Digital Beamforming-Based Massive MIMO Transceiver for 5G Millimeter-Wave Communications

• Published in: IEEE transactions on microwave theory and techniques Vol. 66; no. 7; pp. 3403 - 3418
• Main Authors: Yang, Binqi, Yu, Zhiqiang, Lan, Ji, Zhang, Ruoqiao, Zhou, Jianyi, Hong, Wei
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Array signal processing; Bandwidths; Beamforming; Columns (structural); Data transmission; Digital beamforming (DBF); fifth-generation (5G) communication; Horizontal orientation; massive multiple-input multiple-output (MIMO); Millimeter wave circuits; Millimeter wave communication; Millimeter waves; millimeter-wave; MIMO communication; multibeam system; Substrate integrated waveguides; transceiver; Transceivers
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2018.2829702

A 64-channel massive multiple-input multiple-output (MIMO) transceiver with a fully digital beamforming (DBF) architecture for fifth-generation millimeter-wave communications is presented in this paper. The DBF-based massive MIMO transceiver is operated at 28-GHz band with a 500-MHz signal bandwidth and the time division duplex mode. The antenna elements are arranged as a 2-D array, which has 16 columns (horizontal direction) and 4 rows (vertical direction) for a better beamforming resolution in the horizontal plane. To achieve half-wavelength element spacing in the horizontal direction, a new sectorial transceiver array design with a bent substrate-integrated waveguide is proposed. The measured results show that an excellent RF performance is achieved. The system performance is tested with the over-the-air technique to verify the feasibility of the proposed DBF-based massive MIMO transceiver for high data rate millimeter-wave communications. Using the beam-tracking technique and two streams of QAM-64 signals, the proposed millimeter-wave MIMO transceiver can achieve a steady 5.3-Gb/s throughput for a single user in fast mobile environments. In the multiple-user MIMO scenario, by delivering 20 noncoherent data streams to eight four-channel user terminals, it achieves a downlink peak data rate of 50.73 Gb/s with the spectral efficiency of 101.5 b/s/Hz.