指数韦伯信道下带瞄准误差的相干光通信系统中断概率分析

Outage Probability Analysis of Coherent Optical Communication System with Pointing Error in Exponentiated Weibull Channel

为了研究在大气湍流闪烁效应以及瞄准误差共同作用下空间相干光通信系统的中断概率,基于指数韦伯大气湍流衰减信道,建立了基于平衡探测的相干光通信系统模型,给出了系统受大气湍流闪烁效应和瞄准误差影响下信道衰减的概率密度函数,并推导了系统中断概率的闭合表达式。通过数值仿真,分析了湍流强度、波束宽度、抖动偏差对系统中断概率的影响。结果表明:系统中断概率会随着湍流强度的增强和归一化信噪比的降低而增大;当归一化信噪比大于14dB时,可以通过增大波束宽度降低系统中断概率;当抖动偏差大于2时,增大归一化信噪比并不能有效降低系统中断概率。由基于此模型的仿真分析结论可知,选取合适的波束宽度和抖动偏差能降低系统的中断概率,并提高系统的稳定性。

In order to study the outage probability of spatial coherent optical communication system under the combined effect of atmospheric turbulence scintillation effect and pointing error, a coherent optical communication system model based on balanced detection is established based on the exponentiated Weibull atmospheric turbulence fading channel. A probability density function of channel attenuation of the system under the combined effect of atmospheric turbulence scintillation effect and pointing error is given, and closed expressions of the system outage probability are derived. The effects of turbulence intensity, beam width and jitter deviation on the system outage probability are analyzed through the numerical simulation. The results show that the system outage probability increases with the increasing of the turbulence intensity and the decreasing of the normalized signal-to：noise ratio. The system outage probability can be decreased through increasing the beam width when the normalized signal-to- noise ratio is greater than 14 dB. In addition, the increase of the normalized signal-to-noise ratio cannot effectively reduce the outage probability of the system when the jitter deviation is greater than 2. Based on the simulation results of the proposed model, it is concluded that the appropriate beam width and jitter deviation can reduce the outage probability and improve the stability of the system.