This paper discusses the performance of an improved dual-hop mixed radio frequency (RF) / free space optical (FSO) relay communication system in the present of multiple co-channel interferences (CCIs) at the relay node. Multi-user diversity(MUD) technology has been adopted to improve the RF link performance. In order to improve the performance of the FSO link, multi-aperture receiver scheme has been implemented. The multi-user RF link experiences Nakagami-m fading, while the FSO link is subjected to Exponentiated Weibull distributed atmospheric turbulence. Moreover, the CCIs at the relay node are assumed to undergo Nakagami-m fading. For this proposed system, the exact closed-form expression for the outage probability (OP) has been derived. To quickly understand the effects of different parameters on the system performance, the asymptotic expression for the case of high signal-to-noise (SNR) has been further presented. Results show that the diversity order of this proposed system is min (αβM/2,m ₁ K), where M represents the number of receiver apertures; K denotes the number of users; α, β and m ₁ are the channel parameters. Additionally, the effects of various parameters on system performance have been investigated. Finally, the numerical results have been validated by Monte-Carlo simulations.

本文讨论了一种改进的双跳混合射频（RF）/自由空间光（FSO）中继通信系统在中继节点存在多个同信道干扰（CCI）的情况下的性能。采用多用户分集（MUD）技术来提高射频链路性能。为了提高 FSO 链路的性能，已经实施了多孔径接收器方案。多用户射频链路经受 Nakagami-m 衰落，而 FSO 链路经受指数 Weibull 分布的大气湍流。此外，假设中继节点的 CCI 经历 Nakagami-m 衰落。对于这个提议的系统，已经导出了停机概率 (OP) 的精确封闭式表达式。为了快速了解不同参数对系统性能的影响，进一步介绍了高信噪比 (SNR) 情况下的渐近表达式。结果表明，该系统的分集阶数为 min (αβM /2, m ₁ K )，其中M表示接收器孔径的数量；K表示用户数；α、β和m ₁是通道参数。此外，还研究了各种参数对系统性能的影响。最后，数值结果已通过蒙特卡罗模拟得到验证。