Energy and spectral efficiency for RIS-aided transmission

Reconfigurable intelligent surface (RIS) appears as an interesting and promising technique for future wireless communication. Given its ability to adapt channel conditions through energy concentration, and interference cancellation through the use of a considerable amount of quasi-passive reflecting elements. In this paper, we discuss the potential applications of RIS in wireless networks operating within the energy efficiency (EE) and spectral efficiency (SE) framework. In this context, we develop energy-efficient solutions; both in terms of transmitting power allocation and number of reflective elements, while ensuring achievable spectral efficiency for the mobile station. The simulation results reveal that the number of RIS reflecting elements plays a crucial role in the overall performance. In addition, comparisons with relay-aided system are also performed to demonstrate the effectiveness of the proposed system in terms of EE and SE.