Research And Analysis Of Links In Non-geostationary Orbit Satellite Constellation Systems

With the rapid development of satellite constellation systems,the number of satellites launched into orbit each year has increased exponentially,and the demand for space frequency orbit resources has increased sharply.Due to the limited space frequency orbit resources,satellite communication networks are about to face a serious shortage of spectrum resources under the wave of global constellation Internet development.With the increase in the number of new non-geostationary orbit(Non Geo Stationary Orbit,NGSO)satellites,spectrum overlap with other satellite systems in orbit has become the norm.If the problem of spectrum overlap between constellation systems cannot be effectively solved,it may cause serious mutual interference between satellites of the same frequency.Due to the large number of NGSO satellites and their relatively time-varying characteristics,it greatly increases the difficulty of interference and coordination.Therefore,interference analysis and avoidance coordination of large-scale broadband NGSO satellite constellation system is the current focus of NGSO satellite constellation system research.By studying the characteristics of the constellation system and the link transmission theory,this paper proposes an interference evaluation scheme suitable for large-scale NGSO satellite constellation systems.First establish the satellite-ground link rainfall attenuation model,and combine the rainfall area range,satellite and rain area moving speed and direction to predict and analyze the rainfall attenuation,and verify it based on the rainfall rate and rainfall attenuation measured data;then the constellation system Research and analyze the characteristics of inter-link interference,establish corresponding interference mathematical models according to the link interference scenarios between different constellation systems,and calculate and analyze the probability of harmful interference between constellation systems at different locations on a global scale,in order to avoid collinear or quasi-common interference.Line interference causes the deterioration of the satellite communication link.According to the interference evaluation criteria,the space isolation angle is added to avoid harmful interference.Finally,the satellite simulation toolkit(Satellite Tool Kit,STK)is used to construct the interference simulation scene to verify the interference mathematical model,interference evaluation method and interference The feasibility and rationality of the evasion plan.The simulation results show that this scheme is suitable for large-scale NGSO satellite systems,and provides a theoretical reference for NGSO constellation system interference and coordination analysis.