Performance Analysis of Hybrid Relay RIS-Assisted NOMA Networks

Wireless communications have progressed remarkably towards Sixth-Generations (6G) which are projected to utilize higher frequencies than those of Fifth-Generation(5G) wireless communications. This advancement will facilitate greater data transmission rates and capacity. In this paper, we introduce an innovative Hybrid Relay-Reflecting Intelligent Surface (HR-RIS) approach for Multiple-Input Multiple-Output (MIMO) systems aided with Non-Orthogonal Multiple Access (NOMA) technology, incorporating a limited number of elements equipped with power amplifiers to operate as active relays, and other elements dedicated to passive signal reflection. This HR-RIS, enhanced with NOMA, is proposed to maximize the spectral efficiency (SE), and the optimization process on the HR-RIS both active and passive elements is facilitated by an Alternating Optimization (AO) strategy. Simulations and numerical results prove that the HR-RIS aided with NOMA can significantly surpass the SE performance of standard RIS. The advantages and effectiveness of the proposed HR-RIS deployment Aided with NOMA are both theoretically and numerically substantiated.