对准误差对前置光放大卫星激光通信系统性能的影响

发射机及接收机的对准误差都会引起前置光放大卫星激光通信系统信号的衰落,在同时考虑发射机、接收机对准误差的条件下优化系统性能非常重要。将接收机对准误差引起的空间光耦合损耗用一个高斯函数近似,并同时考虑发射机对准误差引起的对准损耗,推导出了接收光功率概率密度的近似解析表达式,应用该概率密度函数,建立了基于平均误码率原则的前置光放大卫星激光通信系统的优化模型。仿真结果表明,在给定平均误码率要求及对准误差一定时,存在一个最佳发射光束宽度、接收天线直径及空间光耦合参数,使所需的发射功率最小,采用更大的接收天线并不能降低对发射功率的要求。

Influence of Pointing Error on Laser Satellite Communication System with an Optical Preamplifier

Both transmitter′s and receiver′s pointing errors cause signal fade in optically preamplified laser satellite communication, it is important to optimize the system performance in the presence of both the transmitter's and the receiver′s pointing errors. Approximated the space optical coupling loss induced by receiver′s pointing error to a Gaussian function, combined with the transmitter′s pointing loss, an analytic approximate probability distribution of received optical power is derived. Based on this probability distribution model, a model for optimizing laser satellite communication system with an optical preamplifier is given. Simulation results show that for given root-mean-square (RMS) pointing error and required average bit error rate, there exist optimal transmitting beamwidth, receiver antenna diameter and space optical coupling parameter that minimize transmitted power, the required transmitted power is not decreased even using a receiver antenna larger than optimum antenna.