RIS-Assisted SWIPT-Empowered Cooperative Rate-Splitting Multiple Access for Two Users

This paper proposes a reconfigurable intelligent surface (RIS)-assisted cooperative rate-splitting multiple access (C-RSMA) framework with simultaneous wireless information and power transfer (SWIPT). In the proposed framework, the user with good channel gain can act as a full-duplex (FD) relay to forward the common stream to the user with poor channel gain. Moreover, by leveraging SWIPT technology, the user with good channel gain can simultaneously receive information and harvest energy from the base station (BS). This framework is formulated as an optimization problem by jointly optimizing beamforming vectors at the BS, common stream split, power splitting factor, and phase shift configuration at the RIS with the objective of maximizing the sum rate of both users. To tackle this challenging problem, an alternating optimization algorithm based on the successive convex approximation and difference-of-convex approach is proposed. Numerical results demonstrate that our proposed approach can outperform the baseline schemes.