Performance analysis of STAR-RIS-assisted NOMA communication

Abstract

This paper analyzes the outage probability of a non-orthogonal multiple access (NOMA) system assisted by a reconfigurable smart surface (STAR-RIS) with simultaneous emission and reflection. Among them, the link between the base station and the user is a non-line-of-sight link, which requires relay communication through STAR-RIS. We assume that the channel is a Rayleigh channel, and derive the closed-form expressions of the outage probability of the reflected and refracted users in the NOMA system. The numerical results show that: 1) the outage probability decreases with the increase of the reflective element of STAR-RIS; 2) the outage probability decreases with the decrease of the deployment range of STAR-RIS; 3) increasing the power allocation factor can effectively reduce the outage probability of users; 4) the average energy efficiency of reflective users is inversely proportional to that of refractive users.