有源智能反射面辅助的太赫兹MIMO系统有效秩优化  

Effective Rank Optimization for Active RIS-assisted Terahertz MIMO Systems

作　　者：曹烨 孙强[1] 黄勋[1] 陈晓敏 徐淼淼 CAO Ye;SUN Qiang;HUANG Xun;CHEN Xiaomin;XU Miaomiao(School of Information Science and Technology,Nantong University,Nantong 226019,China)

机构地区：[1]南通大学信息科学技术学院,江苏南通226019

出　　处：《无线电工程》2025年第4期792-799,共8页Radio Engineering

基　　金：国家自然科学基金(61971467)。

摘　　要：在太赫兹视距通信场景下缺乏散射径,信道存在严重秩亏现象,导致多输入多输出(Multiple Input Multiple Output,MIMO)系统丧失空分复用的能力。有源智能反射面(Reconfigurable Intelligent Surface,RIS)作为第六代移动通信的新兴技术之一,能够通过调控反射信号来克服“乘性衰落”效应,显著提高系统的性能。提出了一种多个有源RIS位置部署和相位配置进行联合迭代优化的方案,最大化信道的有效秩,提升系统的频谱效率。该方案采用麻雀搜索算法(Sparrow Search Algorithm,SSA)优化多个有源RIS的位置部署,提出联合多相位的最大交叉交换算法(Joint Multi-phases Maximum Cross-swapping Algorithm,JMMCA)优化其相位配置,通过交替迭代优化解决了有效秩最大化问题。仿真结果表明,所提方案能够有效提升系统的信道有效秩和频谱效率。In terahertz line of sight communication scenarios,the lack of scattering paths results in a severe rank deficiency in channels,leading to the loss of spatial multiplexing capability in Multiple Input Multiple Output(MIMO) systems.As an emerging technology in the sixth generation of mobile communications,active Reconfigurable Intelligent Surface(RIS) can significantly enhance system performance by controlling reflected signals to overcome the “multiplicative fading” effect.A joint iterative optimization scheme for the location deployment and phase configurations of multiple active RISs is proposed to maximize the effective rank of channels and improve spectral efficiency.The proposed scheme utilizes the Sparrow Search Algorithm(SSA) to optimize the location deployment of multiple active RISs and the Joint Multi-phase Maximum Cross-swapping Algorithm(JMMCA) is proposed to optimize their phase configurations.Finally,the problem of maximizing the effective rank is addressed through alternate iterative optimization.Simulation results show that the proposed scheme can effectively improve the channel effective rank and spectral efficiency of the system.

关 键 词：太赫兹通信 多输入多输出 有源智能反射面 信道有效秩 交替迭代优化 

分 类 号：TN929.5[电子电信—通信与信息系统]