Enhancing NOMA Networks via Reconfigurable Multi-Functional Surface

By flexibly manipulating the radio propagation environment, reconfigurable intelligent surface (RIS) is a promising technique for future wireless communications. However, single-side coverage and double-fading attenuation faced by conventional RISs largely restrict their applications. To address this issue, we propose novel concept of multi-functional RIS (MF-RIS), which provides reflection, transmission, amplification simultaneously incident signal. With aim enhancing performance non-orthogonal multiple-access (NOMA) downlink multiuser network, deploy an MF-RIS to maximize sum rate jointly optimizing active beamforming coefficients. Then, alternating optimization algorithm proposed solve formulated non-convex problem exploiting successive convex approximation penalty-based method. Numerical results show that outperforms under different settings.