Interference avoidance beam planning method and system based on spatial isolation restricted area

Abstract

The present invention discloses an interference avoidance beam planning method and system based on a spatial isolation forbidden zone. The method includes: constructing aggregate interference scenarios under co-frequency interference of high-orbit and low-orbit satellite systems based on uplink and downlink links and ground grid division respectively; establishing a worst-case aggregate interference judgment model of the low-orbit satellite system for the uplink and downlink links of the high-orbit satellite arc based on time slicing; constructing a phased array antenna beam planning objective function for frequency sharing between high-orbit and low-orbit satellite systems based on the interference limit standard I / N; and performing beam planning based on a spatial isolation forbidden zone based on the phased array antenna beam planning objective function. The present invention overcomes the disadvantage that the traditional interference avoidance method based on isolation angle or isolation zone needs to shut down all satellite beams, and can effectively avoid interference in interference-exceeding-limit areas under the coverage of NGSO satellite beams, providing a method reference and technical support for protecting the communication link of the GSO satellite system and ensuring the working efficiency of the NGSO satellite system.

Description

Technical Field

[0001] The present invention belongs to the technical field of interference avoidance, and in particular relates to an interference avoidance beam planning method and system based on a spatial isolation restricted area. Background Art

[0002] Low-Earth Orbit (LEO) internet satellite constellations, with their wide communication range, high capacity, and short latency, have become a new frontier in the development of space information networks. Frequency and orbital resources are essential elements for the development of LEO constellations. Large-scale LEO constellations have been deployed and rapidly expanding, with nearly 10,000 satellites currently in orbit. Examples include Starlink, OneWeb, and Telesat, both internationally and domestically, such as StarNet. This has led to increasingly fierce competition for space frequency and orbital resources. The widespread deployment of multiple satellites sharing the same orbit and frequency has led to a depletion of frequency and orbital resources, exacerbating communication interference issues and severely impacting the normal use of geostationary satellite orbit (GSO) satellite systems. Therefore, there is an urgent need to explore reasonable and feasible interference avoidance measures to ensure operational frequency availability for large-scale internet constellations in non-geostationary orbit (NGSO) satellites and protect the normal use of GSO satellite systems.

[0003] Currently, in scenarios where NGSO and GSO satellite systems coexist, to prevent interference from LEO NGSO satellites to GSO systems in high-Earth orbits, LEO satellites must implement measures to comply with ITU-specified interference assessment criteria. To address this, researchers both domestically and internationally have conducted research on interference avoidance techniques between NGSO and GSO satellite systems. Proposed interference avoidance methods can be broadly categorized as those based on power allocation, dynamic spectrum monitoring, polarization isolation, and spatial isolation. For example, Dong Suhui, Pan Ji, Yao Xiujuan, et al. proposed a power allocation strategy that integrates multiple features, such as spatial and beam characteristics, in GSO and NGSO satellite interference scenarios. Wang Chuang, Hu Jing, Li Yongqiang, et al. allocated idle spectrum by dividing channel bands or employing dynamic spectrum monitoring, thereby achieving frequency reuse. International researchers have proposed recommendations for frequency compatibility between LEO and high-Earth orbit satellite systems from the perspective of polarization isolation. Currently, the literature on spatial isolation-based interference avoidance focuses on isolation-based approaches. For example, Zhang Hongxi and Jiang Bofeng proposed a spatial isolation method. By introducing the concept of a GSO satellite isolation zone, they determined the spatial isolation angle of the NGSO-GSO satellite system, thereby achieving interference avoidance between NGSO satellites and GSO satellites. Other researchers further determined the ground interference exclusion zone from a geometric perspective, suggesting that when an NGSO satellite passes through the ground interference exclusion zone, beam deflection can be used to avoid interference. These papers theoretically demonstrate that the spatial isolation angle and interference exclusion zone determination methods are feasible for achieving interference avoidance between NGSO-GSO satellites. However, the proposed measures are only applicable to single-beam satellite constellations and impose strict requirements on constellation density and orbital position. A reasonable constellation configuration is required to ensure uninterrupted communication with ground stations. Large-scale low-orbit constellations increase the complexity of this method, making it difficult to define the spatial isolation angle and accurately determine the exclusion zone. Furthermore, the corresponding beam deflection or switching mechanisms are difficult to implement, reducing its practicality. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and propose an interference avoidance beam planning method and system based on spatial isolation forbidden zone.

[0005] In order to achieve the above technical objectives, the present invention proposes an interference avoidance beam planning method based on spatial isolation forbidden zone, comprising:

[0006] Step 1) Based on the uplink and downlink links and the ground grid division, the aggregate interference scenarios under the co-frequency interference of the high-orbit and low-orbit satellite systems are constructed respectively;

[0007] Step 2) establishing a worst-case aggregate interference determination model for the low-orbit satellite system to the uplink and downlink of the high-orbit satellite arc based on time slicing;

[0008] Step 3) Based on the interference limit standard I / N, a phased array antenna beam planning objective function for frequency sharing between high and low orbit satellite systems is constructed;

[0009] Step 4) According to the phased array antenna beam planning objective function, beam planning is performed based on the spatial isolation restricted area.

[0010] Preferably, the aggregate interference under the co-channel interference in step 1) includes: collinear interference and sidelobe interference; wherein,

[0011] Collinear interference refers to the communication interference caused to the GSO satellite link when the NGSO satellite link and the GSO satellite link overlap or nearly overlap in space;

[0012] The sidelobe interference refers to the interference caused by the sidelobe of the transmitting antenna of the useless signal aligning with the interfered receiver.

[0013] Preferably, the step 1) comprises:

[0014] Based on the uplink and downlink links of the GSO and NGSO satellite systems, an uplink multi-beam satellite system interference scenario and a downlink multi-beam satellite system interference scenario are established respectively;

[0015] The ground is divided into grids according to longitude and latitude, and the interference is calculated using the grid as the basic unit, and a ground station is set at the center of the grid.

[0016] Preferably, the step 2) comprises:

[0017] The aggregate interference of the ground station at the center of the grid is used to replace the aggregate interference of the entire grid;

[0018] For the downlink multi-beam satellite system interference scenario, the single-entry interference satisfies the following equation:

[0019]

[0020] Among them, for the ground grid (i, j), (I / N) i,j represents the single-entry interference in each downward direction of the NGSO satellite antenna, P i,j Indicates the transmission power of NGSO satellite, G t Indicates the NGSO satellite antenna gain, angle represents the launch off-axis angle of the NGSO satellite, G r represents the antenna gain of the GSO satellite earth station, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α thIt represents the angle between the line connecting the earth station and the vertex of its visible GSO satellite arc and the NGSO satellite link;

[0021] The aggregate downlink interference is obtained by summing up all single-entry interference links; all single-entry interference links point to the interfered object, making (I / N) i,j is the largest, and the worst aggregate interference decision model for the downlink is obtained based on time slicing;

[0022] For the uplink multi-beam satellite system interference scenario, the single-entry interference is:

[0023]

[0024] Among them, (I / N) i,j P represents the interference from NGSO ground stations to GSO satellites. i,j Indicates the transmission power of the NGSO ground station, G t Indicates the NGSO satellite receiving antenna gain, angle represents the launch off-axis angle of the NGSO satellite, G r Indicates the GSO satellite receiving antenna gain, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α th It represents the angle between the line connecting the vertices of the GSO satellite arc visible to the earth station and the line connecting the NGSO satellite link;

[0025] The uplink aggregate interference is obtained by summing up all single-entry interference links; all single-entry interference links point to the interfered object, so that (I / N) i,j is the largest, and the uplink worst aggregate interference decision model is obtained based on time slicing.

[0026] Preferably, the step 3) comprises:

[0027] For the downlink multi-beam satellite system interference scenario, the phased array antenna beam planning objective function is:

[0028]

[0029] Where Q represents the downlink beam planning strategy matrix, q i,j Indicates the open and closed status of the NGSO satellite beam during downlink, φ indicates the longitude range covered by the NGSO satellite beam, represents the latitude range covered by the NGSO satellite beam, η th Indicates the interference isolation threshold, which is -12.2dB, R(q i.j ) represents the working efficiency of the NGSO satellite, which satisfies the following formula:

[0030]

[0031] Among them, sum() represents the sum operation;

[0032] For the uplink multi-beam satellite system interference scenario, the phased array antenna beam planning objective function is:

[0033]

[0034]

[0035] Where V represents the uplink beam planning strategy matrix, v i,j Indicates the open and closed state of the NGSO satellite beam in the uplink scenario, P indicates the longitude range covered by the NGSO satellite beam, M indicates the latitude range covered by the NGSO satellite beam, and η th Indicates the interference isolation threshold, which is -12.2dB, R(v i.j ) represents the working efficiency of the NGSO satellite system in the uplink scenario.

[0036] Preferably, the step 4) comprises:

[0037] For downlink multi-beam satellite system interference scenarios, beam planning methods based on spatial isolation exclusion zones include:

[0038] Step S1) setting the NGSO beam to be in a fully open state, that is, all elements in the Q matrix are 1;

[0039] Step S2) Calculate (I / N) for each grid point (i, j) covered by the NGSO satellite beam. i,j ;If (I / N) i,j ≥η th , then q i.j Set to 0 and calculate (I / N) for the grid again i,j Repeat this process until all grid points covered by the NGSO satellite beam meet (I / N) i,j <η th (I / N) i,j ; Go to step S3);

[0040] Step S3) updating the downlink beam planning strategy matrix Q;

[0041] For uplink multi-beam satellite system interference scenarios, beam planning methods based on spatial isolation exclusion zones include:

[0042] Step T1) setting the NGSO beams to be in a fully open state, that is, all elements in the V matrix are 1;

[0043] Step T2) Calculate (I / N) for each grid point (i, j) covered by the NGSO satellite beam. i,j ;If (I / N) i,j ≥η th , then v i,j Set to 0 and calculate (I / N) for the grid again i,j Repeat this process until all grid points covered by the NGSO satellite beam meet (I / N) i,j <η th (I / N) i,j ; Go to step T3);

[0044] Step T3) Update the uplink beam planning strategy matrix V.

[0045] On the other hand, the present invention proposes an interference avoidance beam planning system based on a spatial isolation restricted area, the system comprising:

[0046] The scenario construction module is used to construct the aggregate interference scenario under co-frequency interference of high-orbit and low-orbit satellite systems based on the uplink and downlink, based on the ground grid division;

[0047] A model building module is used to establish a worst-case aggregate interference determination model for the uplink and downlink of a low-orbit satellite system to a high-orbit satellite arc based on time slicing;

[0048] A function building module for constructing a phased array antenna beam planning objective function for frequency sharing between high and low orbit satellite systems based on the interference limit standard I / N; and

[0049] The beam planning module is used to perform beam planning based on the spatial isolation restricted area according to the phased array antenna beam planning objective function.

[0050] Compared with the prior art, the advantages of the present invention are:

[0051] The present invention proposes a method for determining an isolation forbidden zone and an interference avoidance beam planning method for high- and low-orbit satellite interference scenarios. Based on a quantitative description of the interference avoidance isolation forbidden zone, a specific beam planning strategy is proposed. This overcomes the disadvantage of traditional interference avoidance methods based on isolation angles or isolation bands, which require shutting down all satellite beams. It can effectively avoid interference in interference-exceeding areas under the coverage of NGSO satellite beams, providing a method reference and technical support for protecting the communication links of GSO satellite systems and ensuring the working efficiency of NGSO satellite systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of a downlink interference scenario;

[0053] Figure 2 is a schematic diagram of an uplink interference scenario;

[0054] Figure 3 It is a schematic diagram of the downlink beam planning strategy;

[0055] Figure 4 It is a flow chart of the beam planning algorithm for the spatial isolation forbidden zone;

[0056] Figure 5 is a schematic diagram of the uplink beam planning strategy;

[0057] Figure 6 This is the simulation result of interference avoidance beam planning when the satellite is located at (18.481°N, 87.856°E);

[0058] Figure 7 This is the simulation result diagram of interference avoidance beam planning at different longitudes and latitudes;

[0059] Figure 8 This is the sub-satellite interference distribution diagram when the satellite is located at (18.481°N, 87.856°E) before beam planning;

[0060] Figure 9 This is the sub-satellite interference distribution diagram when the satellite is located at (18.481°N, 87.856°E) after beam planning;

[0061] Figure 10 is the beam utilization rate at different longitudes and latitudes. DETAILED DESCRIPTION

[0062] To address the above issues, this paper proposes a novel interference avoidance beam planning method based on spatially isolated forbidden zones. This method first analyzes the interference scenario between NGSO and GSO satellite systems, divides the ground into several grids based on longitude and latitude, and uniformly enumerates satellite ground stations within these grids. Then, based on time slicing or time extrapolation, a model is established to determine the worst-case aggregate interference from a low-orbit satellite system to the uplink and downlink of a high-orbit satellite arc. Based on the interference limit standard I / N, a mapping mechanism for phased array antenna beam planning strategies for frequency sharing between high- and low-orbit satellite systems is constructed. Consequently, a beam planning method is proposed to achieve interference avoidance. Simulation experiments verify the effectiveness of this method, which can provide reference and support for the construction of high- and low-orbit satellite constellation systems.

[0063] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0064] Example 1

[0065] Embodiment 1 of the present invention proposes an interference avoidance beam planning method based on a spatial isolation restricted zone, comprising the following steps:

[0066] 1 Construction of interference scenarios for high and low orbit satellite systems based on ground grid division

[0067] The interference posed by NGSO satellite links on GSO satellite links is complex and diverse. This paper considers the aggregate interference caused by co-channel interference, including collinear interference and sidelobe interference. Collinear interference refers to the communication interference caused to the GSO satellite link when the NGSO satellite link and the GSO satellite link overlap or nearly overlap in space. It is generally the most severe interference to a single link in space, so this type of interference is considered first. Sidelobe interference is caused by the sidelobes of the transmitting antenna of the unwanted signal aligning with the affected receiver. When the number of beams or earth stations in the NGSO satellite system is large, sidelobe interference can easily produce an aggregate effect and exceed the specified interference threshold, so it must also be considered in interference calculations.

[0068] This paper establishes a multi-beam satellite system model interference scenario model for the uplink and downlink of GSO and NGSO satellite systems. The scenario diagram is shown in the figure below. Figure 1 and Figure 2 Assume that both the GSO satellite and the NGSO satellite operate in the Ka band. The NGSO satellite carries M beams that can be dynamically adjusted to open or close. It is assumed that the transmission power and antenna pattern of these beams are the same.

[0069] Taking into account the characteristics of the NGSO satellite-borne phased array antenna and the spatial positional relationship between the NGSO satellite and the GSO satellite system, in order to facilitate the calculation of the interference to the GSO earth station in the area covered by the NGSO satellite beam and to clearly define the size and specific location of the interference isolation zone when the NGSO satellite is located at any position, this paper divides the ground into grids according to longitude and latitude. The grid is used as the basic unit for interference calculation, and a ground station is assumed to exist at the center of the grid. Figure 1 In, θ down The angle at which the carrier received by the GSO earth station deviates from the beam’s aiming direction, β down It refers to the angle at which the mth beam of the NGSO satellite received by the GSO earth station deviates from its beam aiming direction, that is, the transmission off-axis angle, α down The angle at which the mth beam of the NGSO satellite received by the GSO earth station deviates from the aiming direction of the earth station antenna, that is, the isolation angle; Figure 2 In, α up The angle between the line connecting the NGSO earth station and the GSO satellite and the NGSO earth station antenna beam direction, θ up It represents the angle between the line connecting the NGSO earth station and the GSO satellite and the GSO satellite antenna beam direction.

[0070] 2. Spatial Isolation Forbidden Zone Determination and Beam Planning Method

[0071] This section introduces in detail the beam planning method based on spatial isolation restricted area division.

[0072] 2.1 Downlink Beam Planning Method

[0073] 2.1.1 Objective Function Definition

[0074] exist Figure 1 In the interference analysis scenario shown, the aggregate interference within a single ground grid point varies little, so the aggregate interference at the grid center can be used to replace the aggregate interference of the entire grid. Assuming there is an earth station at the grid center, for the interference between NGSO satellites and GSO satellites, the single-entry interference is defined as follows:

[0075]

[0076] Among them, for the ground grid (i, j), (I / N) i,j represents the single-entry interference in each downward direction of the NGSO satellite antenna, P i,j Indicates the transmission power of NGSO satellite, G t Indicates the NGSO satellite antenna gain, angle represents the launch off-axis angle of the NGSO satellite, G r represents the antenna gain of the GSO satellite earth station, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α th It represents the angle between the line connecting the earth station and the vertex of its visible GSO satellite arc and the NGSO satellite link.

[0077] The goal of this paper is to dynamically select a beam planning strategy based on the interference conditions of each GSO satellite ground station within the NGSO satellite coverage area, so that the NGSO satellite beam is accurately shut down, rather than completely shutting down the NGSO satellite due to passing through the GSO isolation zone, thereby maximizing the working efficiency of the NGSO satellite and minimizing the interference conditions of the GSO ground stations under its beam coverage. This problem can be expressed as

[0078]

[0079]

[0080] Where Q represents the beam planning strategy matrix, q i,j Indicates the NGSO satellite beam open / close status, (I / N) i,j Characterizes the interference situation of the GSO ground station under the coverage of the NGSO satellite beam, φ represents the longitude range covered by the NGSO satellite beam, represents the latitude range covered by the NGSO satellite beam, ηth The interference isolation threshold recommended by ITU-R S.1432-1 is -12.2dB, R(q i.j ) represents the working efficiency of NGSO satellites.

[0081]

[0082] 2.1.2 Beam planning method based on spatial isolation exclusion zone

[0083] In the downlink interference avoidance scenario of NGSO satellites to GSO satellite ground stations, the core constraint of the interference avoidance isolation forbidden zone and beam planning mapping mechanism is to avoid interference to the GSO satellite system while taking into account the availability of the GSO satellite system and the NGSO satellite system as much as possible. Therefore, an algorithm is proposed to design the optimal interference avoidance isolation forbidden zone and beam planning mapping mechanism, such as Figure 3 shown.

[0084] First, assume that the beams are all on, that is, all elements in the Q matrix are 1. Then, perform interference calculations on each grid area covered by the NGSO satellite beam. If the grid area exceeds the limit, then q i.j Set it to 0, and then perform interference calculation on the grid again. Repeat this process until the interference level of all grid areas covered by the NGSO satellite beam is reduced to an acceptable range.

[0085] Correspondingly, a beam planning algorithm based on interference isolation forbidden zone is proposed, as shown in Table 1.

[0086] Table 1 Beam planning algorithm based on spatial isolation restricted area

[0087]

[0088] The specific implementation process of the above method is as follows Figure 4 shown.

[0089] 2.2 Uplink Interference Avoidance Beam Planning Method

[0090] 2.2.1 Objective function definition

[0091] The uplink scenario is considered in a similar way to the downlink scenario. The aggregate interference caused by the collinear interference and sidelobe interference under the same frequency interference is considered during the analysis. The ground is divided into grids according to longitude and latitude, and the following grids are established: Figure 2 Similarly, assuming that there is one earth station at the center of each ground grid, and using the transmission power at the grid center to approximately replace the transmission power within the grid, the single-entry interference of the uplink is obtained as:

[0092]

[0093] Among them, (I / N) i,j P represents the interference from NGSO ground stations to GSO satellites. i,j Indicates the transmission power of the NGSO ground station, G t represents the NGSO satellite receiving antenna gain, angle β upi,j represents the launch off-axis angle of the NGSO satellite, G r Indicates the GSO satellite receiving antenna gain, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α th It represents the angle between the line connecting the vertices of the GSO satellite arc visible to the earth station and the line connecting the NGSO satellite links.

[0094] Similarly, the goal can be defined as dynamically selecting the beam communication strategy based on the interference caused by the ground stations within the coverage of the NGSO satellite beam to the GSO satellite, so that the corresponding earth station transmitting antenna and NGSO satellite receiving antenna are accurately shut down (or planned), thereby maximizing the working efficiency of the NGSO satellite system and minimizing the interference to the GSO satellite receiver. This problem can be expressed as

[0095]

[0096]

[0097] Where V represents the beam planning strategy matrix, v i,j Indicates the NGSO satellite beam open / close status, (I / N) i,j Characterizes the interference situation of GSO satellites from various ground stations, P represents the longitude range covered by the NGSO satellite beam, M represents the latitude range covered by the NGSO satellite beam, η th The interference isolation threshold recommended by ITU-R S.1432-1 is -12.2dB, R(v i.j ) represents the working efficiency of the NGSO satellite system. The uplink beam planning strategy is proposed by formula (5), as follows: Figure 5 shown.

[0098] 3 Simulation Analysis

[0099] Taking the downlink as an example, a simulation model is established to demonstrate the method. To facilitate analysis, the interfering NGSO satellite system refers to the orbital configuration of the Starlink constellation, that is, a satellite with an orbital altitude of 630km. The transmit power, carrier bandwidth, and center frequency refer to the beam information registered with the ITU. The antenna model uses the ITU-S-1528 antenna model. The arc segment of the interfered GSO satellite is selected from my country, with a range of 75°E to 135°E. The ground station antenna model uses the ITU-S-580 antenna model, and the angle threshold between the NGSO satellite and the ground station is set to 25°. The remaining parameters are detailed in Table 2:

[0100] Table 2 Related simulation parameters

[0101]

[0102]

[0103] The beam planning area obtained by simulation is as follows Figure 6 、 Figure 7 As shown in .

[0104] Figure 6 and Figure 7 The method demonstrates how the satellite beam state changes with the beam control strategy in different latitude and longitude scenarios. Figure 8 The figure shows the interference-to-noise ratio distribution under the NGSO satellite beam coverage before interference avoidance is implemented. It can be seen that the interference clearly exceeds the limit of -12.2dB (corresponding to the number 0.0603) in the area where beam control is required. Figure 9 The interference-to-noise ratio distribution under the NGSO satellite beam coverage is shown after beam planning interference avoidance. It can be seen that the interference-to-noise ratio is significantly reduced to below the limit, demonstrating the effectiveness of this method.

[0105] In addition, from Figure 6 and Figure 7 It can be seen that during interference avoidance, some beams remain operational. In traditional interference avoidance methods based on isolation angles or isolation bands, NGSO satellite systems use beam switching to achieve interference avoidance. That is, after entering the avoidance area, the satellite needs to shut down all beams, and the ground station needs to communicate with neighboring NGSO satellites that are not in the avoidance band. This places certain requirements on the density of the NGSO satellite constellation and makes the beam utilization of NGSO satellites in the avoidance band approximately 0. To further illustrate the satellite's beam utilization, this article introduces beam utilization as an evaluation indicator, which is specifically defined as the following formula:

[0106]

[0107] in, Indicates the number of closed beams, numK Indicates the total number of beams.

[0108] Figure 10 The beam utilization rate of this method is shown in a single-satellite scenario under different longitude and latitude conditions. It can be seen that the beam utilization rate of this method is not zero under different longitude and latitude scenarios, which shows that this method has engineering advantages in protecting GSO communication links and ensuring the operating efficiency of NGSO satellite systems.

[0109] Example 2

[0110] Embodiment 2 of the present invention proposes an interference avoidance beam planning system based on a spatial isolation restricted area, which is implemented based on the method of embodiment 1. The system includes:

[0111] The scenario construction module is used to construct the aggregate interference scenario under co-frequency interference of high-orbit and low-orbit satellite systems based on the uplink and downlink, based on the ground grid division;

[0112] A model building module is used to establish a worst-case aggregate interference determination model for the uplink and downlink of a low-orbit satellite system to a high-orbit satellite arc based on time slicing;

[0113] A function building module is used to construct a phased array antenna beam planning objective function for frequency sharing between high- and low-orbit satellite systems based on the interference limit standard I / N;

[0114] Beam planning module, used to perform beam planning based on the phased array antenna beam planning objective function and spatial isolation exclusion zone

[0115] in conclusion:

[0116] The present invention proposes a method for determining an isolation forbidden zone and an interference avoidance beam planning method for high- and low-orbit satellite interference scenarios. Based on a quantitative description of the interference avoidance isolation forbidden zone, a specific beam planning strategy is proposed. This overcomes the disadvantage of traditional interference avoidance methods based on isolation angles or isolation bands, which require shutting down all satellite beams. It can effectively avoid interference in interference-exceeding areas under the coverage of NGSO satellite beams, providing a method reference and technical support for protecting the communication links of GSO satellite systems and ensuring the working efficiency of NGSO satellite systems.

[0117] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A beam planning method for interference avoidance based on a spatial isolation restricted zone, comprising: Step 1) Based on the uplink and downlink links and the ground grid division, the aggregate interference scenarios under the co-frequency interference of the high-orbit and low-orbit satellite systems are constructed respectively; Step 2) establishing a worst-case aggregate interference determination model for the low-orbit satellite system to the uplink and downlink of the high-orbit satellite arc based on time slicing; Step 3) Based on the interference limit standard I / N, a phased array antenna beam planning objective function for frequency sharing between high and low orbit satellite systems is constructed; Step 4) performing beam planning based on the spatial isolation restricted area according to the phased array antenna beam planning objective function; The step 1) comprises: Based on the uplink and downlink links of the GSO and NGSO satellite systems, an uplink multi-beam satellite system interference scenario and a downlink multi-beam satellite system interference scenario are established respectively; Divide the ground into grids according to longitude and latitude, use the grid as the basic unit to calculate interference, and set a ground station at the center of the grid; The step 2) comprises: The aggregate interference of the ground station at the center of the grid is used to replace the aggregate interference of the entire grid; For the downlink multi-beam satellite system interference scenario, the single-entry interference satisfies the following equation: Among them, for the ground grid (i, j), (I / N) i,j represents the single-entry interference in each downward direction of the NGSO satellite antenna, P i,j Indicates the transmission power of NGSO satellite, G t Indicates the NGSO satellite antenna gain, angle represents the launch off-axis angle of the NGSO satellite, G r represents the antenna gain of the GSO satellite earth station, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α th It represents the angle between the line connecting the earth station and the vertex of its visible GSO satellite arc and the NGSO satellite link; The aggregate downlink interference is obtained by summing up all single-entry interference links; all single-entry interference links point to the interfered object, making (I / N) i,j is the largest, and the worst aggregate interference decision model for the downlink is obtained based on time slicing; For the uplink multi-beam satellite system interference scenario, the single-entry interference is: Among them, (I / N) i,j P represents the interference from NGSO ground stations to GSO satellites. i,j Indicates the transmission power of the NGSO ground station, G t Indicates the NGSO satellite receiving antenna gain, angle represents the launch off-axis angle of the NGSO satellite, G r Indicates the GSO satellite receiving antenna gain, angle It represents the separation angle between NGSO satellite and GSO satellite, L i,j represents the link loss, β th Indicates the elevation angle of the Earth, α th It represents the angle between the line connecting the vertices of the GSO satellite arc visible to the earth station and the line connecting the NGSO satellite link; The uplink aggregate interference is obtained by summing up all single-entry interference links; all single-entry interference links point to the interfered object, so that (I / N) i,j is the largest, and the uplink worst aggregate interference decision model is obtained based on time slicing.

2. The interference avoidance beam planning method based on spatial isolation forbidden zone according to claim 1, characterized in that: The aggregate interference under the same-frequency interference in step 1) includes: collinear interference and sidelobe interference; wherein, Collinear interference refers to the communication interference caused to the GSO satellite link when the NGSO satellite link and the GSO satellite link overlap or nearly overlap in space; The sidelobe interference refers to the interference caused by the sidelobe of the transmitting antenna of the useless signal aligning with the interfered receiver.

3. The interference avoidance beam planning method based on spatial isolation forbidden zone according to claim 1, characterized in that: The step 3) comprises: For the downlink multi-beam satellite system interference scenario, the phased array antenna beam planning objective function is: Where Q represents the downlink beam planning strategy matrix, q i,j Indicates the open and closed status of the NGSO satellite beam during downlink, φ indicates the longitude range covered by the NGSO satellite beam, represents the latitude range covered by the NGSO satellite beam, η th Indicates the interference isolation threshold, which is -12.2dB, R(q i.j ) represents the working efficiency of the NGSO satellite, which satisfies the following formula: Among them, sum() represents the sum operation; For the uplink multi-beam satellite system interference scenario, the phased array antenna beam planning objective function is: Where V represents the uplink beam planning strategy matrix, v i,j Indicates the open and closed state of the NGSO satellite beam in the uplink scenario, P indicates the longitude range covered by the NGSO satellite beam, M indicates the latitude range covered by the NGSO satellite beam, and η th Indicates the interference isolation threshold, which is -12.2dB, R(v i.j ) represents the working efficiency of the NGSO satellite system in the uplink scenario.

4. The interference avoidance beam planning method based on spatial isolation forbidden zone according to claim 3, characterized in that: The step 4) comprises: For downlink multi-beam satellite system interference scenarios, beam planning methods based on spatial isolation exclusion zones include: Step S1) setting the NGSO beam to be in a fully open state, that is, all elements in the Q matrix are 1; Step S2) Calculate (I / N) for each grid point (i, j) covered by the NGSO satellite beam. i,j ;If (I / N) i,j ≥η th , then q i.j Set to 0 and calculate (I / N) for the grid again i,j Repeat this process until all grid points covered by the NGSO satellite beam meet (I / N) i,j <η th (I / N) i,j ; Go to step S3); Step S3) updating the downlink beam planning strategy matrix Q; For uplink multi-beam satellite system interference scenarios, beam planning methods based on spatial isolation exclusion zones include: Step T1) setting the NGSO beams to be in a fully open state, that is, all elements in the V matrix are 1; Step T2) Calculate (I / N) for each grid point (i, j) covered by the NGSO satellite beam. i,j ;If (I / N) i,j ≥η th , then v i,j Set to 0 and calculate (I / N) for the grid again i,j Repeat this process until all grid points covered by the NGSO satellite beam meet (I / N) i,j <η th (I / N) i,j ; Go to step T3); Step T3) Update the uplink beam planning strategy matrix V.

5. An interference avoidance beam planning system based on spatial isolation forbidden zone, implemented according to any one of the methods of claims 1-4, characterized in that: The system comprises: The scenario construction module is used to construct the aggregate interference scenario under co-frequency interference of high-orbit and low-orbit satellite systems based on the uplink and downlink, based on the ground grid division; A model building module is used to establish a worst-case aggregate interference determination model for the uplink and downlink of a low-orbit satellite system to a high-orbit satellite arc based on time slicing; A function building module for constructing a phased array antenna beam planning objective function for frequency sharing between high and low orbit satellite systems based on the interference limit standard I / N; and The beam planning module is used to perform beam planning based on the spatial isolation restricted area according to the phased array antenna beam planning objective function.

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