Reconfigurable Intelligent Surface Assisted NOMA Empowered Integrated Sensing and Communication

Abstract: This paper exploits the potential of reconfigurable intelligent surface (RIS) to improve radar sensing in a non-orthogonal multiple access (NOMA) empowered integrated sensing and communication (NOMA-ISAC) network. The objective is to maximize the minimum radar beampattern gain by jointly optimizing the active beamforming, power allocation coefficients and passive beamforming. To tackle the formulated non-convex problem, we propose an efficient joint optimization algorithm by invoking alternating optimization, successive convex approximation (SCA) and sequential rank-one constraint relaxation (SRCR) algorithm. Numerical results show that the proposed RIS assisted NOMA-ISAC system, with the aid of proposed scheme, outperforms the RIS assisted ISAC system without NOMA.