Near-field wideband beam training for ELAA with uniform circular array  

作　　者：Yuhao CHEN Linglong DAI 

机构地区：[1]Department of Electronic Engineering,Tsinghua University,Beijing National Research Center for Information Science and Technology BNRist,Beijing 100084,China

出　　处：《Science China(Information Sciences)》2024年第6期366-379,共14页中国科学（信息科学）（英文版）

基　　金：supported by National Key Research and Development Program of China(Grant No.2023YFB3811503)。

摘　　要：Extremely large-scale antenna array(ELAA)at millimeter wave(mmWave)and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications.Uniform circular arrays(UCAs)have attracted much attention because of their ability to provide flat beamforming gain at all angles.To realize efficient beamforming,beam training is widely used to acquire channel state information.However,with a large antenna number,the beam training overhead in ELAA systems becomes overwhelming.Moreover,with a large bandwidth,the beam defocus effect severely degrades beam training accuracy.To address these issues,this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA.Specifically,we first analyze the FDF property of UCA,where signals at different subcarriers can simultaneously focus on different distances.Then,by exploiting the FDF property to search different distances using different subcarriers simultaneously,we design a hierarchical codebook and propose an FDFbased beam training scheme.To reveal the effectiveness of the proposed scheme,we compare its necessary beam training overhead with that of existing schemes.Finally,the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关 键 词：extremely large-scale antenna array(ELAA) uniform circular array(UCA) NEAR-FIELD WIDEBAND beam training 

分 类 号：TN929.5[电子电信—通信与信息系统]