{"title":"Underdetermined AOA Estimation Using Non-Uniform Sub-Connected Hybrid Beamforming Systems","authors":"Yu-Chen Liu;Hsuan-Jung Su;Yasuhiro Takano","doi":"10.1109/OJCOMS.2025.3542843","DOIUrl":null,"url":null,"abstract":"Hybrid beamforming (HBF) is emerging as a key technology for future wireless networks, particularly in millimeter wave (mmWave) bands. In this paper, we present a non-uniform sub-connected hybrid beamforming (NSC-HBF) system that enables the implementation of the difference co-array for the underdetermined angle-of-arrival (AOA) estimation. We propose a broad beam synthesis technique to mitigate performance degradation caused by uneven analog combining gains. To further enhance estimation efficiency, we modified the co-array least mean squares (co-array LMS) method by directly solving the least-squares problem to determine the filter weights. The proposed method reduces computational complexity and eliminates iterative procedures for faster processing. Our numerical results demonstrate the pseudo-spectrum and detection performance for both pencil and broad beams, highlighting the importance of analog combining codebook design. Additionally, the proposed method achieves higher estimation accuracy compared to the co-array root-LMS.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1485-1496"},"PeriodicalIF":6.3000,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10891408","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Open Journal of the Communications Society","FirstCategoryId":"1085","ListUrlMain":"https://ieeexplore.ieee.org/document/10891408/","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Hybrid beamforming (HBF) is emerging as a key technology for future wireless networks, particularly in millimeter wave (mmWave) bands. In this paper, we present a non-uniform sub-connected hybrid beamforming (NSC-HBF) system that enables the implementation of the difference co-array for the underdetermined angle-of-arrival (AOA) estimation. We propose a broad beam synthesis technique to mitigate performance degradation caused by uneven analog combining gains. To further enhance estimation efficiency, we modified the co-array least mean squares (co-array LMS) method by directly solving the least-squares problem to determine the filter weights. The proposed method reduces computational complexity and eliminates iterative procedures for faster processing. Our numerical results demonstrate the pseudo-spectrum and detection performance for both pencil and broad beams, highlighting the importance of analog combining codebook design. Additionally, the proposed method achieves higher estimation accuracy compared to the co-array root-LMS.
期刊介绍:
The IEEE Open Journal of the Communications Society (OJ-COMS) is an open access, all-electronic journal that publishes original high-quality manuscripts on advances in the state of the art of telecommunications systems and networks. The papers in IEEE OJ-COMS are included in Scopus. Submissions reporting new theoretical findings (including novel methods, concepts, and studies) and practical contributions (including experiments and development of prototypes) are welcome. Additionally, survey and tutorial articles are considered. The IEEE OJCOMS received its debut impact factor of 7.9 according to the Journal Citation Reports (JCR) 2023.
The IEEE Open Journal of the Communications Society covers science, technology, applications and standards for information organization, collection and transfer using electronic, optical and wireless channels and networks. Some specific areas covered include:
Systems and network architecture, control and management
Protocols, software, and middleware
Quality of service, reliability, and security
Modulation, detection, coding, and signaling
Switching and routing
Mobile and portable communications
Terminals and other end-user devices
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Communications-based distributed resources control.