Journal
IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS
Volume 40, Issue 10, Pages 2840-2854Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/JSAC.2022.3196090
Keywords
Array signal processing; Wideband; Antenna arrays; Radio frequency; Phase shifters; Computer architecture; Switches; Terahertz (THz) band; hybrid beamforming; dynamic-subarray; fixed true-time-delay; beam squint
Funding
- National Key Research and Development Program of China [2020YFB1805700]
- National Natural Science Foundation of China (NSFC) [62171280]
- Australian Research Council (ARC) [DP190101363]
- ARC Linkage Project [LP170101196]
Ask authors/readers for more resources
This paper introduces a novel DS-FTTD structure to address the beam squint issue in hybrid beamforming, and proposes a low-complexity RD algorithm to design hybrid beamforming matrices, which can significantly improve energy efficiency and array gain.
Hybrid beamforming for Terahertz (THz) ultra-massive multiple-input multiple-output (UM-MIMO) systems is a promising technology for 6G space-air-ground integrated networks, which can overcome huge propagation loss and offer unprecedented data rates. With ultra-wide bandwidth and ultra-large-scale antennas array in THz band, the beam squint becomes one of the critical problems which could reduce the array gain and degrade the data rate substantially. However, the traditional phase-shifters-based hybrid beamforming architectures cannot tackle this issue due to the frequency-flat property of the phase shifters. In this paper, to combat the beam squint while keeping high energy efficiency, a novel dynamic-subarray with fixed true-time-delay (DS-FTTD) architecture is proposed. Compared to the existing studies which use the complicated adjustable TTDs, the DS-FTTD architecture has lower power consumption and hardware complexity, thanks to the low-cost FTTDs. Furthermore, a low-complexity row-decomposition (RD) algorithm is proposed to design hybrid beamforming matrices for the DS-FTTD architecture. Extensive simulation results show that, by using the RD algorithm, the DS-FTTD architecture achieves near-optimal array gain and significantly higher energy efficiency than the existing architectures. Moreover, the spectral efficiency of DS-FTTD architecture with the RD algorithm is robust to the imperfect channel state information.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available