Power Minimization for RIS-Assisted Uplink MIMO-NOMA Systems Based on HBF

Non-orthogonal multiple access (NOMA), multiple-input multiple-output (MIMO), and reconfigurable intelligent surface (RIS) have drawn significant interest in the realm of wireless communication. In this letter, the total transmit power minimization for RIS-assisted uplink MIMO-NOMA systems based on hybrid beamforming (HBF) is studied. Additionally, extended successive interference cancellation (ESIC) is proposed. To be specific, users are grouped based on cascaded channel gains and interference from different groups are suppressed by ESIC. For the purpose of achieving minimal power consumption, we jointly design RIS phase shifts, HBF matrices, and the transmit power allocation. As evidenced by simulation results, the proposed methodology requires lower power consumption than traditional schemes.