Spectral Efficiency Analysis for Dynamic H-RIS-Assisted NOMA Networks

Wireless communications have moved substantially toward sixth-generation (6G), which is projected to employ higher frequencies than Fifth-Generation (5G) wireless communications. This enhancement will allow for increased data transfer speeds and capacity. In this paper, we present an innovative Dynamic Hybrid Reflecting Intelligent Surface (H-RIS) architecture for Multiple-Input Multiple-Output (MIMO) systems aided by Non-Orthogonal Multiple Access (NOMA) technology. This structure contains a restricted quantity of elements incorporated with power amplifiers to function as active relays, along with additional elements assigned to passive signal reflection. This H-RIS, which has been enhanced with NOMA, is offered to maximize spectral efficiency (SE), and Alternating Optimization (AO) and sequential convex approximation (SCA) techniques are utilized to help optimize both active and passive H-RIS elements. Simulations and numerical results demonstrate that H-RIS with NOMA can significantly exceed regular RIS in terms of SE.