智能超表面辅助MIMO系统:单极化与双极化的选择  

Intelligent Surface-Assisted MIMO System:Dual Polarization or Single Polarization

作　　者：郑子洲 张泓亮 黄欢 王刚[2] ZHENG Zizhou;ZHANG Hongliang;HUANG Huan;WANG Gang(School of Electronics,Peking University,Bejing 100871,China;School of Information Science and Engineering,Southeast University,Nanjing 211189,China;State Key Laboratory of Photonics and Communications,Beijing 100871,China;School of Electronic and Information Engineering,Soochow University,Suzhou 215006,China)

机构地区：[1]北京大学电子学院,北京100871 [2]东南大学信息科学与工程学院,江苏南京211189 [3]光子传输与通信国家重点实验室,北京100871 [4]苏州大学电子信息学院,江苏苏州215006

出　　处：《移动通信》2025年第4期28-33,共6页Mobile Communications

基　　金：国家自然科学基金面上项目“面向近场的透射-反射可重构超表面辅助多用户传输技术”(62371011);国家自然科学基金青年科学基金项目“随机配置智能超表面的全无源干扰机制及其防御策略研究”(62401387)。

摘　　要：在移动通信系统中,双极化多输入多输出(DP-MIMO,Dual-Polarized Multiple-Input Multiple-Output)技术通过极化维度的复用与分集增益,显著提升了频谱效率。然而,受限于无线极化信道交叉极化耦合效应,现有DP-MIMO系统容量难以突破单极化(SP-MIMO,Single-Polarized MIMO)架构的性能上限。为此,文章提出双极化可重构智能反射面(DP-RIS,DP Reconfigurable Intelligent Surface)的联合极化相位设计方案,并基于此系统性探究DP-RIS表面尺寸与MIMO系统容量性能的关联机制。具体来说,通过建立极化信道模型,推导了最佳相位设计下的RIS辅助DP/SP-MIMO系统容量闭合表达式。并基于此,给出了DP系统性能优于SP系统的尺寸阈值。理论分析与仿真结果表明:当RIS单元数超过该阈值时,DP-MIMO系统可实现相较于SP-MIMO的容量优势。研究结论为DP-RIS的工程部署提供了关键尺寸设计准则。In mobile communication systems,dual-polarized multiple-input multiple-output(DP-MIMO)technology significantly enhances spectral efficiency through polarization dimension multiplexing and diversity gain.However,due to the crosspolarization coupling effect in wireless polarization channels,the capacity of existing DP-MIMO systems cannot surpass the performance limit of single-polarized MIMO(SP-MIMO)architectures.Therefore,this paper proposes a joint polarization phase design scheme based on DP reconfigurable intelligent surfaces(DP-RISs)and systematically investigates the relationship between the surface size of DP-RIS and MIMO system capacity performance.Specifically,we establish a polarization channel model and derive a closed-form expression for the RIS-assisted DP/SP-MIMO system capacity under the optimal phase design.Based on this,we provide the size threshold at which DP system performance exceeds that of the SP system,Theoretical analysis and simulation results demonstrate that when the number of RIS elements exceeds this size threshold,DP-MIMO system can achieve a capacity advantage over SP-MIMO.The research conclusions offer key size design guidelines for the engineering deployment of DP-MIMO systems with RIS assistance.

关 键 词：可重构智能超表面 双极化 多输入多输出系统 

分 类 号：TN929.5[电子电信—通信与信息系统]