大气湍流和指向误差下混合RF/FSO航空通信系统性能分析  

Performance Analysis for Mixed RF/FSO Airborne Communication Systems over Atmospheric Turbulence and Pointing Error

作　　者：赵静[1] 赵尚弘[1] 赵卫虎[2] 王翔[1] 陈柯帆[1] 

机构地区：[1]空军工程大学信息与导航学院,陕西西安710077 [2]西安通信学院,陕西西安710106

出　　处：《中国激光》2017年第9期170-178,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61571461)

摘　　要：基于解码-转发中继方式,研究了混合射频/自由空间光(RF/FSO)航空通信系统性能。采用副载波多进制相移键控调制方式,建立了孔径平均作用下混合RF/激光通信系统模型,其中FSO通信链路采用指数型Weibull大气湍流信道的同时考虑指向误差影响,射频通信链路为Nakagami-m衰落信道。利用Meijer′s G函数推导得到航空激光通信系统平均误码率和中断概率的闭合表达式。在不同湍流强度和接收孔径大小条件下,对比分析了中断概率及误码率性能。仿真结果表明,与弱湍流条件相比,中等湍流强度条件下指向误差对系统中断性能影响较小;孔径平均效应可有效改善混合RF/FSO传输系统的性能;FSO信道对混合系统性能起主要作用。The performance of the mixed radio frequency/free-space optical （RF/FSO） systems is presented based on decoding and forward relaying. A mixed RF/laser communication system model is constructed with suhcarrier multilevel phase shift keying modulation. The exponentiated Weibull atmospheric turbulence channel with pointing error effect is adopted for FSO communication link and the RF link undergoes the Nakagami-m fading channel. We derive the analytical expressions for cumulative distribution function of equivalent signal-to-noise ratio. The novel mathematical presentations of outage probability and average bit error-rate are developed based on the Meijer＇s G function. The outage probability and the bit error-rate are compared for different turbulence intensities and receiving apertures. The simulation results show that the pointing error has less effect on the outage in moderate atmospheric turbulence than in weak turbulence, the aperture averaging effect improves performance of the mixed RF/FSO communication system effectively, and the FSO channel is dominant in the mixed system.

关 键 词：光通信 混合射频/自由空间光通信系统 指数型Weibull分布模型 NAKAGAMI-M衰落信道 指向误差 中断概率 平均误码率 

分 类 号：TN929.1[电子电信—通信与信息系统]