一种多光束发射和接收FSO系统的信道建模方法

Method of Establishing Channel Model in Multiple-Beam Transmission and Reception FSO Systems

在单光束发射和接收无线光通信(FSO)系统中,目前人们普遍接受的是光强闪烁在强湍流下服从负指数分布,在弱湍流下服从对数正态分布,而在强弱湍流下都适用的Gamma-Gamma分布则是研究的热点。在这几种分布的基础上,将它们推广到多光束发射和接收FSO系统,分别推导出了基于对数正态分布、负指数分布以及Gamma-Gamma分布的多光束发射和接收FSO系统的光强闪烁概率密度分布函数,建立起多光束发射和接收系统光强闪烁信道模型,并对基于负指数分布的多光束信道模型与通信距离、激光波长、接收孔径以及收发天线数目等参数的相互关系进行了具体的仿真分析。这对多光束发射和接收FSO系统的理论分析和系统设计具有一定的指导意义。

In single-beam transmission and reception free-space optical communication（FSO） systems,the intensity scintillation obeys the negative exponential distribution in weak turbulence while in strong turbulence it obeys logarithm normal distribution,which is universally accepted at present.Because the Gamma-Gamma distribution can describe both weak turbulence and strong turbulence,it becomes the hot spot recently.By extending them to multiple-beam transmission and reception FSO systems,the intensity scintillation′s probability density distribution functions are deduced and the channel models are established based on these distributions respectively.At last,the analysis of the influences of communication range,laser wavelength,receiving aperture as well as transmission and receiving antenna numbers on the channel model based on the negative exponential distribution and the simulations are detailedly done.All of these benefit theoretical research and design of the multiple-beam transmission and reception FSO systems.