STAR-RIS Empowered Full Duplex Cooperative Rate Splitting

Abstract

Cooperative rate-splitting (CRS), which takes the advantages of cooperative user relaying and rate-splitting multiple access (RSMA), has gained recognition for its potential in enhancing the spectral efficiency, user fairness, and coverage of wireless networks. In this work, to further strengthen the performance of CRS, we propose a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS)-enabled full-duplex (FD) CRS transmission framework. By jointly designing the active beamforming, common rate allocation, and the STAR-RIS passive transmission and reflection beamforming to maximize the worst case rate among users, we show that the proposed STAR-RIS assisted FD CRS transmission scheme considerably enhances user fairness compared to conventional FD CRS approaches.