Throughput performance of multi-user UAV-relayed RF systems with wireless energy harvesting

This paper investigates a dual-hop UAV-assisted RF wireless communication system incorporating energy harvesting at the relay. A UAV acting as a decode-and-forward (DF) relay facilitates communication between the source and destination in the absence of a direct link, employing a power-splitting relaying (PSR) protocol combined with a harvest-then-cooperate (HTC) strategy. The relay simultaneously decodes the received signal and harvests energy from the incoming RF transmission, which is then used to forward the information to a destination user selected via opportunistic scheduling. The source-to-relay and relay-to-destination channels are modelled using α–κ–μ and Rayleigh fading, respectively. Closed-form expressions for ergodic capacity and throughput are derived using the statistical properties of the individual channels. Numerical results validate the analytical findings and highlight the effects of system parameters, including the power-splitting factor, number of users, fading characteristics, and source-relay distance.