A Review of Codebooks for CSI Feedback in 5G New Radio and Beyond  

作　　者：Qin Ziao Yin Haifan 

机构地区：[1]Air Defense Early Warning Equipment Department of Air Force Early Warning Academy,Wuhan 430019,China [2]School of Electronic Information and Communications,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《China Communications》2025年第2期112-127,共16页中国通信(英文版)

基　　金：supported by the Fundamental Research Funds for the Central Universities;the National Natural Science Foundation of China under Grant 62071191

摘　　要：Codebooks have been indispensable for wireless communication standard since the first release of the Long-Term Evolution in 2009.They offer an efficient way to acquire the channel state information(CSI)for multiple antenna systems.Nowadays,a codebook is not limited to a set of pre-defined precoders,it refers to a CSI feedback framework,which is more and more sophisticated.In this paper,we review the codebooks in 5G New Radio(NR)standards.The codebook timeline and the evolution trend are shown.Each codebook is elaborated with its motivation,the corresponding feedback mechanism,and the format of the precoding matrix indicator.Some insights are given to help grasp the underlying reasons and intuitions of these codebooks.Finally,we point out some unresolved challenges of the codebooks for future evolution of the standards.In general,this paper provides a comprehensive review of the codebooks in 5G NR and aims to help researchers understand the CSI feedback schemes from a standard and industrial perspective.

关 键 词：CODEBOOK CSI 5G NR frequency division duplex Multiple-Input Multiple-Output 

分 类 号：TN929.5[电子电信—通信与信息系统]