Wideband beamforming for hybrid massive MIMO terahertz communications
File(s)
Accepted version
Author(s)
Gao, FeiFei
Wang, Bolei
Xing, C-W
An, J-P
Li, Geoffrey
Type
Journal Article
Abstract
The combination of large bandwidth at terahertz (THz) and the large number of antennas in massive MIMO results in the non-negligible spatial wideband effect in time domain or the corresponding beam squint issue in frequency domain, which will cause severe performance degradation if not properly treated. In particular, for a phased array based hybrid transceiver, there exists a contradiction between the requirement of mitigating the beam squint issue and the hardware implementation of the analog beamformer/combiner, which makes the accurate beamforming an enormous challenge. In this paper, we propose two wideband hybrid beamforming approaches, based on the virtual sub-array and the true-time-delay (TTD) lines, respectively, to eliminate the impact of beam squint. The former one divides the whole array into several virtual sub-arrays to generate a wider beam and provides an evenly distributed array gain across the whole operating frequency band. To further enhance the beamforming performance and thoroughly address the aforementioned contradiction, the latter one introduces the TTD lines and propose a new hardware implementation of analog beamformer/combiner. This TTD-aided hybrid implementation enables the wideband beamforming and achieves the nearoptimal performance close to full-digital transceivers. Analytical and numerical results demonstrate the effectiveness of two proposed wideband beamforming approaches.
Date Issued
2021-04-08
Date Acceptance
2021-03-02
Citation
IEEE Journal on Selected Areas in Communications, 2021, 39 (6), pp.1725-1740
ISSN
0733-8716
Publisher
Institute of Electrical and Electronics Engineers
Start Page
1725
End Page
1740
Journal / Book Title
IEEE Journal on Selected Areas in Communications
Volume
39
Issue
6
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
Identifier
https://ieeexplore.ieee.org/document/9398864
Subjects
0805 Distributed Computing
0906 Electrical and Electronic Engineering
1005 Communications Technologies
Networking & Telecommunications
Publication Status
Published
Date Publish Online
2021-04-08