Journal of Computer Applications ›› 2025, Vol. 45 ›› Issue (12): 3931-3938.DOI: 10.11772/j.issn.1001-9081.2024121805

• Network and communications • Previous Articles     Next Articles

Extremely large-scale MIMO channel estimation in hybrid field based on adaptive gradient matching pursuit algorithm

Zhanjun LIU1,2, Yunpeng SONG1,2, Shengbao WANG1,2   

  1. 1.School of Communications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China
    2.Chongqing Key Laboratory of Mobile Communication Technology (Chongqing University of Posts and Telecommunications),Chongqing 400065,China
  • Received:2024-12-24 Revised:2025-03-21 Accepted:2025-03-25 Online:2025-04-22 Published:2025-12-10
  • Contact: Yunpeng SONG
  • About author:LIU Zhanjun, born in 1975, Ph. D., professor. His research interests include wireless mobile communication.
    SONG Yunpeng, born in 1999, M. S. candidate. His research interests include physical layer algorithms for mobile communication, channel estimation.
    WANG Shengbao, born in 2001, M. S. candidate. His research interests include physical layer algorithms for mobile communication, channel estimation.
  • Supported by:
    Innovation and Development Joint Fund of Chongqing Natural Science Foundation (China Satellite Network)(CSTB2023NSCQ-LZX0114)

基于自适应梯度匹配追踪算法的超大规模多输入多输出混合场信道估计

刘占军1,2, 宋云鹏1,2, 王盛宝1,2   

  1. 1.重庆邮电大学 通信与信息工程学院,重庆 400065
    2.移动通信技术重庆市市级重点实验室(重庆邮电大学),重庆 400065
  • 通讯作者: 宋云鹏
  • 作者简介:刘占军(1975—),男,河北保定人,教授,博士,主要研究方向:无线移动通信
    宋云鹏(1999—),男,山东济南人,硕士研究生,主要研究方向:移动通信物理层算法、信道估计
    王盛宝(2001—),男,湖北荆门人,硕士研究生,主要研究方向:移动通信物理层算法、信道估计。
  • 基金资助:
    重庆市自然科学基金创新发展联合基金(中国星网)资助项目(CSTB2023NSCQ-LZX0114)

Abstract:

In response to the problem of high complexity and low accuracy in hybrid-field channel estimation faced by eXtremely Large-scale Multiple-Input Multiple-Output (XL-MIMO) systems in 6th Generation wireless communication technology (6G) networks, an Adaptive Gradient Matching Pursuit (AGMP) algorithm was proposed. Firstly, the angular-domain transformation matrix was used to estimate far-field components, and the polar-domain transformation matrix was used to estimate near-field components, thereby transforming the channel estimation problem into a sparse reconstruction problem. Then, during the component estimation process, the Least Mean Square (LMS) algorithm was combined with an adaptive gradient search strategy to optimize path component estimation through dynamic adjustment of step-size parameters, and the Minimum Mean Squared Error (MMSE) target was approximated iteratively, thereby optimizing the channel estimation process. Finally, the complete hybrid-field channel was reconstructed by using angular-domain and polar-domain transformation matrices, thereby achieving accurate hybrid-field channel estimation. Simulation results demonstrate that in low-Signal-to-Noise Ratio (SNR) environments, the proposed algorithm improves the achievable rate by 20.46% approximately compared to Orthogonal Matching Pursuit (OMP) algorithm. Furthermore, as the number of User Equipment (UE) antennas increases, the Normalized Mean Squared Error (NMSE) of the proposed algorithm is reduced by 1.2 dB approximately compared to that of OMP algorithm in multi-antenna environment. It can be seen that the proposed algorithm achieves superior estimation performance in low-SNR and multi-antenna UE environments.

Key words: eXtremely Large-scale Multiple-Input Multiple-Output (XL-MIMO), channel estimation, hybrid field, adaptive search, gradient descent

摘要:

针对第六代无线通信技术(6G)网络中超大规模多输入多输出(XL-MIMO)系统在混合场信道估计中面临的高复杂度和低精度问题,提出一种自适应梯度匹配追踪(AGMP)算法。首先,利用角域变换矩阵估计远场分量,并利用极域变换矩阵估计近场分量,从而将信道估计问题转化为稀疏重构问题;其次,在估计分量的过程中,采用最小均方(LMS)算法,并结合自适应梯度搜索策略,通过动态调整步长参数优化路径分量估计,并迭代逼近最小均方误差(MMSE)目标,从而优化信道估计过程;最后,通过角域和极域变换矩阵重建整个混合场信道,从而完成混合场信道的精确估计。仿真实验结果表明,在低信噪比(SNR)环境下,与正交匹配追踪(OMP)算法相比,所提算法的可达速率提升了约20.46%。此外,随着用户设备(UE)天线数量的增加,在多天线环境下,所提算法的归一化均方误差(NMSE)相较于OMP算法降低了约1.2 dB。可见,所提算法在低SNR和多天线UE环境下能获得更好的估计性能。

关键词: 超大规模多输入多输出, 信道估计, 混合场, 自适应搜索, 梯度下降

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