Maximizing User Fairness in Wireless Powered Communication Networks with Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surfaces

The core message of this paper is to enhance user fairness in wireless powered communication networks (WPCNs) by deploying a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS). Two STAR-RIS operating protocol-driven transmission strategies, namely energy splitting non-orthogonal multiple access (ES-NOMA) and time switching time division multiple access (TS-TDMA), are proposed to effectively eliminate the doubly-near-far effect in WPCNs.