Accurate modeling calculation method and device for frequency interference between satellite communication systems

Abstract

The invention provides a precise modeling calculation method for frequency interference between satellite communication systems, and the method comprises the steps: calculating the allowance of a disturbed link in a clear sky environment according to the key information parameters of a satellite communication system in the disturbed link; calculating an out-of-synchronization lumped interference protection limit value, a long-term lumped interference protection limit value and a short-term lumped interference protection limit value based on the disturbed link margin; calculating an interference signal power probability distribution function based on rainfall influence; and respectively comparing the interference signal power complementary cumulative probability distribution function with a protection limit value so as to determine whether the disturbed link is subjected to harmful interference or not based on a comparison result. The invention further provides a device for accurately modeling and calculating the frequency interference between the satellite communication systems. Therefore, the influence of out-of-synchronization, long-term and short-term interference can be effectively evaluated, and the probability distribution of interference signals can be accurately predicted.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular 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 technology, the number of satellites and communication needs around the world continue to increase, especially in geostationary orbit (GEO) and non-geostationary orbit (NGSO) satellite systems. Due to the overlap of frequency bands and the coexistence of satellite systems, frequency interference issues are becoming 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 tasks.

[0003] At present, traditional frequency interference calculation methods mainly rely on theoretical models and empirical formulas. Unreasonable assumptions usually lead to overestimation of interference signals, and it is difficult to fully consider the complex space environment, dynamically changing satellite orbit characteristics, and mutual interference 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, which are difficult to meet the high-precision interference analysis needs of modern satellite communication systems.

[0004] Therefore, there is an urgent need for a modeling method that can accurately calculate the frequency interference between satellite communication systems to solve the problem of insufficient accuracy in modeling and calculation of frequency interference between satellite communication systems. Especially when multiple satellite systems coexist and use the same or adjacent frequency bands, existing methods find it difficult to accurately assess 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, so as to overcome the limitations of the prior art in interference signal power prediction, interference protection limit calculation and interference evaluation under dynamically changing environments, thereby improving the operating stability of satellite communication systems and the efficiency of spectrum resource utilization.

[0006] In order to achieve the above object, on the one hand, the present invention provides a method for accurately modeling and calculating frequency interference between satellite communication systems, comprising the steps of:

[0007] Acquire key information parameters of the disturbed link, the key information parameters including the out-of-synchronization link margin, the bit error rate requirement in the synchronization state and the required signal-to-noise ratio of the link under the bit error rate requirement, and environmental parameters of antenna gain, transmit power and path loss;

[0008] Based on the key information parameters, the disturbed link margin in a clear sky environment is calculated, and the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are determined respectively, where:

[0009] The desynchronization aggregate interference protection limit is determined according to the desynchronization interference ratio and the percentage of time allowed for desynchronization, combined with the allocation of the disturbed link margin;

[0010] The long-term aggregate interference protection limit is determined according to the long-term interference ratio and the time percentage of allowed interference, combined with the disturbed link margin allocation;

[0011] The short-term aggregate interference protection limit is determined according to the short-term interference ratio and the time percentage of allowed interference, combined with the disturbed link margin allocation;

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

[0013] Based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data, calculating a second single-quantity interference signal power probability distribution function taking into account the influence of rainfall;

[0014] If the external interference source composition of the disturbed link is known, then based on the interference signal power probability distribution function affected by rainfall, the probability distribution of each external interference source is superimposed to calculate the aggregate interference signal power probability distribution function of the disturbed link.

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

[0016] Determine the proportion of out-of-synchronization interference caused by other co-frequency satellite communication systems to which the out-of-synchronization link margin is allocated, and the first time percentage for allowing interference to exceed the out-of-synchronization aggregate interference protection limit; and calculate the out-of-synchronization aggregate interference protection limit of the disturbed link based on the out-of-synchronization interference proportion and the first time percentage;

[0017] Determine, according to the operating characteristics of the disturbed link, the proportion of long-term interference from other co-frequency satellite communication systems to be allocated to the disturbed link margin, and a second time percentage during which interference is allowed to exceed a long-term aggregate interference protection limit; and calculate the long-term aggregate interference protection limit of the disturbed link based on the long-term interference proportion 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 aggregate interference protection limit; and based on the short-term interference proportion and the third time percentage, calculate the short-term aggregate interference protection limit of the disturbed link.

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

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

[0021] According to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit, respectively calculate the corresponding out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit and the fourth time percentage during which the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold;

[0022] 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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

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

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

[0025] Calculating the useful signal receiving strength and noise power of the disturbed link;

[0026] The actual signal-to-noise ratio is obtained by subtracting the noise power from the useful signal reception strength; and the required signal-to-noise ratio is subtracted from the actual signal-to-noise ratio to obtain the disturbed link margin in a clear sky environment.

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

[0028]

[0029] Among them, q lossP is the ratio of the desynchronization link margin of the disturbed link to the desynchronization interference caused by other co-frequency satellite communication systems; loss is the first time percentage that the interference is allowed to exceed the aggregate interference protection limit of desynchronization; 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 of the disturbed link is calculated based on the following formula:

[0031]

[0032] Among them, q long The ratio of the disturbed link margin to the long-term interference from other co-frequency satellite communication systems; long is the second time percentage for 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 of the disturbed link is calculated based on the following formula:

[0034]

[0035] Among them, q short The ratio of allocating the disturbed link margin to the short-term interference from other co-frequency satellite communication systems; short is the third time percentage for allowing interference to exceed the short-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.

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

[0037] If the interference signal comes from the geostationary satellite communication system, the interference signal power is calculated by subtracting the path transmission loss from the transmitting end equivalent radiated power and adding the gain of the receiving end antenna of the disturbed link in the direction of the interference link; the interference signal power is counted to obtain the first single quantity interference signal power probability distribution function in a clear sky environment;

[0038] If the interference signal comes from a non-geostationary satellite communication system, the spatial position probability distribution function of the interfering satellite in the visible airspace of the ground station of the disturbed link is calculated, and based on the spatial position probability distribution function and the antenna pointing direction of the satellite and the ground station and the link distance, the first single-quantity interference signal power probability distribution function in a clear sky environment is calculated.

[0039] Optionally, if measured rainfall attenuation data is available, the calculation of the second single-quantity interference signal power probability distribution function taking into account the influence of rainfall based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data includes:

[0040] Collect measured rain attenuation data;

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

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

[0043] Calculate a second single-quantity interference signal power probability distribution function based on rainfall influence according to the probability mass function of rainfall attenuation and the first single-quantity interference signal power probability distribution function;

[0044] The function expression of the second single-quantity interference signal power probability distribution function based on rainfall influence 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 strength I, 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.

[0047] Optionally, if the external interference source of the disturbed link is known and satisfies the first condition, the first condition being that the distance between the interference sources exceeds the distance threshold and the rainfall attenuation is an independent event, then based on the second single quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes:

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

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

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

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

[0052] Optionally, the aggregate 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 i-th interference signal power based on rainfall influence;

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

[0056]

[0057] Among them, P Ai is the probability mass function of the i-th external interference source based on the impact of rainfall.

[0058] Optionally, if the external interference source of the disturbed link is known and satisfies the second condition, the second condition being 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 second single amount interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes:

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

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

[0061] Calculating the aggregate interference signal power of the disturbed link according to the interference signal power;

[0062] According to the joint probability and the aggregate interference signal power, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated.

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

[0064]

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

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

[0067]

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

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

[0070]

[0071] where δ() is the Dirac delta function.

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

[0073] The probability density function of rainfall attenuation is obtained by approximate fitting based on the standard function;

[0074] A second single-quantity interference signal power probability distribution function based on rainfall influence is calculated according to the probability density function of rainfall attenuation and the first single-quantity interference signal power probability distribution function.

[0075] Optionally, the function expression of the second single-quantity interference signal power probability distribution function 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 single-quantity interference signal power considering the influence of rainfall.

[0078] Optionally, the probability density function of rainfall attenuation calculated based on the standard log-normal model is expressed as:

[0079]

[0080] 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.

[0081] Optionally, if the external interference source of the disturbed link is known and satisfies the first condition, the first condition being that the distance between the interference sources exceeds the distance threshold and the rainfall attenuation is an independent event, then based on the second single quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes:

[0082] According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power and probability density function of each external interference source based on the influence of rainfall;

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

[0084] By superimposing the interference signal power and probability density function of each external interference source, the probability density function of the aggregate interference signal power of the disturbed link is calculated;

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

[0086] Based on the probability density function of the aggregate interference signal power, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated.

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

[0088]

[0089] in, Ai is the decibel value of the interference signal power of the i-th external interference source due to the influence of rainfall; is the probability density function of power Ai;

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

[0091]

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

[0093]

[0094] Where A is the aggregate interference signal.

[0095] Optionally, if the external interference source of the disturbed link is known and satisfies the second condition, the second condition being 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 second single amount interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes:

[0096] According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power of each of the external interference sources based on the influence of rainfall;

[0097] Based on the interference signal power, calculating the aggregate interference signal power;

[0098] Based on the aggregate interference signal power and a predefined joint probability density function, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated;

[0099] 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] Where R is the rainfall attenuation value and n is the number of known external interference sources.

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

[0103]

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

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

[0106]

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

[0108] Optionally, according to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit, and the short-term aggregate interference protection limit, the corresponding out-of-synchronization single-amount interference protection limit, the long-term single-amount interference protection limit, the short-term single-amount interference protection limit, and the fourth time percentage during which the power spectral density of the short-term single-amount interference signal is allowed to exceed the protection threshold are calculated respectively, including:

[0109] Divide the out-of-synchronization aggregate interference protection limit by the number of external interference sources to obtain a corresponding out-of-synchronization single-quantity interference protection limit;

[0110] Dividing the long-term aggregate interference protection limit by the number of external interference sources to obtain a corresponding long-term single interference protection limit;

[0111] According to the number of external interference sources and the short-term aggregate interference protection limit, the corresponding short-term single-amount interference protection limit and the fourth time percentage during which the power spectrum density of the short-term single-amount interference signal is allowed to exceed the protection threshold are calculated.

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

[0113]

[0114] Wherein, n is the number of external interference sources; P short-single The fourth time percentage that allows the power spectral density of a short-term single-amount interference signal to exceed the protection threshold; P short is the third time percentage during which interference is allowed to exceed the short-term aggregate interference protection limit; δ is the ratio of signal sources generating stronger interference to the number of external interference sources.

[0115] Optionally, the calculation obtains the probability distribution function of the aggregate interference signal power of the disturbed link, and then further includes:

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

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

[0118] Based on the corresponding comparison results, it is determined whether the first interference signal power complementary cumulative probability distribution satisfies the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit;

[0119] 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.

[0120] Optionally, the second interference signal power complementary cumulative probability distribution is calculated according to the second single-amount interference signal power probability distribution function, and the second interference signal power complementary cumulative probability distribution is respectively compared with the out-of-synchronization single-amount interference protection limit, the long-term single-amount interference protection limit, and the short-term single-amount interference protection limit, and the disturbed link is determined based on the corresponding comparison results. Whether it is subject to harmful interference includes:

[0121] Calculate the complementary cumulative probability distribution of the second interference signal power according to the second single interference signal power probability distribution function;

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

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

[0124] 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.

[0125] Optionally, also include:

[0126] Determining the number of potential interference sources and spectrum allocation information based on the ITU satellite network database;

[0127] According to the number of potential interference sources and their spectrum allocation information, the corresponding interference assessment parameters are adjusted in the calculation of the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit, 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, also include:

[0129] If the current environment meets extreme meteorological conditions, the probability distribution function of the third single quantity interference signal power of extreme rainfall attenuation is constructed using historical attenuation data or regional meteorological models;

[0130] Generate a total interference signal power distribution function under 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, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are recalculated and adjusted.

[0132] Optionally, also include:

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

[0134] According to the spatial distribution characteristics of each external interference source and the correlation of its interference signals, the probability distribution model of rainfall impact is adjusted to generate the probability distribution function of the aggregate interference signal power including correlation correction;

[0135] Based on the corrected aggregate interference signal power probability distribution function, whether the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are met is re-evaluated.

[0136] Optionally, also include:

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

[0138] Adjusting the path loss model according to the terrain height data to generate an interference signal power probability distribution including terrain shielding factors;

[0139] Calculating the interference protection limit value at each terrain location according to the interference signal power probability distribution;

[0140] By evaluating the interference of the current environmental terrain, the interference protection limit value corresponding to the terrain position is selected to optimize the interference protection limit value setting of the disturbed link.

[0141] On the other hand, the present invention also provides a device for accurately modeling and calculating frequency interference between satellite communication systems, the device is used to implement the above-mentioned method for accurately modeling and calculating frequency interference between satellite communication systems, and the device includes:

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

[0143] A disturbed link margin calculation module, used 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 is used to calculate the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit according to the disturbed link margin;

[0145] Interference signal power calculation module, used to calculate the probability distribution function of single interference signal power in a clear sky environment, the probability distribution function of interference signal power based on the influence of rainfall, and the probability distribution function of aggregate interference signal power;

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

[0147] A data storage module is used to store parameter information, calculation results and interference assessment 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 judgment results.

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

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

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

[0152] If the external interference source composition of the disturbed link is known, then based on the second single interference signal power probability distribution function, the aggregate interference signal power probability distribution function of the disturbed link is calculated;

[0153] The first interference signal power complementary cumulative probability distribution is calculated according to the aggregate interference signal power probability distribution function, and then the first interference signal power complementary cumulative probability distribution is compared with the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

[0154] Optionally, the interference determination module is further used to:

[0155] If the external interference source is unknown, the number of external interference sources is determined based on the ITU satellite network database;

[0156] According to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit, respectively calculate the corresponding out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit and the percentage of time during which the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold;

[0157] 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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

[0158] The method for accurately modeling and calculating frequency interference between satellite communication systems described in the present invention is suitable for analyzing frequency interference between geostationary orbit and non-geostationary orbit satellite communication systems. By accurately calculating the power of interference signals and their probability distribution, the interference situation of communication links is evaluated, thereby providing technical support for interference coordination and optimization of satellite communication systems. It can effectively evaluate the impact of long-term and short-term interference, accurately predict the probability distribution of interference signals, and thereby provide support for frequency coordination, interference management and system optimization of satellite communication systems. It will greatly improve the operating efficiency and safety of satellite communication systems and reduce interference conflicts between communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0160] Figure 2 A flowchart showing the steps of calculating each aggregate interference protection limit in a specific implementation of the accurate modeling and calculation method for frequency interference between satellite communication systems provided by an embodiment of the present invention;

[0161] Figure 3 A schematic diagram showing a specific implementation flow 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 A 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 A schematic diagram of the probability distribution of a single interference signal power measured by a method provided by the prior art with rain attenuation measured data and considering the influence of rainfall is shown;

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

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

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

[0167] Fig. 9 A complementary cumulative probability distribution curve of the aggregate interference signal power measured in another specific application example of the accurate modeling and calculation method for frequency interference between satellite communication systems provided by an embodiment of the present invention is shown;

[0168] Figures 10-11 A schematic diagram showing interference impact determination in another specific application example of the method for accurate modeling and calculation of frequency interference between satellite communication systems provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0169] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 intended to limit the present invention.

[0170] It should be noted that references to "one embodiment", "embodiment", "example embodiment", etc. in this specification refer to the embodiment described, which 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. Furthermore, when describing specific features, structures or characteristics in conjunction with an embodiment, 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, certain words are used in the specification and subsequent claims to refer to specific components or parts. Those with ordinary knowledge in the relevant field should understand that manufacturers can use different nouns or terms to refer to the same component or part. This specification and subsequent claims do not use differences in names as a way to distinguish components or parts, but use differences in the functions of components or parts as the criteria for distinction. "Including" and "including" mentioned throughout the specification and subsequent claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the word "connected" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0172] Figure 1 A method for accurately modeling and calculating frequency interference between satellite communication systems provided by an embodiment of the present invention is shown. 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: Acquire key information parameters of the disturbed link, where the key information parameters include a desynchronized link margin, a bit error rate requirement in a synchronized state, a required signal-to-noise ratio of the link under the bit error rate requirement, and environmental parameters of antenna gain, transmit power, and path loss.

[0174] S102: Based on the key information parameters, the disturbed link margin in a clear sky environment is calculated, and the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit, and the short-term aggregate interference protection limit are determined respectively, where:

[0175] The desynchronization aggregate interference protection limit is determined according to the desynchronization interference ratio and the percentage of time allowed for desynchronization, combined with the allocation of the disturbed link margin;

[0176] The long-term aggregate interference protection limit is determined according to the long-term interference ratio and the time percentage of allowed interference, combined with the margin allocation of the disturbed link;

[0177] The short-term aggregate interference protection limit is determined according to the short-term interference ratio and the time percentage of allowed interference, combined with the margin allocation of the disturbed link.

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

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

[0180] In a specific implementation, the calculation of the disturbed link margin in a clear sky environment is based on the key information parameters, including: determining the bit error rate requirement of the satellite communication system in the disturbed link in a synchronized state and the required signal-to-noise ratio of the link under the bit error rate requirement; calculating the useful signal reception strength and noise power of the disturbed link; subtracting the noise power from the useful signal reception strength to obtain the actual signal-to-noise ratio; and subtracting the required signal-to-noise ratio from the actual signal-to-noise ratio to obtain the disturbed link margin in a clear sky environment. Among them, the required signal-to-noise ratio of the link under a specific bit error rate requirement can be determined by looking up a theoretical curve, an empirical formula or referring to relevant standards, and the unit is dB; the useful signal reception strength 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 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); this embodiment will be described in the subsequent description as M representing the disturbed link margin.

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

[0182] S111: Determine the proportion of out-of-synchronization interference caused by other co-frequency satellite communication systems to which the out-of-synchronization link margin is allocated, and the first time percentage during which the interference is allowed to exceed the out-of-synchronization aggregate interference protection limit; and calculate the out-of-synchronization aggregate interference protection limit of the disturbed link based on the out-of-synchronization interference proportion and the first time percentage; that is, determine the out-of-synchronization link margin M of the disturbed link loss The proportion of synchronization interference from other co-frequency satellite communication systems is allocated, and the first percentage of time that the interference is allowed to exceed the desynchronization aggregate interference protection limit.

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

[0184]

[0185] Among them, q loss P is the ratio of the desynchronization link margin of the disturbed link to the desynchronization interference caused by other co-frequency satellite communication systems; loss is the first time percentage that the interference is allowed to exceed the aggregate interference protection limit of desynchronization; N0 is the noise power of the disturbed link, in dBW; M min It is the minimum link margin of the disturbed link under all bit error rate requirements, in dB.

[0186] S112: According to the working characteristics of the disturbed link, determine the proportion of the disturbed link margin allocated to the long-term interference brought by other co-frequency satellite communication systems, and the second time percentage for allowing the interference to exceed the long-term aggregate interference protection limit; and calculate the long-term aggregate interference protection limit of the disturbed link based on the long-term interference proportion and the second time percentage; that is, the disturbed link determines, based on its own working characteristics, the proportion of the calculated link margin M allocated to the long-term interference brought by other co-frequency satellite communication systems, and the second time percentage for allowing the interference to exceed the long-term aggregate interference protection limit; and then calculates the long-term aggregate interference protection limit of the disturbed link based on the determined proportion and the second time percentage.

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

[0188]

[0189] Among them, q long The ratio of the disturbed link margin to the long-term interference from other co-frequency satellite communication systems; long is the second time percentage for 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.

[0190] S113: According to the working characteristics of the disturbed link, determine the proportion of the disturbed link margin allocated to the short-term interference from other co-frequency satellite communication systems, and the third time percentage of allowing interference to exceed the short-term aggregate interference protection limit; and calculate the short-term aggregate interference protection limit of the disturbed link based on the short-term interference proportion and the third time percentage. That is, the disturbed link determines the proportion of the calculated link margin M allocated to the short-term interference from other co-frequency satellite communication systems, and the third time percentage of allowing interference to exceed the short-term aggregate interference protection limit based on its own working characteristics; and then calculates the short-term aggregate interference protection limit of the disturbed link based on the determined proportion and the third time percentage.

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

[0192]

[0193] Among them, q short The ratio of allocating the disturbed link margin to the short-term interference from other co-frequency satellite communication systems; shortis the third time percentage for allowing interference to exceed the short-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.

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

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

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

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

[0198] S104: 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 taking into account the influence of rainfall; in specific implementation, first calculate the probability distribution function of rainfall attenuation, and then calculate the second single-quantity interference signal power probability distribution function taking into account the influence of rainfall based on the probability distribution function of rainfall attenuation and the first single-quantity interference signal power probability distribution function calculated in step S103.

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

[0200] The first method is applicable to the case where measured rain attenuation data can be obtained, and statistical analysis is performed directly based on the measured rain attenuation data; in this method, step S104 specifically includes: collecting measured rain attenuation data; based on the measured rain attenuation data, classifying and counting the time according to the attenuation amount to obtain the frequency of occurrence of different rain attenuation values; normalizing the frequency to generate a probability mass function of rain attenuation; according to the probability mass function of rain attenuation and the first single-quantity interference signal power probability distribution function, a second single-quantity interference signal power probability distribution function based on the influence of rain is calculated. Among them, the measured rain attenuation data can come from the long-term monitoring records of the ground station or other related measurement systems, which usually record the signal attenuation (unit: dB) under different rainfall conditions; then based on the collected measured data, classifying and counting the time according to the attenuation amount to obtain the frequency of occurrence of different attenuation values, and the probability mass function of rain attenuation can be generated by normalizing these data.

[0201] Further, in this embodiment, the variable I represents the first single-quantity interference signal power (unit: dBW) calculated in step S104, and A represents the single-quantity interference signal power based on the influence of rainfall (unit: dBW), that is, A=IR, and R is the attenuation value; when the first method with measured rainfall attenuation data calculates the second single-quantity interference signal power probability distribution function based on the influence of rainfall, since I and R are independent discrete random variables, the function expression of the second single-quantity interference signal power probability distribution function 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 strength I, 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. For this purpose, the probability density function of rainfall attenuation can be obtained by approximate fitting using a standard function.

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

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

[0207]

[0208] 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 single-quantity interference signal power considering the influence of rainfall.

[0209] Lognormal distribution is a common term used to describe the probability distribution model of rainfall attenuation. Assuming that the logarithm of the rainfall attenuation value R (unit: dB) obeys the normal distribution, the expression of the probability density function of rainfall attenuation calculated based on the standard lognormal model is:

[0210]

[0211] Where R is the rainfall attenuation value, μ is the mean of the log-normal distribution, and σ is the standard deviation of the log-normal distribution. When calculating specifically, the specific values ​​of the parameters μ and σ can be determined by referring to historical meteorological data and relevant standards to obtain the probability density function of the rainfall attenuation value R.

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

[0213] In the case where the composition of external interference sources has been mastered, for the scenario where there are multiple interference sources (the number of interference sources is denoted as n), Ii is used to represent the interference signal power (unit: dBW) of the i-th interference source reaching the disturbed link under a clear sky environment; Ri is used to represent the rainfall attenuation of the i-th interference link (unit: dB); Ai is used to represent the i-th interference signal power considering the influence of rainfall (unit: dBW), which can be denoted as Ai=Ii-Ri; A is used to represent the aggregate 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: (i.e., the interference sources are far away from each other, and the rain attenuation is a related independent event; (ii) the interference sources are close to each other, and the rain attenuation is the same or strongly correlated. In this regard, the corresponding conditions formed and satisfied by the external interference sources of the disturbed link are known (the first condition is that the distance between the interference sources exceeds the distance threshold and the rain 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 rain attenuation is the same or strongly correlated). This embodiment processes the situations where different conditions are satisfied as follows:

[0215] (i) If the interference sources are far away from each other, the impact of rainfall attenuation on the interference link is independent, so the single interference signal power considering the impact of rainfall calculated in step S104 is a correlated independent event (that is, when the first condition is met).

[0216] In this case, the analysis will be conducted based on whether or not there is actual rainfall attenuation data.

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

[0218] According to the second single-quantity interference signal power probability distribution function, the interference signal power of each external interference source based on the influence of rainfall and its probability mass function are calculated; based on the interference signal power of each external interference source, the aggregate interference signal power of the disturbed link is superimposed; according to the aggregate interference signal power probability mass function, the aggregate interference signal power probability distribution function of the disturbed link is derived for evaluating whether the link is subject to harmful interference.

[0219] Specifically, according to step S104, the interference signal power Ai and its probability mass function after each interference source is affected by rainfall are calculated, which is recorded as P Ai .

[0220] The aggregate interference signal power A is calculated according to the following formula, that is, the aggregate 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 i-th interference signal power based on rainfall influence;

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

[0224]

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

[0226] 2. If there is no actual rainfall attenuation data, the method for calculating the probability distribution function of the aggregate interference signal power of the disturbed link is as follows:

[0227] According to the second single-quantity interference signal power probability distribution function, the interference signal power and its probability density function of each external interference source based on the influence of rainfall are calculated; the interference signal power of each external interference source is converted into a linear power unit; by superimposing the interference signal power and its probability density function of each external interference source, the probability density function of the aggregate interference signal power of the disturbed link is calculated; the aggregate interference signal power is converted from a linear power unit to a decibel unit, and a probability density function of the aggregate interference signal power is generated; based on the probability density function of the aggregate interference signal power, the probability distribution function of the aggregate interference signal power of the disturbed link is calculated.

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

[0229]

[0230] Then convert Ai from dB units to linear power units, recorded as

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

[0232]

[0233] in, Ai is the interference signal power of the i-th external interference source due to the influence of rainfall.

[0234] The probability density function of the aggregate interference signal (linear power unit) is calculated according to the following formula: yes n times of convolution; that is, the probability density function of the aggregate interference signal is calculated based on the following formula:

[0235]

[0236] Then, the aggregate interference signal P is converted into 总(linear power unit) is converted into an aggregate interference signal A (dB), and the probability density function of A is calculated; that is, the probability distribution function of the aggregate 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 aggregate interference signal.

[0240] (ii) If the interference sources are close to each other, the rainfall attenuation experienced by different interference links is the same or strongly correlated, which results in a correlation between the interference signal powers after rainfall attenuation (i.e., when the second condition is met).

[0241] In this case, the analysis will be conducted based on whether or not there is actual rainfall attenuation data.

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

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

[0244] Specifically, assuming that the rain attenuation has the same effect on the interference links, the interference signal power Ai of each interference source affected by the rain is calculated according to the second single-quantity interference signal power probability distribution function of step S106.

[0245] The joint probability of each interference signal power is calculated. 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, the aggregate interference signal power A is calculated according to the following formula, that is, the aggregate 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 i-th interference signal power based on rainfall influence.

[0251] Furthermore, for each possible combination of (i1,i2,...,in,r), calculate the corresponding A value and joint probability P I1,I2,...,in,R (i1,i2,...,in,r), and then add the probabilities of the same A value to obtain the probability distribution of the aggregate interference signal power A, that is, the probability distribution function of the aggregate 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 the value of 1 when the expression in the brackets is zero and 0 otherwise.

[0254] 2. If there is no actual rainfall attenuation data, the method for calculating the probability distribution function of the aggregate interference signal power of the disturbed link is as follows:

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

[0256] 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 aggregate 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 i-th interference signal power based on rainfall influence;

[0262] The aggregate 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: the probability distribution function of the aggregate 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 the value of 1 when the expression in the brackets is zero and 0 otherwise.

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

[0268] For specific implementation, see Figure 1 , after step S105, further comprising:

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

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

[0271] S213: judging whether the complementary cumulative probability distribution of the first interference signal power satisfies the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit based on the corresponding comparison result;

[0272] S214: If yes, 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. That is, only when all three types of limit values ​​are met can it be determined that the disturbed link is not subjected to harmful interference, otherwise it can be determined that the disturbed link is subjected to harmful interference.

[0273] In another optional implementation of this embodiment, after step S104, the following further includes:

[0274] S106: If the external interference source is unknown, the number of external interference sources is determined based on the ITU satellite network database. That is, when the relevant information of the external interference source is unknown, the number of external interference sources can be determined by referring to the ITU satellite network database; and then the subsequent steps S107 to S108 are used to further analyze whether the disturbed link is subject to harmful interference.

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

[0276] Step S107 of this embodiment includes: dividing the out-of-synchronization aggregate interference protection limit by the number of external interference sources to obtain the corresponding out-of-synchronization single-quantity interference protection limit; dividing the long-term aggregate interference protection limit by the number of external interference sources to obtain the corresponding long-term single-quantity interference protection limit; and calculating the corresponding short-term single-quantity interference protection limit based on the number of external interference sources and the fourth time percentage during which the power spectral density of the short-term single-quantity interference signal is allowed to exceed the protection threshold.

[0277] Specifically, the number of external interference sources is determined based on the ITU satellite network database, denoted as n; the single-amount interference protection limit I for out-of-synchronization single (P loss ) is equal to the out-of-synchronization aggregate interference protection limit I0(P loss ) to the number of external interference sources n; long-term single-source interference protection limit I single (P long ) is equal to the long-term aggregate interference protection limit I0(P long ) to the number of external interference sources n.

[0278] Furthermore, the short-term single-volume interference protection limit is calculated based on the following formula:

[0279]

[0280] Wherein, n is the number of external interference sources; P short-single The fourth time percentage that allows the power spectral density of a short-term single-amount interference signal to exceed the protection threshold; P short is the third time percentage during which interference is allowed to exceed the short-term aggregate interference protection limit; δ is the ratio of signal sources generating stronger interference to the number of external interference sources.

[0281] S108: 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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

[0282] Specifically, step S108 includes: calculating the second interference signal power complementary cumulative probability distribution according to the second single-quantity interference signal power probability distribution function; comparing the second interference signal power complementary cumulative probability distribution with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively; judging whether the second interference signal power complementary cumulative probability distribution satisfies the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit based on the corresponding comparison results; 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.

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

[0284] In an optional implementation, in the interference impact assessment under extreme rainfall environment, this embodiment also includes: if the current environment meets extreme meteorological conditions, then use historical attenuation data or regional meteorological model to construct a third single interference signal power probability distribution function of extreme rainfall attenuation; generate a total interference signal power distribution function under extreme rainfall environment according to the first single interference signal power probability distribution function and the third single interference signal power probability distribution function; based on the total interference signal power distribution function, recalculate and adjust the desynchronization aggregate interference protection limit, long-term aggregate interference protection limit and short-term aggregate interference protection limit. That is, according to the total interference signal power distribution function under extreme rainfall environment, recalculate and adjust the interference protection limit to ensure the communication reliability under extreme environment.

[0285] In an optional implementation, for a situation where the distance between external interference sources is short and the effects of rainfall attenuation are strongly correlated, this embodiment also includes: calculating the interference signal power of each external interference source and its total impact based on a joint probability model, wherein the joint probability model is used to describe the correlation between external interference sources; adjusting the probability distribution model of rainfall effects according to the spatial distribution characteristics of each external interference source and the correlation of its interference signals, and generating an aggregate interference signal power probability distribution function including correlation correction; and re-evaluating whether the out-of-synchronization aggregate interference protection limit, long-term aggregate interference protection limit and short-term aggregate interference protection limit are met based on the corrected aggregate interference signal power probability distribution function.

[0286] In an optional implementation, when performing interference assessment based on the terrain features of the area where the ground station is located, this embodiment also includes: obtaining terrain height data between the satellite and the ground station; adjusting the path loss model according to the terrain height data to generate an interference signal power probability distribution including terrain shielding factors; calculating the interference protection limit of each terrain position according to the interference signal power probability distribution; through the interference assessment of the current environmental terrain, selecting the interference protection limit corresponding to the terrain position to optimize the interference protection limit setting of the disturbed link. That is, using the terrain height data between the satellite and the ground station, adjust the path loss model, generate an interference signal power probability distribution including terrain shielding factors; calculate the interference protection limit of different locations taking into account the terrain factors, and generate a terrain-related interference protection plan based on the calculation results; perform interference assessments in different terrains such as mountains and plains to optimize the interference protection limit setting 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 as follows: Figure 3 As shown in the figure, this method can effectively evaluate the interference situation of the communication link by accurately calculating the interference signal power and its probability distribution, thereby providing technical support for the interference coordination and optimization of the satellite communication system.

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

[0289] Example 1

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

[0291] The disturbed link 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, the link margin of the disturbed link is determined to be 8.2dB when the receiver phase-locked loop works in the critical state of desynchronization, and the bit error rate requirement when the link works in the synchronous 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 required signal-to-noise ratio of the link at this time is 7.5dB. Secondly, according to the equivalent radiated power of the transmitter (46.7dBW), path transmission loss (200.6dB), receiving antenna gain (40.4dBi), and noise power (-124dBW) when the GEO system works in the synchronous state, the received signal strength is calculated to be -112.2dBW, and the link margin is further calculated to be 3dB at this time.

[0293] The aggregate interference protection limit for loss of synchronization, long-term and short-term interference of the disturbed link is calculated as follows:

[0294] The disturbed link allocates 100% of the link margin to the interference that causes desynchronization, and the time percentage requirement is no more than 0.1%; in the link synchronization 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 embodiment of the present invention, the following can be calculated respectively: the total interference protection limit for desynchronization is -116.5dBW, and the time percentage requirement is 0.1%; the total interference protection limit for short-term interference is -128.9dBW, and the time percentage requirement is 1%; the total interference protection limit for long-term interference is -131.2dBW / Hz, and the time percentage requirement is 20%.

[0295] When the actual test results of rain attenuation are available, the probability distribution of the single-volume interference signal power considering the influence of rainfall is as follows: Figure 6As shown. 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 Figure 5 As shown, before the frequency interference precise modeling and calculation method proposed in the present invention is adopted, the interference signal is judged to exceed the protection threshold of the disturbed link. However, after considering the impact of the objective rainfall environment on the interference signal and refining the modeling and calculation, the interference signal meets the protection threshold.

[0296] When there is no actual test result of rain attenuation, it is assumed that the interference signal strength follows the offset log-normal distribution, the offset is -147dBW, the mean is 2, and the standard deviation is 0.5; the rain attenuation follows the log-normal distribution, the mean is 2, and the standard deviation is 1; the probability distribution of the single interference signal power considering the influence of rainfall is as follows Figure 8 As shown. 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 Figure 7 As shown, before the frequency interference precise modeling and calculation method proposed in the present invention is adopted, the interference signal is judged to exceed the protection threshold of the disturbed link. However, after considering the impact of the objective rainfall environment on the interference signal and refining the modeling and calculation, the interference signal meets the protection threshold.

[0297] This example 1 is based on the assumption that the external interference source is only composed of one NGSO satellite communication system. Since there is only one external interference, the aggregate interference signal power probability distribution is consistent with the second single interference signal power probability distribution function calculated in step S106.

[0298] As described above, the complementary cumulative probability distribution result of the first interference signal calculated in step S106 is compared with the three interference protection limits calculated in steps S102 to S104, and it is found that the traditional frequency interference calculation method causes the interference to be overestimated (exceeding the protection threshold). After adopting the precise modeling and calculation method for frequency interference between satellite communication systems provided in an embodiment of the present invention, all interference protection limits are met and the interference is effectively evaluated.

[0299] Example 2

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

[0301] The calculation method of the disturbed link margin M of the disturbed link in a clear sky environment and the aggregate interference protection limit of loss of synchronization, long-term and short-term interference is the same as that of Example 1 above, and will not be repeated here.

[0302] Based on the assumption, it is determined that the external interference source is composed of two NGSO satellite communication systems. The probability distribution of the aggregate interference signal power is as follows: Fig. 9 As shown, 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 aggregate interference signal power.

[0303] See also Figure 10-11 , the calculated complementary cumulative probability distribution result of the first interference signal is compared with the three interference protection limits calculated by steps S102 to S104, and it is found that the aggregate interference signal power meets the aggregate interference protection limit of the long-term and short-term interference of the disturbed link, but exceeds the aggregate interference protection limit of the loss of synchronization, so it is determined that the disturbed link is subjected to harmful interference.

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

[0305] Figure 4Another embodiment of the present invention provides an apparatus for accurately modeling and calculating frequency interference between satellite communication systems. The apparatus is used to implement the accurate modeling and calculating method for frequency interference between satellite communication systems as described in the above 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, wherein:

[0306] The parameter acquisition module 10 is used to obtain key information parameters from the disturbed link, and the key information parameters include link margin, signal-to-noise ratio threshold, bit error rate requirement, and parameters of antenna gain, transmission 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, the long-term aggregate interference protection limit and the 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-volume interference signal power in a clear sky environment, the probability distribution function of the interference signal power based on the influence of rainfall, and the probability distribution function of the aggregate interference signal power; the interference judgment module 50 is used to compare the probability distribution function generated by the interference signal power calculation module 40 with the limit of the interference protection limit calculation module to determine whether the disturbed link is subject to harmful interference; the data storage module 60 is used to store the parameter information, calculation results and interference assessment data of each module; the display and output module 70 is used to display the interference analysis results and output the interference analysis report containing the judgment results.

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

[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; the 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 the aggregate and single-quantity loss of synchronization, long-term and short-term interference protection limits; the 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 a single interference signal power under a clear sky environment based on the data provided by the parameter acquisition module 10, and further calculates the probability distribution of a single interference signal power considering the influence of rainfall, and calculates the probability distribution of the aggregate interference signal power based on the composition of the external interference source; the module includes a rainfall attenuation calculation unit, an interference source composition analysis unit, a single interference signal power calculation unit and an aggregate 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 value calculation module 30, determines whether there is a harmful interference signal, and provides an interference determination result.

[0312] The data storage module 60 is used to store data such as satellite communication system parameter information, disturbed link margin calculation results, various interference protection limits, rainfall attenuation probability distribution, interference source composition, interference signal power distribution and interference determination results, so as to facilitate calling and analysis by other modules.

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

[0314] Furthermore, the interference determination module 50 is specifically used to: calculate a first single-quantity interference signal power probability distribution function under a clear sky environment; calculate a second single-quantity interference signal power probability distribution function taking into account the influence of rainfall based on the first single-quantity interference signal power probability distribution function and rainfall attenuation data; if the external interference source composition of the disturbed link is known, then based on the second single-quantity interference signal power probability distribution function, calculate the aggregate interference signal power probability distribution function of the disturbed link; calculate the first interference signal power complementary cumulative probability distribution according to the aggregate interference signal power probability distribution function, and then compare the first interference signal power complementary cumulative probability distribution with the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit, and determine 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 source is unknown, determining the number of external interference sources based on the ITU satellite network database; calculating the corresponding out-of-synchronization single-quantity interference protection limit, long-term single-quantity interference protection limit, short-term single-quantity interference protection limit and the percentage of time that the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold according to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit;

[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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

[0317] The above modules work together to complete the accurate modeling and calculation of frequency interference between satellite communication systems; the specific calculation and analysis process refers to the method described in the above embodiment and will not be repeated 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 suitable for analyzing the frequency interference between geostationary orbit and non-geostationary orbit satellite communication systems. By accurately calculating the power of interference signals and their probability distribution, the interference situation of communication links is evaluated, thereby providing technical support for interference coordination and optimization of satellite communication systems. It can effectively evaluate the impact of long-term and short-term interference, accurately predict the probability distribution of interference signals, and thereby provide support for frequency coordination, interference management and system optimization of satellite communication systems. It will greatly improve the operating efficiency and safety of satellite communication systems and reduce interference conflicts between communication systems.

[0319] The method according to the present invention can be implemented on a computer as a computer-implemented method, or implemented in dedicated hardware, or implemented in a combination of the two. The executable code or part thereof for the method according to the present invention can be stored on a computer program product. The example of a computer program product includes a memory device, an optical storage device, an integrated circuit, a server, online software, etc. Preferably, the computer program product includes a non-temporary program code component stored on a computer-readable medium so as to perform the method according to the present invention when the program product is executed on a computer.

[0320] In a preferred embodiment, the computer program comprises computer program code means adapted to perform all the steps of the method according to the invention when the computer program is run on a computer.Preferably, the computer program is embodied on a computer readable medium.

[0321] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for accurately modeling and calculating frequency interference between satellite communication systems, characterized in that: Includes steps: Acquire key information parameters of the disturbed link, the key information parameters including the out-of-synchronization link margin, the bit error rate requirement in the synchronization state and the required signal-to-noise ratio of the link under the bit error rate requirement, and environmental parameters of antenna gain, transmit power and path loss; Based on the key information parameters, the disturbed link margin in a clear sky environment is calculated, and the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are determined respectively, where: The desynchronization aggregate interference protection limit is determined according to the desynchronization interference ratio and the percentage of time allowed for desynchronization, combined with the allocation of the disturbed link margin; The long-term aggregate interference protection limit is determined according to the long-term interference ratio and the time percentage of allowed interference, combined with the disturbed link margin allocation; The short-term aggregate interference protection limit is determined according to the short-term interference ratio and the time percentage of allowed interference, combined with the disturbed link margin allocation; Calculate the probability distribution function of the first single interference signal power in a clear sky environment; Based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data, calculating a second single-quantity interference signal power probability distribution function taking into account the influence of rainfall; If the external interference source composition of the disturbed link is known, then based on the interference signal power probability distribution function affected by rainfall, the probability distribution of each external interference source is superimposed to calculate the aggregate interference signal power probability distribution function 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 out-of-synchronization aggregate interference protection limit value, the long-term aggregate interference protection limit value, and the short-term aggregate interference protection limit value of the disturbed link according to the disturbed link margin includes: Determine the proportion of out-of-synchronization interference caused by other co-frequency satellite communication systems to which the out-of-synchronization link margin is allocated, and the first time percentage for allowing interference to exceed the out-of-synchronization aggregate interference protection limit; and calculate the out-of-synchronization aggregate interference protection limit of the disturbed link based on the out-of-synchronization interference proportion and the first time percentage; Determine, according to the operating characteristics of the disturbed link, the proportion of long-term interference from other co-frequency satellite communication systems to be allocated to the disturbed link margin, and a second time percentage during which interference is allowed to exceed a long-term aggregate interference protection limit; and calculate the long-term aggregate interference protection limit 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 aggregate interference protection limit; and based on the short-term interference proportion and the third time percentage, calculate the short-term aggregate interference protection limit of the disturbed link.

3. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: After calculating the second single-quantity interference signal power probability distribution function taking into account the influence of rainfall based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data, the method further includes: If the external interference source is unknown, the number of external interference sources is determined based on the ITU satellite network database; According to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit, respectively calculate the corresponding out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit and the fourth time percentage during which the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold; 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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

4. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: The calculating, based on the key information parameters, the disturbed link margin in a clear sky environment includes: Determine the bit error rate requirement of the satellite communication system in the disturbed link in a synchronized state and the required signal-to-noise ratio of the link under the bit error rate requirement; Calculating the useful signal receiving strength and noise power of the disturbed link; The actual signal-to-noise ratio is obtained by subtracting the noise power from the useful signal reception strength; and the required signal-to-noise ratio is subtracted from the actual signal-to-noise ratio to obtain the disturbed link margin in a clear sky environment.

5. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 2, characterized in that: The aggregate interference protection limit of the loss of synchronization of the disturbed link is calculated based on the following formula: Among them, q loss P is the ratio of the desynchronization link margin of the disturbed link to the desynchronization interference caused by other co-frequency satellite communication systems; loss is the first time percentage that the interference is allowed to exceed the aggregate interference protection limit of desynchronization; 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, characterized in that: The long-term aggregate interference protection limit of the disturbed link is calculated based on the following formula: Among them, q long The ratio of the disturbed link margin to the long-term interference from other co-frequency satellite communication systems; long is the second time percentage for 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.

7. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 2, characterized in that: The short-term aggregate interference protection limit of the disturbed link is calculated based on the following formula: Among them, q short The ratio of allocating the disturbed link margin to the short-term interference from other co-frequency satellite communication systems; short is the third time percentage for allowing interference to exceed the short-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.

8. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: The calculating of the first single-quantity interference signal power probability distribution function in a clear sky environment comprises: If the interference signal comes from the geostationary satellite communication system, the interference signal power is calculated by subtracting the path transmission loss from the transmitting end equivalent radiated power and adding the gain of the receiving end antenna of the disturbed link in the direction of the interference link; the interference signal power is counted to obtain the first single quantity interference signal power probability distribution function in a clear sky environment; If the interference signal comes from a non-geostationary satellite communication system, the spatial position probability distribution function of the interfering satellite in the visible airspace of the ground station of the disturbed link is calculated, and based on the spatial position probability distribution function and the antenna pointing direction of the satellite and the ground station and the link distance, the first single-quantity interference signal power probability distribution function in a clear sky environment is calculated.

9. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: If measured rainfall attenuation data is available, the calculation of a second single-quantity interference signal power probability distribution function taking into account the influence of rainfall based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data includes: Collect measured rain attenuation data; Based on the measured rain attenuation data, classify and count the time according to the attenuation amount to obtain the frequency of occurrence of different rainfall attenuation values; Normalizing the frequency to generate a probability mass function of rainfall attenuation; Calculate a second single-quantity interference signal power probability distribution function based on rainfall influence according to the probability mass function of rainfall attenuation and the first single-quantity interference signal power probability distribution function; The function expression of the second single-quantity interference signal power probability distribution function based on rainfall influence 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-quantity interference signal power considering the influence of rainfall.

10. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 9, characterized in that: If the external interference source composition of the disturbed link is known and satisfies the first condition, the first condition being that the distance between the interference sources exceeds a distance threshold and the rainfall attenuation are independent events, then based on the second single-quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes: According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power and probability mass function of each external interference source under the influence of rainfall; Based on the interference signal power of each external interference source, the aggregate interference signal power of the interfered link is obtained by superposition; By integrating the probability mass function of each external interference source, the probability mass function of the aggregate interference signal power of the disturbed link is calculated; According to the aggregate interference signal power probability mass function, an aggregate interference signal power probability distribution function of the disturbed link is derived for evaluating whether the link is subject to harmful interference.

11. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 10, characterized in that: The aggregate 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 i-th interference signal power based on rainfall influence; The probability distribution function of the aggregate interference signal power of the disturbed link is calculated based on the following formula: Among them, P Ai is the probability mass function of the i-th external interference source based on the impact of rainfall.

12. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 9, characterized in that: If the external interference source composition of the disturbed link is known and satisfies the second condition, where 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 second single-quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes: According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power of each of the external interference sources based on the influence of rainfall; Calculating the joint probability of each of the interference signal powers; Calculating the aggregate interference signal power of the disturbed link according to the interference signal power; According to the joint probability and the aggregate interference signal power, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated.

13. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 12, characterized in that: The joint probability of each of the interference signal powers is calculated based on the following formula: Where R is the rainfall attenuation value, and n is the number of known external interference sources; The aggregate 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 i-th interference signal power based on rainfall influence; The probability distribution function of the aggregate interference signal power of the disturbed link is calculated based on the following formula: where δ() is the Dirac delta function.

14. 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 first single-quantity interference signal power probability distribution function and the rainfall attenuation data, a second single-quantity interference signal power probability distribution function considering the influence of rainfall is calculated, including: The probability density function of rainfall attenuation is obtained by approximate fitting based on the standard function; A second single-quantity interference signal power probability distribution function based on rainfall influence is calculated according to the probability density function of rainfall attenuation and the first single-quantity interference signal power probability distribution function.

15. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 14, characterized in that: The function expression of the second single interference signal power probability distribution function 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 single-quantity interference signal power considering the influence of rainfall.

16. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 15, characterized in that: The probability density function expression of rainfall attenuation calculated based on the standard log-normal model is: 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.

17. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 14, characterized in that: If the external interference source composition of the disturbed link is known and satisfies the first condition, the first condition being that the distance between the interference sources exceeds a distance threshold and the rainfall attenuation are independent events, then based on the second single-quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes: According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power and probability density function of each external interference source based on the influence of rainfall; Converting the interference signal power of each external interference source into a linear power unit; By superimposing the interference signal power and probability density function of each external interference source, the probability density function of the aggregate interference signal power of the disturbed link is calculated; Converting the aggregate interference signal power from a linear power unit to a decibel unit, and generating a probability density function of the aggregate interference signal power; Based on the probability density function of the aggregate interference signal power, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated.

18. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 17, characterized in that: The probability density function of the interference signal power after linear conversion is calculated based on the following formula: in, Ai is the decibel value of the interference signal power of the i-th external interference source due to the influence of rainfall; f Ai (ai) is the probability density function of power Ai; The probability density function of the aggregate interference signal is calculated based on the following formula: The probability distribution function of the aggregate interference signal power of the disturbed link is calculated based on the following formula: Where A is the aggregate interference signal.

19. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 14, characterized in that: If the external interference source composition of the disturbed link is known and satisfies the second condition, where 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 second single-quantity interference signal power probability distribution function, calculating the aggregate interference signal power probability distribution function of the disturbed link includes: According to the second single-quantity interference signal power probability distribution function, calculate the interference signal power of each of the external interference sources based on the influence of rainfall; Based on the interference signal power, calculating the aggregate interference signal power; Based on the aggregate interference signal power and a predefined joint probability density function, a probability distribution function of the aggregate interference signal power of the disturbed link is calculated; 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.

20. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 19, characterized in that: The aggregate 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 i-th interference signal power based on rainfall influence; The probability distribution function of the aggregate interference signal power of the disturbed link is calculated based on the following formula: where δ() is the Dirac delta function.

21. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, characterized in that: According to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit, and the short-term aggregate interference protection limit, the corresponding out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit, and the fourth time percentage during which the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold are calculated respectively, including: Divide the out-of-synchronization aggregate interference protection limit by the number of external interference sources to obtain a corresponding out-of-synchronization single-quantity interference protection limit; Dividing the long-term aggregate interference protection limit by the number of external interference sources to obtain a corresponding long-term single interference protection limit; According to the number of external interference sources and the short-term aggregate interference protection limit, the corresponding short-term single-amount interference protection limit and the fourth time percentage during which the power spectrum density of the short-term single-amount interference signal is allowed to exceed the protection threshold are calculated.

22. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 21, characterized in that: The short-term single-volume interference protection limit is calculated based on the following formula: Wherein, n is the number of external interference sources; P short-single The fourth time percentage that allows the power spectral density of a short-term single-amount interference signal to exceed the protection threshold; P short is the third time percentage during which interference is allowed to exceed the short-term aggregate interference protection limit; δ is the ratio of signal sources generating stronger interference to the number of external interference sources.

23. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: The calculation obtains the probability distribution function of the aggregate interference signal power of the disturbed link, and then further includes: Calculate the complementary cumulative probability distribution of the first interference signal power according to the aggregate interference signal power probability distribution function; Compare the first interference signal power complementary cumulative probability distribution with the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit respectively; Based on the corresponding comparison results, it is determined whether the first interference signal power complementary cumulative probability distribution satisfies the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit; 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.

24. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, characterized in that: The step of calculating the second interference signal power complementary cumulative probability distribution according to the second single-amount interference signal power probability distribution function, and comparing the second interference signal power complementary cumulative probability distribution with the out-of-synchronization single-amount interference protection limit, the long-term single-amount interference protection limit, and the short-term single-amount interference protection limit, respectively, and determining whether the disturbed link is subject to harmful interference based on the corresponding comparison results, including: Calculate the complementary cumulative probability distribution of the second interference signal power according to the second single interference signal power probability distribution function; Compare the second interference signal power complementary cumulative probability distribution with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, and the short-term single-quantity interference protection limit respectively; Based on the corresponding comparison results, it is determined whether the second interference signal power complementary cumulative probability distribution function satisfies the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, and the short-term single-quantity interference protection limit; 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.

25. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 3, characterized in that: Also includes: Determining the number of potential interference sources and spectrum allocation information based on the ITU satellite network database; According to the number of potential interference sources and their spectrum allocation information, the corresponding interference assessment parameters are adjusted in the calculation of the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit, and the fourth time percentage allowing the power spectral density of the short-term single-quantity interference signal to exceed the protection threshold.

26. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1 or 3, characterized in that: Also includes: If the current environment meets extreme meteorological conditions, the probability distribution function of the third single quantity interference signal power of extreme rainfall attenuation is constructed using historical attenuation data or regional meteorological models; Generate a total interference signal power distribution function under 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, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are recalculated and adjusted.

27. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 12 or 19, characterized in that: Also includes: Calculating the interference signal power of each external interference source and its total impact based on a joint probability model, wherein the joint probability model is used to describe the correlation between the external interference sources; According to the spatial distribution characteristics of each external interference source and the correlation of its interference signals, the probability distribution model of rainfall impact is adjusted to generate the probability distribution function of the aggregate interference signal power including correlation correction; Based on the corrected aggregate interference signal power probability distribution function, re-evaluate whether the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit are met.

28. The method for accurately modeling and calculating frequency interference between satellite communication systems according to claim 1, characterized in that: Also includes: Obtain terrain height data between satellite and ground station; Adjusting the path loss model according to the terrain height data to generate an interference signal power probability distribution including terrain shielding factors; Calculating the interference protection limit value at each terrain location according to the interference signal power probability distribution; By evaluating the interference of the current environmental terrain, the interference protection limit value corresponding to the terrain position is selected to optimize the interference protection limit value setting of the disturbed link.

29. An accurate modeling and calculation device for frequency interference between satellite communication systems, characterized in that: The device is used to implement the accurate modeling and calculation method for frequency interference between satellite communication systems as claimed in any one of claims 1 to 28, and the device comprises: A parameter acquisition module, used to acquire key information parameters from the disturbed link, wherein the key information parameters include link margin, signal-to-noise ratio threshold, bit error rate requirement, and antenna gain, transmit power, and path loss parameters; A disturbed link margin calculation module, used to calculate the disturbed link margin in a clear sky environment based on the data provided by the parameter acquisition module; An interference protection limit calculation module is used to calculate the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit according to the disturbed link margin; Interference signal power calculation module, used to calculate the probability distribution function of single interference signal power in a clear sky environment, the probability distribution function of interference signal power based on the influence of rainfall, and the probability distribution function of aggregate interference signal power; An interference determination module, configured to compare the probability distribution function generated by the interference signal power calculation module with the limit value of the interference protection limit value calculation module to determine whether the disturbed link is subject to harmful interference; A data storage module is used to store parameter information, calculation results and interference assessment data of each module; The display and output module is used to display the interference analysis results and output an interference analysis report containing the judgment results.

30. The device for accurately modeling and calculating frequency interference between satellite communication systems according to claim 29, characterized in that: The interference determination module is specifically used for: Calculate the probability distribution function of the first single interference signal power in a clear sky environment; Based on the first single-quantity interference signal power probability distribution function and the rainfall attenuation data, calculating a second single-quantity interference signal power probability distribution function taking into account the influence of rainfall; If the external interference source composition of the disturbed link is known, then based on the second single interference signal power probability distribution function, the aggregate interference signal power probability distribution function of the disturbed link is calculated; The first interference signal power complementary cumulative probability distribution is calculated according to the aggregate interference signal power probability distribution function, and then the first interference signal power complementary cumulative probability distribution is compared with the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

31. The device for accurately modeling and calculating frequency interference between satellite communication systems according to claim 30, characterized in that: The interference determination module is also used for: If the external interference source is unknown, the number of external interference sources is determined based on the ITU satellite network database; According to the number of external interference sources, the out-of-synchronization aggregate interference protection limit, the long-term aggregate interference protection limit and the short-term aggregate interference protection limit, respectively calculate the corresponding out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit, the short-term single-quantity interference protection limit and the percentage of time during which the power spectrum density of the short-term single-quantity interference signal is allowed to exceed the protection threshold; 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 compared with the out-of-synchronization single-quantity interference protection limit, the long-term single-quantity interference protection limit and the short-term single-quantity interference protection limit respectively, and based on the corresponding comparison results, it is determined whether the disturbed link is subject to harmful interference.

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