空地光通信系统空间链路的建模与仿真

用拟合方法得出大气消光系数随高度的变化关系,进而建立激光大气传输衰减模型;以无湍流影响时到达接收机的光强为均值,根据对数振幅起伏方差求出光强闪烁方差,用高斯随机数模拟光强闪烁;建立了光扩束和视轴失配所引起的光损耗模型.在Matlab/Simulink平台上开发了仿真程序,其可作为完整的空间链路模块,在空地光通信仿真中直接使用.仿真结果与理论分析具有一致性.

Modeling and Simulation of Space Link in Space-to-Land Optical Communication System

Curve fitting method was applied to found the relationship between atmospheric extinction coefficient and altitude, and then the atmospheric attenuation model of laser propagation was established. The received optical intensity uninfluenced by atmospheric turbulence was used as the average intensity and the optical intensity scintillation variance was computed according to log-amplitude variance, then Gaussian stochastic number was used to simulate the scintillation. In addition, the optical loss model of beam spreading and mismatch of sight axis between transmitter and receiver was proposed. Based on Matlab/Simulink platform, the simulation program was developed, and it can be used directly as a space link module in a space-to-land optical communication simulation system. The simulation results show consistency with theory analysis.