Performance Analysis of Mixed Weibull and Gamma-Gamma Dual-Hop RF/FSO Transmission Systems

In this paper, we study the performance of a dual-hop amplify-and-forward (AF) communication system over asymmetric links composed of Radio-Frequency (RF) and Free-Space-Optical (FSO) links in the presence of atmospheric turbulence as well as pointing error impairments under both heterodyne detection and intensity modulation with direct detection (IM/DD) techniques. The RF link is assumed to operate under Weibull fading, while the FSO channel undergoes Gamma-Gamma (GG) fading. Using a Channel-State-Information (CSI)-assisted relaying, we derive closed-form expressions for the cumulative distribution function (CDF) and the probability density function (PDF) of the end-to-end signal-to-noise ratio (SNR) for the considered system in terms of the Meijer G-function. Based on these results, a novel closed-form expression of the average symbol error rate (ASER) in terms of the bivariate Fox H-function is derived. Finally, numerical results are presented to validate the analytical expressions.