A dynamic ray tracing wireless channel modeling method, device, equipment and medium

Abstract

The present invention discloses a dynamic ray tracing wireless channel modeling method, apparatus, device, and medium, belonging to the field of wireless communication technology. The method includes: selecting a dynamic scene and configuring scene parameters; determining whether the current simulation time is less than a preset total simulation time, and if so, obtaining the initial ray path through a mirroring method; constructing a double-layer acceleration structure for dynamic objects and static objects; performing an intersection test between rays and hierarchical bounding boxes to obtain geometric information of each reflection point and its minimum bounding box; selecting the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, obtaining and updating the coherence time; performing dynamic ray tracing within the updated coherence time window and updating the simulation time to achieve dynamic ray tracing. The present invention can significantly improve computational efficiency while ensuring high computational accuracy, and is particularly suitable for mobility application scenarios with high requirements for computational efficiency and response speed.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a dynamic ray tracing wireless channel modeling method, apparatus, device and medium. Background Art

[0002] Wireless channel research is crucial for the design, performance evaluation, optimal deployment, security, and standardization of communication systems. As a crucial component of future intelligent transportation systems, the IoV (Internet of Vehicles) (IoV) channel characteristics differ significantly from traditional cellular networks in several respects. First, IoV operating frequencies are primarily concentrated between 5.2 and 5.9 GHz, resulting in a shorter communication range of approximately 10 to 500 meters. Currently deployed cellular systems, however, operate in the 700 to 2100 MHz band, with a range of tens of kilometers. Furthermore, IoV is susceptible to environmental influences such as buildings, pedestrians, and other vehicles, increasing the complexity of channel modeling. Furthermore, the high mobility of IoV increases Doppler spread, and the channel generally lacks wide-sense stationary properties. These characteristics make IoV channels incapable of being directly represented by traditional cellular network channel models. Therefore, research on specialized IoV channel models is essential.

[0003] Building on this foundation, the Sixth Generation (6G) mobile communication system places even higher demands on wireless communications, requiring further improvements in speed, latency, reliability, mobility, and energy consumption. In particular, the increase in mobile speed not only leads to a more severe Doppler effect in the communication channel, but also changes in other aspects of the mobile channel characteristics, such as time-domain nonstationarity. Traditional mobile communication channel models struggle to accurately capture these changes, making current communication system performance unable to meet 6G requirements. Therefore, re-examining the impact of high mobility on wireless channels and establishing more accurate and efficient high-mobility vehicle-to-vehicle channel models have become key tasks in current channel research to better simulate the complex channel characteristics in the vehicle-to-vehicle network.

[0004] Ray tracing (RT), a deterministic wireless channel modeling method, can accurately predict wireless channel path information, such as signal power, delay spread, and path loss, through tracing and calculation. However, due to the high mobility of connected vehicle scenarios, spatially consistent simulation in such scenarios requires considering a large number of continuous environment configurations or "snapshots." This means that RT simulation must be re-run for each movement of an object, which can result in significant computational time and requires processing a large number of environment description files and output files. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides a dynamic ray tracing wireless channel modeling method, apparatus, device and medium, which can solve the problem that the ray tracing algorithm needs to consider a large number of continuous environmental configurations or "snapshots" to achieve spatial consistency simulation in dynamic scenarios, and further improve the computational efficiency of ray tracing.

[0006] The present invention provides the following technical solutions:

[0007] In a first aspect, a dynamic ray tracing wireless channel modeling method is provided, comprising the following steps:

[0008] Step S1: Select a dynamic scene and configure scene parameters, including propagation mechanism and antenna type;

[0009] Step S2: determine whether the current simulation time is less than the preset total simulation time. If so, obtain the initial ray path by the mirror method, where the path point between the transmitting and receiving ends is the reflection point;

[0010] Step S3: constructing a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy;

[0011] Step S4: perform an intersection test between the ray and the hierarchical bounding box to obtain the geometric information of each reflection point and its minimum bounding box;

[0012] Step S5: Select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time based on the minimum size and maximum motion speed;

[0013] Step S6: Perform dynamic ray tracing within the updated coherent time window and update the simulation time, and repeat steps S2 to S6 to implement dynamic ray tracing.

[0014] Optionally, the step S1 is specifically:

[0015] According to the application requirements, select the dynamic scene that needs to be ray traced, and based on the selected dynamic scene, obtain the position, movement speed and direction of the transmitter and receiver, the position, movement speed and direction of the moving object, and set the movement time of each moving object within the simulation time period;

[0016] Configure the propagation mechanism in the scene, including the maximum order of ray reflections;

[0017] Select the appropriate antenna type according to the application scenario and set the antenna's transmit power and polarization mode;

[0018] Set the center frequency for the RT simulation and, based on this frequency, select the electromagnetic parameters of the material required for the simulation, including the dielectric constant, conductivity, and thickness, to complete the simulation setup.

[0019] Optionally, the double-layer acceleration structure in step S3 includes a top-level BVH acceleration structure and a bottom-level BVH acceleration structure, the top-level BVH acceleration structure stores information of static objects, and the bottom-level BVH acceleration structure stores information of all dynamic objects.

[0020] Optionally, the step S4 is specifically:

[0021] From top to bottom, the bounding boxes are traversed to perform fast intersection detection, and the sub-bounding boxes that may intersect with the ray are screened out. The sub-bounding boxes are then refined layer by layer in a recursive manner until the minimum bounding box that intersects with the ray is found or it is determined that the ray does not intersect with any bounding box. When the minimum bounding box that intersects with the ray is found, the geometric information of the minimum bounding box is determined, including the center point and boundary range.

[0022] Optionally, in step S5, an upper limit value of the coherence time is obtained according to the following formula, and the coherence time is updated according to the upper limit value of the coherence time;

[0023] ;

[0024] in, is the coherence time, The minimum size of all minimum bounding boxes, the minimum size is the minimum length, minimum width or minimum height, The maximum speed of all dynamic objects in the application scene.

[0025] Optionally, step S6 specifically includes the following sub-steps:

[0026] Step S61: The receiving end, the transmitting end and the reflecting plane in the scene are I The motion parameters of the corresponding reflection point are converted from the global coordinate system to the reflection plane I In the corresponding local coordinate system, obtain the transmitter, receiver and reflection point on the reflection plane I Corresponding coordinates and velocities in the local coordinate system;

[0027] Step S62: combining the motion information of the transmitting end, the receiving end, and the reflection plane, using the derivative chain criterion to determine the instantaneous velocity of each reflection point in the local coordinate system, and obtaining the instantaneous acceleration of each reflection point by taking the derivative;

[0028] ;

[0029] in, and are the instantaneous velocities of the transmitter and receiver in the local coordinate system respectively; Reflection plane I The instantaneous velocity of the corresponding reflection point in the local coordinate system; Reflection plane I The coordinates of the corresponding reflection point in the local coordinate system, is the coordinate of the transmitter in the local coordinate system, is the coordinate of the receiving end in the local coordinate system, is the scale factor, , is a parameter used only to simplify the calculation. ;

[0030] Step S63: Set time step , iteratively update the positions and velocities of all interaction points, where all interaction points include all reflection points, transmitters and receivers;

[0031] ;

[0032] ;

[0033] in, )for t The instantaneous acceleration of the reflection point in the local coordinate system at time , for t The position of the interaction point in the local coordinate system at that moment, for t The instantaneous velocity of the interaction point in the local coordinate system at the moment, for The position of the interaction point in the local coordinate system at that moment; for The instantaneous velocity of the interaction point in the local coordinate system at that moment;

[0034] Step S64: Update simulation time , repeat steps S2 to S6 to achieve dynamic ray tracing.

[0035] Optionally, in step S61, the receiving end, the transmitting end and the reflecting plane in the scene are I The motion parameters of the corresponding reflection point are converted from the global coordinate system to the reflection plane I When the global coordinate system is in the corresponding local coordinate system, the global coordinate system is converted to the reflection plane I The corresponding local coordinate system and the reflection plane I Located at y=0.

[0036] In a second aspect, a dynamic ray tracing wireless channel modeling device is provided, comprising:

[0037] Configuration module, used to select dynamic scenarios and configure scenario parameters, including propagation mechanism and antenna type;

[0038] The initial ray path acquisition module is used to determine whether the current simulation time is less than the preset total simulation time. If so, the initial ray path including all reflection points is obtained by the mirror method.

[0039] An acceleration structure building module, which is used to build a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy;

[0040] The intersection test module is used to perform the intersection test between the ray and the hierarchical bounding box to obtain the geometric information of each reflection point and its minimum bounding box;

[0041] The coherence time dynamic update module is used to select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time based on the minimum size and maximum motion speed;

[0042] The dynamic ray tracing module is used to perform dynamic ray tracing within the updated coherence time window and update the simulation time. At the same time, based on the updated simulation time, it repeats the initial ray path acquisition, double-layer acceleration structure construction, intersection test between rays and hierarchical bounding boxes, calculation and update of coherence time, and tracing of dynamic rays in the coherence time window until the total simulation time is reached.

[0043] According to a third aspect, a computer device is provided, comprising a processor and a memory; wherein, when the processor executes a computer program stored in the memory, the steps of the dynamic ray tracing wireless channel modeling method described in any one of the first aspects are implemented.

[0044] In a fourth aspect, a computer-readable storage medium is provided for storing a computer program; when the computer program is executed by a processor, the steps of the dynamic ray tracing wireless channel modeling method described in any one of the first aspects are implemented.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention proposes a dynamic ray tracing wireless channel modeling method based on hierarchical bounding box acceleration. The present invention combines the speed and size characteristics of the object and replaces the static coherence time setting by dynamically updating the coherence time of ray tracing, thereby improving the adaptability of the algorithm in dynamic scenes. Under the premise of knowing the position and movement mode of each object in the scene, the application uses geometric relationships to predict the evolution process of multipath propagation, and by tracking the position of the reflection point, combined with the analytical extrapolation formula, avoids the repetition of the complete ray tracing calculation due to scene changes within the coherence time range, thereby significantly reducing the computational overhead and realizing continuous dynamic ray tracing. Compared with traditional methods, this algorithm effectively balances computing performance and simulation accuracy in high-dynamic scenes, and is particularly suitable for mobility application scenarios with high requirements for computing efficiency and response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a flow chart of the dynamic ray tracing wireless channel modeling method of the present invention;

[0048] Figure 2 This is a schematic diagram of an urban vehicle-to-vehicle scenario according to Example 2 of the present invention;

[0049] Figure 3 is a comparison chart of received power results of dynamic ray tracing according to Example 2 of the present invention;

[0050] Figure 4 is a comparison diagram of path loss results of dynamic ray tracing according to Example 2 of the present invention;

[0051] Figure 5 is a comparison diagram of the delay spread results of dynamic ray tracing according to Example 2 of the present invention;

[0052] Figure 6 This is a diagram of the Doppler power spectrum density results of dynamic ray tracing according to Example 2 of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that the term "comprising" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0054] Example 1

[0055] like Figure 1 As shown, a dynamic ray tracing wireless channel modeling method is provided, comprising the following steps:

[0056] Step S1: Select a dynamic scenario and configure scenario parameters, including propagation mechanism and antenna type.

[0057] Step S1 is specifically as follows:

[0058] S11. According to the application requirements, a dynamic scene that needs to be ray traced is selected, and based on the selected dynamic scene, the position, movement speed and direction of the transmitter and receiver, the position, movement speed and direction of the moving object are obtained, and the movement time of each moving object within the simulation time period is set.

[0059] S12. Configure the propagation mechanism in the scene, including the highest order of ray reflections.

[0060] S13. Select an appropriate antenna type according to the application scenario and set the antenna's transmit power and polarization mode.

[0061] S14. Set the center frequency of the RT simulation and select the electromagnetic parameters of the material required for the simulation based on the frequency, including dielectric constant, conductivity and thickness, to complete the simulation settings.

[0062] It is worth noting that the position, movement speed and direction of the transmitting end and the receiving end of this application, and the position, movement speed and direction of the moving object are all in the global coordinate system. The propagation mechanism of the rays of this application does not consider diffraction and other situations, but only considers reflection.

[0063] Step S2: determine whether the current simulation time is less than the preset total simulation time. If so, obtain the initial ray path by the mirror method, wherein the path point between the transmitting and receiving ends is the reflection point.

[0064] Get the current simulation time and compare it with the preset total simulation time. If the current time is less than the total simulation time, continue the simulation process; if the current time is greater than or equal to the total simulation time, end the simulation.

[0065] Under the condition that the current time is less than the preset total simulation time, the initial ray path is calculated using the image method. The image method calculates the initial ray propagation path from the transmitter to the receiver by mirroring the reflecting surface. The image method (IM) can refer to existing technologies for calculating the initial ray path. The transmitting and receiving ends are the receiver and the transmitter.

[0066] Step S3: construct a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy.

[0067] The dual-layer acceleration structure consists of a top-level Bounding Volume Hierarchy (BVH) acceleration structure and a bottom-level BVH acceleration structure. The top-level BVH acceleration structure stores information about static objects, while the bottom-level BVH acceleration structure stores information about all dynamic objects. The top-level BVH acceleration structure ensures that static objects do not need to be updated frequently, while the bottom-level BVH acceleration structure improves the access and update efficiency of dynamic objects.

[0068] In this embodiment, static objects always maintain their initial position, with no changes in size or orientation. Dynamic objects, on the other hand, may shift position or change shape between any two consecutive frames. Based on this characteristic, objects are classified into two categories: dynamic and static, to optimize the updating efficiency of the hierarchical bounding box structure.

[0069] For static objects, a smaller threshold for the number of triangles in leaf nodes is used to improve the accuracy of intersection testing. For dynamic objects, the threshold for the number of triangles in leaf nodes is appropriately relaxed to reduce the computational overhead of reconstructing the hierarchical bounding box and reduce unnecessary structural updates.

[0070] The method for constructing a two-layer acceleration structure for dynamic and static objects can refer to existing technologies. Specifically, the bounding boxes that contain all triangular facets in the dynamic and static objects are calculated separately; the optimal partitioning strategy is selected to divide the triangular facets into left and right child nodes; the above steps are repeated, recursively constructing a bounding box tree until the number of triangular facets within the bounding box is less than a preset threshold for the number of triangular facets within the bounding box of the leaf node, at which point the bounding box tree construction is terminated. The optimal partitioning plane can be selected using a surface area heuristic algorithm for both dynamic and static objects, and the cost function for the optimal scoring of dynamic and static object partitioning can be adjusted based on actual conditions.

[0071] Step S4: perform an intersection test between the ray and the hierarchical bounding box to obtain geometric information of each reflection point and its minimum bounding box.

[0072] In this embodiment, step S4 is specifically as follows:

[0073] A fast intersection check is performed by traversing the bounding box hierarchy, starting with the top-level bounding box. Sub-bounding boxes that may intersect with the ray are screened out, and the process is recursively refined layer by layer until a minimum bounding box that intersects the ray is found, or the ray is determined to not intersect with any bounding box. Once a minimum bounding box that intersects the ray is found, its geometry is determined, including its center point and bounding box. For fast intersection detection and determining the minimum bounding box's geometry, refer to existing techniques.

[0074] Step S5: Select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time according to the minimum size and the maximum motion speed.

[0075] Step S5 further comprises:

[0076] S51. Each triangle where the reflection point is located has a bounding box that surrounds it. Select the minimum size (i.e., the minimum length, width, or height) of these bounding boxes and record it as .

[0077] S52, select the maximum speed of the receiving end, the transmitting end and all objects, recorded as .

[0078] S53 , based on the bounding box size and the maximum motion speed, obtain the upper limit of the coherence time according to the following formula, and update the coherence time according to the upper limit of the coherence time.

[0079]

[0080] in, is the coherence time, The minimum size of all minimum bounding boxes, the minimum size is the minimum length, minimum width or minimum height, The maximum speed of all dynamic objects in the application scene.

[0081] Step S6: Perform dynamic ray tracing within the updated coherent time window and update the simulation time, and repeat steps S2 to S6 to implement dynamic ray tracing.

[0082] Step S6 specifically includes the following sub-steps:

[0083] Step S61: The receiving end, the transmitting end and the reflecting plane in the scene are I The motion parameters of the corresponding reflection point are converted from the global coordinate system to the reflection plane I In the corresponding local coordinate system, obtain the transmitter, receiver and reflection point on the reflection plane I Corresponding to the coordinates and speed in the local coordinate system.

[0084] Specifically, assuming that in the coherence time window All motion parameters remain constant; in step S11, the initial positions and velocities of the transmitter and receiver in the global coordinate system, as well as the initial positions and velocities of all reflective surfaces in the environment (such as buildings, vehicles, etc.) are stored.

[0085] Select the local coordinate system where the reflection plane is located, transform the global coordinate system to the local coordinate system, and make the reflection plane located at y =0, obtain the homogeneous transformation matrix of coordinate transformation; use the homogeneous transformation matrix to transform the reflection plane, receiving end and transmitting end from the global coordinate system to the local coordinate system, and obtain the transmitting end and receiving end in the first I The coordinates of each reflection point in the local coordinate system are obtained based on the initial ray path obtained in step S2.

[0086] Step S62: Combine the motion information of the transmitting end, the receiving end and the reflection plane, use the derivative chain criterion to determine the instantaneous velocity of each reflection point in the local coordinate system, and obtain the instantaneous acceleration of each reflection point after differentiation.

[0087] ;

[0088] in, and are the instantaneous velocities of the transmitter and receiver in the local coordinate system respectively; Reflection plane I The instantaneous velocity of the corresponding reflection point in the local coordinate system; Reflection plane I The coordinates of the corresponding reflection point in the local coordinate system, is the coordinate of the transmitter in the local coordinate system, is the coordinate of the receiving end in the local coordinate system, is the scale factor, , is a parameter used only to simplify the calculation. .

[0089] Step S63: Set time step , iteratively update the positions and velocities of all interaction points, where all interaction points include all reflection points, transmitters and receivers;

[0090]

[0091]

[0092] in, )for t The instantaneous acceleration of the reflection point in the local coordinate system at time , for t The position of the interaction point in the local coordinate system at that moment, for t The instantaneous velocity of the interaction point in the local coordinate system at the moment, for The position of the interaction point in the local coordinate system at that moment; for The instantaneous velocity of the interaction point in the local coordinate system at time .

[0093] Step S64: Update simulation time , repeat steps S2 to S6 to achieve dynamic ray tracing.

[0094] Example 2

[0095] A specific example of a dynamic ray tracing wireless channel modeling method is provided, and the specific steps are as follows:

[0096] Step 1: Select a dynamic scenario and configure the scenario parameters, including propagation mechanism and antenna type.

[0097] Based on the application requirements, an urban vehicle-to-vehicle scenario was selected. Based on the selected scenario, the transmitter's initial position was determined to be (13.5, 16, 3.7) m, moving along the positive x-axis at a constant speed of 15 m / s. The receiver's initial position was determined to be (100, 20, 1.6) m, moving along the negative x-axis at a constant speed of 10 m / s. The moving object and the transmitter were located in the same lane and traveled at the same speed and in the same direction. The overall simulation time was set to 4 seconds. The highest reflection order was set to 3, and diffraction was not considered. The antenna was set to a vertically polarized, isotropic, omnidirectional antenna with a gain of 0 dBi. The simulation center frequency was set to 5.9 GHz. The materials selected for this scenario were concrete, soil, metal, and tempered glass, with specific dielectric constants, conductivity, and thicknesses set based on this frequency.

[0098] Step 2: Determine whether the current time is less than the preset total simulation time. If so, obtain the initial ray path through the mirror method.

[0099] Step 3: Use the surface area heuristic strategy to construct a two-layer organizational structure of dynamic and static objects.

[0100] Objects are classified into dynamic and static objects to optimize the update efficiency of the hierarchical bounding box structure. For static objects, the threshold for the number of triangles in leaf nodes is set to 50 to improve the accuracy of intersection testing. For dynamic objects, the threshold for the number of triangles in leaf nodes is set to 250 to reduce the computational overhead of reconstructing the hierarchical bounding box and eliminate unnecessary structural updates. A two-layer organizational structure is constructed for dynamic and static objects. The top layer stores information about the entire static scene, ensuring that the static part does not need to be updated frequently. The bottom layer stores information about local moving objects to improve the access and update efficiency of dynamic objects.

[0101] Step 4: Perform an intersection test between the ray and the hierarchical bounding box to obtain the geometric information of the path point and its minimum bounding box.

[0102] Step 5: Calculate and update the coherence time.

[0103] Step 6: Perform dynamic ray tracing within the coherent time window and update the simulation time, and repeat steps 2 to 6.

[0104] The dynamic ray tracing wireless channel modeling method (Dynamic Ray Tracing, DRT) proposed in this paper is compared with the mirror method and Wireless InSite (WI) simulation software, and Figure 2 The simulation results of receiving power are shown in Figure 2. Figure 3As shown in Figure 2. Through comparative analysis, the root mean square error of the received power of the DRT algorithm with WI is 0.9138 dB, and the root mean square error with IM is 0.8815 dB, which reflects the applicability of the DRT algorithm in dynamic propagation environments. The path loss fitting results are shown in Figure 2. Figure 4 The relevant parameters are summarized in Table 1. In each distance segment, the simulation results of the DRT algorithm are consistent with the scatter distribution trend of other algorithms, and the fitting curves almost overlap in most areas. The delay spread characteristics within 0 to 4 seconds are shown in Figure 5 As shown in the figure, the delay spread distribution trends of each algorithm show that as delay spread increases, the cumulative distribution function value gradually increases and approaches 1 in the high-delay range. This phenomenon is consistent with the typical delay spread distribution pattern. Overall, the delay spread results of the DRT algorithm are very close to those of IM, WI, and other methods, demonstrating good consistency and comparability. Figure 6 The distribution of the time-varying Doppler power spectral density obtained by the DRT algorithm is shown. It can be seen that the DRT algorithm can effectively capture and represent the Doppler frequency shift in the channel, meet the requirements of the Doppler characteristics, and ensure the accuracy of channel estimation in dynamic environments.

[0105] Table 1 Logarithmic distance path loss model parameters

[0106]

[0107] To compare the computational time differences between the DRT algorithm and the traditional RT algorithm, we conducted all simulation experiments using a standard desktop computer equipped with an Intel Core i7-10700 2.9 GHz CPU and 32 GB of memory. Table 2 reports the simulation times for the two algorithms. As can be seen from the table, the total simulation time for the RT algorithm is approximately four times that of the DRT algorithm, demonstrating that the DRT algorithm can significantly reduce computational time.

[0108] Table 2 Comparison of simulation time between RT and DRT algorithms

[0109]

[0110] In summary, the dynamic ray tracing wireless channel modeling method provided by the present invention solves the problem that the ray tracing algorithm needs to consider a large number of continuous environmental configurations or "snapshots" to achieve spatial consistency simulation in dynamic scenarios, further improving the computational efficiency of ray tracing.

[0111] Example 3

[0112] A dynamic ray tracing wireless channel modeling device, comprising:

[0113] Configuration module, used to select dynamic scenarios and configure scenario parameters, including propagation mechanism and antenna type;

[0114] The initial ray path acquisition module is used to determine whether the current simulation time is less than the preset total simulation time. If so, the initial ray path including all reflection points is obtained by the mirror method.

[0115] An acceleration structure building module, which is used to build a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy;

[0116] The intersection test module is used to perform the intersection test between the ray and the hierarchical bounding box to obtain the geometric information of each reflection point and its minimum bounding box;

[0117] The coherence time dynamic update module is used to select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time based on the minimum size and maximum motion speed;

[0118] The dynamic ray tracing module is used to perform dynamic ray tracing within the updated coherence time window and update the simulation time. At the same time, based on the updated simulation time, it repeats the initial ray path acquisition, double-layer acceleration structure construction, intersection test between rays and hierarchical bounding boxes, calculation and update of coherence time, and tracing of dynamic rays in the coherence time window until the total simulation time is reached.

[0119] For more specific details about the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be described again here.

[0120] Example 4

[0121] The present invention provides a computer device comprising a processor and a memory; wherein the processor implements the steps of the above-mentioned dynamic ray tracing wireless channel modeling method when executing a computer program stored in the memory.

[0122] For more specific details about the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be described again here.

[0123] Example 5

[0124] The present invention provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the above-mentioned dynamic ray tracing wireless channel modeling method are implemented.

[0125] For more specific details about the above method, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be described again here.

[0126] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. References to the same or similar parts between the various embodiments will be sufficient. The systems, devices, and storage media disclosed in the embodiments are described briefly because they correspond to the methods disclosed in the embodiments. For relevant details, refer to the method description.

[0127] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software and a necessary general-purpose hardware platform. Based on this understanding, the technical solutions in the embodiments of the present invention, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, or an optical disk, and includes instructions for enabling a computer device (such as a personal computer, server, or network device) to execute the methods described in various embodiments of the present invention, or portions thereof.

[0128] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A dynamic ray tracing wireless channel modeling method, characterized in that: The following steps are involved: Step S1: Select a dynamic scene and configure scene parameters, including propagation mechanism and antenna type; Step S2: determine whether the current simulation time is less than the preset total simulation time. If so, obtain the initial ray path by the mirror method. If not, terminate the simulation. The path point between the transmitting and receiving ends is the reflection point. Step S3: constructing a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy; Step S4: perform an intersection test between the ray and the hierarchical bounding box to obtain the geometric information of each reflection point and its minimum bounding box; Step S5: Select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time based on the minimum size and maximum motion speed; Step S6: Perform dynamic ray tracing within the updated coherent time window and update the simulation time, and repeat steps S2 to S6 to implement dynamic ray tracing.

2. The dynamic ray tracing wireless channel modeling method according to claim 1, characterized in that: The step S1 is specifically as follows: According to the application requirements, select the dynamic scene that needs to be ray traced, and based on the selected dynamic scene, obtain the position, movement speed and direction of the transmitter and receiver, the position, movement speed and direction of the moving object, and set the movement time of each moving object within the simulation time period; Configure the propagation mechanism in the scene, including the maximum order of ray reflections; Select the appropriate antenna type according to the application scenario and set the antenna's transmit power and polarization mode; Set the center frequency for the RT simulation and, based on this frequency, select the electromagnetic parameters of the material required for the simulation, including the dielectric constant, conductivity, and thickness, to complete the simulation setup.

3. The dynamic ray tracing wireless channel modeling method according to claim 1, characterized in that: The double-layer acceleration structure in step S3 includes a top-level BVH acceleration structure and a bottom-level BVH acceleration structure. The top-level BVH acceleration structure stores information of static objects, and the bottom-level BVH acceleration structure stores information of all dynamic objects.

4. The dynamic ray tracing wireless channel modeling method according to claim 1, characterized in that: The step S4 is specifically as follows: From top to bottom, the bounding boxes are traversed to perform fast intersection detection, and the sub-bounding boxes that may intersect with the ray are screened out. The sub-bounding boxes are then refined layer by layer in a recursive manner until the minimum bounding box that intersects with the ray is found or it is determined that the ray does not intersect with any bounding box. When the minimum bounding box that intersects with the ray is found, the geometric information of the minimum bounding box is determined, including the center point and boundary range.

5. The dynamic ray tracing wireless channel modeling method according to claim 1, characterized in that: In step S5, an upper limit value of the coherence time is obtained according to the following formula, and the coherence time is updated according to the upper limit value of the coherence time; ； in, is the coherence time, The minimum size of all minimum bounding boxes, the minimum size is the minimum length, minimum width or minimum height, The maximum speed of all dynamic objects in the application scene.

6. The dynamic ray tracing wireless channel modeling method according to claim 1, characterized in that: The step S6 specifically includes the following sub-steps: Step S61: The receiving end, the transmitting end and the reflecting plane in the scene are I The motion parameters of the corresponding reflection point are converted from the global coordinate system to the reflection plane I In the corresponding local coordinate system, obtain the transmitter, receiver and reflection point on the reflection plane I Corresponding coordinates and velocities in the local coordinate system; Step S62: combining the motion information of the transmitting end, the receiving end, and the reflection plane, using the derivative chain criterion to determine the instantaneous velocity of each reflection point in the local coordinate system, and obtaining the instantaneous acceleration of each reflection point by taking the derivative; ； in, and are the instantaneous velocities of the transmitter and receiver in the local coordinate system respectively; Reflection plane I The instantaneous velocity of the corresponding reflection point in the local coordinate system; Reflection plane I The coordinates of the corresponding reflection point in the local coordinate system, is the coordinate of the transmitter in the local coordinate system, is the coordinate of the receiving end in the local coordinate system, is the scale factor, , is a parameter used only to simplify the calculation. ; Step S63: Set time step , iteratively update the positions and velocities of all interaction points, where all interaction points include all reflection points, transmitters and receivers; ； ； in, )for t The instantaneous acceleration of the reflection point in the local coordinate system at time , for t The position of the interaction point in the local coordinate system at that moment, for t The instantaneous velocity of the interaction point in the local coordinate system at the moment, for The position of the interaction point in the local coordinate system at that moment; for The instantaneous velocity of the interaction point in the local coordinate system at that moment; Step S64: Update simulation time , repeat steps S2 to S6 to achieve dynamic ray tracing.

7. The dynamic ray tracing wireless channel modeling method according to claim 6, characterized in that: In step S61, the receiving end, the transmitting end and the reflecting plane in the scene are I The motion parameters of the corresponding reflection point are converted from the global coordinate system to the reflection plane I When the global coordinate system is in the corresponding local coordinate system, the global coordinate system is converted to the reflection plane I The corresponding local coordinate system and the reflection plane I Located at y=0.

8. A dynamic ray tracing wireless channel modeling device, characterized in that: include: Configuration module, used to select dynamic scenarios and configure scenario parameters, including propagation mechanism and antenna type; The initial ray path acquisition module is used to determine whether the current simulation time is less than the preset total simulation time. If so, the initial ray path is obtained by the mirror method, including all reflection points. If not, the simulation is terminated. An acceleration structure building module, which is used to build a double-layer acceleration structure of dynamic objects and static objects using a surface area heuristic strategy; The intersection test module is used to perform the intersection test between the ray and the hierarchical bounding box to obtain the geometric information of each reflection point and its minimum bounding box; The coherence time dynamic update module is used to select the maximum speed of all dynamic objects in the application scene and the minimum size of all minimum bounding boxes, and obtain and update the coherence time based on the minimum size and maximum motion speed; The dynamic ray tracing module is used to perform dynamic ray tracing within the updated coherence time window and update the simulation time. At the same time, based on the updated simulation time, it repeats the initial ray path acquisition, double-layer acceleration structure construction, intersection test between rays and hierarchical bounding boxes, calculation and update of coherence time, and tracing of dynamic rays in the coherence time window until the total simulation time is reached.

9. A computer device, characterized in that: The method comprises a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the dynamic ray tracing wireless channel modeling method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that Used to store a computer program; when the computer program is executed by a processor, the steps of the dynamic ray tracing wireless channel modeling method according to any one of claims 1 to 7 are implemented.

Images