中文摘要：

在大气强湍流条件下,对并行中继自由空间光通信系统的中断概率进行了研究。考虑大气衰减、大气湍流和指向误差对自由空间光通信系统传输性能的影响,建立了自由空间光通信系统的复合信道模型。基于此信道模型,推导了并行中继自由空间光通信系统端到端中断概率的解析表达式。最后,通过计算机仿真分析了发送功率、指向误差及通信距离对通信系统中断概率的影响。仿真结果表明,并行中继传输技术可以有效提高自由空间光通信系统的中断性能。此外,所推导中断概率的解析表达式可准确地评估并行中继自由空间光通信系统的传输性能,为未来自由空间光通信系统的设计提供理论依据。

英文摘要：

This paper studies the outage probability for parallel relay Free-space Optical（FSO） communication systems under a condition of strong turbulence.By considering the influences of atmospheric attenuation,atmospheric turbulence and pointing errors on the transmission performance of FSO communication systems,this paper establishes a composite channel model.Based on the model,an analytical expression is further derived for the end-to-end outage probability of parallel relay FSO communication systems.Finally,the effects of transmitted powers,pointing errors and communication distances on outage probability are analyzed through computer simulation.Simulation results show that parallel relay transmission is a promising technology to increase the outage performance and the de-rived analytical expression can provide sufficient precision for evaluating the outage performance of parallel relay free-space optical communication systems,which is helpful to the design of future free space optical communication systems.