Performance Analyses of RIS-Assisted Stochastic UAV mmWave Relay Communication System With Moment Matching Estimation

This letter proposes a reconfigurable intelligent surface (RIS)-assisted stochastic unmanned aerial vehicle (UAV) millimeter wave relay communication system. Regarding characteristics of stochastic distance in UAV links, inherent identities of the path loss, as well as the molecular absorption impacts, the probability density function and cumulative distribution function of the proposed system are formulated with the help of the moment matching estimation method. Based on this, we determine the metric expressions of the outage probability (OP), average bit error rate (BER), and ergodic capacity. Specifically, we further provide formulae regarding OP and average BER in high signal-to-noise rate regions. Monte Carlo simulations are performed to validate the correctness of the derived formulae. In addition, the results unravel the influence of the RIS reflector numbers, millimeter wave molecular absorption, and stochastic distance towards the system performance.