为了改善雨、雾、雪等环境因素对大气激光通信系统性能的影响，建立了一种新的多脉冲位置调制(MPPM)系统。在新系统中不但加入了RS编译码器，而且对接收到的信号采用了最大似然检测技术。分析了信噪比、保护时隙持续时间、信息时隙宽度等性能参数。仿真结果表明，适当地选择参数，可以最大程度减少环境因素对大气激光通信的影响，提高大气激光通信系统的性能。

A new MultiPulse Position Modulation(MPPM) system is established to decrease the effect of such weather as rain, fog or snow on the performance of atmosphere laser communication system. ReedSolomon(RS) encoder/decoder and maximumlikelihood detection are used in the new system. Signal noise ratio, protective time slot and information time slot are analyzed. The simulation results show that the performance of atmosphere laser communication system can be improved when proper parameters are selected.