透射反射双功能RIS辅助的SWIPT系统研究OA

A Simultaneously Transmitting and Reflecting Reconfigurable Intelligent Surface(STAR-RIS)assisted Simultaneous Wireless Information and Power Transfer(SWIPT)system is studied.Specifically,a STAR-RIS is deployed to assist in the information or power transfer from a multi-antenna Access Point(AP)to multiple single-antenna Information Decoding Receiver(IDR)and Energy Harvesting Receiver(EHR)respectively.The goal is to minimize the transmit power at the AP via jointly optimizing the transmission precoding matrices and the transmission-and reflection-coefficient matrices of the STAR-RIS under the communication rate constraints at IDRs and the energy harvesting constraints at EHRs.However,this optimization problem is non-convex with intricately coupled variables.To solve the problem,an alternating optimization algorithm is employed to decouple the coupled variables.Then,the transmission precoding matrices and the transmission-and reflection-coefficient matrices of the STAR-RIS can be optimized by using a semidefinite relaxation method and penalty-based algorithm respectively.The simulation results show that STAR-RIS system scheme can achieve better performance than conventional reflecting or transmitting-only RIS.