Systems Engineering and Electronics ›› 2025, Vol. 47 ›› Issue (8): 2744-2752.doi: 10.12305/j.issn.1001-506X.2025.08.32

• Communications and Networks • Previous Articles     Next Articles

Terahertz extremely large-scale MIMO hybrid field channel estimation

Bo GAO1,2(), Youhua FU1,2,*, Chen LIU1,2   

  1. 1. College of Electronic and Optical Engineering and College of Flexible Electronics (Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,China
    2. National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology,Nanjing University of Posts and Telecommunications,Nanjing 210023,China
  • Received:2024-06-12 Online:2025-08-31 Published:2025-09-04
  • Contact: Youhua FU E-mail:gb191230@163.com

Abstract:

The extremely large-scale multiple-input-multiple-output (XL-MIMO) has become an innovative technique for the future 6G communications. In XL-MIMO wireless systems, due to the increase in the number of antennas at the base station, channel modeling needs to consider both the near-field spherical waves and the far-field plane waves. In order to reduce the guide frequency overhead of channel estimation, a hybrid-field channel estimation method based on a convex optimization approach is proposed. The uplink hybrid-field XL-MIMO system channel shows sparsity after the far-field angular-domain transformations and the near-field polar-domain transformations, and the channel estimation problem is an optimization problem with $ {\ell _0} $ norm constraints. Due to the nonconvexity of the obtained problem, the problem is transformed into a convex problem by relaxing the number of $ {\ell _0} $ norms to $ {\ell _1} $ norms, and two hybrid field channel estimation algorithms are proposed by applying the proximal gradient (PG) approach and the alternating direction method of multipliers (ADMM), respectively. The different frequency subcarriers of a wireless communication terahertz system cannot be approximated equal, so the dictionaries at the corresponding frequencies are used for the different frequency subcarriers. Compared with the traditional channel estimation algorithms based on the orthogonal tracking matching for the near and far fields, the proposed hybrid-field algorithm does not require the number of paths in the near and far field as priori condition and has higher accuracy.

Key words: hybrid field, sparsity, channel estimation, terahertz

CLC Number: 

[an error occurred while processing this directive]