JP2016213835A - Method, apparatus, and system for tracking electromagnetic wave propagation path - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, an apparatus and a system for tracking an electromagnetic wave propagation path.SOLUTION: The method comprises: determining an effective plane of the transmission point on the basis of a predetermined effective plane selection radius; detecting an intersection point of the ray and the effective plane along the direction of the ray for each ray emitted by the transmission point; and when an intersection point of the ray and the effective plane is present and a path cumulative reflection equivalent passing through an effective intersection point of the ray is not more than a predetermined maximum reflection equivalent amount, determining the next path direction of the ray until the ray reaches the receiving area of the receiving point or the path accumulative reflection equivalent passing through the effective intersection of the ray is larger than the predetermined maximum reflection equivalent. According to the embodiment of the present invention, it is possible to reduce the complexity of the calculation process in the path tracking process, to realize more efficient and accurate simulation of the electromagnetic transmission path, and to acquire electromagnetic wave propagation characteristics in the observed wireless network.SELECTED DRAWING: Figure 10

Description

  The present invention relates to the field of communication technology, and more particularly to an electromagnetic wave propagation path tracking method, apparatus, and system.

  With the rapid development of wireless communication, various wireless applications that provide services for human life and work are increasing. Accordingly, demands on the performance of wireless communication systems for applications based on various services are increasing. Wireless communication systems are always available in a variety of different environmental scenarios, such as urban environments with buildings, large and unshielded suburban environments, or vegetated forest environments, according to different application requirements. Has been placed. The method of acquiring propagation characteristics in a specific environment of a wireless system has very important significance for predicting the signal electric field strength of the wireless network, more rational planning of the wireless network, and improving the performance of the wireless network.

  There are various differences in the deployment environment of wireless networks. From the viewpoint of factors such as the relative complexity of the environment and the scale of network coverage, it is impractical to acquire radio propagation characteristics through actual measurements. The cost is too high in terms of human resources, material resources and measurement difficulty. For this reason, the wireless propagation model has become a common, low-cost, and quicker effective means in the process of acquiring the propagation characteristics of a wireless network.

  Many mature models are already widely used in wireless propagation modeling methods. Conventional wireless modeling methods are mainly divided into two types: an empirical model based on mathematical theory and a deterministic model based on electromagnetic wave propagation theory. The deterministic model is more accurate than the empirical model and helps to predict environmental parameters.

  Ray-tracing is one of the modeling methods often used for studying radio propagation characteristics among deterministic models. The basic concept of the path tracking method is based on geometric optical theory, and it is possible to effectively track the propagation path of electromagnetic waves by simple geometric calculations, and to effectively predict the electric field strength at each location. . For conventional ordinary wireless communication systems, such as the Wifi system and the Zigbee system, the frequency of the radio signal is usually high, so the wavelength of the electromagnetic wave is very small compared to the size of the building. In modeling, as shown in FIG. 1, it is usually considered that each electromagnetic wave is an optical ray.

  The path-tracing method mainly includes two modeling methods, that is, an imaging method (Imaging) and a ray-launching method (Ray-launching). The imaging method (Imaging) is based on the optical mirror image principle, and is a tracking technique that effectively determines an electromagnetic wave propagation path. The method considers all obstacles as potential transmission sources, determines the position of the reflection point by finding the multi-stage mirror point for each obstacle plane in the transmission point (reception point) scenario, Simulate the propagation path in the electromagnetic wave transmission environment. In the mirror image method, the accuracy of the modeling method is determined by the calculation of the mirror image point complexity, is relatively complex, and for relatively large scale scenarios, the mirror image point acquisition process is complex, and This leads to a time-consuming calculation process.

  It should be noted that the above description regarding the background art is merely for explaining the technical solution of the present invention more clearly and completely, and is intended to allow those skilled in the art to understand. Since these technical solutions are described in the background section of the present invention, they should not be construed as techniques well known to those skilled in the art.

  Embodiments of the present invention provide a method, an apparatus, and a system for tracking an electromagnetic wave propagation path that can realize more efficient and accurate simulation of an electromagnetic transmission path and that can acquire electromagnetic wave propagation characteristics in an observed wireless network. Objective.

  According to a first aspect of an embodiment of the present invention, there is a method for tracking an electromagnetic wave propagation path, the step of determining an effective plane of a transmission point based on a predetermined effective plane selection radius, and each of the emission points emitted by the transmission point Detecting an intersection between the ray and the effective plane along the ray direction, and a cumulative path reflection where the intersection between the ray and the effective plane exists and passes through the effective intersection of the ray. When the equivalent is less than or equal to a predetermined maximum reflection equivalent, until the ray reaches the reception area of the reception point, or the path cumulative reflection equivalent passing through the effective intersection of the ray becomes larger than the predetermined maximum reflection equivalent Determining a next path direction of the ray.

  According to a second aspect of the embodiment of the present invention, there is provided a tracking device for an electromagnetic wave propagation path, a determination unit that determines an effective plane of a transmission point based on a predetermined effective plane selection radius, and a light emitted by the transmission point For each ray, detection means for detecting an intersection of the ray and the effective plane along the ray direction, and a path through which the intersection of the ray and the effective plane exists and passes through the effective intersection of the ray When the cumulative reflection equivalent is less than or equal to a predetermined maximum reflection equivalent, the ray reaches the reception area of the reception point, or the path cumulative reflection equivalent passing through the effective intersection of the ray is greater than the predetermined maximum reflection equivalent. And a processing means for determining a next path direction of the ray.

  According to a third aspect of an embodiment of the present invention, there is provided a computer system including the electromagnetic wave propagation path tracking device according to the second aspect.

  As a beneficial effect of the embodiment of the present invention, according to the embodiment of the present invention, it is possible to reduce the complexity of the calculation process in the path tracking process, to realize a more efficient and accurate simulation of the electromagnetic transmission path, The electromagnetic wave propagation characteristics in the observed wireless network can be acquired.

  As shown in the following description and drawings, specific embodiments of the present invention are disclosed in detail and show the manner in which the principles of the invention can be employed. The scope of the embodiment of the present invention is not limited to these. The embodiments of the present invention include changes, modifications and equivalents within the spirit and scope of the appended claims.

  Features described and / or illustrated features in one embodiment may be used in one or more other embodiments in the same or similar manner, and may be combined with features in other embodiments. It may replace the feature in other embodiments.

  In this context, the term “include / include” refers to the presence of a feature, member, step or component and does not exclude the presence or addition of one or more other features, members, steps or components.

The drawings included are used to further understand the examples of the present invention, constitute part of the specification, and are used to illustrate the embodiments of the present invention. explain. The drawings described below are merely some embodiments of the present invention, and those skilled in the art can easily conceive other drawings based on these drawings.
It is a figure which shows an example of the propagation path of an optical ray. It is a two-dimensional figure which shows that a transmission point emits electromagnetic wave rays uniformly. It is a figure which shows an example of a ray firing method. It is a figure which shows an example of the receiving area | region of a ray emission method. It is a figure which shows an example of the intersection of a ray and an obstruction plane. 2 is a flowchart of one aspect of a method for tracking an electromagnetic wave propagation path according to the first embodiment. It is a figure which shows an example of the effective plane of the transmission point determined by the effective plane selection radius. It is a figure which shows the direct path | route tracking of a ray. It is a figure which shows ray reflection path tracking. 3 is a flowchart of the entire route tracking process. It is a figure which shows a receiving area radius. It is a figure which shows the calculation principle of a receiving area radius. It is a figure which shows that neither ray passes a receiving area. It is a figure which shows solving that a ray does not pass a receiving area by enlarging a receiving area. It is a figure which shows ray path | route rotation. It is a figure which shows the structure of the one aspect | mode of the tracking apparatus of the electromagnetic wave propagation path of Example 2. FIG. FIG. 10 illustrates a configuration of a computer system according to a third embodiment.

  The above and other features of the present invention will be described with reference to the drawings. As shown in the following description and drawings, specific embodiments of the present invention are disclosed in detail and some of the embodiments that can employ the principles of the present invention are shown. The scope of the embodiment of the present invention is not limited to these. The embodiments of the present invention include changes, modifications and equivalents within the spirit and scope of the appended claims.

  The basic concept of ray-launching assumes that electromagnetic waves emitted by transmission points are propagated in space as equally spaced scattered rays in three-dimensional space. As shown in FIG. 2, the angular interval of the electromagnetic wave ray (abbreviated as ray or electromagnetic wave) emitted by the transmission point Tx is θ, and by finding the electromagnetic wave ray in the vicinity of the receiver at the reception point Rx. Determine the electromagnetic path that really reached the receiving point.

  In the ray launching method (Ray-launching), a method for determining that an electromagnetic wave ray has reached a reception point is defined. As shown in FIG. 3, since the electromagnetic wave emitted from the transmission point Tx is assumed to be a scattered ray having a constant interval in the method, the electromagnetic wave ray that has reached the position of the reception point is accurately obtained. It is relatively difficult to do. According to the method, a reception area having a reasonable size is determined around the reception point Rx, the area is regarded as a receivable area for the electromagnetic wave of the reception point, and when the electromagnetic wave ray passes through the determination area, It is assumed that the signal indicated by the electromagnetic wave ray has been received at the receiving point. Otherwise, it is considered that the signal indicated by the electromagnetic wave ray is not received at the receiving point.

  In this case, a method of setting a reasonably sized reception area is the most important issue. As shown in FIG. 4, if the set reception area is too small, some electromagnetic waves that should be received by the reception point in the scenario may not pass through the reception area, resulting in leakage of received signals. An error occurs when the received signal is calculated. If the determined reception area is too large, the number of electromagnetic wave rays passing through the reception area increases, causing a problem that double calculation is performed for the same path ray at the reception point, and an error occurs.

  On the other hand, in the ray emission method, the transmission point emits an electromagnetic wave ray, tracks each ray, and determines whether the ray collides with an obstacle or passes through a reception area around the reception point. When the ray passes through the reception area of the reception point, a contribution degree to the reception signal at the reception point of the ray is calculated. The ray collides with an obstacle on the way, determines the ray path type (for example, reflection type, diffraction type, etc.) based on conditions such as the geometrical characteristics of the incident, determines the next path direction of the ray, Keep track of the ray.

  In the ray tracing process of each ray, the ray always strikes several different obstacles, causing diffraction, passing through these obstacles, and projecting and reflecting on the surfaces of these obstacles. Therefore, in the ray path determination process, as shown in FIG. 5, it is necessary to perform an operation for obtaining a solution with respect to the intersection of the firing ray and each modeling plane according to a geometric method.

  In the ray path determination process, the operation for obtaining the intersection is a complicated process and a time-consuming process. In calculating the intersection point, the process of determining whether or not the ray intersects the plane using geometric information, the process of obtaining the geometric position of the intersection point by finding the solution, and whether the calculated intersection point really exists And the process of determining the next propagation direction of a ray path using the obtained intersection information. For a complex and large-scale scenario, it is necessary to perform an operation for obtaining the intersection of each ray and each plane, and accordingly, the calculation complexity and the time required are greatly increased.

  From the above description, in the ray emission method, it is a problem to be first considered to rationally plan the size of the reception area of the reception point. When determining the propagation path of electromagnetic waves using the ray emission method, it is necessary to consider all the emission rays, which plane each ray intersects during propagation, and where the intersecting intersection is located In particular, in a complicated scenario environment, processes such as acquisition of an intersection between a ray and a plane and determination of a reflection point are complicated processes that require a large amount of calculation and take time. Third, as a problem inherent in the ray emission method, how to prevent double calculation for the same signal after planning the size of the reception area of the reception point is the problem when using this method. Points still need to be considered and avoided.

  In view of various problems in the ray emission method, an embodiment of the present invention provides a method for tracking an electromagnetic wave propagation path with low computational complexity and high accuracy based on the ray emission method. Since the method is based on geometric optics theory, the construction and analysis of all scenarios will ultimately apply to a three-dimensional coordinate environment.

  In 3D coordinates, first, the observed scenario area is planned based on the detailed scenario information acquired, the position of each object in the scenario is determined in 3D space, and the object in the scenario is determined based on the corresponding coordinates. Place within the planned area. After the position is determined, each object (obstacle) present in the scenario is converted into a plane or polyhedron having a material characteristic of the corresponding thickness, height, and electrical parameters (dielectric constant, conductivity, etc.). May be approximated to a polyhedron constructed by connecting small planes).

  After the modeling of the radio signal propagation scenario is completed, the transmission point Tx and the reception point Rx are arranged at the correct positions in the three-dimensional coordinate environment based on the request (number, arrangement position, etc.), and the radio transmission / reception node parameters, For example, transmission power, transmission / reception antenna type (omnidirectional antenna, directional antenna, etc.), antenna height, antenna attribute, etc. are set. Thus, scenario modeling of the observed wireless network has been completed.

  Embodiments of the present invention are implemented in the above scenario, and the following describes embodiments of the present invention with reference to the drawings.

<Example 1>
An embodiment of the present invention provides a method for tracking an electromagnetic wave propagation path, which method is applied to a radio signal propagation scenario, and a process for constructing the propagation scenario is as described above. FIG. 6 is a flowchart of the method. As shown in FIG. 6, the method includes the following steps.

  Step 601: An effective plane of a transmission point is determined based on a predetermined effective plane selection radius.

  Step 602: For each ray emitted by the transmission point, an intersection between the ray and the effective plane is detected along the ray direction.

  Step 603: When an intersection of the ray and the effective plane exists and a path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent, the ray is in the reception area of the reception point. The next path direction of the ray is determined until the cumulative reflection equivalent that reaches or passes through the effective intersection of the ray is greater than a predetermined maximum reflection equivalent. Thus, the propagation path of the ray is acquired, and the electromagnetic wave propagation path of the transmission point is acquired.

  In this example, after the above scenario configuration work was completed, it was configured to reduce the complexity of the observed scenario to some extent in advance, and to reduce the complexity of related calculations in the subsequent electromagnetic path tracking process. Operate the area classification for the scenario.

  In this embodiment, all the objects in the scenario are simplified to a polyhedral structure surrounded by several planes, the effective area is segmented in the scenario, and the obstacle plane is located in the effective area. The object plane is referred to as the effective plane, and in the subsequent electromagnetic wave path tracking process, the effective plane is regarded as a plane that may reflect the electromagnetic ray, and the obstacle plane is located outside the effective area. The obstacle plane is referred to as an invalid plane, and in the later electromagnetic wave path tracking process, the invalid plane does not reflect the electromagnetic ray, and related operations such as acquisition of the intersection do not consider the invalid plane located outside the effective area.

  In the present embodiment, the effective area is determined by a predetermined effective plane selection radius L, and even if the transmission point Tx is a reference point (circular center) and the coverage radius is a circular area having the effective plane selection radius L, Good. In the configured scenario, if the distance between the obstacle plane and the reference point Tx is larger than the effective plane selection radius L, that is, if the obstacle plane is located outside the circular coverage area of radius L, the plane Is not considered in the calculation process of the subsequent intersection acquisition and is considered an invalid plane. On the other hand, when the plane of the obstacle is located within the area covered by the effective plane selection radius L, the plane is regarded as an effective plane. Therefore, the effective plane of the transmission point can be determined based on the predetermined effective plane selection radius.

  Here, regarding the effective plane, the electromagnetic wave may collide with the plane in the propagation process and be reflected, and the electromagnetic path may contribute to the reception signal at the reception point. This means that it is necessary to consider intersection calculation. As shown in FIG. 7, a large-scale complex scenario is modeled as required, and the distance t between each plane of each obstacle in the scenario and the reference point Tx is calculated using the transmission point Tx as a reference point. Then, the distance t is compared with a predetermined effective area selection radius L to determine the effective plane of the transmission point.

  As shown in FIG. 7, the circular region is an effective region configured with Tx as the center and L as the radius, and when the distance t between the plane n and the reference point Tx is larger than L, the circular region is Since the plane n is located outside the effective area, it is considered that there is no electromagnetic wave reflection path that has passed through the plane n, or that the contribution of the reception point of the reflection path to the received signal is weak. Considering a plane, the plane n does not have to be taken into account in the subsequent intersection acquisition calculation.

  In this embodiment, the radius L of the effective area may be set based on different calculation accuracy requirements. When the accuracy requirement is high, the calculation process considers the influence of more obstacles on electromagnetic wave propagation. Therefore, the threshold (effective plane selection radius L) may be set to a relatively large numerical value. For example, the threshold may be set to the maximum communication range supported by the currently observed wireless network. When the distance from the plane reference point Tx is larger than the communication distance supported by the system, the plane may be regarded as an invalid plane. This is because if the distance between the plane and the transmission point is larger than the maximum distance (that is, the communication distance) that the electromagnetic wave signal emitted by the transmission point can propagate, the plane does not reflect the electromagnetic wave or the reflected signal is very This is because it may be considered to be weak, and it does not have a great influence on the reception performance of the reception point. Therefore, the plane may be regarded as an invalid plane.

  In the present embodiment, an information list of all obstacles may be maintained in advance for the obstacles arranged in the radio signal propagation scenario. As shown in Table 1, the obstacle information table includes the obstacle information table. ID item (Object ID), obstacle entity name item (Object name), number of planes included in the obstacle (Plane amount), and plane ID items included in the obstacle (Plane IDs in Object) May be included.

Table 1: Obstacle information table

  Here, the item of the obstacle ID indicates a unique identifier in the scenario of the obstacle, and the item of the obstacle entity name indicates a corresponding name in the actual environment of the obstacle (for example, building, wall, mountain, etc.). The number of planes included in the obstacle field indicates the number of planes constituting the current obstacle, and each plane constituting the obstacle has a unique identifier in the scenario, and the plane ID included in the obstacle The item of indicates a unique identifier of all planes constituting the current obstacle.

  In this embodiment, as shown in Table 2, a plane information list corresponding to each obstacle plane may be maintained for the radio signal propagation scenario. The plane information table mainly includes a plane ID item (Plane ID), an obstacle ID (Object ID), a plane vertex coordinate item (Coordinateate of vertex), and a distance item between a plane and a transmission point ( (Distance with Tx), an effective reflection plane flag item (Effective plane flag), an electrical parameter item (Electrical parameters), and the like.

Table 2: Obstacle plane information table

  The plane ID item indicates the unique identifier of the current corresponding plane, the belonging obstacle ID indicates the unique identifier in the scenario of the obstacle to which the current plane belongs, and the distance between the plane and the transmission point Item indicates the distance between the current plane and the transmission point Tx, and the item compares the set effective plane selection radius L to determine whether or not the current plane is an effective plane. Used for. When the distance indicated by the item is smaller than the threshold value L, it is determined that the current plane is an effective plane, and the item of the effective reflection plane flag in the list may be indicated by 1. When the distance indicated by the item is larger than the threshold value L, it may be determined that the current plane is an invalid plane, and the item of the effective reflection plane flag may be indicated by 0.

  As shown in Table 2, in this example, geometric position information and electrical parameter information regarding the plane A are defined. The electrical parameter information includes two physical properties, the dielectric constant and conductivity of the material used for the current plane. In the existing path tracking method, the material physical property parameter related to the electrical parameter is set for the entire obstacle, that is, the physical property value can be manipulated only for the entire obstacle constituted by different planes. However, in reality, the same obstacle is composed of different planes with different materials, and the propagation characteristics caused by collision of electromagnetic wave signals with different material planes are different. Then, when the electromagnetic wave signal collides with different planes of the same obstacle, it is impossible to embody different influences on the electromagnetic wave of the surface of different materials, and eventually it is impossible to accurately simulate the transmission characteristics of the electromagnetic wave in the real environment. Therefore, in the method of the present embodiment, by setting the related information table individually for each plane, the physical characteristic value can be set for a single plane, and the accuracy of path tracking can be further improved.

  In this embodiment, the effective plane of the transmission point is determined in step 601 and the reflection surfaces that do not need to be considered are filtered, so that the calculation process of intersection acquisition and subsequent calculation of the reflection path can be greatly reduced.

  In this embodiment, the electromagnetic ray ray path tracking process may be performed after the effective plane of the transmission point is determined. In the path tracking process, for each ray emitted by the transmission point, an intersection point between the ray and the effective plane may be detected along the direct direction of the ray.

  Here, in the actual transmission process of electromagnetic waves, obstacles in the effective area range in which electromagnetic waves have passed in the ray direct direction are sequentially found along the direct direction of the ray, and the obstacles on the ray and the direct path are detected. Calculate the intersection with the object plane. As shown in FIG. 8, the ray i passes through three obstacles located in the effective area, that is, the obstacle A, the obstacle B, and the obstacle C, and the ray i is a surface A1 and a surface of the obstacle A. Since the plane B1 and the plane B2 of the obstacle B and the plane C1 and the plane C2 of the obstacle C respectively intersect with A2, the intersection of the ray and the three obstacles is A1, A2, B1, and B2. , C1 and C2. Since the ray i is reflected at the point A1 on the surface A1, the intersection A1 is set as a reflection point, that is, an effective intersection on the direct path of the electromagnetic wave ray.

  In this embodiment, after obtaining the effective intersection (reflection point) A1, the next path direction of the electromagnetic wave propagation may be determined based on the geometric information of the reflection point A1. When the ray is received by the reception point in the path direction, that is, when the reception area of the reception point is reached, the ray tracking may be stopped, and in this case, the reception signal of the ray may be calculated. On the other hand, when the ray is not received by the receiving point in the path direction, the electromagnetic wave propagation path of the ray may continue to be traced along the path direction, for example, in the direction of the ray in the path direction. You may continue to find the obstacle plane that has passed through, find the intersection with the obstacle plane, and select the effective intersection among them.

  As shown in FIG. 9, after determining the effective intersection A1, the next propagation direction of the electromagnetic wave is determined based on the geometric information of the point A1, and in the reflection path direction passing through A1, first, the reflection path is It is determined whether or not the reception point has been reached, and as shown in FIG. 9, when the electromagnetic wave ray has not reached the reception point in the path, the obstacle that has passed along the reflection path direction as shown in FIG. Continue to find things. In this example, the electromagnetic wave ray passes through the obstacle D and the obstacle E in the reflection path and intersects with the planes (surface D1, surface D2, surface E1, and surface E2) on the obstacle, and the calculated electromagnetic wave ray is calculated. Are intersection points D1, D2, E1, and E2, respectively. As a result of the determination, D1 is selected as another effective intersection point that has passed through the propagation path of the electromagnetic wave. By following the same process, the subsequent electromagnetic wave propagation path is continuously tracked.

  In the present embodiment, when there is no intersection between the ray and the effective plane and the ray reaches the reception area of the reception point, the received signal of the ray may be directly calculated. On the other hand, when the intersection of the ray and the effective plane does not exist and the ray has not reached the reception area of the reception point, the next ray is directly traced without tracing this ray. Also good.

  In this embodiment, the concept of reflection equivalent is defined in order to avoid tracking one ray indefinitely. In the entire electromagnetic wave propagation process, the electromagnetic wave collides with a plurality of obstacles made of different materials, and the electromagnetic wave is reflected a plurality of times. In this embodiment, since the reflection action to the electromagnetic waves of the obstacle planes of different materials is different, in order to represent the different reflection action levels to the electromagnetic waves of the obstacle planes of different materials, as shown in Table 3, for each material, Define the corresponding equivalent reflection equivalent value.

Table 3: Equivalent reflection equivalent table for different materials

  When an electromagnetic wave passes through an obstacle plane of a certain material, the reflection action of the plane on the electromagnetic wave is calculated based on the corresponding level value in the equivalent reflection equivalent table. For electromagnetic wave propagation paths reflected a plurality of times, it is necessary to accumulate corresponding equivalent reflection equivalents when passing through each obstacle plane. As shown in Table 3, taking the obstacles made of glass and brick as an example, the equivalent reflection equivalent corresponding to the obstacle made of glass is 4, and the equivalent reflection equivalent corresponding to the obstacle made of brick is The numerical value is 1, and the reflection effect on the electromagnetic wave on the glass surface is four times the reflection effect on the electromagnetic wave on the brick surface, that is, one reflection of the electromagnetic wave on the glass is four reflections of the electromagnetic wave on the brick. Is equivalent to From the viewpoint of signal energy loss, it may be considered that the loss due to the reflection effect on the electromagnetic wave on the glass surface corresponds to four times the loss due to the reflection effect on the electromagnetic wave on the brick surface.

  After the electromagnetic wave signal is reflected a plurality of times, it may be considered that the contribution of the electromagnetic wave signal that has passed through the propagation path to the reception point is very weak. For this reason, in this embodiment, the maximum reflection equivalent is reduced so as to limit the influence of reflection on the electromagnetic wave signal of the obstacle plane on each transmission path, reduce unnecessary calculation amount, and reduce the calculation complexity of the method. K is set in advance.

  In this embodiment, the electromagnetic wave reflection path determination process considers only that the cumulative reflection equivalent is equal to or less than the maximum reflection equivalent K when the electromagnetic wave is propagated to a certain position in the scenario. That is, in the ray propagation path, when the cumulative reflection equivalent of the path passing through the effective intersection of the ray is less than or equal to the predetermined maximum reflection equivalent, the ray is continuously tracked and based on the geometric information of the effective intersection. Determine the next path direction of the ray. On the other hand, if the cumulative path reflection equivalent passing through the effective intersection of the ray is greater than the predetermined maximum reflection equivalent, then stop tracking this ray and another untracked new emitted from the transmission point. Invoke ray path tracking process. This avoids the process of calculating the electromagnetic wave path that reaches the receiving point with multiple reflections.

  Here, for the propagation path of a ray, whether or not the ray has reached the reception area of the reception point may be determined based on the direction of the propagation path. May be traced, and another electromagnetic ray path emitted from the transmission point may be traced. If the reception area of the reception point is not reached, the direction of the propagation path is The above process may be repeated by continuously detecting the intersection with the effective plane. Here, when the reception area of the reception point is reached, the reception signal of the ray may be calculated, that is, the degree of contribution to the reception signal of the reception point of the ray may be calculated.

  FIG. 10 is a flowchart of the entire path tracking process. As shown in FIG. 10, the path tracking process mainly includes the following steps.

  Step 1001: A radio signal propagation scenario is configured.

  Here, as described above, in this step, based on the actual scenario information, the observed scenario region is divided, the position of each object in the scenario is determined in the three-dimensional space, and each object is planar or planar. The transmission / reception node parameters may be set by arranging the transmission point and the reception point.

  Step 1002: An effective plane is determined.

  Here, as described above, in this step, an effective area may be determined based on a predetermined effective plane selection radius, and an obstacle plane within the effective area range may be set as an effective plane.

  Step 1003: It is determined whether or not the cumulative ray tracking number has reached the total number of rays. If YES, step 1004 is executed, and if not, the process ends.

  Here, the path is traced for each ray emitted from the transmission point, and if it is determined YES in this step, it means that the total number of rays has not been reached and there are still untraced rays. Step 1004 is executed. When it is determined as NO, it means that the tracking is finished for all the rays, thereby acquiring the propagation path of the ray emitted from the transmission point and acquiring the electromagnetic wave propagation path of the transmission point.

  Step 1004: An intersection point is detected along the ray direction.

  Here, in this step, the intersection of the ray and the effective plane is detected.

  Step 1005: It is determined whether or not an intersection with the object exists. If YES, step 1006 is executed, and if not, step 1011 is executed.

  Here, when there is an intersection between the ray and the object (effective plane), an effective intersection, for example, a reflection point is selected from the ray and the object (effective plane) so as to continue tracking the ray. If there is no intersection with the ray, tracking of the ray may be stopped.

  Step 1006: A valid intersection is selected.

  Here, as described above, there are intersections between the ray and the object (effective plane), but some intersections, for example, the intersections A2, B1, B2, C1, and C2 shown in FIG. 8 may be invalid. is there. In this step, an effective intersection, for example, the intersection A1 shown in FIG. 8 is selected.

  Step 1007: Calculate the cumulative cumulative reflection equivalent passing through the effective intersection of the ray.

  Here, as described above, the path cumulative reflection equivalent passing through the effective intersection of the ray is the sum of the cumulative reflection equivalent in the propagation process before the ray and the equivalent reflection equivalent of the material of the effective intersection. Here, the equivalent reflection equivalent corresponding to the material of the effective intersection may be determined based on an equivalent reflection equivalent table for different materials stored in advance, for example, Table 3.

  Step 1008: It is determined whether the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than the maximum reflection equivalent K. If YES, step 1009 is executed; otherwise, step 1012 is executed. To do.

  Here, if it is determined YES, it means that the reflection of the ray can contribute to the received signal, and the ray may be traced. If it is determined NO, the received signal of the reflection of the ray This means that the contribution to is not large, and the ray tracking may be stopped.

  Step 1009: Determine the next route direction of the ray.

  Here, the next route direction of the ray can be obtained using the effective intersection.

  Step 1010: It is determined whether or not the ray has reached the reception area of the reception point. If YES, step 1013 is executed, otherwise, the process returns to step 1004.

  Here, when it is determined YES, this means that this ray has already arrived at the reception area of the reception point and has acquired the propagation path of this ray, and the degree of contribution to the received signal at the reception point of this propagation path May be calculated, and if it is determined NO, this means that this ray is still being propagated and may continue to be tracked.

  Step 1011: It is determined whether or not the ray has reached the reception area of the reception point. If YES, step 1013 is executed, and if not, step 1012 is executed.

  When it is determined YES, this means that this ray has already arrived at the reception area of the reception point and has acquired the propagation path of this ray, and the contribution degree to the received signal at the reception point of the propagation path is calculated. If it is determined as NO, this means that this ray is still propagating, and there is no intersection with the object, so it is not necessary to track the ray.

  Step 1012: Trace a new ray.

  Step 1013: Calculate a received signal.

  According to the method of this embodiment, according to the embodiment of the present invention, some invalid obstacle planes are filtered using the effective plane selection radius L, and some reflection paths are used using the maximum reflection equivalent K. Can be reduced, the number of intersections (intersections between rays and obstacles) that need to be calculated can be reduced, computation complexity can be reduced, and computation time can be shortened.

  In this embodiment, the reception area of the reception point is a spherical area having a radius of θd / 2, θ is the angular interval of adjacent rays, and d is the length of the electromagnetic wave propagation path from the transmission point to the reception point. . In the conventional ray emission method, rays are scattered into the space by transmission points at uniform angular intervals, while a reception area of a reasonable size is divided around the reception point and which ray passes through the reception area. It may be determined that a ray that has passed through the reception area is received by the reception point. For this reason, in the ray emission method, the size of the reception area of the reception point is very important for accurately determining the reception ray. If the designed reception area is too small, a ray that has passed through the reception area cannot be found at the position on the reception side, which leads to a problem of signal leakage during calculation. If the designed reception area is too large, it leads to a problem of performing double calculation for the same ray path. Further, as shown in FIG. 11, reception areas having different sizes may be designed for reception points at different positions. There is a proportional relationship between the size of the reception area and the length of the electromagnetic wave transmission path between the transmitter and the receiver. As the path length increases, the size of the reception area increases accordingly.

  In the present embodiment, a spherical region having an angular interval θ and a linear distance R between two adjacent rays having a diameter is used as a receiving region of the receiving point. The reason is as follows. In the ray firing method, the set ray angle interval θ is usually very small (in the modeling process, the user may set the angle interval according to the requirement of calculation accuracy, and the set angle interval is small. As shown in FIG. 12, the electromagnetic wave propagation path length between the transmitting and receiving points may be approximated as the arc length corresponding to the angular interval. Assuming that d is d, the arc length θd can be calculated based on the arc length calculation formula, that is, the linear distance R between two adjacent rays may be approximated as θd. Since the present embodiment is based on a three-dimensional environment, in the three-dimensional environment, the method of the present embodiment has a spherical area having a radius r of θd / 2 with the receiving point Rx as the center of the sphere, and the ray is a space. The reception area for determining whether or not the signal is received by the reception point in FIG. The size of the reception area can ensure that only one of the electromagnetic wave rays passing through the same path passes through the reception area, and an error due to double calculation can be avoided efficiently.

  In the present embodiment, as described above, in a three-dimensional environment, the reception area of the reception point is designed to be a spherical area having a radius of θd / 2, thereby avoiding double calculation of the electromagnetic ray of the same path by the reception point. However, there is a special area in the space, and if the reception point is set in such a special area, the reception point cannot detect a ray passing through the reception area.

  As shown in FIG. 12, the depression angle between two adjacent rays is set to θ, and the path length between the transmission point Tx and the reception point Rx is set to d. The distance between two rays can be approximated based on the arc length to obtain θd. Thus, for each three adjacent rays in space, it may be assumed that a virtual sphere is constructed in each ray, and the center of the sphere is located at a position d from the start point of each ray in each ray. The radius of the sphere at is θd / 2, and the sphere at each ray maintains a circumscribed relationship. Therefore, the three spheres through which three adjacent rays pass form a gap region that does not belong to any sphere between them, and the gap region is the special region described above.

  As shown in FIG. 13, the left side is a view seen in the vertical direction, and the right side is a view seen from the side. Regardless of the position of the reception point in the gap area and the position of the reception point in the area, there is no ray in the reception area centered on the reception point and having a radius of θd / 2. Does not pass through, the problem of reception signal leakage arises, and an error occurs when calculating the reception side signal.

  In order to solve this problem, a solution is provided. The solution shown in FIG. 14 uses a method of increasing the radius of the reception area in order to avoid the problem of signal leakage due to the reception point being located in the special area. This method can avoid the problem of signal leakage due to the reception point being located in the special area, but since the reception area is enlarged, the number of electromagnetic wave rays passing through the reception area is also increased. Since a plurality of electromagnetic waves passing through the same path again pass through the receiving area, a double calculation problem occurs.

  In the present embodiment, in order to solve the problem and avoid double calculation of electromagnetic waves in the same path, a method of rotating the transmission point by θ / 2, for example, the transmission point rotates by θ / 2. Adopt to control as follows. The method still uses θ / 2 as the radius of the spherical reception area and does not change the size of the reception area. As shown in FIG. 15, when no electromagnetic wave path passes through the receiving area having a radius of θ / 2, the transmission point rotates in the horizontal direction (or vertical direction) in space, and accordingly Thus, the entire ray sphere formed by the rays emitted from the transmission point also rotates, and when the rotation angle is set to θ / 2, each ray emitted from the transmission point also rotates by an angle θ / 2 accordingly. After the rotation, when the electromagnetic wave ray passing through the region is searched for the reception region of the reception point, there is a ray passing through the reception region. Thus, according to this method, the problem of double calculation of the same path can be avoided, and the problem of signal leakage that occurs during the calculation can be avoided.

  According to the embodiment of the present invention, it is possible to reduce the complexity of the calculation process in the path tracking process, to realize a more efficient and accurate simulation of the electromagnetic transmission path, and to acquire the electromagnetic wave propagation characteristics in the observed wireless network. .

<Example 2>
Since the embodiment of the present invention further provides an apparatus for tracking an electromagnetic wave propagation path, and the principle of solving the problem of the apparatus is similar to the method of the first embodiment, the specific implementation refers to the implementation of the method of the first embodiment. The description of the overlapping contents may be omitted.

  FIG. 16 is a diagram showing the configuration of the tracking device for the electromagnetic wave propagation path of this embodiment. As shown in FIG. 16, the apparatus 1600 includes a determination unit 1601, a detection unit 1602, and a processing unit 1603.

  The determination unit 1601 determines the effective plane of the transmission point based on a predetermined effective plane selection radius.

  Here, as described in the first embodiment, in the radio signal propagation scenario, when the distance between the obstacle plane and the transmission point is larger than the effective plane selection radius, the plane is an invalid plane. On the other hand, if the distance between the plane of the obstacle and the transmission point is smaller than the effective plane selection radius, it is determined that the plane is an effective plane. Some obstacle planes were filtered by the determination unit to reduce the amount of calculation.

  The detection unit 1602 detects the intersection of the ray and the effective plane along the direction of the ray for each ray emitted by the transmission point.

  Here, as described in the first embodiment, whether or not there is an intersection between the ray and the effective plane may be determined in accordance with the emission method of each ray. When an intersection exists, there is a possibility that a reflection path having an effective intersection as a reflection point exists for the ray, and the ray may be continuously tracked. If no intersection exists, the ray does not intersect all obstacle planes and there is no need to keep track of the ray.

  The processing unit 1603 receives the reception of the reception point when the intersection between the ray and the effective plane exists and the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent. The next path direction of the ray is determined until the cumulative path reflection equivalent that reaches the region or passes through the effective intersection of the ray is greater than a predetermined maximum reflection equivalent. Thereby, the propagation path of the ray can be acquired, and the electromagnetic wave propagation path of the transmission point can be acquired.

  Here, as described in the first embodiment, there are two termination conditions in the electromagnetic wave ray tracking process, and one is that the path of the electromagnetic wave ray has reached the reception area of the reception point. One is that the cumulative reflection equivalent has reached the maximum reflection equivalent, and when one of the two conditions is satisfied, the current ray tracking process is terminated and the new ray tracking process is continued. In addition, when the intersection exists and the cumulative reflection equivalent that passes through the effective intersection of the ray in the current propagation path does not reach the maximum reflection equivalent, the processing unit 1603 performs the next route of the ray. The direction may be tracked, and when the ray does not reach the reception area of the reception point in the route direction, the intersection point may be continuously detected along the route direction of the ray. Further, when the intersection does not exist and the ray has not reached the reception area of the reception point, a new ray path is traced. When the intersection does not exist and the ray reaches the reception area of the reception point, a reception signal of the ray may be calculated and a new ray path may be traced.

  In this embodiment, the effective plane selection radius may be the maximum communication distance supported by the observed wireless network.

  In the present embodiment, the reception area of the reception point may be a spherical area having a radius of θd / 2, θ is an angular interval between adjacent rays, and d is an electromagnetic wave propagation path from the transmission point to the reception point. Length. This avoids double calculations.

  In this embodiment, the processing unit 1603 causes the transmission point so that the detection unit 1602 continues to detect the ray emitted by the rotated transmission point when none of the rays pass through the reception area of the reception point. May be rotated by θ / 2.

  In the present embodiment, the apparatus 1600 may further include a storage unit 1604 that stores an obstacle information table of obstacles in the propagation scenario and / or a plane information table of each plane. Here, the obstacle information table may include an obstacle ID, an obstacle name, the number of planes included in the obstacle, and a plane ID included in the obstacle. Table 1 is an example of the obstacle information table. is there. Here, the plane information table may include a plane ID, belonging obstacle ID, plane vertex coordinates, distance to the transmission point, effective reflection plane flag, and electrical parameters, and Table 2 is an example of the plane information table. It is. The storage unit 1604 may further store an equivalent reflection equivalent table for different obstacle surface materials, and Table 3 is an example of an equivalent reflection equivalent table.

  According to the apparatus of the present embodiment, the complexity of the calculation process in the path tracking process can be reduced, more efficient and accurate simulation of the electromagnetic transmission path can be realized, and the electromagnetic wave propagation characteristics in the observed wireless network can be acquired. .

<Example 3>
The embodiment of the present invention further provides a computer system, which may include the electromagnetic wave propagation path tracking device described in the second embodiment.

  FIG. 17 is a diagram showing the configuration of the computer system of this embodiment. As shown in FIG. 17, the computer system 1700 may include a central processing unit (CPU) 1701 and a storage device 1702. The storage device 1702 is connected to the central processing unit 1701. The storage device 1702 may store various data, further stores an information processing program, and the program is executed under the control of the central processing unit 1701.

  In one aspect, the function of the tracking device of the electromagnetic wave propagation path described in the second embodiment may be integrated into the central processing unit.

  In another aspect, the electromagnetic wave propagation path tracking device described in the second embodiment is arranged away from the central processing unit 1701, for example, the electromagnetic wave propagation path tracking device is a chip connected to the central processing unit 1701, The function of the tracking device for the electromagnetic wave propagation path may be fulfilled by the control of the processing device 1701.

  As shown in FIG. 17, the computer system 1700 may further include an input device 1703, an output device 1704, and the like. The function of the above apparatus is similar to that of the prior art, and the description thereof is omitted. Note that the computer system 1700 does not necessarily include all the devices shown in FIG. The computer system 1700 may further include devices not shown in FIG. 17 and may refer to the prior art.

  According to the computer system of this embodiment, it is possible to reduce the complexity of the calculation process in the path tracking process, to realize more efficient and accurate simulation of the electromagnetic transmission path, and to acquire the electromagnetic wave propagation characteristics in the observed wireless network. it can.

  According to an embodiment of the present invention, when executing a program in an electromagnetic wave propagation path tracking apparatus or computer system, the computer causes the computer to execute the method described in Embodiment 1 in the electromagnetic wave propagation path tracking apparatus or computer system. Further provided is a readable program.

  An embodiment of the present invention further provides a storage medium storing a computer-readable program for causing a computer to execute the method described in Embodiment 1 in an electromagnetic wave propagation path tracking apparatus or a computer system.

  The above apparatus and method of the present invention may be realized by hardware, or may be realized by combining hardware and software. The present invention relates to a computer-readable program. When the program is executed by a logic unit, the logic unit realizes the above-described apparatus or configuration requirements, or the logic unit realizes various methods or steps described above. Can be made. The present invention relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, and the like.

  Although the present invention has been described above with reference to specific embodiments, the above description is merely illustrative and does not limit the scope of protection of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and principle of the present invention, and these changes and modifications are also within the scope of the present invention.

Moreover, the following additional remarks are disclosed regarding the embodiment including the above-described examples.
(Appendix 1)
An electromagnetic wave propagation path tracking method,
Determining an effective plane of the transmission point based on a predetermined effective plane selection radius;
Detecting for each ray emitted by the transmission point the intersection of the ray and the effective plane along the direction of the ray;
When the intersection of the ray and the effective plane exists, and the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent, the ray reaches the reception area of the reception point, Or determining the next path direction of the ray until a path cumulative reflection equivalent passing through the effective intersection of the ray is greater than a predetermined maximum reflection equivalent.
(Appendix 2)
Determining that the plane is an invalid plane if the distance between the plane of the obstacle in the propagation scenario and the transmission point is greater than the effective plane selection radius;
The method according to claim 1, wherein the plane is determined to be an effective plane when a distance between an obstacle plane and the transmission point in the propagation scenario is smaller than the effective plane selection radius.
(Appendix 3)
The method of claim 1, wherein the effective plane selection radius is a maximum communication distance supported by the observed wireless network.
(Appendix 4)
When the intersection of the ray and the effective plane does not exist and the ray reaches the reception area of the reception point, the reception signal of the ray is calculated,
The method according to claim 1, wherein if the intersection between the ray and the effective plane does not exist and the ray has not reached the reception area of the reception point, the next ray is tracked.
(Appendix 5)
When the ray reaches the reception area of the reception point, the received signal of the ray is calculated,
The method of claim 1, wherein the next ray is tracked when a path cumulative reflection equivalent passing through the effective intersection of the rays is greater than a predetermined maximum reflection equivalent.
(Appendix 6)
The reception area of the reception point is a spherical area having a radius of θd / 2, θ is an angular interval between adjacent rays, and d is a length of an electromagnetic wave propagation path from the transmission point to the reception point. The method described.
(Appendix 7)
Appendix 6 further comprising the step of rotating the transmission point by θ / 2 so as to keep track of the ray emitted by the rotated transmission point when none of the rays pass through the reception area of the reception point. The method described in 1.
(Appendix 8)
An electromagnetic wave propagation path tracking device,
Determining means for determining an effective plane of the transmission point based on a predetermined effective plane selection radius;
Detection means for detecting an intersection of the ray and the effective plane along the direction of the ray for each ray emitted by the transmission point;
When the intersection of the ray and the effective plane exists, and the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent, the ray reaches the reception area of the reception point, Or processing means for determining a next path direction of the ray until a path cumulative reflection equivalent passing through the effective intersection of the ray becomes larger than a predetermined maximum reflection equivalent.
(Appendix 9)
The determination means determines that the plane is an invalid plane when the distance between the plane of the obstacle in the propagation scenario and the transmission point is larger than the effective plane selection radius, and the obstacle in the propagation scenario. The apparatus according to claim 8, wherein the plane is determined to be an effective plane when the distance between the plane and the transmission point is smaller than the effective plane selection radius.
(Appendix 10)
The apparatus according to appendix 8, wherein the effective plane selection radius is a maximum communication distance supported by the observed wireless network.
(Appendix 11)
When the intersection between the ray and the effective plane does not exist and the ray reaches the reception area of the reception point, the processing means calculates a reception signal of the ray and tracks the next ray. The apparatus according to appendix 8, wherein when the intersection between the ray and the effective plane does not exist and the ray has not reached the reception area of the reception point, the next ray is tracked.
(Appendix 12)
The processing means calculates a received signal of the ray when the ray reaches the reception area of the reception point, and a path cumulative reflection equivalent passing through the effective intersection of the ray is larger than a predetermined maximum reflection equivalent. The apparatus of claim 8 that, when larger, tracks the next ray.
(Appendix 13)
The reception area of the reception point is a spherical area having a radius of θd / 2, θ is an angular interval between adjacent rays, and d is a length of an electromagnetic wave propagation path from the transmission point to the reception point. The device described.
(Appendix 14)
The processing means sets the transmission point by θ / 2 so that the detection means continues to detect the ray emitted by the transmission point after rotation when no rays pass through the reception area of the reception point. The apparatus according to appendix 13, wherein the apparatus is rotated.
(Appendix 15)
The apparatus according to appendix 8, further comprising storage means for storing an obstacle information table of obstacles in a propagation scenario and / or a plane information table of each plane, and an equivalent reflection equivalent table for different obstacle surface materials.
(Appendix 16)
The apparatus according to appendix 15, wherein the obstacle information table includes an obstacle ID, an obstacle name, the number of planes included in the obstacle, and a plane ID included in the obstacle.
(Appendix 17)
The apparatus according to appendix 15, wherein the plane information table includes a plane ID, a belonging obstacle ID, a plane vertex coordinate, a distance to a transmission point, an effective reflection plane flag, and an electrical parameter.
(Appendix 18)
A computer system including the apparatus according to appendix 8.

Claims (18)

An electromagnetic wave propagation path tracking device,
Determining means for determining an effective plane of the transmission point based on a predetermined effective plane selection radius;
Detection means for detecting an intersection of the ray and the effective plane along the direction of the ray for each ray emitted by the transmission point;
When the intersection of the ray and the effective plane exists, and the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent, the ray reaches the reception area of the reception point, Or processing means for determining a next path direction of the ray until a path cumulative reflection equivalent passing through the effective intersection of the ray becomes larger than a predetermined maximum reflection equivalent.   The determination means determines that the plane is an invalid plane when the distance between the plane of the obstacle in the propagation scenario and the transmission point is larger than the effective plane selection radius, and the obstacle in the propagation scenario. The apparatus of claim 1, wherein the plane is determined to be an effective plane if the distance between the plane and the transmission point is less than the effective plane selection radius.   The apparatus of claim 1, wherein the effective plane selection radius is a maximum communication distance supported by the observed wireless network.   When the intersection between the ray and the effective plane does not exist and the ray reaches the reception area of the reception point, the processing means calculates a reception signal of the ray and tracks the next ray. The apparatus of claim 1, wherein the next ray is tracked when an intersection of the ray and the effective plane does not exist and the ray has not reached the reception area of the reception point.   The processing means calculates a received signal of the ray when the ray reaches the reception area of the reception point, and a path cumulative reflection equivalent passing through the effective intersection of the ray is larger than a predetermined maximum reflection equivalent. The apparatus of claim 1, wherein the apparatus tracks the next ray if it is large.   The reception area of the reception point is a spherical area having a radius of θd / 2, θ is an angular interval between adjacent rays, and d is a length of an electromagnetic wave propagation path from the transmission point to the reception point. The device described in 1.   The processing means sets the transmission point by θ / 2 so that the detection means continues to detect the ray emitted by the transmission point after rotation when no rays pass through the reception area of the reception point. The apparatus of claim 6, wherein the apparatus is rotated.   The apparatus according to claim 1, further comprising storage means for storing an obstacle information table of obstacles in the propagation scenario and / or a plane information table of each plane, and an equivalent reflection equivalent table for different obstacle surface materials.   The apparatus according to claim 8, wherein the obstacle information table includes an obstacle ID, an obstacle name, the number of planes included in the obstacle, and a plane ID included in the obstacle.   The apparatus according to claim 8, wherein the plane information table includes a plane ID, a belonging obstacle ID, a plane vertex coordinate, a distance to a transmission point, an effective reflection plane flag, and an electrical parameter.   A computer system comprising the apparatus of claim 1. An electromagnetic wave propagation path tracking method,
Determining an effective plane of the transmission point based on a predetermined effective plane selection radius;
Detecting for each ray emitted by the transmission point the intersection of the ray and the effective plane along the direction of the ray;
When the intersection of the ray and the effective plane exists, and the path cumulative reflection equivalent passing through the effective intersection of the ray is equal to or less than a predetermined maximum reflection equivalent, the ray reaches the reception area of the reception point, Or determining the next path direction of the ray until a path cumulative reflection equivalent passing through the effective intersection of the ray is greater than a predetermined maximum reflection equivalent. Determining that the plane is an invalid plane if the distance between the plane of the obstacle in the propagation scenario and the transmission point is greater than the effective plane selection radius;
13. The method of claim 12, wherein the plane is determined to be an effective plane if a distance between an obstacle plane and the transmission point in the propagation scenario is less than the effective plane selection radius.   The method of claim 12, wherein the effective plane selection radius is a maximum communication distance supported by an observed wireless network. When the intersection of the ray and the effective plane does not exist and the ray reaches the reception area of the reception point, the reception signal of the ray is calculated,
The method according to claim 12, wherein the next ray is traced when there is no intersection between the ray and the effective plane and the ray has not reached the reception area of the reception point. When the ray reaches the reception area of the reception point, the received signal of the ray is calculated,
The method of claim 12, wherein the next ray is tracked if a path cumulative reflection equivalent passing through the effective intersection of the rays is greater than a predetermined maximum reflection equivalent.   The reception area of the reception point is a spherical area having a radius of θd / 2, θ is an angular interval between adjacent rays, and d is a length of an electromagnetic wave propagation path from the transmission point to the reception point. The method described in 1.   The method further comprises the step of rotating the transmission point by θ / 2 so that if no rays pass through the reception area of the reception point, the ray continues to track the rays emitted by the rotated transmission point. 18. The method according to 17.

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