A Communication Link Budget Evaluation Method and System Based on Satellite-Ground Channel Characteristic Model

Abstract

This invention provides a communication link budget evaluation method and system based on a satellite-to-ground channel characteristic model. The method includes: acquiring target parameters of a satellite-to-ground communication scenario; inputting the target parameters into a constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel; calculating the expected received power of the current satellite-to-ground communication based on the path loss; and comparing the expected received power with preset parameters to output an operation strategy, wherein the operation strategy includes at least dynamically adjusting the downlink transmit beam power of the satellite-to-ground communication. This invention aims to achieve a more accurate communication link budget by constructing a probability and path loss model that includes line-of-sight, ground specular reflection, and building specular reflection, thereby providing an engineering decision-making basis for the design and performance evaluation of satellite-to-ground communication systems.

Description

Technical Field

[0001] This invention belongs to the field of communication control technology, and in particular relates to a communication link budget evaluation method and system based on a satellite-to-ground channel characteristic model. Background Technology

[0002] In recent years, low-Earth orbit (LEO) satellites have been considered an important component of future integrated space-air-ground communication networks due to their lower communication latency and transmission loss. Accurate communication link budget assessment is crucial for ensuring the quality of communication services in network planning, resource allocation, and dynamic handover decisions for satellite communication systems.

[0003] However, compared with traditional terrestrial cellular networks, low-Earth orbit (LEO) satellite-to-ground communication links face a more complex propagation environment. When satellite signals reach the ground receiver, they are not only affected by atmospheric absorption, rainfall attenuation, and tropospheric scintillation, but also by severe three-dimensional obstruction and reflection from ground buildings.

[0004] Especially in complex urban scenarios, existing satellite-to-ground link budgeting methods typically rely on traditional empirical models or simplified statistical models. These existing techniques have the following drawbacks: First, they fail to fully consider the stochastic three-dimensional geometric distribution characteristics of urban building heights; second, most models rely solely on simple geometric optical line-of-sight obstruction, neglecting the Fresnel zone effect during electromagnetic wave propagation, resulting in significant prediction errors at high frequencies; third, existing budget assessments often focus only on the direct line-of-sight path, failing to incorporate non-line-of-sight components such as ground specular reflection and building specular reflection into the link budget considerations. Summary of the Invention

[0005] The purpose of this invention is to provide a communication link budget evaluation method and system based on a satellite-to-ground channel characteristic model, which solves the problems of budget result deviation and unreasonable system resource allocation caused by insufficient accuracy of the channel model in the existing satellite-to-ground communication link budget method.

[0006] In a first aspect, the present invention provides a communication link budget evaluation method based on a satellite-to-ground channel characteristic model, the method comprising:

[0007] Obtain target parameters for the satellite-to-ground communication scenario;

[0008] The target parameters are input into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel;

[0009] The expected received power of the current satellite-to-ground communication is calculated based on the path loss.

[0010] An operation strategy is output based on a comparison between the expected received power and preset parameters, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

[0011] In some embodiments of the first aspect of this application, obtaining the target parameters of the satellite-to-ground communication scenario specifically includes:

[0012] The target parameters include physical environment parameters and system parameters, wherein,

[0013] The physical environment parameters are obtained based on the statistical distribution characteristics of the height and density of urban buildings and the reflectivity of the medium.

[0014] The system parameters are obtained based on the current satellite elevation angle, satellite orbital altitude, ground user altitude, and transmission signal frequency.

[0015] In some embodiments of the first aspect of this application, the method further includes constructing the satellite-to-ground channel feature model, specifically including:

[0016] For a single reflection occurring within a defined radius area with a ground user as the receiver, using the Fresnel zone as the analysis region, communication probability models are constructed for line-of-sight paths, ground specular reflection paths, and building specular reflection paths, respectively.

[0017] The communication probability model for the line-of-sight path is constructed as follows:

[0018] ;

[0019] in, This represents the communication probability along the line-of-sight path. This represents the height of the i-th building along the line-of-sight path. This represents the maximum height of the i-th building in the Fresnel zone that does not obstruct the line-of-sight path. Indicates the number of buildings along the line-of-sight path;

[0020] A probabilistic model for satellite-to-ground communication based on the ground-based mirror reflection path is constructed, and its expression is as follows:

[0021] ;

[0022] in, This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the probability that there are no buildings obstructing the Fresnel zone from the satellite to the ground reflection point. This represents the probability that there are no buildings obstructing the Fresnel zone from the ground reflection point to the user's receiver. This indicates the number of buildings from the satellite to the ground reflection point. Indicates the number of buildings along the path of the ground mirror reflection;

[0023] A communication probability model for the reflection path of a building's mirror surface is constructed, expressed as follows:

[0024] ;

[0025] in, This represents the communication probability of the reflection path from the building's mirror surface. This represents the probability that the height of the i-th building is not lower than the minimum height in the Fresnel zone. This represents the probability that the j-th building preceding the i-th building does not obstruct the Fresnel zone. This represents the probability that the k-th building following the i-th building does not obstruct the Fresnel zone. Indicates the number of buildings along the path of a building's mirror reflection. This represents the total number of buildings between the satellite and the i-th building. This represents the total number of buildings between the i-th building and the user's receiving terminal.

[0026] In some embodiments of the first aspect of this application, the step of inputting the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel specifically includes:

[0027] The path loss calculation formula is as follows:

[0028] ;

[0029] in, This represents the path loss. Indicates geometric loss. Indicates dielectric loss. Indicates flicker loss;

[0030] Among them, geometric loss The calculation formula is as follows:

[0031] ;

[0032] in, The transmission gain of the satellite-to-ground channel is expressed by the following formula:

[0033] ;

[0034] in, This represents the communication probability along the line-of-sight path. This represents the propagation gain along the line-of-sight path. This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the propagation gain of the ground-based specular reflection path. This represents the communication probability of the reflection path from the building's mirror surface. This represents the propagation gain of the reflection path from the building's mirror surface.

[0035] In some embodiments of the first aspect of this application, calculating the expected received power of the current satellite-to-ground communication based on the path loss specifically includes:

[0036] The expected received power is calculated based on the communication link budget equation, where the calculation formula is as follows:

[0037] ;

[0038] in, Indicates the received power. Indicates the transmission power. Indicates the transmit antenna gain. Indicates the receiving antenna gain. This represents path loss.

[0039] In some embodiments of the first aspect of this application, the step of comparing the expected received power with preset parameters to output an operation strategy specifically includes:

[0040] The preset parameters include at least a preset threshold;

[0041] An operation strategy is output based on a comparison between the expected received power and the preset parameters.

[0042] When the expected received power is lower than the preset threshold, a power compensation mechanism is triggered to dynamically adjust the transmit power of the subordinate beams in the current satellite network coverage area.

[0043] To achieve the above and other related objectives, a second aspect of this application provides a communication link budget evaluation system based on a satellite-to-ground channel characteristic model, the system comprising:

[0044] The acquisition module is used to acquire target parameters in satellite-to-ground communication scenarios;

[0045] The calculation module is used to input the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel; and to calculate the expected received power of the current satellite-to-ground communication based on the path loss.

[0046] The output module is used to compare the expected received power with preset parameters to output an operation strategy, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

[0047] To achieve the above and other related objectives, a third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the communication link budget evaluation method based on the satellite-to-ground channel characteristic model described in any of the preceding claims.

[0048] To achieve the above and other related objectives, a fourth aspect of this application provides a computer program product comprising computer program code that, when executed on a computer, causes the computer to implement the communication link budget evaluation method based on the satellite-to-ground channel characteristic model described in any of the preceding claims.

[0049] To achieve the above and other related objectives, a fifth aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program to implement the communication link budget evaluation method based on the satellite-to-ground channel characteristic model described in any of the preceding claims.

[0050] As described above, the communication link budget evaluation method and system based on the satellite-to-ground channel characteristic model of the present invention have the following beneficial effects:

[0051] 1. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model proposed in this invention effectively captures the occlusion probability characteristics of the three main paths in the satellite-to-ground link—line-of-sight, ground specular reflection, and building specular reflection—by introducing Fresnel zone theory and considering only one reflection within a limited area around the receiver. It also uses stochastic geometry theory to characterize the Rayleigh distribution and spatial density parameters of building height, ensuring the analytical expression and rapid calculation of the Fresnel zone occlusion probability of each path in different urban scenarios.

[0052] 2. Based on channel characterization, this invention further constructs a complete path loss model that includes geometric loss, dielectric loss, and scintillation loss, realizing end-to-end analytical calculation from blockage probability to link loss, and correlates the loss results with the expected received power of the satellite-to-ground system to achieve satellite-to-ground communication link budget evaluation. In particular, this invention can adaptively characterize satellite-to-ground channel characteristics in multiple scenarios such as line-of-sight and non-line-of-sight, significantly improving the rate and effectiveness of satellite communication link budget and coverage performance evaluation.

[0053] 3. The evaluation method proposed in this invention can avoid the risks of wasted payload resources and abnormal link interruption caused by prediction distortion in traditional empirical models. It has engineering application value and theoretical guidance significance for the design, dynamic resource planning and service quality assurance of future integrated air-space-ground communication networks. Attached Figure Description

[0054] Figure 1 The diagram shows a step-by-step illustration of the communication link budget evaluation method based on the satellite-to-ground channel characteristic model of the present invention in one embodiment;

[0055] Figure 2 The diagram shows a line-of-sight satellite-to-ground communication scenario in one embodiment of the communication link budget evaluation method based on satellite-to-ground channel characteristic model of the present invention.

[0056] Figure 3 The diagram shows a ground-based mirror reflection satellite-to-ground communication scenario in one embodiment of the communication link budget evaluation method based on the satellite-to-ground channel characteristic model of the present invention.

[0057] Figure 4 The diagram shows a building mirror reflection satellite-to-ground communication scenario in one embodiment of the communication link budget evaluation method based on satellite-to-ground channel characteristic model of the present invention.

[0058] Figure 5 The diagram shows the simulation results of the line-of-sight probability changing with the satellite elevation angle in one embodiment of the communication link budget evaluation method based on the satellite-to-ground channel characteristic model of the present invention.

[0059] Figure 6 The diagram shows the simulation results of the ground specular reflection probability changing with the satellite elevation angle in one embodiment of the communication link budget evaluation method based on the satellite-ground channel characteristic model of the present invention.

[0060] Figure 7 The diagram shows the simulation results of the building specular reflection probability changing with satellite elevation angle in one embodiment of the communication link budget evaluation method based on satellite-ground channel characteristic model of the present invention.

[0061] Figure 8 The diagram shows the path loss simulation results for various scenarios in one embodiment of the communication link budget evaluation method based on the satellite-ground channel characteristic model of the present invention.

[0062] Figure 9 The diagram shown is a structural schematic of a communication link budget evaluation system based on a satellite-to-ground channel characteristic model according to an embodiment of the present invention.

[0063] Figure 10 The diagram shown is a structural schematic of an embodiment of the electronic device of the present invention.

[0064] Component designation explanation

[0065] S102~S108 step 90 Communication Link Budget Evaluation System Based on Satellite-Ground Channel Characteristic Model 91 Get Module 92 Calculation module 93 Output module 1000 electronic devices 1001 processor 1002 memory 10021 operating system 10022 app 1003 Network interface 1004 bus system 1005 User Interface Detailed Implementation

[0066] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0067] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0068] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0069] The insufficient accuracy of existing channel models leads to significant deviations in link budget assessments. Overly conservative budget assessments result in excessive satellite power allocation, wasting valuable payload energy; conversely, overly optimistic assessments can easily cause frequent communication link interruptions or handover failures. Therefore, there is an urgent need for a high-precision channel characteristic model that comprehensively integrates the three-dimensional geometric features of urban scenes, Fresnel zones, and multipath propagation probabilities, and based on this model, to implement a more accurate communication link budget assessment method.

[0070] Specifically, this invention proposes a communication link budget evaluation method and system based on a satellite-to-ground channel characteristic model. The method, by introducing Fresnel zone theory and considering only a single reflection within a limited area around the receiver, calculates the obstruction probability of three main paths in the satellite-to-ground link: line-of-sight, ground specular reflection, and building specular reflection. Based on this, the invention further constructs a complete path loss model including geometric loss, dielectric loss, and scintillation loss, performing end-to-end analytical calculations from obstruction probability to link gain. Based on the calculation results, it completes the link budget evaluation of the expected received power, ultimately providing accurate decision-making basis for dynamic power control and handover in satellite communication systems. The technical solutions in the embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0071] like Figure 1 As shown, in one embodiment of the invention, the communication link budget evaluation method based on the satellite-to-ground channel characteristic model of the present invention includes the following steps:

[0072] Step S102: Obtain the target parameters for the satellite-to-ground communication scenario;

[0073] Step S104: Input the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel;

[0074] Step S106: Calculate the expected received power of the current satellite-to-ground communication based on the path loss;

[0075] Step S108: Compare the expected received power with preset parameters to output an operation strategy, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

[0076] It should be noted that, in this embodiment, the target parameters of the satellite-to-ground communication scenario are first obtained, which correspond to the physical environment parameters and system parameters. The physical environment parameters for radio wave propagation include parameters describing the height and density characteristics of building distribution, material medium parameters of the ground surface and buildings, and environmental meteorological parameters. The system parameters to be obtained include the transceiver location information, satellite elevation angle, transmission signal frequency, transceiver antenna gain, and signal transmission power.

[0077] Furthermore, in this embodiment, the target parameters are input into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel. The following embodiments will explain how to construct the satellite-to-ground channel characteristic model, calculate the expected received power of the current satellite-to-ground communication based on the path loss, and compare the expected received power with preset parameters to output an operation strategy. Accordingly, the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power, and also includes satellite switching. The specific process will also be described in detail in the subsequent embodiments.

[0078] Furthermore, in one embodiment of the invention, the method further includes constructing the satellite-to-ground channel feature model, specifically including:

[0079] For a single reflection occurring within a defined radius area with a ground user as the receiver, using the Fresnel zone as the analysis region, communication probability models are constructed for line-of-sight paths, ground specular reflection paths, and building specular reflection paths, respectively.

[0080] The communication probability model for the line-of-sight path is constructed as follows:

[0081] ;

[0082] in, This represents the communication probability along the line-of-sight path. This represents the height of the i-th building along the line-of-sight path. This represents the maximum height of the i-th building in the Fresnel zone that does not obstruct the line-of-sight path. Indicates the number of buildings along the line-of-sight path;

[0083] A probabilistic model for satellite-to-ground communication based on the ground-based mirror reflection path is constructed, and its expression is as follows:

[0084] ;

[0085] in, This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the probability that there are no buildings obstructing the Fresnel zone from the satellite to the ground reflection point. This represents the probability that there are no buildings obstructing the Fresnel zone from the ground reflection point to the user's receiver. This indicates the number of buildings from the satellite to the ground reflection point. Indicates the number of buildings along the path of the ground mirror reflection;

[0086] A communication probability model for the reflection path of a building's mirror surface is constructed, expressed as follows:

[0087] ;

[0088] in, This represents the communication probability of the reflection path from the building's mirror surface. This represents the probability that the height of the i-th building is not lower than the minimum height in the Fresnel zone. This represents the probability that the j-th building preceding the i-th building does not obstruct the Fresnel zone. This represents the probability that the k-th building following the i-th building does not obstruct the Fresnel zone. Indicates the number of buildings along the path of a building's mirror reflection. This represents the total number of buildings between the satellite and the i-th building. This represents the total number of buildings between the i-th building and the user's receiving terminal.

[0089] It should be noted that, in this embodiment, considering the long propagation distance of wireless signals in satellite-to-ground communication and the weak energy of randomly reflected signals far from ground users, this embodiment only considers the impact of a single reflection occurring within a radius of R with the ground user as the receiver. Furthermore, according to the Huygens-Fresnel principle, the energy during wireless signal propagation is not concentrated solely on the direct link between the transmitter and receiver, but is distributed throughout the Fresnel ellipsoid region with the transmitter and receiver as the focal points. Since the first-order Fresnel region carries most of the signal propagation energy, this invention uses the first-order Fresnel region as the main analysis region in channel modeling. Based on the above considerations of propagation distance and energy distribution, this invention focuses on constructing probabilistic models for line-of-sight paths, ground specular reflection paths, and building specular reflection paths to fully characterize the main propagation characteristics of the satellite-to-ground link, where, for example... Figure 2The diagram shown illustrates a line-of-sight satellite-to-ground communication scenario. Figure 3 The image shown is a schematic diagram of a ground-based mirror reflection satellite-to-ground communication scenario. Figure 4 The image shows a schematic diagram of a satellite-to-ground communication scenario reflected by a building's mirror surface.

[0090] Among them, the satellite-to-ground communication probability for line-of-sight (LoS) paths The expression is:

[0091] ;

[0092] in, This represents the height of the i-th building on the path. Let represent the maximum height of the i-th building in the Fresnel zone that is not obscured by the LoS path, and N represent the number of buildings on the line-of-sight path. When the building heights follow a Rayleigh distribution, the probability model is calculated as follows:

[0093] ;

[0094] Where γ represents the scale parameter of the Rayleigh distribution that the building height follows;

[0095] The calculation of the number of buildings N follows a general expression, which is:

[0096] ;

[0097] Where R represents the radius of the urban area, This represents the ratio of the floor area of ​​all buildings to the total floor area considered. This represents the average number of buildings per unit area. It should be noted that specific parameter descriptions and parameter values ​​for different urban scenarios can be found in ITU-R P.1410.

[0098] Similarly, the probability of satellite-to-ground communication for ground-spectral (GS) paths. The expression is:

[0099] ;

[0100] in, This represents the maximum height of the i-th building in the Fresnel zone that is not obscured by the GS path.

[0101] It should be noted that, unlike the line-of-sight path, the ground specular reflection path needs to be calculated in two segments: one from the satellite to the ground reflection point G, and the other from the ground reflection point G to the user receiver. Therefore, the probability model expression can also be expressed as:

[0102] ;

[0103] in, This represents the probability that there are no buildings obstructing the Fresnel zone from the satellite to the ground reflection point. This represents the probability that there are no buildings obstructing the Fresnel zone from the ground reflection point to the user's receiver. This indicates the number of buildings from the satellite to the ground reflection point. Indicates the number of buildings along the path of the ground mirror reflection;

[0104] Furthermore, the satellite-to-ground communication probability for the building specular (BS) path. The expression is:

[0105] ;

[0106] in, This represents the probability that the height of the i-th building is not lower than the minimum height in the Fresnel zone. This represents the probability that the j-th building preceding the i-th building does not obstruct the Fresnel zone. This represents the probability that the k-th building following the i-th building does not obstruct the Fresnel zone. Indicates the number of buildings along the path of a building's mirror reflection. This represents the total number of buildings between the satellite and the i-th building. This represents the total number of buildings between the i-th building and the user's receiving terminal.

[0107] Furthermore, in one embodiment of the invention, acquiring the target parameters of the satellite-to-ground communication scenario specifically includes:

[0108] The target parameters include physical environment parameters and system parameters, wherein,

[0109] The physical environment parameters are obtained based on the statistical distribution characteristics of the height and density of urban buildings and the reflectivity of the medium.

[0110] The system parameters are obtained based on the current satellite elevation angle, satellite orbital altitude, ground user altitude, and transmission signal frequency.

[0111] It should be noted that, in this embodiment, the target parameters of the satellite-to-ground communication scenario are obtained, namely, the physical environment parameters and system parameters. The physical environment parameters are obtained based on the statistical distribution characteristics of the height and density of urban buildings and the medium reflection coefficient, and the system parameters are obtained based on the current satellite elevation angle, satellite orbital altitude, ground user altitude and transmission signal frequency.

[0112] Specifically, in this embodiment, the Fresnel zone radius The calculation expression is as follows:

[0113] ;

[0114] in, Indicates the horizontal distance from the satellite to the user's receiver. This represents the horizontal distance from the i-th building to the satellite, depending on the different urban scenarios. , , The values ​​vary, and the specific values ​​are shown in Table 1.

[0115] Table 1. Parameter values ​​for typical urban scenarios

[0116] Scene Name suburbs 0.1 750 8 City 0.3 500 15 Dense cities 0.5 300 20 High-rise city 0.5 300 50

[0117] Furthermore, considering that 550 km is the typical orbital altitude of current low-Earth orbit satellite constellations and 20 GHz is the typical downlink communication frequency of the Ka band, this invention selects parameters with a satellite altitude of 550 km, a user receiving terminal altitude of 2 m, a ground city radius of 500 m, and a transmission signal frequency of 20 GHz for simulation.

[0118] Furthermore, in one embodiment of the invention, the step of inputting the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel specifically includes:

[0119] The path loss calculation formula is as follows:

[0120] ;

[0121] in, This represents the path loss. Indicates geometric loss. Indicates dielectric loss. Indicates flicker loss;

[0122] Among them, geometric loss The calculation formula is as follows:

[0123] ;

[0124] in, The transmission gain of the satellite-to-ground channel is expressed by the following formula:

[0125] ;

[0126] in, This represents the communication probability along the line-of-sight path. This represents the propagation gain along the line-of-sight path. This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the propagation gain of the ground-based specular reflection path. This represents the communication probability of the reflection path from the building's mirror surface. This represents the propagation gain of the reflection path from the building's mirror surface.

[0127] It should be noted that, in this embodiment, during the propagation of radio waves in the satellite-to-ground channel, the propagation gain of the line-of-sight path... Represented as:

[0128] ;

[0129] in, This represents the straight-line distance between the transmitting and receiving ends. Indicates the signal wavelength;

[0130] Propagation gain for ground-based specular reflection paths Represented as:

[0131] ;

[0132] in, Indicates the distance from the satellite to the ground reflection point. This indicates the distance from the ground reflection point to the receiving end. Indicates the reflection coefficient;

[0133] Similarly, the propagation gain of the reflection path of a building's mirror surface Represented as:

[0134] ;

[0135] in, Indicates the distance from the satellite to the reflecting structure. This indicates the distance from the reflecting building to the user's receiving end;

[0136] Therefore, the transmission gain of the entire satellite-to-ground channel Represented as:

[0137] ;

[0138] Furthermore, converting it to loss in dB, it is expressed as:

[0139] ;

[0140] In the calculation of path loss in the entire satellite-to-ground channel, path loss mainly consists of three parts, including geometric loss. Dielectric loss and flicker loss The path loss of the entire satellite-to-ground channel The expression is represented as:

[0141] ;

[0142] Among them, dielectric loss mainly considers atmospheric absorption, rainfall attenuation, and cloud and fog attenuation, while scintillation loss mainly considers tropospheric scintillation. Dielectric loss includes atmospheric absorption, rainfall loss, and cloud and fog loss. Detailed explanations of atmospheric absorption and rainfall loss can be found in ITU-R Recommendation P.618, and detailed explanations of cloud and fog loss can be found in ITU-R Recommendation P.840. Scintillation loss mainly refers to tropospheric scintillation loss, and detailed explanations can be found in ITU-R Recommendation P.618.

[0143] Specifically, in this embodiment, after obtaining the target parameters, the path loss can be further calculated, such as... Figure 5 The image shows a schematic diagram of the simulation results of the line-of-sight probability changing with the satellite elevation angle. Figure 5 It can be seen that in different urban scenarios, the obstruction of transmission signals by buildings weakens as the satellite elevation angle increases, and the line-of-sight probability increases with the increase of the satellite elevation angle. Among them, at the same elevation angle, the line-of-sight probability is the highest in suburban areas, followed by cities and dense cities, and the line-of-sight probability is the lowest in cities with high-rise buildings. This is because the number of buildings is different in different urban scenarios. The fewer the buildings, the lower the probability of obstructing the line-of-sight path.

[0144] Furthermore, in this embodiment, under the same parameter configuration, such as Figure 6 As shown, this is a schematic diagram illustrating the simulation results of the ground specular reflection probability varying with the satellite elevation angle. Figure 6 As can be seen, the probability of ground specular reflection still increases with increasing satellite elevation angle, but decreases with increasing building height at the same elevation angle; while... Figure 7 The diagram shown illustrates the simulation results of how the specular reflection probability of a building varies with the satellite elevation angle. Figure 7 Unlike other probability models, the ground city radius is set to 200 m. This is because the reflection probability of buildings far from the receiver is negligible, so only buildings close to the receiver need to reflect the light.

[0145] Specifically, in this embodiment, from Figure 7It can be seen that, unlike the line-of-sight probability and the ground specular reflection probability, the building specular reflection probability generally decreases with increasing elevation angle. This is because as the satellite elevation angle increases, the tilt of the communication link increases, thus reducing the probability of buildings acting as reflectors. Furthermore, at low elevation angles, the specular reflection probability of buildings in suburban areas is highest, while the specular reflection probability of buildings in other urban scenes is lower. This is because tall buildings in urban scenes tend to block signals, making the signal more easily obstructed at low elevation angles. As the satellite elevation angle increases, the reflection probability is even higher in urban scenes with a greater number of buildings.

[0146] Furthermore, in this embodiment, when simulating path loss, since the simulation parameters do not point to a specific scenario, the path loss simulation parameter configuration of this invention only considers the collection loss and atmospheric absorption loss related to the simulation frequency band and satellite elevation angle. Specifically, the simulation parameter configuration selects a satellite altitude of 550 km, a user receiving terminal altitude of 2 m, a ground city radius of 500 m, and a transmission signal frequency of 20 GHz. Figure 8 As shown, the simulation results of path loss for various scenarios are illustrated. Figure 8 It can be seen that as the satellite elevation angle increases, the path loss gradually decreases. This indicates that the path loss is mainly affected by the line-of-sight path and the ground specular reflection path. In comparison of different scenarios, the path loss increases with the increase of scenario complexity.

[0147] Furthermore, in one embodiment of the invention, calculating the expected received power of the current satellite-to-ground communication based on the path loss specifically includes:

[0148] The expected received power is calculated based on the communication link budget equation, where the calculation formula is as follows:

[0149] ;

[0150] in, Indicates the received power. Indicates the transmission power. Indicates the transmit antenna gain. Indicates the receiving antenna gain. This represents path loss.

[0151] Furthermore, in one embodiment of the invention, the step of comparing the expected received power with preset parameters to output an operation strategy specifically includes:

[0152] The preset parameters include at least a preset threshold;

[0153] An operation strategy is output based on a comparison between the expected received power and the preset parameters.

[0154] When the expected received power is lower than the preset threshold, a power compensation mechanism is triggered to dynamically adjust the transmit power of the subordinate beams in the current satellite network coverage area.

[0155] It should be noted that, in this embodiment, a communication link budget assessment is performed to guide the network planning and resource allocation strategies of the satellite-to-ground communication system, and the output satellite-to-ground channel path loss is obtained. Then, it is substituted into the communication link budget equation for calculation, where the calculation relationship is as follows:

[0156] ;

[0157] in, Indicates the received power. Indicates the transmission power. Indicates the transmit antenna gain. This indicates the receiving antenna gain.

[0158] Furthermore, once the expected received power is calculated, it can be compared with the preset receiving sensitivity and threshold of the satellite-to-ground communication system to guide communication operation strategies such as power adjustment commands or satellite switching control commands.

[0159] Specifically, in this embodiment, based on the calculated total path loss of the satellite-to-ground channel, combined with the satellite transmit power and transmit / receive antenna gain of the communication system, the received signal power of the ground user receiver is calculated to complete the link budget assessment of satellite-to-ground communication.

[0160] Furthermore, in this embodiment, the calculated expected received power is compared with a preset threshold of the communication system, and the following communication operation strategy is executed, including two strategies:

[0161] One example is Strategy Example 1 (Power Compensation): When the received power is lower than a preset threshold, the satellite-ground system determines that there is severe obstruction in the current urban scene, triggers the power compensation mechanism, and instructs the satellite network to increase the downlink beam transmission power for that specific coverage area; conversely, if there is a margin in the received power, it instructs to reduce the transmission power in order to optimize the payload energy consumption of low-orbit satellites.

[0162] The second strategy is Example 2 (satellite handover): Given that the elevation angle of low-Earth orbit satellites is highly dynamic, the aforementioned steps are performed for a fixed duration to calculate the curve of received power changing with elevation angle. When it is calculated that the received power is about to fall below the communication interruption threshold, a handover command is issued in advance to guide the ground terminal to establish a connection with another low-Earth orbit satellite with better communication conditions, thereby avoiding communication interruption caused by sudden severe obstruction.

[0163] The scope of protection of the communication link budget evaluation method based on the satellite-ground channel characteristic model described in this application is not limited to the execution order of the steps listed in this embodiment. Any scheme implemented by adding, subtracting, or replacing steps in the prior art based on the principles of this application is included within the scope of protection of this application.

[0164] This application also provides a communication link budget evaluation system based on a satellite-to-ground channel characteristic model. The communication link budget evaluation system based on the satellite-to-ground channel characteristic model can implement the communication link budget evaluation method based on the satellite-to-ground channel characteristic model described in this application. However, the implementation device of the communication link budget evaluation method based on the satellite-to-ground channel characteristic model described in this application includes, but is not limited to, the structure of the communication link budget evaluation system based on the satellite-to-ground channel characteristic model listed in this embodiment. All structural modifications and substitutions of the prior art made in accordance with the principles of this application are included within the protection scope of this application.

[0165] Please see Figure 9 In one embodiment, this embodiment provides a communication link budget evaluation system 90 based on a satellite-to-ground channel characteristic model, the system comprising:

[0166] Module 91 is used to acquire target parameters for satellite-to-ground communication scenarios.

[0167] The calculation module 92 is used to input the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel; and to calculate the expected received power of the current satellite-to-ground communication based on the path loss.

[0168] Output module 93 is used to compare the expected received power with preset parameters to output an operation strategy, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

[0169] Since the specific implementation of this embodiment corresponds to the aforementioned method embodiment, the same details will not be repeated here, and those skilled in the art should also understand this. Figure 9 The division of the modules in the embodiments is only a logical functional division. In actual implementation, they can be fully or partially integrated into one or more physical entities. These modules can be fully implemented in software through processing element calls, fully implemented in hardware, or some modules can be implemented in software through processing element calls and some modules can be implemented in hardware.

[0170] In the embodiments provided by this invention, it should be understood that the disclosed apparatus or method can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules / units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or units may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of the apparatus or module or unit may be electrical, mechanical, or other forms.

[0171] The modules / units described as separate components may or may not be physically separate. The components shown as modules / units may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules / units can be selected to achieve the objectives of the embodiments of the present invention, depending on actual needs. For example, the functional modules / units in the various embodiments of the present invention may be integrated into one processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into one module / unit.

[0172] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0173] This invention also provides an electronic device, such as... Figure 10 As shown, the electronic device includes a processor and a memory.

[0174] like Figure 10 As shown, the electronic device includes at least one processor 1001, a memory 1002, at least one network interface 1003, and a user interface 1005. The various components in the device are coupled together via a bus system 1004. It is understood that the bus system 1004 is used to implement communication between these components. In addition to a data bus, the bus system 1004 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in… Figure 10 The general will label all buses as bus systems.

[0175] The user interface 1005 may include a monitor, keyboard, mouse, trackball, clicker, button, touchpad, or touch screen.

[0176] It is understood that memory 1002 can be volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM) or programmable read-only memory (PROM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM) and synchronous static random access memory (SSRAM). The memories described in the embodiments of this invention are intended to include, but are not limited to, these and any other suitable categories of memory.

[0177] In this embodiment of the invention, the memory 1002 is used to store various categories of data to support the operation of the electronic device 1000. Examples of this data include: any executable program for operation on the electronic device 1000, such as the operating system 10021 and application programs 10022; the operating system 10021 contains various system programs, such as the framework layer, core library layer, driver layer, etc., for implementing various basic services and handling hardware-based tasks. Application programs 10022 may contain various applications, such as media players, browsers, etc., for implementing various application services. The methods provided in this embodiment of the invention may be included in application programs 10022.

[0178] The methods disclosed in the above embodiments of the present invention can be applied to or implemented by the processor 1001. The processor 1001 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor 1001 or by instructions in the form of software. The processor 1001 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 1001 can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor 1001 may be a microprocessor or any conventional processor, etc. The steps of the accessory optimization method provided in the embodiments of the present invention can be directly reflected as being executed by a hardware decoding processor, or being executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, which is located in a memory. The processor reads the information in the memory and combines it with its hardware to complete the steps of the aforementioned method.

[0179] In an exemplary embodiment, the electronic device 1000 may be used by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), or complex programmable logic devices (CPLDs) to perform the aforementioned method.

[0180] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the method of any of the embodiments of the communication link budget evaluation method based on the satellite-ground channel characteristic model described above.

[0181] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code, which, when run on a computer, causes the computer to execute the method of any of the embodiments of the communication link budget evaluation method based on the satellite-ground channel characteristic model described above.

[0182] The terms “component,” “module,” “system,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0183] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0184] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0185] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0186] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0187] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0188] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., high-density digital video discs, DVDs), or semiconductor media (e.g., solid-state disks, SSDs, etc.).

[0189] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0190] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0191] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A communication link budget evaluation method based on a satellite-to-ground channel characteristic model, characterized in that, include: Obtain target parameters for the satellite-to-ground communication scenario; The target parameters are input into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel; The expected received power of the current satellite-to-ground communication is calculated based on the path loss. An operation strategy is output based on a comparison between the expected received power and preset parameters, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

2. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model according to claim 1, characterized in that, The acquisition of target parameters for the satellite-to-ground communication scenario specifically includes: The target parameters include physical environment parameters and system parameters, wherein, The physical environment parameters are obtained based on the statistical distribution characteristics of the height and density of urban buildings and the reflectivity of the medium. The system parameters are obtained based on the current satellite elevation angle, satellite orbital altitude, ground user altitude, and transmission signal frequency.

3. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model according to claim 1, characterized in that, The method further includes constructing the satellite-to-ground channel feature model, specifically including: For a single reflection occurring within a defined radius area with a ground user as the receiver, using the Fresnel zone as the analysis region, communication probability models are constructed for line-of-sight paths, ground specular reflection paths, and building specular reflection paths, respectively. The communication probability model for the line-of-sight path is constructed as follows: ； in, This represents the communication probability along the line-of-sight path. This represents the height of the i-th building along the line-of-sight path. This represents the maximum height of the i-th building in the Fresnel zone that does not obstruct the line-of-sight path. Indicates the number of buildings along the line-of-sight path; A probabilistic model for satellite-to-ground communication based on the ground-based mirror reflection path is constructed, and its expression is as follows: ； in, This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the probability that there are no buildings obstructing the Fresnel zone from the satellite to the ground reflection point. This represents the probability that there are no buildings obstructing the Fresnel zone from the ground reflection point to the user's receiver. This indicates the number of buildings from the satellite to the ground reflection point. Indicates the number of buildings along the path of the ground mirror reflection; A communication probability model for the reflection path of a building's mirror surface is constructed, expressed as follows: ； in, This represents the communication probability of the reflection path from the building's mirror surface. This represents the probability that the height of the i-th building is not lower than the minimum height in the Fresnel zone. This represents the probability that the j-th building preceding the i-th building does not obstruct the Fresnel zone. This represents the probability that the k-th building following the i-th building does not obstruct the Fresnel zone. Indicates the number of buildings along the path of a building's mirror reflection. This represents the total number of buildings between the satellite and the i-th building. This represents the total number of buildings between the i-th building and the user's receiving end.

4. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model according to claim 1, characterized in that, The step of inputting the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel specifically includes: The path loss calculation formula is as follows: ； in, This represents the path loss. Indicates geometric loss. Indicates dielectric loss. Indicates flicker loss; Among them, geometric loss The calculation formula is as follows: ； in, The transmission gain of the satellite-to-ground channel is expressed by the following formula: ； in, This represents the communication probability along the line-of-sight path. This represents the propagation gain along the line-of-sight path. This represents the probability of satellite-to-ground communication via the path of a ground-based mirror reflection. This represents the propagation gain of the ground-based specular reflection path. This represents the communication probability of the reflection path from the building's mirror surface. This represents the propagation gain of the reflection path from the building's mirror surface.

5. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model according to claim 1, characterized in that, The calculation of the expected received power for the current satellite-to-ground communication based on the path loss specifically includes: The expected received power is calculated based on the communication link budget equation, where the calculation formula is as follows: ； in, Indicates the received power. Indicates the transmission power. Indicates the transmit antenna gain. Indicates the receiving antenna gain. This represents path loss.

6. The communication link budget evaluation method based on the satellite-to-ground channel characteristic model according to claim 1, characterized in that, The step of comparing the expected received power with preset parameters to output an operation strategy specifically includes: The preset parameters include at least a preset threshold; An operation strategy is output based on a comparison between the expected received power and the preset parameters. When the expected received power is lower than the preset threshold, a power compensation mechanism is triggered to dynamically adjust the transmit power of the subordinate beams in the current satellite network coverage area.

7. A communication link budget evaluation system based on a satellite-to-ground channel characteristic model, characterized in that, include: The acquisition module is used to acquire target parameters in satellite-to-ground communication scenarios; The calculation module is used to input the target parameters into the constructed satellite-to-ground channel characteristic model to calculate the path loss of the satellite-to-ground channel; and to calculate the expected received power of the current satellite-to-ground communication based on the path loss. The output module is used to compare the expected received power with preset parameters to output an operation strategy, wherein the operation strategy includes at least dynamically adjusting the satellite-to-ground downlink transmit beam power.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the communication link budget evaluation method based on the satellite-to-ground channel characteristic model as described in any one of claims 1 to 6.

9. A computer program product, characterized in that, The computer program product includes computer program code, which, when run on a computer, causes the computer to implement the communication link budget evaluation method based on the satellite-to-ground channel characteristic model as described in any one of claims 1 to 6.

10. An electronic device, characterized in that, The electronic device includes a processor and a memory; wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to enable the electronic device to perform the communication link budget evaluation method based on the satellite-to-ground channel characteristic model as described in any one of claims 1 to 6.

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