弱湍流下斜程逆向调制无线光通信性能分析

Performance Analysis for Modulating Retro-reflector FSO Communications in weak turbulent atmosphere on slant path

针对大气湍流影响下的地-空斜程逆向调制无线光(FSO)通信问题,基于三层高度谱模型对逆向调制斜程链路下的光强闪烁进行研究,推导弱湍流下大气湍流衰落系数的概率密度函数表达式,在此基础上深入研究系统的平均中断概率、平均误码率和平均信道容量,分析天顶角、湍流强度以及接收孔径大小等因素对系统通信性能的影响。研究结果表明,在低信噪比和长距离通信的情况下,适当增大接收机孔径,地-空斜程逆向调制无线光通信系统依然可以保持较好的通信性能,随着天顶角和近地大气折射率结构常数的减小,湍流对斜程通信链路的影响也有明显减弱。

Aiming at the problem of ground-space slope reverse modulation wireless optical(FSO) communication under the influence of atmospheric turbulence, the optical intensity scintillation under the reverse modulation slant path link is studied based on the three-layer height spectrum model, and the probability density function expression of the atmospheric turbulence fading coefficient under weak turbulence is derived based on this formula, the average outage probability, average bit error rate and average channel capacity of the system are deeply studied, and the influence of factors such as zenith angle, turbulence intensity and receiving aperture size on the communication performance of the system are analyzed. The research results show that in the case of low signal-to-noise ratio and long-distance communication, the receiver aperture is appropriately increased, and the ground-space reverse modulation slant path wireless optical communication system can still maintain good communication performance. With the decrease of the zenith angle and the refractive index structure constant of the near-earth atmosphere, the influence of turbulence on the slant path communication link is obviously weakened.