A joint decision-making method for frequency interference avoidance zones between satellite constellation systems

Abstract

The present invention relates to a joint decision method for frequency interference avoidance zones between satellite constellation systems, including: setting avoidance zones according to two strategies: first, randomly selecting Nvoid avoidance zones, and second, selecting the first Nvoid avoidance cells according to the expected order of occurrence of interfering constellation satellites in the cell; respectively calculating the minimum visible satellite numbers corresponding to the two avoidance zone strategies; if both minimum visible satellite numbers are not less than 1, respectively calculating the interference-to-noise ratio distributions corresponding to the two avoidance zone strategies, otherwise Nvoid is increased by one; setting a frequency interference degree discrimination threshold I / N_th and a probability discrimination threshold Pth, judging P(I / N_random<I / N_th)-P(I / N_rank<I / N_th)<Pth; if satisfied, for the current Nvoid value, adopting a random selection avoidance zone strategy; otherwise, adopting an expectation-based selection avoidance zone strategy; Nvoid is increased by one until Nvoid is equal to the total number of visible airspace cells. The present invention solves the problem of co-frequency interference between satellite constellation communication systems with overlapping coverage areas.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite constellation systems and relates to a joint decision method for frequency interference avoidance zones between satellite constellation systems. Background Art

[0002] Space radio frequency orbital resources are the basis for the construction and operation of communication satellite systems, and have become an important strategic resource that affects the national economy and even national security. In recent years, large-scale low-orbit constellations have set off a wave of rapid construction and deployment around the world. Based on the basic principle of "first come, first served" of frequency and orbital resources in the current international rules system, resources will inevitably become increasingly tight in the future, forming a situation of multiple satellites in close orbit and multiple satellites on the same frequency. With the development and deployment of 5G / 6G, in non-terrestrial networks (NTN, Non-Terrestrial Network), communication satellites have become an important part of realizing the interconnection between the earth and the sky. In the future, in the planning and construction of communication satellite constellations, systematic frequency interference analysis and comprehensive interference avoidance strategy design can accurately predict the potential frequency interference risks between multi-constellation systems and effectively reduce the probability of harmful interference in actual operations.

[0003] For non-geostationary satellite constellation systems, due to the time-varying characteristics of the satellite's spatial position, the communication link between the satellite and ground users also changes over time. Different satellite constellation systems are usually non-cooperative systems. If they use the same frequency band, there is a high probability of co-frequency signal interference. The existing exploration of frequency interference avoidance methods is mainly carried out in three aspects: time domain, frequency domain, and space domain. For the situation between satellite constellation systems, since different constellation systems belong to different operators, the time domain avoidance method requires multi-system operation strategies and real-time data intercommunication, which is difficult to implement. The advantage of the frequency domain interference avoidance method is that it directly avoids the overlap of the working frequency band and effectively reduces the probability of co-frequency interference. However, the disadvantage is that the frequency domain division of the satellite constellation system reduces the frequency band range of a single system. Under the condition of a certain spectrum utilization rate, this division method directly reduces the system capacity and causes direct loss to the system's capabilities. The design of the spatial domain interference avoidance method is based on the fact that the transmitting and receiving antennas used in high-frequency communication systems can form narrow beams, that is, the radiated power is concentrated in the link direction. In this case, different systems only need to consider the co-linear interference when the link angle is small. When the links between systems form a large angle, even if they work at the same frequency, the same frequency capability can be avoided from coupling into the receivers of other systems. In principle, the present invention is based on interference avoidance in the spatial domain, and designs a joint decision method for frequency interference avoidance zones between satellite constellation systems. Summary of the invention

[0004] The technical problem solved by the present invention is: to solve the problem of co-frequency interference between satellite constellation communication systems with overlapping coverage areas, a joint decision method for frequency interference avoidance zones between satellite constellation systems is proposed.

[0005] The technical solution of the present invention is: in the first aspect, a joint decision method for frequency interference avoidance zone between satellite constellation systems is proposed, comprising the following steps:

[0006] The first step is to set the avoidance zone, including two avoidance zone setting strategies: 1. Randomly select Nvoid avoidance zones; 2. Select the first Nvoid avoidance cells according to the order of expected Es appearing in the visible airspace cells by the interference constellation satellites;

[0007] The second step is to calculate or count the minimum number of visible satellites Nvis_random for the random selection of the avoidance zone strategy, and calculate or count the minimum number of visible satellites Nvis_rank for the selection of the avoidance zone strategy based on the expected Es ranking;

[0008] Step 3: Check if Nvis_random < 1 or Nvis_rank < 1. If either of the two conditions is met, jump to step 6, otherwise go to step 4.

[0009] Step 4: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es;

[0010] The fifth step is to set the frequency interference level judgment threshold I / N_th and the probability judgment threshold Pth, and judge whether the probability P(I / N_random>I / N_th)-probability P(I / N_rank>I / N_th)<Pth is satisfied; if satisfied, for the current Nvoid value, the random selection avoidance zone strategy is adopted; otherwise, for the current Nvoid value, the avoidance zone strategy is selected according to the expected Es;

[0011] Step 6: Increase the number of cells to be avoided Nvoid by one;

[0012] Step 7: Determine if Nvoid is less than the total number of cells Ncell in the visible airspace. If so, jump to step 1; otherwise, the avoidance zone joint decision method ends.

[0013] Furthermore, before setting the avoidance zone, the following steps are also included:

[0014] Set satellite constellation system parameters;

[0015] Set the cell radius Rcell within the visible airspace of the ground station, and calculate the total number of cells Ncell in the visible airspace according to the minimum elevation angle of the ground station communication;

[0016] The third step is to calculate the expected Es of the interference constellation satellite appearing in the visible airspace cell, and sort the cells from large to small according to the expectation;

[0017] The fourth step is to initialize the number of cells to be avoided in the visible airspace Nvoid=1.

[0018] Furthermore, the satellite constellation system parameters are set, including orbital inclination, total number of orbital planes, number of satellites per orbit, orbital altitude, minimum elevation angle of ground station communication, latitude of co-located ground stations, noise temperature of the disturbed constellation receiver, and transmit power and bandwidth of the disturbing constellation.

[0019] Furthermore, the cell radius Rcell within the visible airspace of the ground station is greater than the main lobe half-beam angle of the ground terminal antenna of the disturbed constellation system.

[0020] Further, the calculation of the expected Es of the interference constellation satellite in the visible airspace cell includes:

[0021] Calculate the probability that a satellite appears in a visible airspace cell:

[0022]

[0023] in, is the satellite probability density corresponding to the center point of the cell unit, ψ i is the longitude of the subsatellite point when the satellite appears at the center of the cell unit, The latitude of the sub-satellite point when the satellite appears at the center of the cell; The expression is:

[0024]

[0025] Among them, δ is the inclination of the satellite orbit;

[0026] A c is the spherical degree of the visible airspace cell unit of the ground station, and the expression is:

[0027]

[0028] Among them, Δθ ε and Δθ β are the geocentric angle differences corresponding to the elevation angle differences and azimuth angle differences of the visible airspace cells respectively;

[0029] When the total number of satellites is N, for a certain ground station, the expected value of satellites in its visible airspace cell is:

[0030]

[0031] Furthermore, Δθ ε and Δθ β The geometric relationship between the ground station and the visible airspace cell is obtained as follows:

[0032] θ ε_min =arccos(kcos(ε-R cell) )-(ε-R cell )

[0033] θ ε_max =arccos(kcos(ε+R cell ))-(ε+R cell )

[0034]

[0035] Δθ ε =θ ε_max -θ ε_min

[0036]

[0037]

[0038] Among them, r and R are the radius of the earth and the radius of the satellite's circular orbit, respectively. cell is the radius of the visible airspace cell, and ε is the elevation angle of the ground station corresponding to the center point of the visible airspace cell.

[0039] Further, the setting of the frequency interference degree determination threshold I / N_th includes:

[0040] The frequency interference level judgment threshold I / N_th is assigned with reference to the I / N value recommended by ITU Recommendation S.1323.

[0041] Furthermore, the setting of the probability discrimination threshold Pth includes:

[0042] Pth is set to one tenth of the probability P(I / N_rank>I / N_th).

[0043] In a second aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for joint decision-making of frequency interference avoidance zones between satellite constellation systems are implemented.

[0044] According to a third aspect, a device for joint decision-making of frequency interference avoidance zones between satellite constellation systems is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a method for joint decision-making of frequency interference avoidance zones between satellite constellation systems when executing the computer program.

[0045] The beneficial effects of the present invention compared with the prior art are:

[0046] (1) For two non-cooperative satellite constellation systems with overlapping coverage areas, there is a greater risk of frequency interference when using the same frequency band to establish a satellite user communication link. The present invention can effectively reduce the probability of the same interference-to-noise ratio by designing a joint decision-making method for airspace avoidance zones.

[0047] (2) Compared with the traditional single interference avoidance method, the present invention innovatively proposes a joint decision-making method, which combines the advantages of the random selection of interference avoidance zone strategy and the satellite expectation-based selection of interference avoidance zone strategy, and improves and verifies the effectiveness of the interference avoidance strategy on the basis of simplifying the difficulty of implementing the interference avoidance scheme.

[0048] (3) Aiming at the demand of real-time adjustment of the scope of interference avoidance zone in actual operation system, the present invention proposes a rapid evaluation algorithm based on the minimum number of visible satellites, interference degree judgment threshold and probability judgment threshold. The algorithm can shorten the evaluation decision time of the performance of different avoidance zone selection strategies to milliseconds, thereby realizing rapid evaluation and comparison of avoidance zone selection strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a flow chart of the joint decision-making method for frequency interference avoidance zones between satellite constellation systems of the present invention;

[0050] Figure 2 A schematic diagram of the airspace visible to ground users;

[0051] Figure 3 Schematic diagram of strategy setting for avoidance zone;

[0052] Figure 4 It is a schematic diagram of the geometric relationship between the ground station and its visible airspace cell;

[0053] Figure 5 The expected Es calculation result of the interference constellation satellite in the cell according to the embodiment of the present invention;

[0054] Figure 6 The frequency interference avoidance zone setting result of the embodiment of the present invention (Nvoid=1);

[0055] Figure 7 The calculation result of the minimum number of visible satellites in the embodiment of the present invention (Nvoid=1);

[0056] Figure 8 is the calculation result of the interference-to-noise ratio I / N according to the embodiment of the present invention (Nvoid=1);

[0057] Fig. 9 The frequency interference avoidance zone setting result of the embodiment of the present invention (Nvoid=36);

[0058] Fig.10 The calculation result of the minimum number of visible satellites in the embodiment of the present invention (Nvoid=36);

[0059] Fig.11 is the interference-to-noise ratio I / N calculation result of the embodiment of the present invention (Nvoid=36);

[0060] Fig.12 The frequency interference avoidance zone setting result of the embodiment of the present invention (Nvoid=48);

[0061] Fig.13 The calculation result of the minimum number of visible satellites in the embodiment of the present invention (Nvoid=48);

[0062] Fig.14 is the interference to noise ratio I / N calculation result of the embodiment of the present invention (Nvoid=48);

[0063] Fig.15 The frequency interference avoidance zone setting result of the embodiment of the present invention (Nvoid=70);

[0064] Fig.16 This is the calculation result of the minimum number of visible satellites (Nvoid=70) according to the embodiment of the present invention. DETAILED DESCRIPTION

[0065] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0066] Figure 2 This is a schematic diagram of the visible airspace division of a satellite ground station. The visible airspace of any ground station (i.e., the area with an elevation angle greater than the minimum communication elevation angle) is divided into smaller cell units, divided into regular hexagonal grids. The cell units are closely arranged, and the centers of each area are arranged in a triangular shape. The azimuth of 0° represents the north direction, 90° represents the east direction, and 180° represents the south direction. The length of the polar axis represents the elevation angle range, and the coordinate center point represents the top of the ground station, that is, the elevation angle is 90°.

[0067] For satellite constellations with multiple coverage capabilities, in order to reduce the risk of frequency interference with other satellite systems, avoidance zones can be set within the visible airspace of the ground station (i.e., cells where the main visual axis of the ground station antenna is prohibited from pointing). Figure 3As shown, some cells in the visible airspace are set as frequency interference avoidance zones, where dark dots represent cells in the visible airspace that the main axis of the ground station antenna is prohibited from pointing to. To set an avoidance zone, a certain number of cells can be randomly selected as frequency interference avoidance zones, or the cells can be sorted from large to small according to the size of the expected value of the satellite appearance, and a certain number of cells can be selected in turn as frequency interference avoidance zones. How to evaluate the advantages and disadvantages of the two principles followed in setting the avoidance zone, especially when the range of the avoidance zone changes, how to quickly evaluate the effectiveness of the avoidance zone setting in reducing frequency interference, is the key problem to be solved by the present invention.

[0068] The present invention provides a method for jointly deciding frequency interference avoidance zones between satellite constellation systems, and the specific steps are as follows: Figure 1 As shown:

[0069] The first step is to set the satellite constellation system parameters, including orbital inclination, total number of orbital planes, number of satellites per orbit, orbital altitude, minimum elevation angle for ground station communication, latitude of co-located ground stations, receiver noise temperature of the disturbed constellation, and transmit power and bandwidth of the disturbing constellation.

[0070] The second step is to set the cell radius Rcell in the visible airspace of the ground station, and calculate the total number of cells Ncell in the visible airspace according to the minimum elevation angle of the ground station communication. The value of the cell radius Rcell in the visible airspace of the ground station must be greater than the main lobe half-beam angle of the ground terminal antenna of the disturbed constellation system.

[0071] The third step is to calculate the expected Es of the interference constellation satellite in the visible airspace cell, and sort the cells from large to small according to the expectation. The calculation process of the expected Es of the satellite in the visible airspace cell is as follows:

[0072] Ground station T and its visible airspace cell C i The geometric relationship is as follows Figure 4 As shown, the satellite appears in the visible airspace cell C. i The probability of:

[0073]

[0074] in, is the satellite probability density corresponding to the center point of the cell unit, ψ i is the longitude of the subsatellite point when the satellite appears at the center of the cell unit, The latitude of the sub-satellite point when the satellite appears at the center of the cell; The expression is:

[0075]

[0076] Among them, δ is the inclination of the satellite orbit;

[0077] A c is the spherical degree of the visible airspace cell unit of the ground station, and the expression is:

[0078]

[0079] Among them, Δθ ε and Δθ β They are the geocentric angle differences corresponding to the elevation angle difference and azimuth angle difference of the visible airspace cell, which can be calculated from the geometric relationship between the ground station and the visible airspace cell. The expression is as follows:

[0080] θ ε_min =arccos(kcos(ε-R cell ))-(ε-R cell )

[0081] θ ε_max =arccos(kcos(ε+R cell ))-(ε+R cell )

[0082]

[0083] Δθ ε =θ ε_max -θ ε_min

[0084]

[0085]

[0086] Among them, r and R are the radius of the earth and the radius of the satellite's circular orbit, respectively. cell is the visible airspace cell radius, ε is the visible airspace cell C i The elevation angle of the ground station T corresponding to the center point.

[0087] When the total number of satellites is N, for a certain ground station, its visible airspace cell C i The expected value of the satellite is:

[0088]

[0089] Step 4: Initialize the number of cells to be avoided in the visible airspace Nvoid = 1;

[0090] The fifth step is to set the avoidance zone, including two avoidance zone setting strategies: 1. Randomly select Nvoid avoidance zones; 2. Select the first Nvoid avoidance zones according to the expected Es sorting;

[0091] Step 6: For the random selection of the avoidance zone strategy, calculate or count the minimum number of visible satellites Nvis_random; for the selection of the avoidance zone strategy based on the expected Es ranking, calculate or count the minimum number of visible satellites Nvis_rank;

[0092] Step 7: Check if Nvis_random < 1 or Nvis_rank < 1, that is, for the two strategies, the minimum number of visible satellites for either strategy is less than 1. If either strategy is satisfied, go to step 12, otherwise go to step 8;

[0093] Step 8: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es;

[0094] The ninth step is to set the frequency interference level determination threshold I / N_th and the probability determination threshold Pth. The preferred setting scheme of the frequency interference level determination threshold I / N_th includes: assigning a value to the frequency interference level determination threshold I / N_th with reference to I / N=-12.2dB recommended by ITU Recommendation S.1323.

[0095] The preferred setting scheme of the probability judgment threshold Pth includes: Pth is set to one tenth of the probability that I / N_rank is greater than I / N_th (0.1P(I / N_rank>I / N_th)), that is, when the interference avoidance effect of randomly selecting the avoidance zone is good to a certain extent, the random selection avoidance zone strategy is selected.

[0096] Step 10: Determine whether the probability P(I / N_random>I / N_th)-probability P(I / N_rank>I / N_th)<Pth is satisfied;

[0097] Step 11: If the conditions in step 10 are met, then for the current Nvoid value, a random avoidance zone selection strategy is adopted; if the conditions in step 10 are not met, then for the current Nvoid value, an avoidance zone selection strategy based on expected Es is adopted;

[0098] Step 12: Add one to the number of cells to be avoided: Nvoid=Nvoid+1;

[0099] Step 13: Determine whether Nvoid < Ncell, that is, whether the number of cells to be avoided is less than the total number of cells in the visible airspace. If this condition is met, jump to step 5, otherwise the avoidance zone joint decision method ends.

[0100] Example 1

[0101] In this embodiment, the joint decision-making scheme design of the interference avoidance zone between constellation A (disturbed constellation system) and constellation B (disturbing constellation system) is considered, and the orbital parameters of the two constellations are shown in Table 1.

[0102] Table 1 Orbital parameters of non-geostationary communication constellations

[0103]

[0104] Constellation A is a near-polar orbit constellation, with the main service area being the polar regions and the secondary service area being the mid- and low-latitude regions. Constellation B is an inclined orbit constellation, with the main service area being the region with latitudes less than 60°. The two constellations overlap in the region with latitudes less than 60°, and there is a risk of co-frequency interference. The following frequency interference avoidance scheme is designed using the joint decision-making method of the ground station visible airspace avoidance zone.

[0105] The first step is to set the satellite constellation system parameters, where the orbital inclination, total number of orbital planes, number of satellites per orbit, orbital altitude, and minimum elevation angle for ground station communication are shown in Table 1. The latitude of the co-located ground station is 50°N, the noise temperature of the disturbed constellation receiver is 270K, the disturbing constellation transmit power is 7dBW, and the bandwidth is 200MHz (assuming that the constellation A and constellation B systems operate at the same frequency).

[0106] The second step is to set the cell radius Rcell=5° within the visible airspace of the ground station, and calculate the total number of cells Ncell=95 within the visible airspace based on the minimum elevation angle of 45° for ground station communication.

[0107] The third step is to calculate the expected Es of the interference constellation satellite in the cell, and sort the cells from large to small according to the expected value. The result is as follows: Figure 5 shown.

[0108] The fourth step is to initialize the number of cells to be avoided in the visible airspace Nvoid=1.

[0109] The fifth step is to set the avoidance zone, including two avoidance zone setting strategies: first, randomly select Nvoid avoidance zones, and second, select the first Nvoid avoidance zones according to the expected Es sorting. The results are as follows Figure 6 shown.

[0110] Step 6: For the random selection of avoidance zone strategy, calculate or count the minimum number of visible satellites Nvis_random; for the selection of avoidance zone strategy based on expected Es ranking, calculate or count the minimum number of visible satellites Nvis_rank. The results are as follows: Figure 7 As shown, the minimum number of visible satellites is greater than 8.

[0111] Step 7: Check if Nvis_random < 1 or Nvis_rank < 1, that is, for the two strategies, the minimum number of visible satellites for either strategy is less than 1. If this condition is not met, proceed to step 8.

[0112] Step 8: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es. The results are as follows: Figure 8 shown.

[0113] The ninth step is to set the frequency interference level determination threshold I / N_th to -12.2 dB and the probability determination threshold Pth to 1%.

[0114] The tenth step is to determine whether the condition P(I / N_random>I / N_th)-P(I / N_rank>I / N_th)<Pth is satisfied.

[0115] In the eleventh step, since the conditions in the tenth step are met, for Nvoid=1, a random selection avoidance zone strategy is adopted.

[0116] Step 12: Add one to the number of cells to be avoided: Nvoid=Nvoid+1.

[0117] Step 13. If the condition of Nvoid<Ncell is met, jump to step 5.

[0118] Repeat the above steps, when Nvoid=36:

[0119] The fifth step is to set the avoidance zone, including two avoidance zone setting strategies: first, randomly select Nvoid avoidance zones, and second, select the first Nvoid avoidance zones according to the expected Es sorting. The results are as follows Fig. 9 shown.

[0120] Step 6: For the random selection of avoidance zone strategy, calculate or count the minimum number of visible satellites Nvis_random; for the selection of avoidance zone strategy based on expected Es ranking, calculate or count the minimum number of visible satellites Nvis_rank. The results are as follows: Fig.10 As shown, the minimum number of visible satellites is greater than 3.

[0121] Step 7: Check if Nvis_random < 1 or Nvis_rank < 1, that is, for the two strategies, the minimum number of visible satellites for either strategy is less than 1. If this condition is not met, proceed to step 8.

[0122] Step 8: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es. The results are as follows: Fig.11 shown.

[0123] The ninth step is to set the frequency interference level determination threshold I / N_th to -12.2 dB and the probability determination threshold Pth to 1%.

[0124] The tenth step is to determine whether the condition P(I / N_random>I / N_th)-P(I / N_rank>I / N_th)<Pth is satisfied.

[0125] In the eleventh step, since the conditions in the tenth step are met, for Nvoid=36, a random selection avoidance zone strategy is adopted.

[0126] Step 12: Increase the number of avoided cells by one, Nvoid=Nvoid+1.

[0127] Step 13. If the condition of Nvoid<Ncell is met, jump to step 5.

[0128] Repeat the above steps, when Nvoid=48:

[0129] The fifth step is to set the avoidance zone, including two avoidance zone setting strategies: first, randomly select Nvoid avoidance zones, and second, select the first Nvoid avoidance zones according to the expected Es sorting. The results are as follows Fig.12 shown.

[0130] Step 6: For the random selection of avoidance zone strategy, calculate or count the minimum number of visible satellites Nvis_random; for the selection of avoidance zone strategy based on expected Es ranking, calculate or count the minimum number of visible satellites Nvis_rank. The results are as follows: Fig.13 As shown, the minimum number of visible satellites is greater than 2.

[0131] Step 7: Check if Nvis_random < 1 or Nvis_rank < 1, that is, for the two strategies, the minimum number of visible satellites for either strategy is less than 1. If this condition is not met, proceed to step 8.

[0132] Step 8: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es. The results are as follows: Fig.14 shown.

[0133] The ninth step is to set the frequency interference level determination threshold I / N_th to -12.2 dB and the probability determination threshold Pth to 1%.

[0134] The tenth step is to determine whether the condition P(I / N_random>I / N_th)-P(I / N_rank>I / N_th)<Pth is satisfied.

[0135] In the eleventh step, since the conditions in the tenth step are not satisfied, for Nvoid=48, the strategy of selecting the avoidance zone based on the expected Es is adopted.

[0136] Step 12: Add one to the number of cells to be avoided: Nvoid=Nvoid+1.

[0137] Step 13. If the condition of Nvoid<Ncell is met, jump to step 5.

[0138] Repeat the above steps, when Nvoid=70:

[0139] The fifth step is to set the avoidance zone, including two avoidance zone setting strategies: first, randomly select Nvoid avoidance zones, and second, select the first Nvoid avoidance zones according to the expected Es sorting. The results are as follows Fig.15 shown.

[0140] Step 6: For the random selection of avoidance zone strategy, calculate the minimum number of visible satellites Nvis_random; for the selection of avoidance zone strategy based on expected Es ranking, calculate the minimum number of visible satellites Nvis_rank. The results are as follows: Fig.16 As shown, for the random selection avoidance zone strategy, the minimum number of visible satellites is less than 1.

[0141] Step 7: Check if Nvis_random < 1 or Nvis_rank < 1, that is, for the two strategies, the minimum number of visible satellites in any one of them is less than 1. If this condition is met, jump to step 12.

[0142] The above cycle is repeated until Nvoid=Ncell, and the avoidance area selection decision process ends.

[0143] The present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer executes Figure 1 The method described.

[0144] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0145] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0149] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A joint decision method for frequency interference avoidance zones between satellite constellation systems, characterized in that: The following steps are involved: The first step is to set the avoidance zone, including two avoidance zone setting strategies:

1. Randomly select Nvoid avoidance zones; 2. Select the first Nvoid avoidance zones according to the order of expected Es of the interference constellation satellites in the visible airspace cell; The second step is to calculate or count the minimum number of visible satellites Nvis_random for the random selection of the avoidance zone strategy, and calculate or count the minimum number of visible satellites Nvis_rank for the selection of the avoidance zone strategy based on the expected Es ranking; Step 3: Check if Nvis_random < 1 or Nvis_rank < 1. If either of the two conditions is met, jump to step 6, otherwise go to step 4. Step 4: For the random selection of avoidance zone strategy, calculate the distribution of the interference-to-noise ratio I / N_random of the randomly selected avoidance zone; for the selection of avoidance zone strategy based on the expected Es ranking, calculate the distribution of the interference-to-noise ratio I / N_rank of the avoidance zone selected based on the expected Es; The fifth step is to set the frequency interference level judgment threshold I / N_th and the probability judgment threshold Pth, and judge whether the probability P(I / N_random>I / N_th)-probability P(I / N_rank>I / N_th)<Pth is satisfied; if satisfied, for the current Nvoid value, the random selection avoidance zone strategy is adopted; otherwise, for the current Nvoid value, the avoidance zone strategy is selected according to the expected Es; Step 6: Increase the number of avoidance zones Nvoid by one; Step 7: Determine whether Nvoid is less than the total number of cells Ncell in the visible airspace. If so, jump to the first step, otherwise the avoidance zone joint decision method ends. Before setting the avoidance zone, the following steps are also included: Set satellite constellation system parameters; Set the cell radius R within the visible airspace of the ground station cell , and calculate the total number of cells Ncell in the visible airspace according to the minimum elevation angle of the ground station communication; Calculate the expected Es of the interference constellation satellite appearing in the visible airspace cell, and sort the cells from large to small according to the expectation; Initialize the number of avoidance zones in the visible airspace Nvoid = 1; The step of calculating the expected Es of the interference constellation satellite in the visible airspace cell includes: Calculate the probability that a satellite appears in a visible airspace cell: in, is the satellite probability density corresponding to the center point of the cell unit, ψ i is the longitude of the subsatellite point when the satellite appears at the center of the cell unit, The latitude of the sub-satellite point when the satellite appears at the center of the cell; The expression is: Among them, δ is the inclination of the satellite orbit; A c is the spherical degree of the visible airspace cell unit of the ground station, and the expression is: Among them, Δθ ε and Δθ β are the geocentric angle differences corresponding to the elevation angle differences and azimuth angle differences of the visible airspace cells respectively; When the total number of satellites is N, for a certain ground station, the expected value of satellites in its visible airspace cell is: Δθ ε and Δθ β The geometric relationship between the ground station and the visible airspace cell is obtained as follows: i ε_min =arccos(kcos(ε-R cell ))-(e-R cell ) i ε_max =arccos(kcos(ε+R cell ))-(ε+R cell ) Dth ε =θ ε_max -θ ε_min Among them, r and R are the radius of the earth and the radius of the satellite's circular orbit, respectively. cell is the radius of the cell in the visible airspace, and ε is the elevation angle of the ground station corresponding to the center point of the cell in the visible airspace.

2. The method for joint decision-making of frequency interference avoidance zones between satellite constellation systems according to claim 1, characterized in that: The satellite constellation system parameters are set, including orbital inclination, total number of orbital planes, number of satellites per orbit, orbital altitude, minimum elevation angle for ground station communication, latitude of co-located ground stations, noise temperature of the disturbed constellation receiver, and transmit power and bandwidth of the disturbing constellation.

3. The method for joint decision-making of frequency interference avoidance zones between satellite constellation systems according to claim 1, characterized in that: The radius of the cell within the visible airspace of the ground station is R cell The value is greater than the half-beam angle of the main lobe of the ground terminal antenna of the disturbed constellation system.

4. The method for joint decision-making of frequency interference avoidance zones between satellite constellation systems according to claim 1, characterized in that: The setting of the probability discrimination threshold Pth includes: Pth is set to one tenth of the probability P(I / N_rank>I / N_th).

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

6. A satellite constellation system frequency interference avoidance zone joint decision device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

Images