Performance Evaluation of a Hybrid RF/FSO SWIPT Relay System With IRS-Assisted RF Link and UAV-Based Relaying Under Pointing Error Constraints

Abstract

We propose a hybrid radio-frequency/free-space optical (RF/FSO) communication architecture with simultaneous wireless information and power transfer (SWIPT), where an intelligent reflecting surface (IRS) enhances the RF hop and an uncrewed aerial vehicle (UAV) operates as a decode-and-forward relay. A single-antenna transmitter communicates with the UAV through an IRS-assisted RF channel, enabling the UAV to concurrently extract information and harvest energy from the received signal. The decoded data are then forwarded to the destination via an FSO link. The RF channel is characterized by Nakagami-m fading, whereas the optical link incorporates double generalized gamma (DGG) atmospheric turbulence, misalignment-induced pointing errors, and different optical detection techniques. Exact analytical expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio are derived using Meijer’s G-function.Simulation findings, bolstered by Monte Carlo analysis, assess the impact of IRS dimensions, UAV deployment strategies, and SWIPT power-splitting protocols, uncovering essential trade-offs among harvested energy, transmission dependability, and system intricacy. These findings indicate that the proposed framework is a promising solution for energy-constrained hybrid RF/FSO communication systems.