Outage Performance Analysis of STAR-RIS-NOMA Networks under Imperfect CSI

Abstract

In this paper, we investigate the performance of simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs)-assisted non-orthogonal multiple access (NOMA) networks under imperfect channel state information (CSI). Furthermore, we derive the exact analytical equations for the OP of two users. To obtain insight into the high power domain, the asymptotic analysis outage probability (OP) is studied. Further, the Monte-Carlo methods verified the tightness of all derivations. Finally, the results indicate that when increasing the number of elements of STAR-RIS, the STAR-RIS-NOMA networks can achieve improved outage performance.