Ding Junrong, Xie Xiaolong, Wang Ling, Tan Liying, Ma Jing, Kang Dongpeng
Appl Opt. 2022 Mar 10;61(8):2079-2088. doi: 10.1364/AO.448381.
We investigate the performance of a dual-hop mixed free space optical (FSO) /radio frequency (RF) system with fixed-gain relaying under direct detection and heterodyne detection techniques. The FSO link is modeled by the Fisher-Snedecor distribution, which matches well with the experimental data under weak-to-strong turbulence regimes. The RF link experiences - shadowed fading, which unifies popular RF fading models. The - shadowed distribution is approximated by an - distribution. Capitalizing on this approximation, closed-form approximate expressions for the cumulative distribution function, the average bit error rate of different modulation schemes, and the ergodic capacity are derived in terms of the bivariate Fox's H function. Moreover, asymptotic analysis is carried out at a high signal-to-noise ratio to further illustrate the obtained diversity order and the influence of system and channel parameters. Numerical results and Monte Carlo simulations are presented to validate the derived approximate expressions.
我们研究了在直接检测和外差检测技术下具有固定增益中继的双跳混合自由空间光（FSO）/射频（RF）系统的性能。FSO链路由费希尔-斯内德科尔分布建模，该分布在弱到强湍流条件下与实验数据匹配良好。RF链路经历阴影衰落，它统一了流行的RF衰落模型。阴影分布由分布近似。利用这种近似，根据双变量福克斯H函数推导了累积分布函数、不同调制方案的平均误码率和遍历容量的闭式近似表达式。此外，在高信噪比下进行了渐近分析，以进一步说明所获得的分集阶数以及系统和信道参数的影响。给出了数值结果和蒙特卡罗模拟，以验证所推导的近似表达式。
