Energy efficiency maximisation for STAR‐RIS assisted full‐duplex communications

Abstract Reconfigurable intelligent surface (RIS) has emerged as a promising technique for enhancing the performance of wireless networks. However, traditional reflecting‐only RIS requires that transmitter and receiver ought to be on same side RIS, limiting flexibility deployment. To overcome this drawback, new simultaneous transmission reflection reconfigurable (STAR‐RIS) been proposed. Different from STAR‐RIS assisted half‐duplex systems in existing literature, work investigates novel aided full‐duplex (FD) communication system. An FD base station (BS) communicates with an uplink (UL) user downlink simultaneously over time‐frequency dimension by STAR‐RIS. The authors aim maximise energy efficiency jointly optimising transmit power BS UL passive beamforming at decouple non‐convex problem into two subproblems optimise them iteratively. Dinkelbach's method is used solve optimisation subproblem, whereas penalty‐based successive convex approximation are applied design beamforming. convergence complexity proposed algorithm also analysed. simulation results demonstrate superior scheme compared other baseline schemes.