Inter-satellite Communication And Ranging System Based On GMSK+PN And Its Applications In Satellite Cluster

In recent years,The formation flying of micro/nano-satellite clusters is widely concerned by aerospace industry all over the world.In this paper,technology for multi-satellite communication and ranging based on GMSK+PN modulation is proposed,which is aimed at inter-satellite communication and high precision ranging of micro-nano satellites whose volume,weight and power are strictly limited.Through this method,the urgent need for the communication and ranging of micro/nano-satellites in cluster formation can be solved.The main content of this papaer include:Algorithms for GMSK+PN modulation,GMSK+PN demodulation,PN separation,PN acquisition and PN tracking are investigated.After finishing the algorithm design of carrier synchronization,bit synchronization and loop filter,the influence of the PN code addition method,the modulation index and the loop filter bandwidth on the demodulation performance is analysised.Furtherly,the acquisition accuracy of PN under different SNR is analyzed.A relative positioning method between multi micro/nano-satellites based on inter-satellite communication and ranging is proposed.It solves the problem of fast and accurate measurement of cluster configuration.On this basis,the influence of ranging errors on positioning accuracy is further analyzed.Then,the shortest time for solving the cluster configuration based on this method is obtained in theory.Finally,the prototype for inter-satellite communication and ranging system is completed,The core algorithm for communication and ranging is experimentally verified,and the ranging function is realized.The results show that the principle of intersatellite communication and ranging technology based on GMSK+PN is correct and the performance is reasonable,and can be applied to the future micro/nano-satellite clusters.