GEO与LEO间激光通信轨道特性仿真

为了优化GEO与LEO间激光通信系统的性能，建立了卫星通信轨道特性仿真模型。通过对一年内卫星数据的分析可知，卫星通信终端间的多普勒频移变化范围约为5109 Hz，可以使用多普勒频移补偿方法减少GEO与LEO之间的多普勒频移影响。对于相干通信，终端必须进行频移补偿；提前量角的范围大于激光束散角，因此终端需要进行提前量补偿，激光通信系统可根据提前量角对视轴进行提前修正，以减少相对速度对激光通信的影响；太阳干扰和地球遮挡的时间较长，应该进行卫星组网以改善可通率，在通信过程中应根据通信终端时间，优化两个通信终端的工作流程；GEO和LEO终端的视轴变化情况不同，因此应该为卫星设计不同结构。

Simulation of orbit characteristic between GEO and LEO laser communication

In order to optimize the performance of GEO and LEO laser communication system, the simulation model of satellite communication orbit characteristic was established. The simulation model was designed. Through analysis of satellite data within one year, the range of Doppler frequency shift of satellite communication terminal is 5109 Hz, Doppler frequency shift compensation method can be used to reduce the influence of Doppler frequency shift between GEO and LEO. For coherent communication, frequency shift must be compensated by terminal. The range of point-ahead was larger than laser beam divergence angle, so the lead angle should be compensated by terminal, in order to reduce the influence of relative velocity on laser communication; the laser communication system need amend early according to point-ahead of LOS, the sun interference and earth occlusion have a longer time, satellite network should be carried out to improve the available probability, in the communication process the work flow of the two communication terminals was optimized based on the communication terminal time; LOS changing situation of GEO and LEO terminal was different, so different structures of the satellite should be designed.