Precise Modeling Calculation Method and Device for Frequency Interference between Satellite Communication Systems

Abstract

The present invention provides a method for accurately modeling and calculating frequency interference between satellite communication systems. According to the key information parameters of the satellite communication system in the disturbed link, the margin of the disturbed link in a clear sky environment is calculated; based on the margin of the disturbed link, the protection limit of desynchronized lumped interference, the protection limit of long-term lumped interference, and the protection limit of short-term lumped interference are calculated; and the probability distribution function of the interference signal power affected by rainfall is calculated; then, the complementary cumulative probability distribution function of the interference signal power is respectively compared with the protection limits to determine whether the disturbed link is subject to harmful interference based on the comparison results. The present invention also provides an apparatus for accurately modeling and calculating frequency interference between satellite communication systems. Thus, the present invention can effectively evaluate the impacts of desynchronization, long-term, and short-term interference and accurately predict the probability distribution of interference signals.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and particularly to a method and device for accurately modeling and calculating frequency interference between satellite communication systems. Background Art

[0002] With the rapid development of satellite communication technologies, the number of satellites and communication demands globally continue to increase. Especially in geostationary orbit (GEO) and non-geostationary orbit (NGSO) satellite systems, due to overlapping frequency bands and coexistence of satellite systems, the problem of frequency interference has become increasingly prominent. Frequency interference not only affects the stability and reliability of satellite communication links but may also lead to a decline in communication quality, link interruption, and even seriously affect the execution of critical missions.

[0003] Currently, traditional methods for calculating frequency interference mainly rely on theoretical models and empirical formulas. Unreasonable assumptions usually lead to overestimation of interference signals and it is difficult to fully consider complex space environments, dynamically changing satellite orbit characteristics, and mutual interference problems between communication links. Especially in the accurate modeling and calculation of frequency interference between satellite systems, most existing methods have problems such as insufficient calculation accuracy and poor adaptability, and are difficult to meet the high-precision interference analysis requirements of modern satellite communication systems.

[0004] Therefore, there is an urgent need for a modeling method that can accurately calculate frequency interference between satellite communication systems to solve the problem of insufficient accuracy in modeling and calculating frequency interference between satellite communication systems. Especially when multiple satellite systems coexist and use the same or adjacent frequency bands, existing methods are difficult to accurately evaluate the impact of interference. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for accurately modeling and calculating frequency interference between satellite communication systems to overcome the limitations of existing technologies in aspects such as interference signal power prediction, interference protection limit calculation, and interference assessment in dynamically changing environments, thereby improving the operational stability of satellite communication systems and the utilization efficiency of spectrum resources.

[0006] To achieve the above purpose, on the one hand, the present invention provides a method for accurately modeling and calculating frequency interference between satellite communication systems, including the steps of:

[0007] Obtain key information parameters of the disturbed link, where the key information parameters include out-of-sync link margin, bit error rate requirement under the synchronous state, and signal-to-noise ratio required by the link under the bit error rate requirement, as well as environmental parameters such as antenna gain, transmit power, and path loss;

[0008] Based on the key information parameters, calculate the disturbed link margin in clear sky environment, and respectively determine the desynchronization aggregated interference protection limit, the long-term aggregated interference protection limit and the short-term aggregated interference protection limit, where:

[0009] The desynchronization aggregated interference protection limit is determined by allocating in combination with the disturbed link margin according to the desynchronization interference ratio and the time percentage allowing desynchronization;

[0010] The long-term aggregated interference protection limit is determined by allocating in combination with the disturbed link margin according to the long-term interference ratio and the time percentage allowing interference;

[0011] The short-term aggregated interference protection limit is determined by allocating in combination with the disturbed link margin according to the short-term interference ratio and the time percentage allowing interference;

[0012] Calculate the probability distribution function of the first single-source interference signal power in clear sky environment;

[0013] Based on the probability distribution function of the first single-source interference signal power and the rainfall attenuation data, calculate the probability distribution function of the second single-source interference signal power considering the influence of rainfall;

[0014] If the composition of the external interference sources of the disturbed link is known, based on the probability distribution function of the interference signal power affected by rainfall, superimpose the probability distributions of each of the external interference sources, and calculate the probability distribution function of the aggregated interference signal power of the disturbed link.

[0015] Optionally, calculating the desynchronization aggregated interference protection limit, the long-term aggregated interference protection limit and the short-term aggregated interference protection limit of the disturbed link according to the disturbed link margin includes:

[0016] Determine the desynchronization interference ratio brought by other co-frequency satellite communication systems to which the desynchronization link margin is allocated, and the first time percentage allowing the interference to exceed the desynchronization aggregated interference protection limit; and calculate the desynchronization aggregated interference protection limit of the disturbed link based on the desynchronization interference ratio and the first time percentage;

[0017] According to the working characteristics of the disturbed link, determine the long-term interference ratio brought by other co-frequency satellite communication systems to which the disturbed link margin is allocated, and the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit; and calculate the long-term aggregated interference protection limit of the disturbed link based on the long-term interference ratio and the second time percentage;

[0018] According to the operating characteristics of the disturbed link, determine the proportion of the disturbed link margin allocated to the short-term interference caused by other co-frequency satellite communication systems, and the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value; and calculate the short-term aggregated interference protection limit value of the disturbed link based on the short-term interference proportion and the third time percentage.

[0019] Optionally, after calculating the second single-interference signal power probability distribution function considering rainfall influence based on the first single-interference signal power probability distribution function and rainfall attenuation data, it further includes:

[0020] If the external interference source is unknown, determine the number of external interference sources based on the ITU satellite network database.

[0021] According to the number of external interference sources, the desynchronization aggregated interference protection limit value, the long-term aggregated interference protection limit value, and the short-term aggregated interference protection limit value, calculate the corresponding desynchronization single-interference protection limit value, long-term single-interference protection limit value, short-term single-interference protection limit value, and the fourth time percentage allowing the short-term single-interference signal power spectral density to exceed the protection threshold respectively.

[0022] According to the second single-interference signal power probability distribution function, calculate the second interference signal power complementary cumulative probability distribution, and compare the second interference signal power complementary cumulative probability distribution with the desynchronization single-interference protection limit value, the long-term single-interference protection limit value, and the short-term single-interference protection limit value respectively, and determine whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

[0023] Optionally, calculating the disturbed link margin in clear sky environment based on the key information parameters includes:

[0024] Determine the bit error rate requirement of the satellite communication system in the disturbed link in the synchronized state and the signal-to-noise ratio required by the link under the bit error rate requirement.

[0025] Calculate the received strength of the useful signal and the noise power of the disturbed link.

[0026] Obtain the actual signal-to-noise ratio by subtracting the noise power from the received strength of the useful signal; and obtain the disturbed link margin in clear sky environment by subtracting the required signal-to-noise ratio from the actual signal-to-noise ratio.

[0027] Optionally, the desynchronization aggregated interference protection limit value of the disturbed link is calculated based on the following formula:

[0028]

[0029] where q lossThe desynchronization interference ratio allocated to the desynchronized link margin of the disturbed link due to interference from other co-frequency satellite communication systems; P loss The first percentage of time allowing interference to exceed the desynchronization aggregate interference protection limit value; N0 is the noise power of the disturbed link; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

[0030] Optionally, the long-term aggregate interference protection limit value of the disturbed link is calculated based on the following formula:

[0031]

[0032] where q long is the long-term interference ratio allocated to the disturbed link margin due to interference from other co-frequency satellite communication systems; P long is the second percentage of time allowing interference to exceed the long-term aggregate interference protection limit; N0 is the noise power of the disturbed link; M is the disturbed link margin; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

[0033] Optionally, the short-term aggregate interference protection limit value of the disturbed link is calculated based on the following formula:

[0034]

[0035] where q short is the short-term interference ratio allocated to the disturbed link margin due to interference from other co-frequency satellite communication systems; P short is the third percentage of time allowing interference to exceed the short-term aggregate interference protection limit value; N0 is the noise power of the disturbed link; M is the disturbed link margin; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

[0036] Optionally, calculating the probability distribution function of the first single quantity interference signal power in clear sky environment includes:

[0037] If it is for the interference signal from the geostationary orbit satellite communication system, then subtract the path transmission loss from the equivalent radiated power at the transmitter and add the gain of the receiving end antenna of the disturbed link in the interference link direction to calculate the interference signal power; statistically analyze the interference signal power to obtain the probability distribution function of the first single quantity interference signal power in clear sky environment;

[0038] For the interference signals from the non-geostationary orbit satellite communication system, calculate the spatial position probability distribution function of the interfering satellites within the visible airspace of the ground station of the disturbed link, and calculate the probability distribution function of the power of the first single-source interference signal in a clear sky environment based on the spatial position probability distribution function and the antenna pointing and link distance between the satellite and the ground station.

[0039] Optionally, if measured rainfall attenuation data is available, calculating the probability distribution function of the power of the second single-source interference signal considering rainfall effects based on the probability distribution function of the power of the first single-source interference signal and the rainfall attenuation data includes:

[0040] Collect measured rain attenuation data;

[0041] Based on the measured rain attenuation data, classify and statistically analyze the time according to the attenuation amount to obtain the frequency of different rainfall attenuation values;

[0042] Normalize the frequency to generate the probability mass function of rainfall attenuation;

[0043] Calculate the probability distribution function of the power of the second single-source interference signal considering rainfall effects based on the probability mass function of rainfall attenuation and the probability distribution function of the power of the first single-source interference signal;

[0044] Among them, the functional expression of the probability distribution function of the power of the second single-source interference signal considering rainfall effects is:

[0045] P A (a)=∑ r P I (a + r)×P R (r);

[0046] Among them, P I (i) is the probability mass function of the interference signal intensity I, P R (r) is the probability mass function of the rainfall attenuation value R, and A represents the power of the single-source interference signal considering rainfall effects.

[0047] Optionally, if the composition of the external interference sources of the disturbed link is known and satisfies the first condition, where the first condition is that the interference sources are separated from each other by a distance exceeding the distance threshold and the rainfall attenuations are independent events, calculating the probability distribution function of the total interference signal power of the disturbed link based on the probability distribution function of the power of the second single-source interference signal includes:

[0048] According to the probability distribution function of the power of the second single-source interference signal, calculate the interference signal power of each external interference source under rainfall effects and its probability mass function;

[0049] Based on the interference signal power of each external interference source, the lumped interference signal power of the disturbed link is obtained by superposition;

[0050] By integrating the probability mass function of each external interference source, the probability mass function of the lumped interference signal power of the disturbed link is calculated;

[0051] Based on the probability mass function of the lumped interference signal power, the probability distribution function of the lumped interference signal power for evaluating whether the link is subject to harmful interference of the disturbed link is derived.

[0052] Optionally, the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0053]

[0054] where n is the number of known external interference sources; A i is the interference signal power of the i-th based on the influence of rainfall;

[0055] The probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0056]

[0057] where P Ai is the probability mass function of the i-th external interference source based on the influence of rainfall.

[0058] Optionally, if the composition of the external interference sources of the disturbed link is known and satisfies the second condition, the second condition is that the distance between the interference sources does not exceed the distance threshold and the rainfall attenuation is the same or strongly correlated, then based on the probability distribution function of the second single quantity interference signal power, calculating the probability distribution function of the lumped interference signal power of the disturbed link includes:

[0059] According to the probability distribution function of the second single quantity interference signal power, the interference signal power of each external interference source based on the influence of rainfall is calculated;

[0060] Calculate the joint probability of each of the interference signal powers;

[0061] According to the interference signal power, calculate the lumped interference signal power of the disturbed link;

[0062] According to the joint probability and the lumped interference signal power, calculate the probability distribution function of the lumped interference signal power of the disturbed link.

[0063] Optionally, the joint probability of each of the interference signal powers is calculated based on the following formula:

[0064]

[0065] Among them, R is the rainfall attenuation value, and n is the number of known external interference sources;

[0066] The total interference signal power of the disturbed link is calculated based on the following formula:

[0067]

[0068] Among them, n is the number of known external interference sources; A i is the power of the i-th interference signal based on the influence of rainfall;

[0069] The probability distribution function of the total interference signal power of the disturbed link is calculated based on the following formula:

[0070]

[0071] Among them, δ() is the Dirac δ function.

[0072] Optionally, if there is no measured rainfall attenuation data, then based on the probability distribution function of the first single quantity interference signal power and the rainfall attenuation data, calculate the probability distribution function of the second single quantity interference signal power considering the influence of rainfall, including:

[0073] Obtain the probability density function of rainfall attenuation by approximate fitting according to the standard function;

[0074] According to the probability density function of the rainfall attenuation and the probability distribution function of the first single quantity interference signal power, calculate the probability distribution function of the second single quantity interference signal power based on the influence of rainfall.

[0075] Optionally, the function expression of the probability distribution function of the second single quantity interference signal power is:

[0076]

[0077] Among them, f I (i) is the probability density function of the interference signal strength I; f R (r) is the probability density function of the rainfall attenuation value R; A represents the power of the single quantity interference signal considering the influence of rainfall.

[0078] Optionally, the expression of the probability density function of rainfall attenuation deduced based on the standard lognormal model is:

[0079]

[0080] Among them, R is the rainfall attenuation value, μ is the mean of the lognormal distribution, and σ is the standard deviation of the lognormal distribution.

[0081] Optionally, if the external interference sources of the disturbed link are known to constitute and satisfy the first condition, where the first condition is that the interference sources are separated from each other by a distance exceeding a distance threshold and the rainfall attenuations are independent events, calculating the probability density function of the total interference signal power of the disturbed link based on the probability density function of the second single-source interference signal power includes:

[0082] Calculating, according to the probability density function of the second single-source interference signal power, the interference signal power of each external interference source affected by rainfall and its probability density function;

[0083] Converting the interference signal power of each external interference source into a linear power unit;

[0084] Calculating the probability density function of the total interference signal power of the disturbed link by superimposing the interference signal power of each external interference source and its probability density function;

[0085] Converting the total interference signal power from the linear power unit to the decibel unit and generating the probability density function of the total interference signal power;

[0086] Calculating the probability distribution function of the total interference signal power of the disturbed link based on the probability density function of the total interference signal power.

[0087] Optionally, the probability density function after the linear conversion of the interference signal power is calculated based on the following formula:

[0088]

[0089] where Ai is the decibel value of the interference signal power of the i-th external interference source affected by rainfall; is the probability density function of the power Ai;

[0090] The probability density function of the total interference signal is calculated based on the following formula:

[0091]

[0092] The probability distribution function of the total interference signal power of the disturbed link is calculated based on the following formula:

[0093]

[0094] where A is the total interference signal.

[0095] Optionally, if the external interference sources of the disturbed link are known to constitute and satisfy the second condition, where the second condition is that the interference sources are not more than a distance threshold from each other and the rainfall attenuation is the same or strongly correlated, calculating the probability distribution function of the lumped interference signal power of the disturbed link based on the probability distribution function of the second single-interference signal power includes:

[0096] Calculating the interference signal power of each of the external interference sources based on rainfall influence according to the probability distribution function of the second single-interference signal power;

[0097] Calculating the lumped interference signal power based on the interference signal power;

[0098] Calculating the probability distribution function of the lumped interference signal power of the disturbed link based on the lumped interference signal power and a predefined joint probability density function;

[0099] Wherein, the predefined joint probability density function is:

[0100] f I1,I2,...,In,R (i1,i2,r)=f I1 (i1)×f I2 (i2)×...f In (in)×f R (r);

[0101] Wherein, R is the rainfall attenuation value and n is the number of known external interference sources.

[0102] Optionally, the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0103]

[0104] Wherein, n is the number of known external interference sources; A i is the interference signal power of the i-th based on rainfall influence;

[0105] The probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0106]

[0107] Wherein, δ() is the Dirac delta function.

[0108] Optionally, calculating the corresponding desynchronization single-interference protection limit, long-term single-interference protection limit, short-term single-interference protection limit, and the fourth time percentage allowing the short-term single-interference signal power spectral density to exceed the protection threshold according to the number of external interference sources, the desynchronization lumped interference protection limit, the long-term lumped interference protection limit, and the short-term lumped interference protection limit, includes:

[0109] Divide the desynchronization aggregated interference protection limit value by the number of the external interference sources to obtain the corresponding desynchronization single - quantity interference protection limit value;

[0110] Divide the long - term aggregated interference protection limit value by the number of the external interference sources to obtain the corresponding long - term single - quantity interference protection limit value;

[0111] According to the number of the external interference sources and the short - term aggregated interference protection limit value, calculate the corresponding short - term single - quantity interference protection limit value and the fourth time percentage that allows the power spectral density of the short - term single - quantity interference signal to exceed the protection threshold.

[0112] Optionally, the short - term single - quantity interference protection limit value is calculated based on the following formula:

[0113]

[0114] where n is the number of the external interference sources; P short-single is the fourth time percentage that allows the power spectral density of the short - term single - quantity interference signal to exceed the protection threshold; P short is the third time percentage that allows the interference to exceed the short - term aggregated interference protection limit value; δ is the proportion of the signal sources generating stronger interference in the number of the external interference sources.

[0115] Optionally, after calculating the aggregated interference signal power probability distribution function of the disturbed link, it further includes:

[0116] Calculate the first complementary cumulative probability distribution of the interference signal power according to the aggregated interference signal power probability distribution function;

[0117] Compare the first complementary cumulative probability distribution of the interference signal power with the desynchronization aggregated interference protection limit value, the long - term aggregated interference protection limit value, and the short - term aggregated interference protection limit value respectively;

[0118] Based on the corresponding comparison results, determine whether the first complementary cumulative probability distribution of the interference signal power satisfies the desynchronization aggregated interference protection limit value, the long - term aggregated interference protection limit value, and the short - term aggregated interference protection limit value;

[0119] If so, determine that the disturbed link is not affected by harmful interference; otherwise, determine that the disturbed link is affected by harmful interference.

[0120] Optionally, calculating a second complementary cumulative probability distribution of interference signal power based on the second single - quantity interference signal power probability distribution function, and comparing the second complementary cumulative probability distribution of interference signal power with the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value respectively, and determining whether the disturbed link is subject to harmful interference based on the corresponding comparison results, includes:

[0121] Calculating a second complementary cumulative probability distribution of interference signal power according to the second single - quantity interference signal power probability distribution function;

[0122] Comparing the second complementary cumulative probability distribution of interference signal power with the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value respectively;

[0123] Based on the corresponding comparison results, determining whether the second complementary cumulative probability distribution function of interference signal power satisfies the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value;

[0124] If so, determining that the disturbed link is not subject to harmful interference; otherwise, determining that the disturbed link is subject to harmful interference.

[0125] Optionally, it further includes:

[0126] Based on the ITU satellite network database, determining the number of potential interference sources and spectrum allocation information;

[0127] According to the number of potential interference sources and their spectrum allocation information, adjusting the corresponding interference evaluation parameters in the calculation of the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, the short - term single - quantity interference protection limit value, and the fourth time percentage allowing the power spectral density of the short - term single - quantity interference signal to exceed the protection threshold.

[0128] Optionally, it further includes:

[0129] If the current environment meets extreme meteorological conditions, using historical attenuation data or a regional meteorological model to construct a third single - quantity interference signal power probability distribution function of extreme rainfall attenuation;

[0130] Generating a total interference signal power distribution function in an extreme rainfall environment according to the first single - quantity interference signal power probability distribution function and the third single - quantity interference signal power probability distribution function;

[0131] Based on the total interference signal power distribution function, recalculating and adjusting the out - of - synchronization aggregated interference protection limit value, the long - term aggregated interference protection limit value, and the short - term aggregated interference protection limit value.

[0132] Optionally, it further includes:

[0133] Calculating the interference signal power and its total impact of each external interference source based on a joint probability model, where the joint probability model is used to describe the correlation between external interference sources;

[0134] According to the spatial distribution characteristics of each external interference source and the correlation of its interference signal, adjusting the probability distribution model of the rainfall impact, and generating a lumped interference signal power probability distribution function including correlation correction;

[0135] Based on the corrected lumped interference signal power probability distribution function, re-evaluating whether the desynchronization lumped interference protection limit, long-term lumped interference protection limit, and short-term lumped interference protection limit are satisfied.

[0136] Optionally, it further includes:

[0137] Obtaining the terrain height data between the satellite and the ground station;

[0138] Adjusting the path loss model according to the terrain height data, and generating a probability distribution of the interference signal power including terrain occlusion factors;

[0139] Calculating the interference protection limit of each terrain position according to the probability distribution of the interference signal power;

[0140] Through the interference assessment of the current environmental terrain, selecting the interference protection limit corresponding to the terrain position to optimize the setting of the interference protection limit of the disturbed link.

[0141] On the other hand, the present invention also provides a device for accurate modeling and calculation of inter-system frequency interference in a satellite communication system, and the device is used to implement the above-mentioned method for accurate modeling and calculation of inter-system frequency interference in a satellite communication system. The device includes:

[0142] A parameter acquisition module, configured to acquire key information parameters from the disturbed link, where the key information parameters include link margin, signal-to-noise ratio threshold, bit error rate requirement, and parameters of antenna gain, transmit power, and path loss;

[0143] A disturbed link margin calculation module, configured to calculate the disturbed link margin in a clear sky environment based on the data provided by the parameter acquisition module;

[0144] An interference protection limit calculation module, configured to calculate the desynchronization lumped interference protection limit, long-term lumped interference protection limit, and short-term lumped interference protection limit according to the disturbed link margin;

[0145] The interference signal power calculation module is used to calculate the probability distribution function of the single - quantity interference signal power in a clear - sky environment, the probability distribution function of the interference signal power affected by rainfall, and the probability distribution function of the lumped interference signal power;

[0146] The interference determination module is used to compare the probability distribution function generated by the interference signal power calculation module with the limit value of the interference protection limit calculation module to determine whether the disturbed link is affected by harmful interference;

[0147] The data storage module is used to store the parameter information, calculation results and interference evaluation data of each module;

[0148] The display and output module is used to display the interference analysis results and output an interference analysis report containing the determination results.

[0149] Optionally, the interference determination module is specifically used for:

[0150] Calculating the probability distribution function of the first single - quantity interference signal power in a clear - sky environment;

[0151] Based on the probability distribution function of the first single - quantity interference signal power and the rainfall attenuation data, calculating the probability distribution function of the second single - quantity interference signal power considering rainfall influence;

[0152] If the composition of the external interference sources of the disturbed link is known, based on the probability distribution function of the second single - quantity interference signal power, calculating the probability distribution function of the lumped interference signal power of the disturbed link;

[0153] Calculating the complementary cumulative probability distribution of the first interference signal power according to the probability distribution function of the lumped interference signal power, and then comparing the complementary cumulative probability distribution of the first interference signal power with the desynchronization lumped interference protection limit, the long - term lumped interference protection limit and the short - term lumped interference protection limit respectively, and determining whether the disturbed link is affected by harmful interference based on the corresponding comparison results.

[0154] Optionally, the interference determination module is also used for:

[0155] If the external interference sources are unknown, determining the number of external interference sources based on the ITU satellite network database;

[0156] According to the number of external interference sources, the desynchronization lumped interference protection limit, the long - term lumped interference protection limit and the short - term lumped interference protection limit, calculating the corresponding desynchronization single - quantity interference protection limit, long - term single - quantity interference protection limit, short - term single - quantity interference protection limit and the time percentage allowing the short - term single - quantity interference signal power spectral density to exceed the protection threshold respectively;

[0157] According to the second single - quantity interference signal power probability distribution function, calculate the second interference signal power complementary cumulative probability distribution, compare the second interference signal power complementary cumulative probability distribution with the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value respectively, and determine whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

[0158] The method for accurately modeling and calculating frequency interference between satellite communication systems of the present invention is applicable to analyzing frequency interference between geostationary orbit and non - geostationary orbit satellite communication systems. By accurately calculating the interference signal power and its probability distribution, it evaluates the disturbed situation of the communication link, and further provides technical support for interference coordination and optimization of satellite communication systems; it can effectively evaluate the impacts of long - term and short - term interference, accurately predict the probability distribution of interference signals, and further provide support for frequency coordination, interference management, and system optimization of satellite communication systems; it will greatly improve the operation efficiency and security of satellite communication systems and reduce interference conflicts between communication systems. Brief Description of the Drawings

[0159] Figure 1 The flowchart showing the steps of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention;

[0160] Figure 2 The flowchart showing the steps of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention for calculating each lumped interference protection limit value in a specific implementation manner;

[0161] Figure 3 The schematic diagram showing the specific implementation process of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention;

[0162] Figure 4 The schematic diagram showing the structure of the device for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention;

[0163] Figure 5 The schematic diagram showing the probability distribution of single - quantity interference signal power measured by the method provided by the prior art considering rainfall influence with rain attenuation measured data;

[0164] Figure 6 The schematic diagram showing the probability distribution of single - quantity interference signal power measured in a specific application example of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention considering rainfall influence with rain attenuation measured data;

[0165] Figure 7Shows a schematic diagram of the probability distribution of the power of a single interference signal measured by the method provided by the prior art without considering the influence of rainfall with actual rain attenuation data;

[0166] Figure 8 Shows a schematic diagram of the probability distribution of the power of a single interference signal measured in a specific application example of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention without considering the influence of rainfall with actual rain attenuation data;

[0167] Figure 9 Shows a complementary cumulative probability distribution curve of the total interference signal power measured in another specific application example of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention;

[0168] Figures 10 - 11 Shows a schematic diagram for determining the interference influence in another specific application example of the method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention. Detailed implementation manners

[0169] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0170] It should be noted that the references in this specification to "an embodiment", "embodiment", "example embodiment", etc. mean that the described embodiment may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Further, when combining embodiments to describe specific features, structures or characteristics, whether or not there is an explicit description, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures or characteristics into other embodiments.

[0171] In addition, in the specification and subsequent claims, certain terms are used to refer to specific components or parts. Those of ordinary skill in the art should understand that manufacturers may use different nouns or terms to refer to the same component or part. The specification and subsequent claims do not use the difference in name as a way to distinguish components or parts, but use the difference in function of components or parts as the criterion for distinction. The terms "including" and "comprising" mentioned throughout the specification and subsequent claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the term "connected" herein includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0172] Figure 1 Disclosed is a method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention. The method is applicable to analyzing frequency interference between geostationary orbit and non-geostationary orbit satellite communication systems, and includes the following steps:

[0173] S101: Obtain the key information parameters of the disturbed link. The key information parameters include the out-of-synchronization link margin, the bit error rate requirement in the synchronous state, and the signal-to-noise ratio required by the link under the bit error rate requirement, as well as environmental parameters such as antenna gain, transmit power, and path loss.

[0174] S102: Based on the key information parameters, calculate the disturbed link margin in clear sky environment, and respectively determine the out-of-synchronization total interference protection limit, the long-term total interference protection limit, and the short-term total interference protection limit, where:

[0175] The out-of-synchronization total interference protection limit is determined by allocating in combination with the disturbed link margin according to the out-of-synchronization interference ratio and the time percentage allowing out-of-synchronization;

[0176] The long-term total interference protection limit is determined by allocating in combination with the disturbed link margin according to the long-term interference ratio and the time percentage allowing interference;

[0177] The short-term total interference protection limit is determined by allocating in combination with the disturbed link margin according to the short-term interference ratio and the time percentage allowing interference.

[0178] The disturbed link referred to in this embodiment is the link that needs to analyze whether it is suffering from harmful interference; first, the key information parameters of the satellite communication system in the disturbed link need to be obtained, and then based on the obtained key information parameters, the disturbed link margin of the disturbed link in clear sky environment is analyzed and calculated. The disturbed link margin refers to the margin that the communication link can still work normally in the presence of interference.

[0179] Step S102 is to calculate the disturbed link margin based on the key information parameters after obtaining the key information parameters, and then further calculate the out-of-synchronization total interference protection limit, the long-term total interference protection limit, and the short-term total interference protection limit corresponding to the disturbed link based on the disturbed link margin.

[0180] In specific implementation, calculating the disturbed link margin in a clear sky environment based on the key information parameters includes: determining the bit error rate requirement of the satellite communication system in the disturbed link in the synchronous state and the required signal-to-noise ratio of the link under the bit error rate requirement; calculating the received intensity of the useful signal and the noise power of the disturbed link; obtaining the actual signal-to-noise ratio by subtracting the noise power from the received intensity of the useful signal; and obtaining the disturbed link margin in a clear sky environment by subtracting the required signal-to-noise ratio from the actual signal-to-noise ratio. Among them, the required signal-to-noise ratio of the link under a specific bit error rate requirement can be determined by looking up the theoretical curve, empirical formula or referring to relevant standards, with the unit of dB; the received intensity of the useful signal of the disturbed link can be obtained by subtracting the path transmission loss (unit: dB) from the equivalent radiated power of the transmitting end (unit: dBW), and then adding the gain of the receiving end antenna in the direction of the disturbed link; the noise power of the disturbed link (unit: dBW) is equal to the Boltzmann constant (unit: dB(J / K)) plus the noise temperature (unit: dBK), plus the signal bandwidth (unit: dBHz); in this embodiment, M is used to represent the disturbed link margin and will be described in the following.

[0181] See Figure 2 , further, calculating the desynchronization aggregate interference protection limit, long-term aggregate interference protection limit and short-term aggregate interference protection limit of the disturbed link according to the disturbed link margin includes:

[0182] S111: determining the proportion of the desynchronization interference allocated to the desynchronization interference brought by other co-frequency satellite communication systems, and the first time percentage allowing the interference to exceed the desynchronization aggregate interference protection limit; and calculating the desynchronization aggregate interference protection limit of the disturbed link based on the desynchronization interference proportion and the first time percentage; that is, determining the desynchronization link margin M of the disturbed link loss The proportion of the synchronization interference allocated to the synchronization interference brought by other co-frequency satellite communication systems, and the first time percentage allowing the interference to exceed the desynchronization aggregate interference protection limit.

[0183] The desynchronization aggregate interference protection limit of the disturbed link in this embodiment is calculated based on the following formula:

[0184]

[0185] Among them, q loss is the proportion of the desynchronization interference allocated to the desynchronization interference brought by other co-frequency satellite communication systems; P loss is the first time percentage allowing the interference to exceed the desynchronization aggregate interference protection limit; N0 is the noise power of the disturbed link, with the unit of: dBW; M min is the minimum link margin of the disturbed link under all bit error rate requirements, with the unit of dB.

[0186] S112: Determine the proportion of the margin of the disturbed link allocated to the long-term interference caused by other co-frequency satellite communication systems, and the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit value according to the operating characteristics of the disturbed link; and calculate the long-term aggregated interference protection limit value of the disturbed link based on the long-term interference proportion and the second time percentage. That is, starting from its own operating characteristics, the disturbed link determines the proportion of the calculated link margin M allocated to the long-term interference caused by other co-frequency satellite communication systems, and the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit value. Furthermore, calculate the long-term aggregated interference protection limit value of the disturbed link based on the determined proportion and the second time percentage.

[0187] The long-term aggregated interference protection limit value of the disturbed link in this embodiment is calculated based on the following formula:

[0188]

[0189] where q long is the proportion of the margin of the disturbed link allocated to the long-term interference caused by other co-frequency satellite communication systems; P long is the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit; N0 is the noise power of the disturbed link; M is the margin of the disturbed link; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

[0190] S113: Determine the proportion of the margin of the disturbed link allocated to the short-term interference caused by other co-frequency satellite communication systems, and the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value according to the operating characteristics of the disturbed link; and calculate the short-term aggregated interference protection limit value of the disturbed link based on the short-term interference proportion and the third time percentage. That is, starting from its own operating characteristics, the disturbed link determines the proportion of the calculated link margin M allocated to the short-term interference caused by other co-frequency satellite communication systems, and the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value. Furthermore, calculate the short-term aggregated interference protection limit value of the disturbed link based on the determined proportion and the third time percentage.

[0191] The short-term aggregated interference protection limit value of the disturbed link in this embodiment is calculated based on the following formula:

[0192]

[0193] where q short is the proportion of the margin of the disturbed link allocated to the short-term interference caused by other co-frequency satellite communication systems; P shortis the third time percentage that allows interference to exceed the short-term aggregated interference protection limit value; N0 is the noise power of the disturbed link; M is the margin of the disturbed link; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

[0194] S103: Calculate the probability distribution function of the first single interference signal power in a clear sky environment.

[0195] In this embodiment, there are different calculation methods for the probability distribution function of the first single interference signal power when the interference signals come from the geostationary orbit satellite communication system and the non-geostationary orbit satellite communication system respectively, which are as follows:

[0196] If it is for the interference signal from the geostationary orbit satellite communication system, the interference signal power (dBW) is calculated by subtracting the path transmission loss (unit: dB) from the equivalent isotropic radiated power of the transmitting end (unit: dBW) and adding the gain of the receiving end antenna of the disturbed link in the interference link direction (unit: dBi); the interference signal power is statistically analyzed to obtain the probability distribution function of the first single interference signal power in a clear sky environment;

[0197] If it is for the interference signal from the non-geostationary orbit satellite communication system, the probability distribution function of the spatial position of the interfering satellite within the visible airspace of the ground station of the disturbed link is calculated, and based on the probability distribution function of the spatial position and the satellite's antenna pointing and link distance from the ground station, the probability distribution function of the first single interference signal power in a clear sky environment is calculated.

[0198] S104: Based on the probability distribution function of the first single interference signal power and the rainfall attenuation data, calculate the probability distribution function of the second single interference signal power considering the influence of rainfall; in specific implementation, first calculate the probability distribution function of rainfall attenuation, and then calculate the probability distribution function of the second single interference signal power considering the influence of rainfall based on the probability distribution function of rainfall attenuation and the probability distribution function of the first single interference signal power obtained in step S103.

[0199] In order to accurately evaluate the attenuation effect of rainfall on the satellite communication link, this embodiment will provide two methods for calculating the probability distribution function of rainfall attenuation:

[0200] The first method is applicable to the situation where measured rainfall attenuation data can be obtained, and statistical analysis is directly carried out based on the measured rainfall attenuation data; in this method, step S104 specifically includes: collecting measured rain attenuation data; based on the measured rain attenuation data, classifying and statistically analyzing time according to the attenuation amount to obtain the frequencies of different rainfall attenuation values; normalizing the frequencies to generate the probability mass function of rainfall attenuation; according to the probability mass function of rainfall attenuation and the probability distribution function of the first single quantity interference signal power, calculating to obtain the probability distribution function of the second single quantity interference signal power based on the influence of rainfall. Among them, the measured rain attenuation data can come from the long-term monitoring records of ground stations or other relevant measurement systems, and these data usually record the signal attenuation amount (unit: dB) under different rainfall conditions; furthermore, based on the collected measured data, classifying and statistically analyzing time according to the attenuation amount to obtain the frequencies of different attenuation values, and the probability mass function of rainfall attenuation can be generated after normalizing these data.

[0201] Furthermore, in this embodiment, the variable I is used to represent the first single quantity interference signal power (unit: dBW) calculated in step S104, and the variable A is used to represent the single quantity interference signal power based on the influence of rainfall (unit: dBW), that is, A = I - R, where R is the attenuation value; when calculating the probability distribution function of the second single quantity interference signal power based on the influence of rainfall in the first method with measured rainfall attenuation data, since I and R are independent discrete random variables, therefore, the function expression of the probability distribution function of the second single quantity interference signal power based on the influence of rainfall is:

[0202] P A (a) = ∑ r P I (a + r) × P R (r);

[0203] Among them, P I (i) is the probability mass function of the interference signal intensity I, and P R (r) is the probability mass function of the rainfall attenuation value R, and A represents the single quantity interference signal power considering the influence of rainfall.

[0204] The second method is applicable to the situation where rainfall attenuation data cannot be directly obtained. In this case, the probability density function of rainfall attenuation can be approximately fitted by a standard function;

[0205] In this method, step S104 includes: approximately fitting the probability density function of rainfall attenuation by a standard function; according to the probability density function of rainfall attenuation and the probability distribution function of the first single quantity interference signal power, calculating to obtain the probability distribution function of the second single quantity interference signal power based on the influence of rainfall.

[0206] Since I and R are independent and continuous random variables, the functional expression of the probability distribution function of the second single-source interference signal power is as follows:

[0207]

[0208] where f I (i) is the probability density function of the interference signal strength I; f R (r) is the probability density function of the rainfall attenuation value R; A represents the single-source interference signal power considering the influence of rainfall.

[0209] The lognormal distribution is a probability distribution model commonly used to describe rainfall attenuation. Assuming that the logarithm of the rainfall attenuation value R (unit: dB) follows a normal distribution, the expression of the probability density function of rainfall attenuation deduced based on the standard lognormal model is:

[0210]

[0211] where R is the rainfall attenuation value, μ is the mean of the lognormal distribution, and σ is the standard deviation of the lognormal distribution. Specifically, when calculating, after determining the specific values of the parameters μ and σ by referring to historical meteorological data and relevant standards, the probability density function of the rainfall attenuation value R can be obtained.

[0212] S105: If the composition of the external interference sources of the disturbed link is known, then based on the probability distribution function of the interference signal power considering the influence of rainfall, superimpose the probability distributions of each external interference source to calculate the probability distribution function of the total interference signal power of the disturbed link. That is, before this step S105, it is necessary to first analyze whether the composition of the external interference sources is mastered. Specifically, if the composition of the interference sources and the specific system parameter information can be mastered based on the previous international and domestic coordination experience, then calculate the probability distribution function of the total interference signal power of the disturbed link through step S105.

[0213] For the case where the composition of the external interference sources is known, in the scenario where there are multiple interference sources (the number of interference sources is denoted as n), use Ii to represent the interference signal power (unit: dBW) of the i-th interference source reaching the disturbed link in clear sky conditions; use Ri to represent the rainfall attenuation (unit: dB) of the i-th interference link; use Ai to represent the i-th interference signal power (unit: dBW) considering the influence of rainfall, which can be denoted as Ai = Ii - Ri; use A to represent the total interference signal power (unit: dBW) received by the disturbed link.

[0214] In the analysis and calculation of this step S105 (i.e., when the external interference sources are known), the following two situations may exist: (1) The interference sources are far from each other, and the rainfall attenuation is an independent event; (2) The interference sources are close to each other, and the rainfall attenuation is the same or strongly correlated. In this regard, the composition of the external interference sources of the disturbed link and the corresponding conditions satisfied are known (the first condition is that the distance between the interference sources exceeds the distance threshold and the rainfall attenuation is an independent event, and the second condition is that the distance between the interference sources does not exceed the distance threshold and the rainfall attenuation is the same or strongly correlated). The following is the processing for different conditions satisfied in this embodiment:

[0215] (1) If the interference sources are far from each other, the influence of rainfall attenuation on the interference link is independent. Therefore, the single - quantity interference signal powers considering the influence of rainfall calculated according to step S104 are independent events (i.e., when the first condition is satisfied).

[0216] In this case, it will be further analyzed by distinguishing whether there is measured rainfall attenuation data.

[0217] 1. When there is actual rainfall attenuation data, the method for calculating the probability distribution function of the total interference signal power of the disturbed link is as follows:

[0218] According to the second single - quantity interference signal power probability distribution function, calculate the interference signal power and its probability mass function of each external interference source based on the influence of rainfall; based on the interference signal power of each external interference source, superimpose to obtain the total interference signal power of the disturbed link; according to the probability mass function of the total interference signal power, deduce the probability distribution function of the total interference signal power of the disturbed link used to evaluate whether the link is subject to harmful interference.

[0219] Specifically, according to step S104, calculate the interference signal power Ai and its probability mass function of each interference source affected by rainfall, denoted as P Ai 。

[0220] Calculate the total interference signal power A according to the following formula, that is, the total interference signal power of the disturbed link is calculated based on the following formula:

[0221]

[0222] where n is the number of known external interference sources; A i is the interference signal power of the i - th based on the influence of rainfall;

[0223] Furthermore, the probability distribution function of the total interference signal power of the disturbed link is calculated based on the following formula:

[0224]

[0225] where, P Ai is the probability mass function of the i-th external interference source based on the influence of rainfall.

[0226] 2. When actual rainfall attenuation data is not available, the method for calculating the probability distribution function of the total interference signal power of the disturbed link is as follows:

[0227] According to the probability distribution function of the second single interference signal power, calculate the interference signal power and its probability density function of each external interference source based on the influence of rainfall; convert the interference signal power of each external interference source into a linear power unit; by superimposing the interference signal power and its probability density function of each external interference source, calculate the probability density function of the total interference signal power of the disturbed link; convert the total interference signal power from the linear power unit to the decibel unit, and generate the probability density function of the total interference signal power; based on the probability density function of the total interference signal power, calculate the probability distribution function of the total interference signal power of the disturbed link.

[0228] Specifically, according to step S104, calculate the interference signal power Ai and its probability density function of each interference source affected by rainfall, denoted as f Ai (ai);

[0229]

[0230] Then convert Ai from the dB unit to the linear power unit, denoted as

[0231] Furthermore, calculate P according to the following formula Ai The probability density function, that is, the probability density function after the conversion of the interference signal power, is calculated based on the following formula:

[0232]

[0233] where, Ai is the interference signal power of the i-th external interference source based on the influence of rainfall.

[0234] Calculate the probability density function of the total interference signal (linear power unit) according to the following formula, is the n-fold convolution of; that is, the probability density function of the total interference signal is calculated based on the following formula:

[0235]

[0236] Then convert the total interference signal P 总(Linear power unit) is converted to the lumped interference signal A (dB), and the probability density function of A is calculated; that is, the probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0237] A = 10log 10 (P 总 );

[0238]

[0239] where A is the lumped interference signal.

[0240] (2) If the interference sources are close to each other, then the rainfall attenuation suffered by different disturbed links is the same or strongly correlated, which makes the interference signal powers after considering the rainfall attenuation correlated (that is, under the condition of satisfying the second condition).

[0241] In this case, it will be further analyzed by distinguishing whether there is measured rainfall attenuation data or not.

[0242] 1. When there is actual rainfall attenuation data, the method for calculating the probability distribution function of the lumped interference signal power of the disturbed link is as follows:

[0243] According to the probability distribution function of the second single interference signal power, calculate the interference signal power of each external interference source based on the influence of rainfall; calculate the joint probability of each interference signal power; according to the interference signal power, calculate the lumped interference signal power of the disturbed link; according to the joint probability and the lumped interference signal power, calculate the probability distribution function of the lumped interference signal power of the disturbed link.

[0244] Specifically, assuming that the influence of rainfall attenuation on the disturbed link is the same, then according to the probability distribution function of the second single interference signal power in step S106, calculate the interference signal power Ai of each interference source after being affected by rainfall.

[0245] Calculate the joint probability of each interference signal power. Specifically, the joint probability of each interference signal power is calculated based on the following formula:

[0246]

[0247] where R is the rainfall attenuation value and n is the number of known external interference sources.

[0248] Then calculate the lumped interference signal power A according to the following formula, that is, the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0249]

[0250] where n is the number of known external interference sources; Ai is the power of the i-th interference signal based on the influence of rainfall.

[0251] Furthermore, for each possible combination of (i1, i2,..., in, r), calculate the corresponding A value and the joint probability P I1,I2,...,in,R (i1, i2,..., in, r), and then add up the probabilities with the same A value to obtain the probability distribution of the lumped interference signal power A. That is, the probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula:

[0252]

[0253] where δ() is the Dirac delta function, which takes 1 when the expression inside the parentheses is zero and 0 otherwise.

[0254] 2. When actual rainfall attenuation data is not available, the method for calculating the probability distribution function of the lumped interference signal power of the disturbed link is as follows:

[0255] According to the second single-source interference signal power probability distribution function, calculate the interference signal power of each external interference source based on the influence of rainfall; based on the interference signal power, calculate the lumped interference signal power; based on the lumped interference signal power and the predefined joint probability density function, calculate the probability distribution function of the lumped interference signal power of the disturbed link.

[0256] where the predefined joint probability density function is:

[0257] f I1,I2,...,In,R (i1, i2, r) = f I1 (i1) × f I2 (i2) ×... f In (in) × f R (r);

[0258] where R is the rainfall attenuation value and n is the number of known external interference sources.

[0259] The lumped interference signal power of the disturbed link is calculated based on the following formula:

[0260]

[0261] where n is the number of known external interference sources; A i is the power of the i-th interference signal based on the influence of rainfall;

[0262] The lumped interference intensity A is a function of I1, I2,..., In and R:

[0263] A = 10log 10 (10 (I1-R) / 10+10 (I2-R) / 10 +...+10 (In-R) / 10 );

[0264] Its probability density function is as follows, that is, the probability distribution function of the total interference signal power of the disturbed link is calculated based on the following formula:

[0265]

[0266] where δ() is the Dirac delta function, which takes 1 when the expression in the parentheses is zero and 0 otherwise.

[0267] For the case of knowing the composition of the external interference source and the specific system parameter information, it is necessary to further calculate the complementary cumulative probability distribution of the first interference signal power based on the probability distribution function of the total interference signal power calculated in step S105, and then compare it with the desynchronization total interference protection limit, long-term total interference protection limit, and short-term total interference protection limit calculated in steps S111, S112, and S113 to determine whether the disturbed link is subject to harmful interference.

[0268] Specifically in implementation, refer to Figure 1 , after step S105, it further includes:

[0269] S211: Calculate the complementary cumulative probability distribution of the first interference signal power according to the probability distribution function of the total interference signal power;

[0270] S212: Compare the complementary cumulative probability distribution of the first interference signal power with the desynchronization total interference protection limit, long-term total interference protection limit, and short-term total interference protection limit respectively;

[0271] S213: Based on the corresponding comparison results, determine whether the complementary cumulative probability distribution of the first interference signal power satisfies the desynchronization total interference protection limit, long-term total interference protection limit, and short-term total interference protection limit;

[0272] S214: If so, it is determined that the disturbed link is not subject to harmful interference; otherwise, it is determined that the disturbed link is subject to harmful interference. That is, only when all three types of limits are satisfied is it determined that the disturbed link is not subject to harmful interference, otherwise it can be determined that the disturbed link is subject to harmful interference.

[0273] In another alternative implementation manner of this embodiment, after step S104, it further includes:

[0274] S106: If the external interference source is unknown, determine the number of external interference sources based on the ITU satellite network database. That is, when the relevant information of the external interference source is not known, the ITU satellite network database can be referred to determine the number of external interference sources; and then further analyze whether the disturbed link is subject to harmful interference through the subsequent steps S107 - S108.

[0275] S107: According to the number of external interference sources, the desynchronization aggregated interference protection limit value, the long-term aggregated interference protection limit value, and the short-term aggregated interference protection limit value, calculate the corresponding desynchronization single-quantity interference protection limit value, long-term single-quantity interference protection limit value, short-term single-quantity interference protection limit value, and the fourth time percentage allowing the short-term single-quantity interference signal power spectral density to exceed the protection threshold respectively.

[0276] Step S107 of this embodiment includes: dividing the desynchronization aggregated interference protection limit value by the number of external interference sources to obtain the corresponding desynchronization single-quantity interference protection limit value; dividing the long-term aggregated interference protection limit value by the number of external interference sources to obtain the corresponding long-term single-quantity interference protection limit value; and calculating the corresponding short-term single-quantity interference protection limit value according to the number of external interference sources and the fourth time percentage allowing the short-term single-quantity interference signal power spectral density to exceed the protection threshold.

[0277] Specifically, determine the number of external interference sources based on the ITU satellite network database, denoted as n; the desynchronization single-quantity interference protection limit value I single (P loss ) is equal to the ratio of the desynchronization aggregated interference protection limit value I0(P loss ) calculated in step S102 to the number of external interference sources n; the long-term single-quantity interference protection limit value I single (P long ) is equal to the ratio of the long-term aggregated interference protection limit value I0(P long ) calculated in step S103 to the number of external interference sources n.

[0278] Further, the short-term single-quantity interference protection limit value is calculated based on the following formula:

[0279]

[0280] where n is the number of external interference sources; P short-single is the fourth time percentage allowing the short-term single-quantity interference signal power spectral density to exceed the protection threshold; P short is the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value; and δ is the proportion of the signal sources generating stronger interference in the number of external interference sources.

[0281] S108: According to the second single - quantity interference signal power probability distribution function, calculate the complementary cumulative probability distribution of the second interference signal power, and compare the complementary cumulative probability distribution of the second interference signal power with the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value respectively, and determine whether the disturbed link is subjected to harmful interference based on the corresponding comparison results.

[0282] Specifically, step S108 includes: calculating the complementary cumulative probability distribution of the second interference signal power according to the second single - quantity interference signal power probability distribution function; comparing the complementary cumulative probability distribution of the second interference signal power with the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value respectively; judging whether the complementary cumulative probability distribution of the second interference signal power satisfies the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value based on the corresponding comparison results; if so, it is determined that the disturbed link is not subjected to harmful interference; otherwise, it is determined that the disturbed link is subjected to harmful interference.

[0283] In an optional implementation manner, for the case of an unknown number of external interference sources, this embodiment further includes: determining the number and spectrum allocation information of potential interference sources based on the ITU satellite network database; adjusting the corresponding interference evaluation parameters in the calculation of the out - of - synchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, the short - term single - quantity interference protection limit value, and the fourth time percentage allowing the power spectral density of the short - term single - quantity interference signal to exceed the protection threshold according to the number and spectrum allocation information of the potential interference sources. That is, based on the ITU satellite network database, the number and spectrum allocation information of potential interference sources can be determined; when calculating the single - quantity interference protection limit value, the long - term interference protection limit value, and the short - term interference protection limit value, the interference evaluation parameters can be adjusted according to the distribution and signal characteristics of potential interference sources to adapt to possible interference changes.

[0284] In an optional implementation manner, in the interference impact assessment in an extreme rainfall environment, this embodiment further includes: if the current environment meets the extreme meteorological conditions, constructing a third single - quantity interference signal power probability distribution function of extreme rainfall attenuation using historical attenuation data or a regional meteorological model; generating a total interference signal power distribution function according to the first single - quantity interference signal power probability distribution function and the third single - quantity interference signal power probability distribution function; recalculating and adjusting the out - of - synchronization aggregated interference protection limit value, the long - term aggregated interference protection limit value, and the short - term aggregated interference protection limit value based on the total interference signal power distribution function. That is, the interference protection limit value can be recalculated and adjusted according to the total interference signal power distribution function in the extreme rainfall environment to ensure communication reliability in the extreme environment.

[0285] In an alternative embodiment, in a scenario where the distance between external interference sources is relatively close and the influence of rainfall attenuation is strongly correlated, this embodiment further includes: calculating the interference signal power and its total influence of each external interference source based on a joint probability model, where the joint probability model is used to describe the correlation between external interference sources; adjusting the probability distribution model of rainfall influence according to the spatial distribution characteristics of each external interference source and the correlation of its interference signals, and generating a lumped interference signal power probability distribution function including correlation correction; based on the corrected lumped interference signal power probability distribution function, re-evaluating whether the desynchronization lumped interference protection limit, long-term lumped interference protection limit, and short-term lumped interference protection limit are met.

[0286] In an alternative embodiment, when performing interference assessment based on the terrain characteristics of the area where the ground station is located, this embodiment further includes: obtaining the terrain height data between the satellite and the ground station; adjusting the path loss model according to the terrain height data, and generating a probability distribution of interference signal power including terrain occlusion factors; calculating the interference protection limit for each terrain position according to the probability distribution of interference signal power; through the interference assessment of the current environmental terrain, selecting the interference protection limit corresponding to the terrain position to optimize the setting of the interference protection limit of the disturbed link. That is, using the terrain height data between the satellite and the ground station to adjust the path loss model and generate a probability distribution of interference signal power including terrain occlusion factors; calculating the interference protection limits at different positions considering terrain factors, and generating a terrain-related interference protection scheme based on the calculation results; performing interference assessment separately under different terrains such as mountains and plains to optimize the setting of the interference protection limit of the communication link.

[0287] The specific process of the method for accurately modeling and calculating frequency interference between satellite communication systems described in this embodiment is shown as Figure 3 shown; by accurately calculating the interference signal power and its probability distribution, this method can effectively evaluate the disturbed situation of the communication link, and further provide technical support for the interference coordination and optimization of the satellite communication system.

[0288] Two specific application examples of using the method for accurately modeling and calculating frequency interference between satellite communication systems described in this embodiment will be introduced below: Example 1 and Example 2.

[0289] Example 1

[0290] This Example 1 is for the frequency interference analysis between a geostationary orbit (GEO) and a non-geostationary orbit (NGSO) satellite communication system; in this Example 1, the disturbed link GEO satellite operates at the 136°E orbital position, the earth station is deployed at (109°E, 20°N), the maximum transmit gain of the satellite antenna is 53.4 dBi, and the maximum transmit power is 15 dBW; the interfering NGSO satellite communication constellation consists of 400 satellites, evenly distributed on 20 orbital planes, with an orbital altitude of 1000 km and an inclination of 60 degrees, and 20 satellites are evenly deployed on each orbital plane. The maximum transmit gain of the satellite antenna is 34.9 dBi, the maximum transmit power is 2 dBW, and the earth station is also deployed at (109°E, 20°N).

[0291] The margin M of the disturbed link in a clear sky environment is calculated as follows:

[0292] First, according to the design requirements of the GEO satellite communication system, it is determined that the link margin when the receiver phase-locked loop of the disturbed link operates in the critical state of out-of-synchronization is 8.2 dB, and the bit error rate requirement when the link operates in the synchronized state but there is data packet loss is 10-7. By looking up the bit error rate and signal-to-noise ratio curve of the DVB-S2 system, it is determined that the signal-to-noise ratio required for the link at this time is 7.5 dB. Second, according to the equivalent radiated power at the transmitting end (46.7 dBW), path transmission loss (200.6 dB), receiving antenna gain (40.4 dBi), and noise power (-124 dBW) when the GEO system operates in the synchronized state, the received signal strength is calculated to be -112.2 dBW, and further calculation shows that the link margin at this time is 3 dB.

[0293] The calculation of the aggregated interference protection limits for out-of-synchronization, long-term, and short-term interference of the disturbed link is as follows:

[0294] The disturbed link allocates 100% of the link margin to the interference causing out-of-synchronization, and the time percentage requirement is not more than 0.1%; in the link synchronized state, the disturbed link allocates 25% and 40% of the link margin to long-term and short-term interference respectively, and the time percentage requirements are 20% and 1% respectively. According to the method provided in the embodiments of the present invention, the following can be calculated respectively: the aggregated interference protection limit for out-of-synchronization: -116.5 dBW, and the time percentage requirement is 0.1%; the aggregated interference protection limit for short-term interference: -128.9 dBW, and the time percentage requirement is 1%; the aggregated interference protection limit for long-term interference: -131.2 dBW / Hz, and the time percentage requirement is 20%.

[0295] When there are actual test results with rain fade, the probability distribution of the single interference signal power considering the impact of rainfall is as Figure 6As shown. Among them, the red curve is the complementary cumulative probability distribution curve of the interference signal power in a clear sky environment, and the blue curve is the complementary cumulative probability distribution curve of the interference signal power after considering rainfall attenuation. It can be seen that, as Figure 5 shown, before the accurate modeling and calculation method of frequency interference proposed by the present invention is adopted, the interference signal is determined to exceed the protection threshold of the disturbed link. However, after considering the influence of the objective rainfall environment on the interference signal and performing refined modeling and calculation, the interference signal meets the protection threshold.

[0296] In the case of actual test results without rain attenuation, it is assumed that the interference signal strength follows a shifted lognormal distribution with a shift of -147 dBW, a mean of 2, and a standard deviation of 0.5; the rain attenuation follows a lognormal distribution with a mean of 2 and a standard deviation of 1; the probability distribution of the single-amount interference signal power considering the influence of rainfall is as Figure 8 shown. Among them, the red curve is the complementary cumulative probability distribution curve of the interference signal power in a clear sky environment, and the black curve is the complementary cumulative probability distribution curve of the interference signal power after considering rainfall attenuation. It can be seen that, as Figure 7 shown, before the accurate modeling and calculation method of frequency interference proposed by the present invention is adopted, the interference signal is determined to exceed the protection threshold of the disturbed link. However, after considering the influence of the objective rainfall environment on the interference signal and performing refined modeling and calculation, the interference signal meets the protection threshold.

[0297] In this Example 1, based on the assumption premise, it is determined that the external interference source is only composed of one NGSO satellite communication system. Since there is only one external interference, the probability distribution of the lumped interference signal power is consistent with the probability distribution function of the second single-amount interference signal power calculated by using Step S106.

[0298] As described above, by comparing the first interference signal complementary cumulative probability distribution result calculated in Step S106 with the three interference protection limits calculated in Steps S102 to S104, it is found that the traditional frequency interference calculation method leads to an overestimation of interference (exceeding the protection threshold). However, after adopting the accurate modeling and calculation method of frequency interference between satellite communication systems provided by the embodiments of the present invention, all interference protection limits are met, and the interference is effectively evaluated.

[0299] Example 2

[0300] Example 2 specifically involves the frequency interference analysis between a geostationary orbit (GEO) and two non-geostationary orbit (NGSO) satellite communication systems; in this Example 2, the disturbed link GEO satellite operates at the 136°E orbital position, the earth station is deployed at (109°E, 20°N), the maximum transmit gain of the satellite antenna is 53.4 dBi, and the maximum transmit power is 15 dBW; the interfering NGSO satellite communication constellation 1 contains 400 satellites, evenly distributed on 20 orbital planes, with an orbital altitude of 1000 km and an inclination of 60 degrees, and 20 satellites are evenly deployed on each orbital plane, the maximum transmit gain of the satellite antenna is 34.9 dBi, the maximum transmit power is 2 dBW, and the earth station is also deployed at (109°E, 20°N); the interfering NGSO satellite communication constellation 2 contains 400 satellites, evenly distributed on 20 orbital planes, with an orbital altitude of 1300 km and an inclination of 65 degrees, and 20 satellites are evenly deployed on each orbital plane, the maximum transmit gain of the satellite antenna is 34.9 dBi, the maximum transmit power is 2 dBW, and the earth station is deployed at (108°E, 20°N).

[0301] The calculation method of the margin M of the disturbed link and the lumped interference protection limits of desynchronization, long-term and short-term interference in the clear sky environment of the disturbed link is the same as that in Example 1 above, and will not be elaborated here.

[0302] Based on the assumed premise, it is determined that the external interference source consists of two NGSO satellite communication systems. The probability distribution of the lumped interference signal power is as Figure 9 shown, where the blue curve represents the complementary cumulative probability distribution curve of the signal power of interference source 1 after considering rainfall attenuation. The red curve represents the complementary cumulative probability distribution curve of the signal power of interference source 2 after considering rainfall attenuation. The black curve is the complementary cumulative probability distribution curve of the lumped interference signal power.

[0303] See Figures 10 - 11 and compare the calculated complementary cumulative probability distribution results of the first interference signal with the three interference protection limits calculated through steps S102 - S104. It is found that the lumped interference signal power meets the lumped interference protection limits of the long-term and short-term interference of the disturbed link, but exceeds the desynchronization lumped interference protection limit. Therefore, it is determined that the disturbed link is subject to harmful interference.

[0304] Of course, the present invention is not limited to the applications such as Example 1 and Example 2. In practical applications, it can be flexibly adjusted and expanded according to different demand scenarios and technical conditions.

[0305] Figure 4Shows a precise modeling and calculation device for inter - satellite - communication - system frequency interference provided by another embodiment of the present invention. The device is used to implement the precise modeling and calculation method for inter - satellite - communication - system frequency interference as described in the above - mentioned embodiment, and includes a parameter acquisition module 10, a disturbed - link margin calculation module 20, an interference protection limit calculation module 30, an interference signal power calculation module 40, an interference determination module 50, a data storage module 60, and a display and output module 70, where:

[0306] The parameter acquisition module 10 is used to acquire key information parameters from the disturbed link. The key information parameters include link margin, signal - to - noise ratio threshold, bit - error rate requirement, and parameters of antenna gain, transmit power, and path loss; the disturbed - link margin calculation module 20 is used to calculate the disturbed - link margin in a clear - sky environment based on the data provided by the parameter acquisition module 10; the interference protection limit calculation module 30 is used to calculate the desynchronization aggregate interference protection limit, long - term aggregate interference protection limit, and short - term aggregate interference protection limit according to the disturbed - link margin; the interference signal power calculation module 40 is used to calculate the probability distribution function of the single - quantity interference signal power in a clear - sky environment, the probability distribution function of the interference signal power affected by rainfall, and the probability distribution function of the aggregate interference signal power; the interference determination module 50 is used to compare the probability distribution function generated by the interference signal power calculation module 40 with the limit value of the interference protection limit calculation module to determine whether the disturbed link is subjected to harmful interference; the data storage module 60 is used to store the parameter information, calculation results, and interference evaluation data of each module; the display and output module 70 is used to display the interference analysis results and output an interference analysis report including the determination result.

[0307] The parameter acquisition module 10 is the starting point for the operation of the device and is responsible for acquiring key information parameters from the satellite communication system, such as satellite orbit data, antenna parameters of the transmitting and receiving ends, link status (including signal power, bandwidth, bit - error rate requirement, path loss, noise temperature, etc.), and external environment parameters (such as environmental data under rainfall conditions), etc.

[0308] The disturbed - link margin calculation module 20 calculates the disturbed - link margin in a clear - sky environment according to the data provided by the parameter acquisition module 10; this module includes a transmitting - end equivalent radiated power calculation unit, a path transmission loss calculation unit, a receiving - end antenna gain calculation unit, and a noise power calculation unit.

[0309] The interference protection limit calculation module 30 calculates various interference protection limits according to the calculation results output by the disturbed - link margin calculation unit 20, specifically including aggregate and single - quantity desynchronization, long - term, and short - term interference protection limits; this module includes a disturbed - link margin allocation unit and an interference event percentage allocation unit.

[0310] The interference signal power calculation module 40 calculates the probability distribution of the single - quantity interference signal power in a clear - sky environment based on the data provided by the parameter acquisition module 10, further calculates the probability distribution of the single - quantity interference signal power considering the influence of rainfall, and calculates the probability distribution of the lumped interference signal power according to the composition of the external interference sources; this module includes a rainfall attenuation calculation unit, an interference source composition analysis unit, a single - quantity interference signal power calculation unit, and a lumped interference signal power calculation unit.

[0311] The interference determination module 50 compares the calculation result provided by the interference signal power calculation module 40 with the interference protection limit value output by the interference protection limit calculation module 30 to determine whether there is a harmful interference signal and gives an interference determination result.

[0312] The data storage module 60 is used to store data such as satellite communication system parameter information, the calculation result of the disturbed link margin, various interference protection limit values, the probability distribution of rainfall attenuation, the composition of interference sources, the interference signal power distribution, and the interference determination result, which is convenient for other modules to call and analyze.

[0313] The display and output module 70 is used to display the calculation result and determination conclusion, output an interference analysis report, and provide a basis for subsequent system optimization and frequency scheduling.

[0314] Further, the interference determination module 50 is specifically used for: calculating the probability distribution function of the first single - quantity interference signal power in a clear - sky environment; based on the probability distribution function of the first single - quantity interference signal power and rainfall attenuation data, calculating the probability distribution function of the second single - quantity interference signal power considering the influence of rainfall; if the composition of the external interference sources of the disturbed link is known, then based on the probability distribution function of the second single - quantity interference signal power, calculating the probability distribution function of the lumped interference signal power of the disturbed link; calculating the complementary cumulative probability distribution of the first interference signal power according to the probability distribution function of the lumped interference signal power, and then comparing the complementary cumulative probability distribution of the first interference signal power with the desynchronization lumped interference protection limit value, the long - term lumped interference protection limit value, and the short - term lumped interference protection limit value respectively, and determining whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

[0315] The interference determination module 50 is also used for: if the external interference sources are unknown, determining the number of external interference sources based on the ITU satellite network database; according to the number of external interference sources, the desynchronization lumped interference protection limit value, the long - term lumped interference protection limit value, and the short - term lumped interference protection limit value, calculating the corresponding desynchronization single - quantity interference protection limit value, long - term single - quantity interference protection limit value, short - term single - quantity interference protection limit value, and the time percentage allowing the short - term single - quantity interference signal power spectral density to exceed the protection threshold respectively.

[0316] According to the second single - quantity interference signal power probability distribution function, the second interference signal power complementary cumulative probability distribution is calculated, and the second interference signal power complementary cumulative probability distribution is respectively compared with the desynchronization single - quantity interference protection limit value, the long - term single - quantity interference protection limit value, and the short - term single - quantity interference protection limit value, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

[0317] The above - mentioned modules work together to jointly complete the accurate modeling and calculation of frequency interference between satellite communication systems; the specific calculation and analysis process refer to the method described in the above - mentioned embodiments, and will not be elaborated here.

[0318] In summary, the method and device for accurate modeling and calculation of frequency interference between satellite communication systems provided by the present invention are applicable to analyzing the frequency interference between geostationary orbit and non - geostationary orbit satellite communication systems. By accurately calculating the interference signal power and its probability distribution, the disturbed situation of the communication link is evaluated, and thus technical support is provided for the interference coordination and optimization of the satellite communication system; it can effectively evaluate the influence of long - term and short - term interference, accurately predict the probability distribution of the interference signal, and thus provide support for the frequency coordination, interference management, and system optimization of the satellite communication system; it will greatly improve the operation efficiency and security of the satellite communication system and reduce the interference conflict between communication systems.

[0319] The method according to the present invention can be implemented on a computer as a computer - implemented method, or in dedicated hardware, or in a combination of both. The executable code or a part thereof for the method according to the present invention can be stored on a computer program product. Examples of computer program products include memory devices, optical storage devices, integrated circuits, servers, online software, etc. Preferably, the computer program product includes a non - temporary program code component stored on a computer - readable medium so as to execute the method according to the present invention when the program product is executed on a computer.

[0320] In a preferred embodiment, the computer program includes computer program code components suitable for executing all steps of the method according to the present invention when the computer program runs on a computer. Preferably, the computer program is embodied on a computer - readable medium.

[0321] Certainly, the present invention can also have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A precise modeling and calculation method for inter-frequency interference between satellite communication systems, characterized in that, Including the steps: Obtain the key information parameters of the disturbed link, where the key information parameters include the desynchronization link margin, the bit error rate requirement under the synchronization state, and the signal-to-noise ratio required by the link under the bit error rate requirement, as well as the environmental parameters of antenna gain, transmit power, and path loss; Based on the key information parameters, calculate the disturbed link margin in a clear sky environment, and respectively determine the desynchronization aggregated interference protection limit, the long-term aggregated interference protection limit, and the short-term aggregated interference protection limit, where: The desynchronization aggregated interference protection limit is determined by allocating according to the desynchronization interference ratio and the percentage of the time allowed for desynchronization, in combination with the disturbed link margin; The long-term aggregated interference protection limit is determined by allocating according to the long-term interference ratio and the percentage of the time allowed for interference, in combination with the disturbed link margin; The short-term aggregated interference protection limit is determined by allocating according to the short-term interference ratio and the percentage of the time allowed for interference, in combination with the disturbed link margin; Calculate the probability distribution function of the first single-source interference signal power in a clear sky environment; The calculation of the probability distribution function of the first single-source interference signal power in a clear sky environment includes: If it is for the interference signal from the geostationary satellite communication system, then calculate the interference signal power by subtracting the path transmission loss from the equivalent isotropic radiated power at the transmitter and adding the gain of the receiving antenna of the disturbed link in the direction of the interference link; statistically analyze the interference signal power to obtain the probability distribution function of the first single-source interference signal power in a clear sky environment; If it is for the interference signal from the non-geostationary satellite communication system, then calculate the probability distribution function of the spatial position of the interfering satellites within the visible airspace of the ground station of the disturbed link, and based on the probability distribution function of the spatial position and the satellite-ground station antenna pointing and link distance, calculate the probability distribution function of the first single-source interference signal power in a clear sky environment; Based on the probability distribution function of the first single-source interference signal power and the rainfall attenuation data, calculate the probability distribution function of the second single-source interference signal power considering the influence of rainfall; If the composition of the external interference sources of the disturbed link is known, then based on the probability distribution function of the interference signal power affected by rainfall, superimpose the probability distributions of each of the external interference sources to calculate the probability distribution function of the aggregated interference signal power of the disturbed link.

2. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that Calculating the desynchronization aggregated interference protection limit, the long-term aggregated interference protection limit, and the short-term aggregated interference protection limit of the disturbed link according to the disturbed link margin includes: Determine the desynchronization interference ratio brought by the desynchronization from other co-frequency satellite communication systems to the desynchronization link margin, and the first percentage of the time allowed for the interference to exceed the desynchronization aggregated interference protection limit; and based on the desynchronization interference ratio and the first percentage of the time, calculate the desynchronization aggregated interference protection limit of the disturbed link; According to the operating characteristics of the disturbed link, determine the proportion of the disturbed link margin allocated to the long-term interference caused by other co-frequency satellite communication systems, and the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit value; and calculate the long-term aggregated interference protection limit value of the disturbed link based on the long-term interference proportion and the second time percentage. According to the operating characteristics of the disturbed link, determine the proportion of the disturbed link margin allocated to the short-term interference caused by other co-frequency satellite communication systems, and the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value; and calculate the short-term aggregated interference protection limit value of the disturbed link based on the short-term interference proportion and the third time percentage.

3. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, wherein After calculating the second single-link interference signal power probability distribution function considering rainfall impact based on the first single-link interference signal power probability distribution function and rainfall attenuation data, it further includes: If the external interference source is unknown, determine the number of external interference sources based on the ITU satellite network database. According to the number of external interference sources, the out-of-synchronization aggregated interference protection limit value, the long-term aggregated interference protection limit value, and the short-term aggregated interference protection limit value, calculate the corresponding out-of-synchronization single-link interference protection limit value, long-term single-link interference protection limit value, short-term single-link interference protection limit value, and the fourth time percentage allowing the short-term single-link interference signal power spectral density to exceed the protection threshold, respectively. Based on the second single-link interference signal power probability distribution function, calculate the complementary cumulative probability distribution of the second interference signal power, and compare the complementary cumulative probability distribution of the second interference signal power with the out-of-synchronization single-link interference protection limit value, the long-term single-link interference protection limit value, and the short-term single-link interference protection limit value respectively, and determine whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

4. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, wherein The calculation of the margin of the disturbed link in clear sky environment based on the key information parameters includes: Determine the bit error rate requirement of the satellite communication system in the disturbed link in the synchronized state and the signal-to-noise ratio required by the link under the bit error rate requirement. Calculate the received strength of the useful signal and the noise power of the disturbed link. Subtract the noise power from the received strength of the useful signal to obtain the actual signal-to-noise ratio; and subtract the required signal-to-noise ratio from the actual signal-to-noise ratio to obtain the margin of the disturbed link in clear sky environment.

5. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 2, wherein The out-of-synchronization aggregated interference protection limit value of the disturbed link is calculated based on the following formula: where q loss is the desynchronization interference ratio brought by the desynchronization link margin allocation of the disturbed link to other co-frequency satellite communication systems; P loss is the first time percentage allowing the interference to exceed the desynchronization total interference protection limit value; N0 is the noise power of the disturbed link; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

6. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 2, wherein The long-term aggregated interference protection limit value of the disturbed link is calculated based on the following formula: where q long is the long-term interference ratio caused by allocating the disturbed link margin to other co-frequency satellite communication systems; P long is the second time percentage allowing interference to exceed the long-term total interference protection limit; N0 is the noise power of the disturbed link; M is the disturbed link margin; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

7. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 2, wherein The short-term aggregated interference protection limit value of the disturbed link is calculated based on the following formula: where q short is the proportion of the short-term interference caused by allocating the disturbed link margin to other co-frequency satellite communication systems; P short is the third time percentage that allows the interference to exceed the short-term total interference protection limit value; N0 is the noise power of the disturbed link; M is the disturbed link margin; M min is the minimum link margin of the disturbed link under all bit error rate requirements.

8. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, wherein If measured rainfall attenuation data is available, the calculation of the second single-link interference signal power probability distribution function considering rainfall impact based on the first single-link interference signal power probability distribution function and rainfall attenuation data includes: Collect measured rainfall attenuation data. Based on the measured rainfall attenuation data, classify and statistically analyze the time according to the attenuation amount to obtain the frequency of different rainfall attenuation values. Normalize the frequency to generate the probability mass function of rainfall attenuation. Based on the probability mass function of the rainfall attenuation and the probability distribution function of the first single - quantity interference signal power, calculate the probability distribution function of the second single - quantity interference signal power affected by rainfall; Among them, the functional expression of the probability distribution function of the second single - quantity interference signal power affected by rainfall is: P A (a) = ∑ r P I (a + r) × P R (r); Among them, P I (i) is the probability mass function of the interference signal strength I, P R (r) is the probability mass function of the rainfall attenuation value R, and A represents the single interference signal power considering the influence of rainfall.

9. The method for accurately modeling and calculating the frequency interference between satellite communication systems according to claim 8, characterized in that, If the composition of the external interference sources of the disturbed link is known and satisfies the first condition, the first condition being that the interference sources are separated from each other by a distance exceeding a distance threshold and the rainfall attenuations are independent events, then calculating the probability distribution function of the lumped interference signal power of the disturbed link based on the probability distribution function of the second single - quantity interference signal power includes: Based on the probability distribution function of the second single - quantity interference signal power, calculate the interference signal power and its probability mass function of each external interference source under the influence of rainfall; Based on the interference signal powers of each external interference source, superimpose to obtain the lumped interference signal power of the disturbed link; By integrating the probability mass functions of each external interference source, calculate the probability mass function of the lumped interference signal power of the disturbed link; Based on the probability mass function of the lumped interference signal power, derive the probability distribution function of the lumped interference signal power of the disturbed link for evaluating whether the link is subject to harmful interference.

10. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 9, characterized in that, The lumped interference signal power of the disturbed link is calculated based on the following formula: where n is the number of known external interference sources; A i is the power of the i-th interference signal based on the influence of rainfall; The probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula: where P Ai is the probability mass function of the i-th external interference source based on the influence of rainfall.

11. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 8, characterized in that If the composition of the external interference sources of the disturbed link is known and satisfies the second condition, the second condition being that the interference sources are separated from each other by a distance not exceeding the distance threshold and the rainfall attenuations are the same or strongly correlated, then calculating the probability distribution function of the lumped interference signal power of the disturbed link based on the probability distribution function of the second single - quantity interference signal power includes: Based on the probability distribution function of the second single - quantity interference signal power, calculate the interference signal power of each of the external interference sources affected by rainfall; Calculate the joint probability of the respective interference signal powers; Based on the interference signal powers, calculate the lumped interference signal power of the disturbed link; Based on the joint probability and the lumped interference signal power, calculate the probability distribution function of the lumped interference signal power of the disturbed link.

12. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 11, wherein The joint probability of the respective interference signal powers is calculated based on the following formula: Among them, R is the rainfall attenuation value, and n is the number of known external interference sources; The lumped interference signal power of the disturbed link is calculated based on the following formula: where n is the number of known external interference sources; A i is the power of the i-th interference signal based on the impact of rainfall; The probability distribution function of the lumped interference signal power of the disturbed link is calculated based on the following formula: Among them, δ() is the Dirac delta function.

13. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that If there is no measured rainfall attenuation data, then based on the probability distribution function of the first single - quantity interference signal power and rainfall attenuation data, calculate the probability distribution function of the second single - quantity interference signal power considering rainfall influence, including: Obtain the probability density function of rainfall attenuation by approximating and fitting with a standard function; Based on the probability density function of the rainfall attenuation and the probability distribution function of the first single - quantity interference signal power, calculate the probability distribution function of the second single - quantity interference signal power affected by rainfall.

14. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 13, characterized in that, The functional expression of the probability distribution function of the second single - quantity interference signal power is: Among them, f I (i) is the probability density function of the interference signal strength I; f R (r) is the probability density function of the rainfall attenuation value R; A represents the power of a single interference signal considering the influence of rainfall.

15. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 14, wherein The expression of the probability density function of rainfall attenuation deduced based on the standard lognormal model is as follows: where R is the rainfall attenuation value, μ is the mean of the lognormal distribution, and σ is the standard deviation of the lognormal distribution.

16. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 13, wherein If the external interference sources of the disturbed link are known and satisfy the first condition, where the first condition is that the interference sources are separated from each other by a distance exceeding a distance threshold and the rainfall attenuations are independent events, then calculating the probability density function of the aggregated interference signal power of the disturbed link based on the probability density function of the second single-source interference signal power includes: Calculating, according to the probability density function of the second single-source interference signal power, the interference signal power of each external interference source based on the influence of rainfall and its probability density function; Converting the interference signal power of each external interference source into a linear power unit; Calculating, by superimposing the interference signal power and its probability density function of each external interference source, the probability density function of the aggregated interference signal power of the disturbed link; Converting the aggregated interference signal power from a linear power unit to a decibel unit and generating the probability density function of the aggregated interference signal power; Calculating the probability distribution function of the aggregated interference signal power of the disturbed link based on the probability density function of the aggregated interference signal power.

17. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 16, wherein The probability density function after linear conversion of the interference signal power is calculated based on the following formula: Among them, Ai is the decibel value of the interference signal power of the i-th external interference source based on the influence of rainfall; The probability density function of the aggregated interference signal is calculated based on the following formula: The probability distribution function of the aggregated interference signal power of the disturbed link is calculated based on the following formula: where A is the aggregated interference signal.

18. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 13, wherein If the external interference sources of the disturbed link are known and satisfy the second condition, where the second condition is that the interference sources are separated from each other by a distance not exceeding a distance threshold and the rainfall attenuations are the same or strongly correlated, then calculating the probability distribution function of the aggregated interference signal power of the disturbed link based on the probability density function of the second single-source interference signal power includes: Calculating, according to the probability density function of the second single-source interference signal power, the interference signal power of each external interference source based on the influence of rainfall; Calculating the aggregated interference signal power based on the interference signal power; Calculating the probability distribution function of the aggregated interference signal power of the disturbed link based on the aggregated interference signal power and a predefined joint probability density function; where the predefined joint probability density function is: f I1,I2,...,In,R (i1, i2, r) = f I1 (i1) × f I2 (i2) ×... f In (in) × f R (r); where R is the rainfall attenuation value and n is the number of known external interference sources.

19. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 18, wherein The aggregated interference signal power of the disturbed link is calculated based on the following formula: where n is the number of known external interference sources; A i is the power of the i-th interference signal based on the influence of rainfall; The probability distribution function of the aggregated interference signal power of the disturbed link is calculated based on the following formula: where δ() is the Dirac delta function.

20. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, wherein Calculating the corresponding out-of-sync single-source interference protection limit, long-term single-source interference protection limit, short-term single-source interference protection limit, and the fourth time percentage allowing the short-term single-source interference signal power spectrum density to exceed the protection threshold according to the number of external interference sources, the out-of-sync aggregated interference protection limit, the long-term aggregated interference protection limit, and the short-term aggregated interference protection limit, respectively, includes: Dividing the out-of-sync aggregated interference protection limit by the number of external interference sources to obtain the corresponding out-of-sync single-source interference protection limit; Divide the long-term aggregated interference protection limit value by the number of external interference sources to obtain the corresponding long-term single-source interference protection limit value; Based on the number of external interference sources and the short-term aggregated interference protection limit value, calculate the corresponding short-term single-source interference protection limit value and the fourth time percentage that allows the short-term single-source interference signal power spectral density to exceed the protection threshold.

21. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 20, characterized in that, The short-term single-source interference protection limit value is calculated based on the following formula: where n is the number of the external interference sources; P short-single is the fourth time percentage allowing the power spectral density of the short-term single amount interference signal to exceed the protection threshold; P short is the third time percentage allowing the interference to exceed the short-term aggregated interference protection limit value; P long is the second time percentage allowing the interference to exceed the long-term aggregated interference protection limit; δ is the proportion of the signal sources generating strong interference in the number of the external interference sources.

22. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, wherein After calculating the aggregated interference signal power probability distribution function of the disturbed link, it further includes: Calculate the first interference signal power complementary cumulative distribution based on the aggregated interference signal power probability distribution function; Compare the first interference signal power complementary cumulative distribution with the out-of-synchronization aggregated interference protection limit value, the long-term aggregated interference protection limit value, and the short-term aggregated interference protection limit value respectively; Based on the corresponding comparison results, determine whether the first interference signal power complementary cumulative distribution satisfies the out-of-synchronization aggregated interference protection limit value, the long-term aggregated interference protection limit value, and the short-term aggregated interference protection limit value; If so, determine that the disturbed link is not affected by harmful interference; otherwise, determine that the disturbed link is affected by harmful interference.

23. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, wherein The method of calculating the second interference signal power complementary cumulative distribution based on the second single-source interference signal power probability distribution function, and comparing the second interference signal power complementary cumulative distribution with the out-of-synchronization single-source interference protection limit value, the long-term single-source interference protection limit value, and the short-term single-source interference protection limit value respectively, and determining whether the disturbed link is affected by harmful interference based on the corresponding comparison results includes: Calculate the second interference signal power complementary cumulative distribution based on the second single-source interference signal power probability distribution function; Compare the second interference signal power complementary cumulative distribution with the out-of-synchronization single-source interference protection limit value, the long-term single-source interference protection limit value, and the short-term single-source interference protection limit value respectively; Based on the corresponding comparison results, determine whether the second interference signal power complementary cumulative distribution function satisfies the out-of-synchronization single-source interference protection limit value, the long-term single-source interference protection limit value, and the short-term single-source interference protection limit value; If so, determine that the disturbed link is not affected by harmful interference; otherwise, determine that the disturbed link is affected by harmful interference.

24. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, wherein It further includes: Based on the ITU satellite network database, determine the number and spectrum allocation information of potential interference sources; According to the number of potential interference sources and their spectrum allocation information, adjust the corresponding interference evaluation parameters in the calculation of the out-of-synchronization single-source interference protection limit value, the long-term single-source interference protection limit value, the short-term single-source interference protection limit value, and the fourth time percentage that allows the short-term single-source interference signal power spectral density to exceed the protection threshold.

25. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1 or 3, characterized in that, It further includes: If the current environment meets extreme meteorological conditions, use historical attenuation data or regional meteorological models to construct a third single-source interference signal power probability distribution function of extreme rainfall attenuation; Generate the total interference signal power distribution function in an extreme rainfall environment according to the first single - quantity interference signal power probability distribution function and the third single - quantity interference signal power probability distribution function; Based on the total interference signal power distribution function, recalculate and adjust the desynchronization aggregated interference protection limit, the long - term aggregated interference protection limit, and the short - term aggregated interference protection limit.

26. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 11 or 18, characterized in that, It further includes: Calculate the interference signal power and its total impact of each external interference source based on a joint probability model, where the joint probability model is used to describe the correlation between external interference sources; According to the spatial distribution characteristics of each external interference source and the correlation of its interference signals, adjust the probability distribution model of rainfall impact to generate an aggregated interference signal power probability distribution function with correlation correction; Based on the corrected aggregated interference signal power probability distribution function, re - evaluate whether the desynchronization aggregated interference protection limit, the long - term aggregated interference protection limit, and the short - term aggregated interference protection limit are satisfied.

27. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, wherein It further includes: Obtain the terrain height data between the satellite and the ground station; Adjust the path loss model according to the terrain height data to generate the interference signal power probability distribution including terrain occlusion factors; Calculate the interference protection limit for each terrain position according to the interference signal power probability distribution; Through the interference assessment of the current environmental terrain, select the interference protection limit corresponding to the terrain position to optimize the setting of the interference protection limit of the disturbed link.

28. An accurate modeling and calculation device for inter-frequency interference between satellite communication systems, characterized in that The device is used to implement the precise modeling and calculation method for frequency interference between satellite communication systems as described in any one of claims 1 to 27. The device includes: A parameter acquisition module, used to acquire key information parameters from the disturbed link. The key information parameters include link margin, signal - to - noise ratio threshold, bit error rate requirement, and parameters of antenna gain, transmit power, and path loss; A disturbed link margin calculation module, used to calculate the disturbed link margin in clear - sky conditions based on the data provided by the parameter acquisition module; An interference protection limit calculation module, used to calculate the desynchronization aggregated interference protection limit, the long - term aggregated interference protection limit, and the short - term aggregated interference protection limit according to the disturbed link margin; An interference signal power calculation module, used to calculate the single - quantity interference signal power probability distribution function in clear - sky conditions, the interference signal power probability distribution function considering rainfall impact, and the aggregated interference signal power probability distribution function; An interference determination module, used to compare the probability distribution function generated by the interference signal power calculation module with the limit value of the interference protection limit calculation module to determine whether the disturbed link is subject to harmful interference; A data storage module, used to store the parameter information, calculation results, and interference assessment data of each module; A display and output module, used to display the interference analysis result and output an interference analysis report including the determination result.

29. The satellite communication system - to - satellite frequency interference precise modeling and calculation device according to claim 28, wherein, The interference determination module is specifically used for: Calculate the first single - quantity interference signal power probability distribution function in clear - sky conditions; Based on the first single - quantity interference signal power probability distribution function and rainfall attenuation data, calculate the second single - quantity interference signal power probability distribution function considering rainfall impact; If the composition of the external interference sources of the disturbed link is known, calculate the probability distribution function of the total interference signal power of the disturbed link based on the probability distribution function of the second single-amount interference signal power; Calculate the complementary cumulative distribution function of the first interference signal power based on the probability distribution function of the total interference signal power, and then compare the complementary cumulative distribution function of the first interference signal power with the desynchronization total interference protection limit value, the long-term total interference protection limit value and the short-term total interference protection limit value, respectively, and determine whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

30. The satellite communication system inter-frequency interference precise modeling and calculation device according to claim 29, characterized in that, The interference determination module is further configured to: If the external interference sources are unknown, determine the number of external interference sources based on the ITU satellite network database; Calculate the corresponding desynchronization single-amount interference protection limit value, long-term single-amount interference protection limit value, short-term single-amount interference protection limit value and the percentage of the time that the power spectral density of the allowable short-term single-amount interference signal exceeds the protection threshold according to the number of external interference sources, the desynchronization total interference protection limit value, the long-term total interference protection limit value and the short-term total interference protection limit value, respectively; Calculate the complementary cumulative distribution function of the second interference signal power according to the probability distribution function of the second single-amount interference signal power, and compare the complementary cumulative distribution function of the second interference signal power with the desynchronization single-amount interference protection limit value, the long-term single-amount interference protection limit value and the short-term single-amount interference protection limit value, respectively, and determine whether the disturbed link is subject to harmful interference based on the corresponding comparison results.

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