Energy Harvesting in Multi-Hop UAV-Assisted FSO Communication Systems

Abstract

In this paper, we analyze the performance of a multi-hop unmanned aerial vehicle (UAV)-based free space optics (FSO) communication system over the recently introduced doubly inverted Gamma-Gamma (IGGG) turbulence channel model. The system assumes a decode-and-forward (DF) relaying strategy, enabling flexible deployment for line-of-sight (LoS) communication between UAVs and ground nodes. Linear energy harvesting techniques are employed at each relay to improve power efficiency. The channel modeling incorporates key impairments, including atmospheric turbulence, non-zero boresight pointing errors, path loss, and angle-of-arrival (AoA) fluctuations. We derive the closed-form expressions for the proposed system's probability density function (PDF), cumulative distribution function (CDF), outage probability, and ergodic capacity. In addition, the diversity gain and outage floor are calculated from the asymptotic analysis. The derived analytical expressions are validated through Monte-Carlo simulations, showing excellent agreement with numerical results. © 2025 IEEE.