大气到海洋激光通信信道仿真

Simulation of Laser Communication Channel from Atmosphere to Ocean

详细分析了蓝绿激光穿过大气海洋信道的信道效应和物理特性,利用理论分析和蒙特卡罗模拟方法完成对光信道仿真。介绍了大气海洋激光通信蒙特卡罗模拟方法及计算步骤。研究了不同厚度云层对光束投影面积的展宽,和光脉冲穿过不同深度海水后的空间分布和时域信号波形,讨论了其不同的展宽机理,并对信道的噪声分布进行了分析。发现云层对光脉冲展宽作用在云层厚度500 m时达到饱和,信号能量的随机起伏随海水深度的增加而增大,但能量分布的半峰全宽并不增加,大气海洋的综合信道效应可以用时延滤波器进行建模。

The characteristics of laser pulse transmitting through atmosphere to oceanic channel is analyzed in detail. The method of Monte Carlo and theoretical analysis are adopted for modeling the laser communication channel. The method and procedure for simulation are introduced. The beam projected area spread of laser pulses transmitting through different thickness of cloud, and the pulse-energy distributions in spatial and temporal domain through different depth of sea water, and the broadening mechanism and channel noise are also studied. The conclusion is that broadening effect by cloud is saturated when the cloud thickness exceeds 500 m, and the random fluctuation of signal energy is increased for deeper water, but the full width at half width of energy distribution is not increased. The overall atmospheric and oceanic channel can be described by time-delay filter model.