An Unmanned aerial vehicle and its application in communication are of great interest these days. This paper an-alyzes a UAV-based system model that replaces the conventional relay and derives the closed-loop expression for performance metrics like outage and throughput over Nakagami-m Channel. The results are validated using the simulation results. All the analyses are done considering selection combining (SC) as the diversity technique, Non-orthogonal multiple access techniques (NOMA) as the multiple access technique, and imperfect succes-sive interference cancellation (SIC) at the receiver. To add more novelty to the work, we have incorporated an energy harvesting technique i.e., power splitting approach (PS).