Reconfigurable Intelligent Surface Empowered Downlink Non-Orthogonal Multiple Access

Understand

Power-domain non-orthogonal multiple access (NOMA) has become a promising technology to exploit the new dimension of the power domain to enhance the spectral efficiency of wireless networks.

• However, most existing NOMA schemes rely on the strong assumption that users' channel gains are quite different, which may be invalid in practice.
• To unleash the potential of power-domain NOMA, we will propose a reconfigurable intelligent surface (RIS)-empowered NOMA network to introduce desirable channel gain differences among the users by adjusting the phase shifts at RIS.
• Our goal is to minimize the total transmit power by jointly optimizing the beamforming vectors at the base station and the phase-shift matrix at the RIS.