UAV-Assisted Data Collection System Based on Rate-Splitting Multiple Access

This letter investigates an unmanned aerial vehicle (UAV)-assisted uplink data collection system empowered by rate-splitting multiple access (RSMA). To better reflect practical deployment scenarios, the system model incorporates both geometry-induced blockage effects and imperfect channel state information (CSI). Aiming to enhance max-min fairness (MMF) among ground sensors, we formulate a joint optimization of the sensor transmit power, RSMA decoding order, and UAV hovering position. The resulting highly-coupled mixed-integer non-convex problem is challenging to solve. To tackle this, we develop a penalty-based successive convex approximation (SCA) framework that transforms the original problem into a sequence of efficiently solvable convex subproblems. Simulation results demonstrate that the proposed RSMA scheme significantly outperforms conventional orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) benchmarks in terms of max-min fairness, and robustness against CSI imperfections.