Method, device, equipment and readable storage medium for constructing radio environment map

Abstract

The present invention provides a method, apparatus, device, and readable storage medium for constructing a radio environment map, relating to the field of radio communication technology. The method comprises constructing antenna positions within a large-scale area, setting radiation source parameters, wherein the radiation source parameters include antenna height, directional pattern, antenna height, and transmit power; dividing local area coordinates, and using a grid subdivision algorithm to map the local domain to a global domain and generate a global grid; optimizing the global grid based on the antenna position to obtain a multi-grid; and calculating the multi-grid according to the paraxial approximation principle, and mapping the calculation results to the global grid, thereby constructing a radio environment map for a large-scale area. The present invention has the beneficial effect of using a deterministic model to quickly and accurately generate a radio environment map for a large-scale area in a complex environment, thereby improving the accuracy and efficiency of REM construction in a large-scale area in a complex environment.

Description

Technical Field

[0001] The present invention relates to the field of radio communication technology, and in particular to a method, apparatus, device and readable storage medium for constructing a radio environment map. Background Art

[0002] Radio Environment Maps (REMs) are a crucial component of cognitive radio systems (CRSs). They are widely used as a tool for visualizing the spatial distribution of spectrum in indoor and outdoor environments, providing powerful support for spectrum management, network monitoring, and positioning. In recent years, various methods for constructing REMs have emerged, with direct and indirect methods being the most commonly used.

[0003] The direct method is based on interpolation techniques such as linear interpolation, polynomial interpolation, curve interpolation and kriging. The signal strength at the location of interest is estimated by interpolating discrete measured signal strengths. The construction accuracy of the direct method depends largely on the available measurement signals. However, these signal databases can only be obtained in certain specific areas (for example, indoor and urban areas where measurements are taken). It is unrealistic to obtain data through field measurements in all environments, especially in large-scale regional environments with complex terrain. So far, there is still a lack of sufficient available signals to construct large-scale regional radio environment maps.

[0004] Indirect methods use transmitter parameters and propagation models to construct more accurate REMs, but this increases computational overhead. Propagation models directly based on Maxwell's equations—deterministic models—can not only simulate specific environmental elements, such as topography and landforms, but also apply appropriate radio propagation prediction algorithms in corresponding propagation scenarios, resulting in highly accurate spatial distributions of electromagnetic fields in certain propagation scenarios. Ray tracing algorithms are currently one of the most widely used tools for solving radio propagation problems in indoor and outdoor environments. However, to simulate electromagnetic wave propagation in complex environments, ray tracing methods must introduce various criteria and equivalent sub-models, which increases the computational complexity and time required to construct REMs for large-scale regional environments, making them difficult to implement. Summary of the Invention

[0005] The present invention aims to provide a method, apparatus, device, and readable storage medium for constructing a radio environment map to improve the above-mentioned problem. To achieve the above-mentioned object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for constructing a radio environment map, comprising:

[0007] Constructing antenna positions within a large-scale area and setting radiation source parameters, wherein the radiation source parameters include antenna height, radiation pattern, antenna height, and transmission power;

[0008] Divide the local area coordinates, use the grid subdivision algorithm to map the local domain to the global domain and generate the global grid;

[0009] Based on the antenna positions, the global grid is optimized to obtain a multi-grid;

[0010] Based on the paraxial approximation principle, calculations are performed on multiple grids and the calculation results are mapped to the global area to construct a large-scale regional radio environment map.

[0011] Preferably, mapping the local domain to the global domain and generating a global grid comprises:

[0012] Acquire first data, where the first data includes a position vector of the local area coordinates and a distance vector between the global source point and the local source point;

[0013] Calculating the first data using a transformation matrix method to obtain a first coordinate mapping result;

[0014] The first coordinate mapping result is calculated according to the triangulation linear interpolation method and a global grid is generated.

[0015] Preferably, the global grid is optimized based on the antenna position to obtain a multi-grid, which includes:

[0016] Obtain the terrain of the main antenna's environment in a large area, including mountains, valleys, buildings, and plains;

[0017] The terrain of the main antenna environment is divided into grids, and the terrain corresponding to each grid node is marked. The ground features of the terrain are calculated based on the marked content. The formula is as follows:

[0018]

[0019] Where H A , H B With H C are the heights of nodes A, B and their midpoint C, respectively, |H T | is the height of the protrusion;

[0020] Local refinement is performed between two adjacent nodes in the ground feature to obtain a multi-grid.

[0021] Preferably, the local refinement processing is performed between two adjacent nodes in the ground feature, wherein the local refinement processing formula includes:

[0022]

[0023] Where, T criterion is the mesh refinement parameter, |H T | is the height of the protrusion, h r is the receiver height;

[0024] The mesh refinement parameter is judged. The judgment process is as follows: if the mesh refinement parameter is 1, local iterative refinement calculation is performed until the conditions are met for output; if the mesh refinement parameter is not 1, it is directly output to complete the calculation.

[0025] Preferably, the process of constructing antenna positions within a large-scale area, setting radiation source parameters, and then selecting a grid cylindrical coordinate parabolic equation includes:

[0026] In the same calculation scenario, the first signal reception strength value and the second signal reception strength value are calculated using the coarse grid method and the multi-grid cylindrical coordinate parabolic equation respectively, where the same calculation scenario is a scenario within the same large-scale area;

[0027] Based on a preset third signal reception strength value, calculating the difference between the first signal reception strength value and the second signal reception strength value and the third signal reception strength value, respectively, to obtain a first difference value and a second difference value; wherein the third signal reception strength value is a received signal strength value obtained using the fine grid cylindrical coordinate parabolic equation;

[0028] The absolute values ​​of the first difference value and the second difference value are compared, and the grid cylindrical coordinate parabolic equation corresponding to the difference value with the smaller absolute value is selected as the final grid setting.

[0029] In a second aspect, the present application also provides a device for constructing a radio environment map, including a construction module, a generation module, an optimization module, and a calculation module, wherein:

[0030] Construction module: used to construct antenna positions within a large-scale area and set radiation source parameters, where the radiation source parameters include antenna height, radiation pattern, antenna height and transmission power;

[0031] Generation module: used to divide the local area coordinates, use the grid subdivision algorithm to map the local domain to the global domain and generate the global grid;

[0032] Optimization module: used to optimize the global grid based on antenna positions to obtain multiple grids;

[0033] Calculation module: used to calculate multiple grids based on the paraxial approximation principle and map the calculation results to the global level to construct a large-scale regional radio environment map.

[0034] In a third aspect, the present application further provides a device for constructing a radio environment map, comprising:

[0035] Memory for storing computer programs;

[0036] A processor is configured to implement the steps of the method for constructing a radio environment map when executing the computer program.

[0037] In a fourth aspect, the present application further provides a readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the above-mentioned method based on constructing a radio environment map are implemented.

[0038] The beneficial effects of the present invention are:

[0039] The present invention does not rely on measured data, and adopts a deterministic model to quickly and accurately generate a radio environment map in a large-scale regional complex environment, thereby improving the accuracy and efficiency of REM construction in a large-scale regional complex environment.

[0040] The present invention uses a method of mapping local coordinates to global coordinates and a cylindrical coordinate system parabolic equation model to quickly construct a radio environment map. It can also generate a radio environment map for a large area through a data mapping mechanism from the local domain to the global domain, solving the problem of difficulty in processing multiple sources and moving sources in the global cylindrical coordinate system.

[0041] The present invention changes the traditional coarse grid or fine grid mode, optimizes the grid division strategy, obtains multiple grids, and improves calculation accuracy and efficiency.

[0042] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the embodiments of the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 A schematic flow chart of a method for constructing a radio environment map according to an embodiment of the present invention;

[0045] Figure 2This is a schematic structural diagram of a device for constructing a radio environment map according to an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of the structure of a device for constructing a radio environment map according to an embodiment of the present invention;

[0047] Figure 4 A pseudo-color schematic diagram of the received signal strength distribution at a height of 2 m above the ground calculated for the fine grid used to construct the radio environment map described in an embodiment of the present invention;

[0048] Figure 5 A first schematic diagram of received signal strength and absolute error generated by a coarse grid for constructing a radio environment map according to an embodiment of the present invention;

[0049] Figure 6 A second schematic diagram of received signal strength and absolute error generated by a coarse grid for constructing a radio environment map according to an embodiment of the present invention;

[0050] Figure 7 A first schematic diagram of received signal strength and absolute error generated by multiple grids for constructing a radio environment map according to an embodiment of the present invention;

[0051] Figure 8 A second schematic diagram of received signal strength and absolute error generated by multiple grids for constructing a radio environment map according to an embodiment of the present invention;

[0052] Figure 9 A schematic diagram of signal reception strength generated by different grids at 3 km from the set terrain for constructing a radio environment map according to an embodiment of the present invention;

[0053] Figure 10 A schematic diagram showing a comparison of absolute errors of signal reception strength generated by coarse grids and multiple grids under different terrains for constructing a radio environment map according to an embodiment of the present invention;

[0054] In the figure: 701, construction module; 7011, signal strength value calculation unit; 7012, difference value calculation unit; 7013, selection unit; 702, generation module; 7021, first acquisition unit; 7022, calculation unit; 7023, mapping unit; 703, optimization module; 7031, second acquisition unit; 7032, division marking unit; 7033, processing unit; 70331, local processing unit; 70332, judgment unit; 704, calculation module; 800, device for constructing radio environment map; 801, processor; 802, memory; 803, multimedia component; 804, I / O interface; 805, communication component. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0056] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are used only to distinguish the description and should not be understood as indicating or implying relative importance.

[0057] Example 1:

[0058] This embodiment provides a method for constructing a large-scale regional radio environment map.

[0059] See also Figure 1 , the figure shows that the method includes step S100, step S200, step S300 and step S400.

[0060] S100: Construct antenna positions within a large-scale area and set radiation source parameters, wherein the radiation source parameters include antenna height, radiation pattern, antenna height, and transmission power.

[0061] It is understood that the steps S100 and S1001, S1002 and S1003 are included after this step S100, wherein:

[0062] S1001. In the same calculation scenario, using a coarse grid method and a multi-grid cylindrical coordinate parabolic equation, respectively calculate a first signal reception strength value and a second signal reception strength value, wherein the same calculation scenario is a scenario within the same large-scale area;

[0063] S1002. Calculate the difference between the first signal reception strength value and the second signal reception strength value, respectively, and the third signal reception strength value based on a preset third signal reception strength value, to obtain a first difference value and a second difference value; wherein the third signal reception strength value is a received signal strength value obtained using a fine grid cylindrical coordinate parabolic equation;

[0064] S1003 : Compare the absolute values ​​of the first difference value and the second difference value, and select the grid cylindrical coordinate parabolic equation corresponding to the difference value with the smaller absolute value as the final grid setting.

[0065] It should be noted that, in the same calculation scenario, the signal reception strength is calculated using the coarse grid cylindrical coordinate parabolic equation and the multi-grid cylindrical coordinate parabolic equation. The settlement results are as follows: Figure 5 and Figure 7 As shown, the calculation time is calculated. Taking the received signal strength obtained by the fine grid cylindrical coordinate parabolic equation as a reference, the absolute error corresponding to the two grid division schemes is calculated as follows: Figure 6 and Figure 8 As shown in the figure, it can be seen that the distribution of signal receiving strength of the two calculation methods is almost completely consistent with the reference grid. The largest absolute error occurs in the hilly island area with large height fluctuations. Figure 9 The received signal strength at different angles and different grids with a fixed distance of 3 km between the receiver and the radiation source was calculated. In areas with steep terrain changes, the multi-grid method is more consistent with the calculation results of the fine grid and has higher calculation accuracy.

[0066] In this embodiment, the root mean square errors of the coarse grid cylindrical coordinate parabolic equation and the multi-grid cylindrical coordinate parabolic equation relative to the fine grid cylindrical coordinate parabolic equation are calculated respectively. The root mean square error can be used to measure the difference between the two different grid cylindrical coordinate parabolic equations and the fine grid cylindrical coordinate parabolic equation. The calculation formula is expressed as:

[0067]

[0068] Where, E ij ′ represents the signal receiving strength of the coarse grid cylindrical coordinate parabolic equation or the multi-grid cylindrical coordinate parabolic equation, N is the number of nodes, E ij represents the signal receiving strength calculated by the fine grid cylindrical coordinate parabolic equation. ∑ is the summation symbol, ∑ i Indicates the sum of the array with the subscript i, where i represents the sequence number of each point in the horizontal grid, ∑ j Indicates the sum of the array with subscript j, where j represents the serial number of each point in the vertical grid. Both data matrices contain i rows and j columns, ∑ i represents the sum of all rows, ∑ j Indicates the sum of all columns. ∑ i ∑ j It means to add up all the data in the matrix.

[0069] Figure 10The root mean square errors of the two grid cylindrical coordinate parabolic equation models relative to the fine grid cylindrical coordinate parabolic equation in three regions: global, hilly islands, and open sea. It can be seen that in hilly island areas with sudden terrain changes, the multi-grid cylindrical coordinate parabolic equation has higher accuracy than the coarse grid cylindrical coordinate parabolic equation by refining the terrain to cover the local grid.

[0070] In this experimental example, the computational time costs for the fine grid cylindrical coordinate parabolic equation, the coarse grid cylindrical coordinate parabolic equation, and the multi-grid cylindrical coordinate parabolic equation are 44.0s, 6.6s, and 9.5s, respectively. This experimental example shows that the multi-grid cylindrical coordinate parabolic equation significantly improves computational efficiency while taking into account computational accuracy. Figure 4 A pseudo-color map of the received signal strength distribution on the ground at a height of 2 meters above the ground is drawn.

[0071] S200 , dividing the local area coordinates, using a grid subdivision algorithm to map the local domain to the global domain and generate a global grid.

[0072] It can be understood that step S200 includes S201, S202 and S203, wherein:

[0073] S201, obtaining first data, where the first data includes a position vector of a local area coordinate and a distance vector between a global source point and a local source point;

[0074] S202: Calculate the first data using a transformation matrix method to obtain a first coordinate mapping result; wherein the coordinate mapping method is as follows:

[0075] The coordinate relationship between the two systems is as follows:

[0076]

[0077] Among them, P G and P L are the position vectors of the field point in global and local coordinates, respectively. is the transformation matrix from local coordinates to global rectangular coordinates, assuming that the radiation source is located at the coordinate (x s ,y s ,z s ), then R oo′ =x s e x +y s e y +z s e z is the distance vector between the global source point and the local source point.

[0078]

[0079] Where, is the transformation matrix from local coordinates to global rectangular coordinates.

[0080] S203 , calculating the first coordinate mapping result according to the triangulation linear interpolation method and generating a global grid.

[0081] It should be noted that the calculation area of ​​the cylindrical coordinate parabolic equation model is centered on the location of the radiation source. Because it is difficult to handle multiple sources or moving sources within the same cylindrical coordinate grid, it is not suitable for directly constructing radio environment maps. If a fine grid is used in the local area to achieve the same resolution as the global radio environment map, the local data can be mapped from local coordinates to global rectangular coordinates.

[0082] This method of mapping local coordinates to global coordinates can help us quickly construct radio environment maps using the parabolic equation model in the cylindrical coordinate system; and radio environment maps of large areas can be generated through a data mapping mechanism that maps from the local domain to the global domain, solving the problem of difficulty in processing multiple sources and moving sources in the global cylindrical coordinate system.

[0083] Specifically, when coarse grids and multigrids are adopted, when the calculated data in the local grids are insufficient to fill the global grid, linear interpolation is used for triangulation to interpolate the data set to the global rectangular grid.

[0084] S300: Optimize the global grid based on the antenna position to obtain a multi-grid.

[0085] It is understandable that the step S300 includes S301, S302 and S303, wherein:

[0086] S301, obtaining the terrain of the environment in which the main antenna is located in a large-scale area, wherein the environment includes mountains, valleys, buildings, and plains;

[0087] It should be noted that the environment in which the main antenna is located includes large-area environments such as mountains, valleys, buildings, plains and the high seas; and the radiation source parameters are set, including the radiation pattern, antenna height, operating frequency and transmission power.

[0088] S302: Divide the terrain of the environment where the main antenna is located into grids, mark the terrain corresponding to each grid node after division, and calculate the ground features of the terrain based on the marked content. The formula is as follows:

[0089]

[0090] Where H A , H B With H C are the heights of nodes A, B and their midpoint C, respectively, |HT | is the height of the protrusion.

[0091] It should be noted that solving the parabolic equation model in cylindrical coordinates on a cylindrical grid generates a radially regular grid with uniform discretization. This radially regular grid is composed of non-uniform fan-shaped grids that tend to be sparse along the propagation direction. When the terrain in the calculation area changes, the accuracy of the parabolic equation model in cylindrical coordinates is reduced. Therefore, it is necessary to optimize the grid division strategy. Traditional coarse or fine grid divisions suffer from low computational accuracy and low efficiency. This paper proposes a multi-grid cylindrical coordinate method to achieve the corresponding computational accuracy and efficiency.

[0092] Specifically, large-scale areas often feature a variety of terrains, including mountains, valleys, buildings, plains, and the open ocean. These varying terrains and landforms can have varying effects on radio propagation, leading to sudden changes in the electromagnetic field. Therefore, it's necessary to apply grid refinement techniques in areas with varying terrain.

[0093] S303: Perform local refinement processing between two adjacent nodes in the ground feature to obtain a multi-grid.

[0094] It should be noted that after the terrain is meshed, the terrain corresponding to each grid node is recorded as node A and node B, the midpoint between A and B is recorded as C, and the terrain protrusion height between nodes A and B is introduced to quantitatively express the ground characteristics:

[0095]

[0096] Where H A 、H B With H C is the height of nodes A, B and their midpoint C, which is positive for convex terrain, zero for flat terrain, and negative for concave terrain. r Below the raised height |H T |, there is non-line-of-sight (NLOS) between A and B. This radio wave caused by the terrain has shadow effects, diffraction and scattering.

[0097] It is understandable that the step S303 includes S3031 and S3032:

[0098] S3031. Refine the grid to represent the fluctuation of the radio wave. Therefore, the grid refinement criterion between two adjacent nodes is:

[0099]

[0100] Where, T criterion is the mesh refinement parameter, |H T | is the height of the protrusion, hr is the receiver height;

[0101] S3032. Determine the mesh refinement parameter. If the mesh refinement parameter is 1, perform local iterative refinement calculation until the conditions are met for output. If the mesh refinement parameter is not 1, directly output and complete the calculation.

[0102] It should be noted that, in the above formula, T criterion is the mesh refinement decision parameter, if T criterion =1, the local grid is refined; otherwise, the current network size is maintained; local grid refinement can be repeated multiple times to form multiple grids until the spatial grid division accuracy requirements are met.

[0103] Specifically, this step is mainly to generate multiple grids to prepare for the calculation of the parabolic equation model in the cylindrical coordinate system in the next step.

[0104] S400: Calculate multiple grids based on the paraxial approximation principle and map the calculation results to the global area, thereby constructing a large-scale regional radio environment map.

[0105] It can be understood that in this step, the cylindrical coordinate system parabolic equation model is in the cylindrical coordinate system The following is a paraxial approximate propagation method derived from the Helmholtz equation. When the source is located in the region r≤r0, the frequency domain electric field formula for the region r>r0 is as follows:

[0106]

[0107] Where k0 is the free space beam, n is the refractive index, and Π e and Π h Represent the electric field vector potential and magnetic field vector potential respectively; for the TE case, For the TM case, Wave impedance Ψ is represented by the superposition of TM field and TE field, and Ψ satisfies the following equation:

[0108]

[0109] In the above formula, r is the radius of the cylindrical coordinate system, is the angle, z is the height; ignoring the backscattered field and adopting the Feit and Fleck approximation, the solution of the above equation is:

[0110]

[0111] Where, e is the base of the natural constant, j is the imaginary number symbol, △r is the radial step length in the cylindrical coordinate system, is the first kind of Hankel function, kr is the spatial beam at r, and are the Fourier transform and inverse Fourier transform in the angular spectrum domain and spatial domain. This equation can be solved by the step-by-step method by setting boundary conditions and initial values.

[0112] This formula shows that the cylindrical coordinate parabolic equation model can handle diffraction, refraction, reflection or other similar electromagnetic wave effects during the simulation process, revealing the inherent characteristics of radio wave propagation and the interaction mechanism between radio waves and the environment.

[0113] It should be noted that, in addition, during the simulation of the multi-grid cylindrical coordinate parabolic equation model, the data exchange problem between multi-scale grids should also be paid attention to. The present invention uses the "Whitney-Shannon" (finite band) interpolation method to spatially interpolate the calculated data at the interface between grids of different resolutions. That is, based on the value of Ψ at a finite number of points, the approximate value at other points is estimated. Its expression is:

[0114]

[0115] In the above formula, n is an integer ranging from -∞ to ∞. is the grid scale of angles in the cylindrical coordinate system. It should be noted that by filling the calculated frequency-domain electric field into the divided grid, a radio environment map in the local coordinate system is constructed. By mapping the local coordinate system to the global coordinate system, a radio environment map for a large and complex environment is completed.

[0116] Example 2:

[0117] like Figure 2 As shown, this embodiment provides a device for constructing a radio environment map, see Figure 2 The apparatus includes a construction module 701, a generation module 702, an optimization module 703 and a calculation module 704, wherein:

[0118] Construction module 701: used to construct antenna positions within a large-scale area and set radiation source parameters, wherein the radiation source parameters include antenna height, radiation pattern, antenna height and transmission power;

[0119] Generation module 702: used to divide the local area coordinates, use the grid subdivision algorithm to map the local domain to the global domain and generate a global grid;

[0120] Optimization module 703: used to optimize the global grid based on the antenna position to obtain a multi-grid;

[0121] The calculation module 704 is used to calculate multiple grids according to the paraxial approximation principle and map the calculation results to the global area, thereby constructing a large-scale regional radio environment map.

[0122] Specifically, the construction module 701 includes a signal strength value calculation unit 7011, a difference value calculation unit 7012, and a selection unit 7013, wherein:

[0123] The signal strength value calculating unit 7011 is configured to calculate the first signal reception strength value and the second signal reception strength value respectively using the coarse grid method and the multi-grid cylindrical coordinate parabolic equation in the same calculation scenario, wherein the same calculation scenario is a scenario within the same large-scale area;

[0124] The difference value calculating unit 7012 is configured to calculate the difference between the first signal reception strength value and the second signal reception strength value and the third signal reception strength value, respectively, based on a preset third signal reception strength value, to obtain a first difference value and a second difference value; wherein the third signal reception strength value is a received signal strength value obtained using a fine grid cylindrical coordinate parabolic equation;

[0125] The selection unit 7013 is used to compare the absolute values ​​of the first difference value and the second difference value, and select the grid cylindrical coordinate parabolic equation corresponding to the difference value with the smaller absolute value as the final grid setting.

[0126] Specifically, the generation module 702 includes a first acquisition unit 7021, a calculation unit 7022, and a mapping unit 7023, wherein:

[0127] A first acquisition unit 7021 is configured to acquire first data, where the first data includes a position vector of the local area coordinates and a distance vector between the global source point and the local source point;

[0128] Calculation unit 7022: used to calculate the first data using a transformation matrix method to obtain a first coordinate mapping result;

[0129] Mapping unit 7023: used to calculate the first coordinate mapping result according to the triangulation linear interpolation method and generate a global grid.

[0130] Specifically, the optimization module 703 includes a second acquisition unit 7031, a division marking unit 7032, and a processing unit 7033, wherein:

[0131] The second acquisition unit 7031 is used to acquire the terrain of the environment in which the main antenna is located in a large-scale area, where the environment includes mountains, valleys, buildings and plains;

[0132] The division and marking unit 7032 is used to divide the terrain of the environment where the main antenna is located into grids, mark the terrain corresponding to each grid node after division, and calculate the ground features of the terrain based on the marked content. The formula is as follows:

[0133]

[0134] Where H A , H B With H C are the heights of nodes A, B and their midpoint C, respectively, |H T | is the height of the protrusion;

[0135] Processing unit 7033: used to perform local refinement processing between two adjacent nodes in the ground feature to obtain a multi-grid.

[0136] Specifically, the processing unit 7033 further includes a local processing unit 70331 and a judgment unit 70332, wherein:

[0137] The local processing unit 70331 is used to perform local refinement processing between two adjacent nodes in the ground feature, wherein the local refinement processing formula includes:

[0138]

[0139] Where, T criterion is the mesh refinement parameter, |H T | is the height of the protrusion, h r is the receiver height;

[0140] Judgment unit 70332: used to judge the grid refinement parameter, wherein the judgment process is as follows: if the grid refinement parameter is 1, local iterative refinement calculation is performed until the conditions are met for output; if the grid refinement parameter is not 1, direct output is performed to complete the calculation.

[0141] Specifically, the process of constructing the antenna position in the large-scale area and selecting the grid cylindrical coordinate parabolic equation after setting the radiation source parameters includes a signal strength value calculation unit 7011, a difference value calculation unit 7012 and a selection unit 7013, wherein:

[0142] The signal strength value calculating unit 7011 calculates the first signal reception strength value and the second signal reception strength value respectively using a coarse grid method and a multi-grid cylindrical coordinate parabolic equation in the same calculation scenario, wherein the same calculation scenario is a scenario within the same large-scale area;

[0143] The difference value calculating unit 7012 calculates the difference between the first signal reception strength value and the second signal reception strength value and the third signal reception strength value, respectively, based on a preset third signal reception strength value, to obtain a first difference value and a second difference value; wherein the third signal reception strength value is a received signal strength value obtained using the fine grid cylindrical coordinate parabolic equation;

[0144] Selection unit 7013: compares the absolute values ​​of the first difference value and the second difference value, and selects the grid cylindrical coordinate parabolic equation corresponding to the difference value with the smaller absolute value as the final grid setting.

[0145] It should be noted that, regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated on here.

[0146] Example 3:

[0147] Corresponding to the above method embodiment, this embodiment further provides a device for constructing a radio environment map. The device for constructing a radio environment map described below and the method for constructing a radio environment map described above can refer to each other.

[0148] Figure 3 FIG. 8 is a block diagram of a device 800 for constructing a radio environment map according to an exemplary embodiment. Figure 3 As shown, the apparatus 800 for constructing a radio environment map includes: a processor 801 and a memory 802. The apparatus 800 for constructing a radio environment map also includes one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0149] The processor 801 is used to control the overall operation of the device 800 for constructing a radio environment map to complete all or part of the steps in the above-mentioned method for constructing a radio environment map. The memory 802 is used to store various types of data to support the operation of the device 800 for constructing a radio environment map. Such data may include, for example, instructions for any application or method operating on the device 800 for constructing a radio environment map, as well as application-related data, such as contact data, sent and received messages, pictures, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may be further stored in the memory 802 or transmitted via the communication component 805. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 804 provides an interface between the processor 801 and other interface modules, which may be a keyboard, mouse, or buttons. These buttons may be virtual buttons or physical buttons. The communication component 805 is used for wired or wireless communication between the device 800 for building the radio environment map and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination of one or more thereof, may include a Wi-Fi module, a Bluetooth module, or an NFC module.

[0150] In an exemplary embodiment, the device 800 for constructing a radio environment map can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the above-mentioned method for constructing a radio environment map.

[0151] In another exemplary embodiment, a computer-readable storage medium including program instructions is further provided. When executed by a processor, the program instructions implement the steps of the above-described method for constructing a radio environment map. For example, the computer-readable storage medium may be the aforementioned memory 802 including the program instructions. The program instructions may be executed by the processor 801 of the apparatus 800 for constructing a radio environment map to implement the above-described method for constructing a radio environment map.

[0152] Example 4:

[0153] Corresponding to the above method embodiment, this embodiment further provides a readable storage medium. The readable storage medium described below and the method for constructing a radio environment map described above can refer to each other.

[0154] The readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for constructing a radio environment map in the above method embodiment are implemented.

[0155] The readable storage medium may specifically be any readable storage medium that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0156] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0157] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for constructing a radio environment map, characterized in that: include: Constructing antenna positions within a large-scale area and setting radiation source parameters, wherein the radiation source parameters include antenna height, radiation pattern, antenna height, and transmission power; Divide the local area coordinates, use the grid subdivision algorithm to map the local domain to the global domain and generate the global grid; Based on the antenna positions, the global grid is optimized to obtain a multi-grid; Based on the paraxial approximation principle, multiple grids are calculated and the results are mapped to the global map to construct a large-scale regional radio environment map. The step of optimizing the global grid based on the antenna position to obtain a multi-grid includes: Obtain the terrain of the main antenna's environment in a large area, including mountains, valleys, buildings, and plains; The terrain of the main antenna environment is divided into grids, and the terrain corresponding to each grid node is marked. The ground features of the terrain are calculated based on the marked content. The formula is as follows: Where H A , H B With H C are the heights of nodes A, B and their midpoint C, respectively, |H T | is the height of the protrusion; Perform local refinement between two adjacent nodes in the ground feature to obtain a multi-grid; The local refinement processing is performed between two adjacent nodes in the ground feature, wherein the local refinement processing formula includes: Where, T criterion is the mesh refinement parameter, |H T | is the height of the protrusion, h r is the receiver height; The mesh refinement parameter is judged. The judgment process is as follows: if the mesh refinement parameter is 1, local iterative refinement calculation is performed until the conditions are met for output; if the mesh refinement parameter is not 1, it is directly output to complete the calculation.

2. The method for constructing a radio environment map according to claim 1, wherein: The method maps the local domain to the global domain and generates a global mesh, including: Acquire first data, where the first data includes a position vector of the local area coordinates and a distance vector between the global source point and the local source point; Calculating the first data using a transformation matrix method to obtain a first coordinate mapping result; The first coordinate mapping result is calculated according to the triangulation linear interpolation method and a global grid is generated.

3. The method for constructing a radio environment map according to claim 1, wherein: The process of constructing antenna positions within a large-scale area, setting radiation source parameters, and selecting a grid cylindrical coordinate parabolic equation includes: In the same calculation scenario, the first signal reception strength value and the second signal reception strength value are calculated using the coarse grid method and the multi-grid cylindrical coordinate parabolic equation respectively, where the same calculation scenario is a scenario within the same large-scale area; Based on a preset third signal reception strength value, calculating the difference between the first signal reception strength value and the second signal reception strength value and the third signal reception strength value, respectively, to obtain a first difference value and a second difference value; wherein the third signal reception strength value is a received signal strength value obtained using the fine grid cylindrical coordinate parabolic equation; The absolute values ​​of the first difference value and the second difference value are compared, and the grid cylindrical coordinate parabolic equation corresponding to the difference value with the smaller absolute value is selected as the final grid setting.

Images