Outage Analysis of Mixed Dual-Hop RF-FSO Communication System Over Fading Channels with Pointing Errors

In this paper, we consider a mixed dual-hop RF-FSO communication system, where RF link is subjected to Rice fading, while FSO link experience double generalized Gamma (GG) turbulence with pointing errors. The double GG distribution is a newly developed turbulence model, which contains commonly used turbulence models as its special case and matches excellently with the existing experimental data. The Rician fading model represents propagation conditions which include the presence of the line-of-sight component and also, it includes the Rayleigh fading model as its special cases. Here we first derive a novel, analytical closed-form expression for the cumulative distribution function for the end-to-end signal-to-noise ratio of the considered system. We show that our derived result contains the existing results presented in the literature as its special case. Then, relaying on the developed analytical results, we derive a closed-form expression for the outage probability and using it, we analyze the outage performance of the mixed dual-hop RF_FSO system and investigate the impact of the pointing errors. Numerical results are further demonstrated to confirm the analytical results.