LEO And GEO Spectrum Sharing Method Based On Interference Control

With the rapid development of global informatization,people's demand for high-quality,high-speed communication services is becoming more and more significant.Due to the limitations of terrestrial cellular communications,users in remote areas cannot receive services.Satellite communications can be used as a supplement to terrestrial communications to provide services for users due to its long communications distance and stable communications quality.Low earth orbit(LEO)satellites have low orbital heights and small communications delays.Compared with geostationary orbit(GEO)satellites are more suitable for the transmission of voice and data services.The coverage of LEO satellites is small and requires large-scale networking.With the continuous increase in the number of satellites in space,the problem of the shortage of spectrum resources in space has become increasingly serious,and the shortage of spectrum resources has restricted the development of satellite communications.This paper studies the spectrum sharing of LEO satellites and GEO satellites,solving the problem of spectrum scarcity and improving spectrum efficiency.However,the LEO and GEO spectrum sharing has the problem of co-channel interference,which causes the communication quality of LEO satellites and GEO satellites to decline.Therefore,studying a spectrum sharing method of LEO and GEO satellites based on interference control is a hot spot of current research.This paper first sorts out the research status of LEO and GEO spectrum sharing and analyzes the current main research directions,advantages and disadvantages of LEO and GEO spectrum sharing.Establish an interference model in the inter-satellite spectrum sharing scenario,analyze the uplink and down link co-frequency interference during spectrum sharing,and the analysis results show that the main influencing factors of interference are antenna gain and free space loss.Based on interference analysis,a static spectrum sharing method that relies on th e isolation angle of the ground station is studied.When the satellite enters the isolation area,a part of the beam is closed to achieve spectrum sharing.Static spectrum sharing has the problem of large throughput loss.A beam-hopping beam-hopping spectrum sharing method based on interference avoidance is further proposed.LEO satellites use beam-hopping beam load to achieve time-domain interference avoidance by optimizing the beam-hopping pattern.After that,this paper proposes a joint optimization algorithm for LEO and GEO power based on interference control.Combined with the idea of power control,the LEO multi-beam power control algorithm is first proposed.The second transformation method in fractional programming is used to convert the optimization problem into a solvable convex optimization problem while introducing the idea of spatially isolated isolation regions to reduce the complexity of the algorithm.Given the large performance loss of LEO multi-beam power control algorithm LEO system,a joint optimization algorithm of LEO and GEO is proposed to jointly optimize the beam transmission power of LEO and GEO.On the premise of ensuring the quality of GEO satellite communication,improve the system capacity and system spectrum efficiency,and realize the spectrum sharing between LEO and GEO.