Outage Probability and Throughput Analysis of UAV-Assisted Rate-Splitting Multiple Access

This work studies an unmanned aerial vehicle (UAV)-assisted wireless communication system where UAV acts as an aerial base station (BS) and serves multiple ground users simultaneously using rate-splitting multiple access (RSMA). We propose a new architecture called RSMA-UAV that leverages the interplay between rate-splitting (RS) and UAV and shows the effect of RSMA on system performance. Further, we derive closed-form expressions of outage probability and corresponding throughput at each user considering independent and non-identical Nakagami-m small-scale fading. In addition to this, we also highlight the importance of the judicious selection of the power allocation coefficient in order to enhance the overall throughput performance of the system. Moreover, we show that hovering the UAV near certain coordinates can maximize the sum throughput of the system. Hence, we formulate an optimization problem to find the UAV coordinates. Finally, the accuracy of the derived analytical expressions is verified using the Monte-Carlo simulations.