Secrecy Offloading Performance Analysis for UAV Relay-assisted NOMA MEC System

This paper investigates a secure offloading system for nonorthogonal multiple access (NOMA) mobile edge computing (MEC) in the Internet of Things (IoT), utilizing an unmanned aerial vehicle (UAV) as a relay. We focus on a scenario where two edge devices (EDs) with limited resources need to offload their tasks to a base station (BS) through the UAV relay. To evaluate secrecy performance, we derive a closed-form expression for the secrecy successful computation probability (SSCP) under the Nakagami-m fading channel model. Numerical results reveal the influence of key system parameters, including the average transmit power at the EDs and UAV, UAV altitude, and power allocation coefficient (PAC). These results indicate that there is an optimal UAV altitude and PAC value that enhances secure offloading performance. The accuracy of our analysis is confirmed through Monte Carlo simulations.