Delay-Aware and Energy-Efficient Resource Allocation for Reconfigurable Intelligent Surfaces

Reconfigurable intelligent surfaces (RISs) have emerged as one of the most promising techniques for future 6G wireless networks. However, the energy efficiency and the latency of RIS-based communications have not received enough attention. This letter proposes a novel framework that addresses this gap through the consideration of the effective energy efficiency (EEE) metric. EEE maximization is performed in a RIS-based multi-carrier link, with respect to the transmit powers and RIS phase shifts. Numerical results show that the proposed procedure improves the performance of the considered system.