Performance Analysis of RIS-Assisted UAV Communication Systems

In this work, we study the performance of a reconfigurable intelligent surface (RIS)-aided unmanned aerial vehicle (UAV) system where an RIS is installed on a UAV to reflect the signal to the ground user from the sky. More specifically, we present two different methods to denote the probability density functions (PDFs) of the instantaneous signal-to-noise ratio (SNR). With these two distributions, closed-form expressions for the outage probability, average bit error rate (BER), and average sum-rate are derived, respectively. Additionally, we develop the analysis on the optimal UAV altitude and location. Finally, numerical results are given to verify our analysis.