Performance analysis of full duplex relay assisted mixed RF/FSO system

Abstract

In this paper, we analyze the performance of a full duplex (FD) relay assisted mixed radio frequency (RF)/free space optical (FSO) system with self-interference. The RF links follow Nakagami-m distribution, and FSO links adopt Gamma–Gamma atmospheric turbulence model. We derive the exact and asymptotic outage probability (OP) expressions of the system. Based on the cumulative distribution function (CDF), the bit error rate (BER) and average capacity expressions are further presented. To verify the superiority of FD relay system, we deduce the average capacity of half duplex (HD) relay system and investigate the performance differences between FD relay system and HD relay system. Furthermore, the residual self-interference condition is discussed in this paper. Simulation results show that, when the self-interference coefficient (SIC) is large, the capacity of FD relay system declines severely and behaves even worse than HD relay system. Moreover, there is a tradeoff between SIC and system performance, because the transmission power of the second hop RF link is also the self-interference of the first hop.