenuation curve showing a propagation model when a radio wave passes through two environments, an environment of the 2.5th power law and an environment of the 3rd power law, from the emission source to the reception point.

At this time, as shown in FIG. 12, the propagation loss calculation unit 114 sets the propagation model of the category I as a propagation model corresponding to the environment of the 2.5th power law. Further, the propagation loss calculation unit 114 starts from the point P1 indicating the amount of attenuation by the propagation model of the 2.5th power law at the boundary a as the propagation model of the division II, and the slope (degree of change) is the cubic law in the division II. The curve should be the slope (degree of change) of the attenuation curve showing the propagation model of. In this way, the propagation loss calculation unit 114 generates a propagation model when the radio wave passes through the divisions I and II as shown by the solid line.

Next, a method of calculating the propagation loss from the emission source to the reception point b will be described. The propagation loss calculation unit 114 calculates the attenuation Loss (a) by the propagation model of the 2.5th power law at the boundary a using the following equation 6.

Further, the propagation loss calculation unit 114 calculates the attenuation amount Loss (a') by the propagation model of the cube law at the boundary a using the following equation 7.

Further, the propagation loss calculation unit 114 uses the following equation 8 to reduce the amount of attenuation Loss (a) by the propagation model of the 2.5th power law and the amount of attenuation Loss (a'by the propagation model of the third power law) at the boundary a. ) And the difference Loss (aa') are calculated.

Further, the propagation loss calculation unit 114 calculates the attenuation amount Loss (b) at the receiving point b using the following equation 9. In addition, Equation 9 is obtained by adding the difference calculated by Equation 8 to the amount of attenuation by the propagation model of the cube law at the receiving point b.

This attenuation amount Loss (b) corresponds to the propagation loss of the radio wave from the emission source to the reception point b. Further, this attenuation amount Loss (b) is the attenuation amount at the distance from the emission source to the reception point b in the propagation model (attenuation curve shown by the solid line in FIG. 12) when the radio wave passes through the divisions I and II. be.

FIG. 13 is a diagram for explaining a second specific example of the propagation loss calculation method according to the first embodiment. In the second embodiment, the propagation path passes through three environments. In the second specific example, as shown in FIG. 13, the division I from the emission source to the boundary a is an environment corresponding to the 2.5th power law, and the division II from the boundary a to the boundary b is the third power law. It is a corresponding environment, and the division III from the boundary c to the receiving point b is an environment corresponding to the fourth power law. Further, the distance A from the emission source to the boundary a is 500 [m], the distance from the emission source to the boundary b is 1500 [m], and the distance from the emission source to the reception point c is 2000 [m]. be.

FIG. 14 is a diagram illustrating a propagation model in the second specific example. In FIG. 14, the dotted line represents a damping curve showing a propagation model corresponding to a 2.5 power law environment. Also, the alternate long and short dash line represents an attenuation curve showing a propagation model corresponding to the environment of the cube law. Further, the broken line represents a damping curve showing a propagation model corresponding to the environment of the fourth power law. The solid line with triangular dots is the propagation of radio waves from the source to the receiving point when they pass through three environments: a 2.5th power environment, a 3rd power environment, and a 4th power environment. Represents a damping curve that shows the model.

At this time, as shown in FIG. 14, the propagation loss calculation unit 114 sets the propagation model of the category I as a propagation model corresponding to the environment of the 2.5th power law. Further, the propagation loss calculation unit 114 starts from the point P1 indicating the amount of attenuation by the propagation model of the 2.5th power law at the boundary a as the propagation model of the division II, and the inclination (degree of change) is the cuber law in the division II. The curve should be the slope (degree of change) of the decay curve showing the propagation model of. Further, the propagation loss calculation unit 114 starts with the point P2 indicating the amount of attenuation by the propagation model at the boundary b as the propagation model of the division III, and the attenuation (degree of change) indicates the attenuation model of the fourth power law in the division III. The curve should be such that the slope of the curve (degree of change) is obtained. In this way, the propagation loss calculation unit 114 generates a propagation model when a radio wave passes through Category I, Category II, and Category III, as shown by a solid line with triangular dots.

Next, a method of calculating the propagation loss from the emission source to the reception point c will be described. The propagation loss calculation unit 114 calculates the attenuation amount Loss (a) by the propagation model of the 2.5th power law at the boundary a using the above equation 6. The propagation loss calculation unit 114 calculates the attenuation Loss (a') by the propagation model of the cube law at the boundary a using the above equation 7. Using the above equation 8, the propagation loss calculation unit 114 uses the above equation 8 to determine the attenuation amount Loss (a) by the propagation model of the 2.5th power law and the attenuation amount Loss (a') by the propagation model of the cubic law at the boundary a. The difference Loss (aa') of is calculated. The propagation loss calculation unit 114 calculates the attenuation Loss (b) at the boundary b using the above equation 9.

The propagation loss calculation unit 114 calculates the attenuation Loss (b') by the propagation model of the fourth power law at the boundary b using the following equation 10.

Further, the propagation loss calculation unit 114 uses the following equation 11 to determine the attenuation amount Loss (b) by the propagation model of the cube law and the attenuation amount Loss (b') by the propagation model of the fourth power law at the boundary b. The difference Loss (bb') of is calculated.

Further, the propagation loss calculation unit 114 calculates the attenuation amount Loss (c) at the receiving point c by using the following equation 12. In addition, Equation 12 is obtained by adding the difference calculated by Equation 11 to the amount of attenuation by the propagation model of the fourth power law at the receiving point c.

This attenuation amount Loss (c) corresponds to the propagation loss of the radio wave from the emission source to the reception point c. Further, this attenuation amount Loss (c) is received from the emission source in the propagation model (attenuation curve shown by the solid line with triangular dots in FIG. 14) when the radio wave passes through the divisions I, II and III. The amount of attenuation at the distance to point c.

(Modification example)
The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit. For example, in the above-mentioned flowchart, the order of each process (step) can be changed as appropriate. Moreover, one or more of a plurality of processes (steps) may be omitted. For example, the process of S108 in FIG. 9 may be omitted.

Further, in the above-described embodiment, the propagation loss (attenuation amount) is expressed in decibels (dB; logarithmic), but when calculating the propagation loss, it is not necessary to calculate the propagation loss as decibels (dB). That is, the propagation loss may be calculated as the true value (watt (W)) without being converted into decibels. In this case, the difference in the amount of attenuation as in Equation 8 means the ratio of the true values of the amount of attenuation. In other words, the concept of "difference in attenuation" includes the concept of "ratio of true values of attenuation".

In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable medium. Non-temporary computer-readable media include various types of tangible storage media. Examples of non-temporary computer-readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs. CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)) are included. The program may also be supplied to the computer by various types of transient computer readable medium. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

Some or all of the above embodiments may also be described, but not limited to:
(Appendix 1)
An environment-identifying means that identifies one or more environments through which a propagation path between a radio wave source and a reception point passes.
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. An information processing device having a calculation means for calculating the propagation loss of radio waves from the emission source to the reception point.
(Appendix 2)
The calculation means is a propagation model showing the relationship between the distance from the emission source and the attenuation amount of radio waves, and is the propagation model corresponding to the environment before the change and the propagation corresponding to the environment after the change. The information processing apparatus according to Appendix 1, which calculates the propagation loss of radio waves from the emission source to the reception point using a model.
(Appendix 3)
The calculation means determines the degree of change in the amount of attenuation with respect to the distance from the emission source for the propagation path in the changed environment, and the degree of change in the attenuation curve indicating the propagation model corresponding to the changed environment. Correspondingly, the information processing apparatus according to Appendix 2, which calculates the propagation loss of radio waves from the emission source to the reception point.
(Appendix 4)
The calculation means is
Using the propagation model corresponding to the environment before the change, the amount of attenuation at the boundary where the environment changes is calculated.
Using the propagation model corresponding to the changed environment, the amount of attenuation at the boundary is calculated.
Calculate the difference between the amount of attenuation calculated using the propagation model corresponding to the environment before the change and the amount of attenuation calculated using the propagation model corresponding to the environment after the change at the boundary. ,
The amount of attenuation at the receiving point is calculated using the propagation model corresponding to the environment of the receiving point.
The information processing apparatus according to Appendix 3, which calculates the propagation loss of radio waves from the emission source to the reception point by using the calculated difference and the calculated attenuation amount at the reception point.
(Appendix 5)
The calculation means uses the propagation model corresponding to the plurality of environments to generate the propagation model corresponding to the section from the emission source to the reception point, thereby from the emission source to the reception point. The information processing device according to any one of Appendix 2 to 4, which calculates the propagation loss of radio waves.
(Appendix 6)
Further having a storage means for storing an environment table for preliminarily associating each of the plurality of environments with the propagation model corresponding to the environment.
The information processing apparatus according to any one of Supplementary note 2 to 5, wherein the calculation means calculates the propagation loss of radio waves from the emission source to the reception point by referring to the environment table.
(Appendix 7)
Identify one or more environments through which the propagation path between the source and receive point of the radio wave passes.
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. A propagation loss calculation method for calculating the propagation loss of radio waves from a source to the receiving point.
(Appendix 8)
A propagation model showing the relationship between the distance from the emission source and the amount of radio wave attenuation, using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. The method for calculating the propagation loss according to Appendix 7, wherein the propagation loss of the radio wave from the emission source to the reception point is calculated.
(Appendix 9)
A propagation model showing the relationship between the distance from the emission source and the amount of radio wave attenuation, using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. , The propagation loss calculation method according to Appendix 8 for calculating the propagation loss of radio waves from the emitting source to the receiving point.
(Appendix 10)
With respect to the propagation path in the changed environment, the degree of change in the amount of attenuation with respect to the distance from the source is made to correspond to the degree of change in the attenuation curve showing the said propagation model corresponding to the changed environment. The method for calculating the propagation loss according to Appendix 9, wherein the propagation loss of the radio wave from the emission source to the reception point is calculated.
(Appendix 11)
Using the propagation model corresponding to the environment before the change, the amount of attenuation at the boundary where the environment changes is calculated.
Using the propagation model corresponding to the changed environment, the amount of attenuation at the boundary is calculated.
Calculate the difference between the amount of attenuation calculated using the propagation model corresponding to the environment before the change and the amount of attenuation calculated using the propagation model corresponding to the environment after the change at the boundary. ,
The amount of attenuation at the receiving point is calculated using the propagation model corresponding to the environment of the receiving point.
The propagation loss calculation method according to Appendix 10, wherein the propagation loss of a radio wave from the emission source to the reception point is calculated by using the calculated difference and the calculated attenuation amount at the reception point.
(Appendix 12)
By using the propagation model corresponding to the plurality of environments to generate the propagation model corresponding to the section from the emission source to the reception point, the propagation loss of the radio wave from the emission source to the reception point can be reduced. Calculation The propagation loss calculation method according to any one of Appendix 8 to 11.
(Appendix 13)
Any one of Appendix 8 to 12 for calculating the propagation loss of radio waves from the emission source to the reception point by referring to an environment table in which each of the plurality of environments and the propagation model corresponding to the environment are associated in advance. The propagation loss calculation method described in the section.
(Appendix 14)
Steps to identify one or more environments through which the propagation path between the source and receive point of a radio wave passes, and
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. A program that causes a computer to perform steps to calculate the propagation loss of radio waves from the source to the receiving point.

1 Information processing device 2 Environment specification unit 4 Calculation unit 100 Information processing device 110 Environment information acquisition unit 112 Environment specification unit 114 Propagation loss calculation unit 116 Environment table storage unit 118 Propagation loss output unit

Claims (10)

An environment-identifying means that identifies one or more environments through which a propagation path between a radio wave source and a reception point passes.
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. An information processing device having a calculation means for calculating the propagation loss of radio waves from the emission source to the reception point. The calculation means is a propagation model showing the relationship between the distance from the emission source and the attenuation amount of radio waves, and is the propagation model corresponding to the environment before the change and the propagation corresponding to the environment after the change. The information processing apparatus according to claim 1, wherein the propagation loss of radio waves from the emission source to the reception point is calculated by using a model. The calculation means determines the degree of change in the amount of attenuation with respect to the distance from the emission source for the propagation path in the changed environment, and the degree of change in the attenuation curve indicating the propagation model corresponding to the changed environment. The information processing apparatus according to claim 2, wherein the propagation loss of radio waves from the emission source to the reception point is calculated correspondingly. The calculation means is
Using the propagation model corresponding to the environment before the change, the amount of attenuation at the boundary where the environment changes is calculated.
Using the propagation model corresponding to the changed environment, the amount of attenuation at the boundary is calculated.
Calculate the difference between the amount of attenuation calculated using the propagation model corresponding to the environment before the change and the amount of attenuation calculated using the propagation model corresponding to the environment after the change at the boundary. ,
The amount of attenuation at the receiving point is calculated using the propagation model corresponding to the environment of the receiving point.
The information processing apparatus according to claim 3, wherein the calculated difference and the calculated attenuation amount at the receiving point are used to calculate the propagation loss of radio waves from the emitting source to the receiving point. The calculation means uses the propagation model corresponding to the plurality of environments to generate the propagation model corresponding to the section from the emission source to the reception point, thereby from the emission source to the reception point. The information processing apparatus according to any one of claims 2 to 4, which calculates the propagation loss of radio waves. Further having a storage means for storing an environment table for preliminarily associating each of the plurality of environments with the propagation model corresponding to the environment.
The information processing apparatus according to any one of claims 2 to 5, wherein the calculation means calculates the propagation loss of radio waves from the emission source to the reception point by referring to the environment table. Identify one or more environments through which the propagation path between the source and receive point of the radio wave passes.
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. A propagation loss calculation method for calculating the propagation loss of radio waves from a source to the receiving point. A propagation model showing the relationship between the distance from the emission source and the amount of radio wave attenuation, using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. The propagation loss calculation method according to claim 7, wherein the propagation loss of radio waves from the emission source to the reception point is calculated. A propagation model showing the relationship between the distance from the emission source and the amount of radio wave attenuation, using the propagation model corresponding to the environment before the change and the propagation model corresponding to the environment after the change. The propagation loss calculation method according to claim 8, wherein the propagation loss of radio waves from the emission source to the reception point is calculated. Steps to identify one or more environments through which the propagation path between the source and receive point of a radio wave passes, and
When the propagation path passes through a plurality of environments, the degree of change in the amount of attenuation with respect to the distance from the emission source is changed according to the change in the environment when the radio wave propagates in the propagation path. A program that causes a computer to perform steps to calculate the propagation loss of radio waves from the source to the receiving point.

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