动态捷变全息MIMO:自由度、分集增益和阵列增益分析  

Dynamic agile reconfigurable holographic MIMO:DoF,diversity gain,and array gain analysis

作　　者：白家乐 王慧明[1,2] 金梁[3] 楼洋明[3] Jiale BAI;Hui-Ming WANG;Liang JIN;Yangming LOU(School of Information and Communications Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Ministry of Education Key Laboratory for Intelligent Networks and Network Security,Xi’an 710049,China;Institute of Information Technology,Information Engineering University,Zhengzhou 450003,China)

机构地区：[1]西安交通大学信息与通信工程学院,西安710049 [2]智能网络与网络安全教育部重点实验室,西安710049 [3]信息工程大学信息技术研究所,郑州450003

出　　处：《中国科学:信息科学》2025年第3期639-653,共15页Scientia Sinica(Informationis)

基　　金：国家自然科学基金面上项目(批准号:62171364);国家自然科学基金区域重点项目(批准号:U22A2001)资助。

摘　　要：本文提出了一种基于智能超材料表面的动态捷变双端全息MIMO无线通信系统.充分利用智能超表面能够灵活动态调控电磁信号的特点,将其作为一种具有动态捷变能力的MIMO天线配置在发射端和接收端.基于此提出了全息MIMO阵列的空时动态捷变框架,在同一符号持续期内多次捷变超表面单元的相位响应,构造等效扩展空时信道矩阵,从而充分挖掘系统的通信能力.论文详细分析了多径衰落信道下系统的复用增益(自由度)、分集增益和阵列增益.结果揭示了:(1)自由度与捷变频率、径簇角度扩展、天线尺寸和收发端天线数的明确关系式,该结论表明当接收天线数少于发射天线数时,超表面单元相位响应动态捷变能够提高系统自由度;(2)分集增益与捷变频率和自由度的明确关系式,分集增益随捷变频率增加而增加;(3)阵列增益和全息MIMO阵列尺寸成正比.In this study,we propose a dynamic agile reconfigurable holographic multi-input-multi-output(DARH-MIMO)wireless communication system utilizing intelligent metasurfaces.By fully utilizing the ability of metasurfaces to dynamically manipulate electromagnetic signals,we deploy these structures as MIMO antennas with agile reconfiguration capabilities for both the transmitter and receiver.Subsequently,we introduce a spatialtemporal dynamic agile reconfigurable framework for this DARH-MIMO system.Within this framework,the phase response of each metasurface element is reconfigured multiple times within a single symbol duration,enabling the construction of an equivalent extended spatial-temporal channel and enhancing communication potential.We then analyze the system’s multiplexing gain(degrees of freedom,DoF),diversity gain,and array gain under multipath fading channel conditions.The results highlight the following:(1)A clear relationship between the DoF and parameters such as agile frequency,angular spread,antenna size,and number of antennas.This conclusion indicates that when the number of receive antennas is smaller than that of transmit antennas,the dynamic agile reconfiguration of metasurface element phase response significantly enhances DoF.(2)A direct relationship between diversity gain,agile frequency,and DoF,indicating that diversity gain increases with higher agile frequency.(3)A proportional relationship between array gain and the size of the DARH-MIMO array size.Thesefindings provide valuable insights into optimizing holographic MIMO systems for next-generation wireless communication.

关 键 词：智能超表面 全息MIMO 自由度 分集增益 阵列增益 

分 类 号：TN929.5[电子电信—通信与信息系统]