Semi-Definite Relaxation Based Beamforming Design for Double-RIS Aided MISO System with Limited Feedback  

作　　者：Shang Sihui Ren Pinyi Xu Dongyang 

机构地区：[1]School of Information and Communication Engineering,Xi’an Jiaotong University,Xi’an 710049,China [2]Shaanxi Smart Networks and Ubiquitous Access Research Center,Xi’an 710049,China

出　　处：《China Communications》2025年第4期309-321,共13页中国通信(英文版)

基　　金：supported the Innovation Talents Promotion Program of Shaanxi Province under Grant No.2021TD-08。

摘　　要：The reconfigurable intelligent surfaces(RIS)can reconfigure the wireless channel environment by manipulating the propagation of incident electromagnetic waves.Specifically,we consider using multi-RIS to improve the system throughput of limited feedback multiple input single output(MISO)system in an energy efficiency manner.The critical challenge lies in the joint design of channel acquisition and beamforming which are usually based on codebook with limited precision.To solve this,we propose a semi-definite relaxation(SDR)based beamforming design scheme while considering the effect of cascaded channel acquisition.First,a channel quantization scheme is proposed by exploiting the channel sparsity in double-RIS aided MISO system.Second,an optimization problem of maximizing the system throughput is established to derive the channel quantization vector which also serves as the beamforming vector,with the consideration of the constraints of transmission power,RISs phase-shift.Third,a SDR based iterative optimization algorithm is proposed to solve the problem with low complexity.Finally,simulation results show that our proposed algorithm can improve the system throughput efficiently.

关 键 词：BEAMFORMING cascaded channel double-RIS semi-definite relaxation 

分 类 号：TN929.5[电子电信—通信与信息系统]