{"title":"Near-Field Channel Estimation and Sparse Reconstruction for FDD XL-MIMO Systems","authors":"Ze Wang;Guoping Zhang;Ji Wang;Hongbo Xu","doi":"10.1109/LCOMM.2025.3542482","DOIUrl":null,"url":null,"abstract":"The exponential growth of antennas in extremely large-scale MIMO (XL-MIMO) systems can lead to substantial overhead in pilot transmission for channel estimation and feedback, resulting in a decline in spectrum efficiency. This letter proposes a deep learning (DL)-based framework tailored for frequency division duplex (FDD) XL-MIMO, focusing on specialized neural networks for channel estimation and sparse reconstruction. For channel estimation, we design frequency-aware pilots by using dense layers according to the signal model and develop an attention mechanism-based residual channel estimation (A-RCE) network, which leverages inherent correlations within the channel matrix across subcarriers and antennas to improve estimation accuracy. To reduce channel state information (CSI) feedback overhead, we introduce a trainable fast iterative shrinkage thresholding (TFIST) network that leverages the polar-domain sparsity of the near-field channel to achieve a low-dimensional sparse representation. The simulation results validate the effectiveness of our proposed scheme, which can significantly enhance the estimation performance compared to other benchmark schemes.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 4","pages":"744-748"},"PeriodicalIF":3.7000,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Communications Letters","FirstCategoryId":"94","ListUrlMain":"https://ieeexplore.ieee.org/document/10891049/","RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"TELECOMMUNICATIONS","Score":null,"Total":0}
引用次数: 0
Abstract
The exponential growth of antennas in extremely large-scale MIMO (XL-MIMO) systems can lead to substantial overhead in pilot transmission for channel estimation and feedback, resulting in a decline in spectrum efficiency. This letter proposes a deep learning (DL)-based framework tailored for frequency division duplex (FDD) XL-MIMO, focusing on specialized neural networks for channel estimation and sparse reconstruction. For channel estimation, we design frequency-aware pilots by using dense layers according to the signal model and develop an attention mechanism-based residual channel estimation (A-RCE) network, which leverages inherent correlations within the channel matrix across subcarriers and antennas to improve estimation accuracy. To reduce channel state information (CSI) feedback overhead, we introduce a trainable fast iterative shrinkage thresholding (TFIST) network that leverages the polar-domain sparsity of the near-field channel to achieve a low-dimensional sparse representation. The simulation results validate the effectiveness of our proposed scheme, which can significantly enhance the estimation performance compared to other benchmark schemes.
期刊介绍:
The IEEE Communications Letters publishes short papers in a rapid publication cycle on advances in the state-of-the-art of communication over different media and channels including wire, underground, waveguide, optical fiber, and storage channels. Both theoretical contributions (including new techniques, concepts, and analyses) and practical contributions (including system experiments and prototypes, and new applications) are encouraged. This journal focuses on the physical layer and the link layer of communication systems.