Outage Performance of RIS-Assisted Wireless-Powered Multi-user UAV Networks

Abstract

In this paper, we consider a reconfigurable intelligent surface (RIS)-assisted wireless-powered multi-user UAV network (RWMUN), where an energy-constrained unmanned aerial vehicle (UAV) communicates with a selected mobile user uniformly located inside its beam coverage on ground. Here, the UAV employs a time-splitting based harvest-then-transmit protocol, where it first harvests energy from the radio-frequency signal received from an energy source via RIS. The energy thus harvested is then utilized by the UAV for downlink communications with a closest mobile user located inside its beam coverage. By considering the Nakagami-m fading as well as random distances for UAV-to-mobile user links, we derive a new outage probability expression of the system for an arbitraryvalued fading severity parameter. We quantify the performance gains of the considered RWMUN through numerical analysis and validate our theoretical results by simulations.