Comprehensive Performance Analysis of UAV-Assisted Mixed FSO-RF Communication System With Nonlinear Energy Harvesting

In this article, we investigate the comprehensive performance of a mixed free space optics-radio frequency (FSO-RF) communication system using an unmanned aerial vehicle (UAV) as a relay. The FSO link is modeled using the recently introduced doubly inverted Gamma-Gamma turbulence channel model, with a comprehensive 3D pointing error model, path loss, and angle of arrival (AoA) fluctuations under both direct detection (DD) and heterodyne detection (HD) techniques at the receiver, and the RF link is modeled using the generalized shadowed κ μ fading model. We have employed both amplify-and-forward (AF) and decode-and-forward (DF) relaying strategies along with linear and nonlinear energy harvesting (EH) techniques. We have obtained the closed-form expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the output instantaneous SNR and derived the expressions for outage probability (OP), average symbol error rate (ASER), and ergodic capacity (EC). In addition, diversity gains are calculated using asymptotic analysis. The derived analytical expressions are validated through Monte-Carlo simulations and show excellent agreement with the numerical results.