Accurate Performance Analysis of Reconfigurable Intelligent Surfaces Over Rician Fading Channels

We consider in this letter the performance of reconfigurable intelligent surface (RIS)-aided wireless networks over Rician fading channels. We derive new accurate closed-form approximations for several performance measures, including the outage probability, average symbol error probability (ASEP), and the channel capacity. Additionally, to get more insights into the system behavior, we derive asymptotic expression for the outage probability at high signal-to-noise ratio (SNR) values, and provide closed-form expressions for the system diversity order and coding gain. Findings show that the considered RIS scenario can provide a diversity order of a+1/2, where a is a function of the Rician channel K-factor, Rician channel scale parameter Ω and the number of reflecting elements N.