MIMO performance enhancement of MIMO arrays using PCS-based near-field optimization technique  

作　　者：Yipeng WANG Xiaoming CHEN Huiling PEI Wei E.I.SHA Yi HUANG Ahmed A.KISHK 

机构地区：[1]School of Information and Communications Engineering,Xi’an Jiaotong University,Xi’an,710049,China [2]Key Laboratory of Micro-Nano Electronic Devices and Smart Systems of Zhejiang Province,College of Information Science and Electronic Engineering,Zhejiang University,Hangzhou,310027,China [3]Department of Electrical Engineering and Electronics,University of Liverpool,Liverpool,L693GJ,UK [4]Department of Electrical and Computer Engineering,Concordia University,Montreal,QC,3F 1M8,Canada

出　　处：《Science China(Information Sciences)》2023年第6期166-181,共16页中国科学（信息科学）（英文版）

基　　金：supported in part by National Natural Science Foundation of China (Grant No.62171362)。

摘　　要：Extensive efforts have been made in designing large multiple-input multiple-output(MIMO)arrays.Nevertheless,improvements in conventional antenna characteristics cannot ensure significant MIMO performance improvement in realistic multipath environments.Array decorrelation techniques have been proposed,achieving correlation reductions by either tilting the antenna beams or shifting the phase centers away from each other.Hence,these methods are mainly limited to MIMO terminals with small arrays.To avoid such problems,this work proposes a decorrelation optimization technique based on phase correcting surface(PCS)that can be applied to large MIMO arrays,enhancing their MIMO performances in a realistic(non-isotropic)multipath environment.First,by using a near-field channel model and an optimization algorithm,a near-field phase distribution improving the MIMO capacity is obtained.Then the PCS(consisting of square elements)is used to cover the array’s aperture,achieving the desired near-field phase distribution.Two examples demonstrate the effectiveness of this PCS-based near-field optimization technique.One is a1×4 dual-polarized patch array(working at 2.4 GHz)covered by a 2×4 PCS with 0.6λcenter-to-center distance.The other is a 2×8 dual-polarized dipole array,for which a 4×8 PCS with 0.4λcenter-to-center distance is designed.Their MIMO capacities can be effectively enhanced by 8%and 10%in single-cell and multi-cell scenarios,respectively.The PCS has insignificant effects on mutual coupling,matching,and the average radiation efficiency of the patch array,and increases the antenna gain by about 2.5 dB while keeping broadside radiations to ensure good cellular coverage,which benefits the MIMO performance of the array.The proposed technique offers a new perspective for improving large MIMO arrays in realistic multipath in a statistical sense.

关 键 词：antenna correlation array antenna multiple-input multiple-output(MIMO)capacity 

分 类 号：TN929.5[电子电信—通信与信息系统]