3D Hybrid Beamforming with 2D Planar Antenna Arrays for Downlink Massive MIMO Systems

Abstract

We consider a millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) system in which a base station (BS) is equipped with a 2D planar hybrid antenna array. By exploiting the capability of scanning in both elevation and azimuth directions, 3D hybrid beamforming is performed to enhance both throughput and coverage of cellular systems. Joint optimization of 3D beamforming and user scheduling is proposed with the help of codebook-based selection algorithm under the practical channel state information (CSI) feedback framework. Comprehensive numerical simulation is performed by reflecting high frequency channel characteristics such as rain and gas losses provided by the third generation partnership project (3GPP) and the international telecommunication union (ITU). Numerical evaluation demonstrates that the proposed scheme is able to provide improved throughput with reduced hardware cost and low computational complexity.