湍流信道下中继辅助非共面紫外光散射通信性能分析

Performance analysis of relay-assisted noncoplanar ultraviolet scattering communication over turbulent channels

非直视紫外光通信能够在复杂环境和特殊地形下工作,但大气吸收、散射及湍流会造成信号强度的快速衰减,从而极大地限制了传输距离.协同中继是克服这一缺点、扩大通信范围的有效手段.针对大气湍流条件下非共面中继辅助紫外散射系统,推导获得了译码转发(DF)和放大转发(AF)两种协议下中断概率的闭式表达式.通过蒙特卡洛仿真,验证了理论分析结果的正确性.仿真结果表明:DF的中断性能优于AF,且光发送功率越大、接收仰角和偏轴角越小,系统的中断性能越好.偏轴角不同,中断概率随发送仰角的变化规律不同.

Non-line-of-sight ultraviolet communication can be competent for complex environment and special terrain.However,atmospheric absorption,scattering and turbulence can result in rapid attenuation of signal intensity,which greatly limits the transmission distance.Cooperative relay is an effective method to overcome this shortcoming and expand the communication range.For the non-coplanar relay assisted ultraviolet scattering system in atmospheric turbulence,the closed-form expressions of outage probability under decode-and-fbrward(DF)proto col as well as amplify-and-forward(AF)protocol are derived.The correctness of the theoretical analysis results is verified through Monte Carlo simulation.The simulation results show that the outage performance of DF is bet ter than that of AF.And the higher the optical transmission power,the smaller the receiving elevation and the offset angle,the better the outage performance of the system.Moreover,the change rule of outage probability with transmission elevation is different when the offset angle is different.