Performance Analysis of Reconfigurable Intelligent Surfaces over Nakagami-m Fading Channels

Abstract

This letter studies the performance of reconfigurable intelligent surface (RIS)-aided networks over Nakagami-m fading channels. First, we derive accurate closed-form approximations for the system channel distributions, and then, use them in deriving closed-form approximations for the outage probability, average symbol error probability (ASEP), and the average channel capacity. In addition, to get more insights at the system performance, we derive asymptotic expression for the outage probability at the high signal-to-noise ratio (SNR) regime, and provide closed-form expressions for the system diversity order and coding gain. Results show that the considered RIS scenario can provide a diversity order of a+1/2, where a is a function of the Nakagami-m fading parameter m and the number of reflecting elements N. Furthermore, results illustrate that m is more impactful on the diversity order and the system performance than N. Finally, the provided results are valid for arbitrary number of reflecting elements N and non-integer m.