Generalized performance analysis of uplink and downlink dual-hop AF mixed RF/FSO relaying systems with pointing errors

We present the performance analysis of dual-hop mixed radio frequency (RF)/free space optical (FSO) systems with fixed-gain amplify-and-forward (AF) relaying in the presence of pointing errors. The RF link undergoes the kappa-mu shadowed fading and the FSO link experiences Fisher-Snedecor F turbulence with pointing errors. For uplink and downlink scenarios, we derive closed-form approximate expressions of the end-to-end signal-to-noise ratio (SNR) statistics, such as the cumulative distribution function (CDF) and the probability density function (PDF). By using both two statistics, the average bit error rate (BER), the ergodic capacity (EC), and the effective capacity are derived in terms of the bivariate Fox's H function. These results illustrate the effects of system and channel parameters on the considered system, including atmospheric turbulence, pointing errors, multipath cluster numbers, shadowing parameter, quality parameter and different modulation schemes. Note that our results provide more general expressions. Finally, the derived approximate expressions are confirmed through Monte Carlo (MC) simulations. This work would contribute to the design and development of dual-hop mixed RF/FSO relaying systems.