3-D Hybrid Beamforming for Terahertz Broadband Communication System With Beam Squint

In this paper, the three-dimensioned (3D) hybrid beamforming is designed for the terahertz (THz) based broadband broadcasting communication system with beam squint. Specifically, the full-dimensional THz massive multiple input multiple output (M-MIMO) channel model and the array gain of the uniform planar array (UPA) are first analyzed in the context of the beam squint effect. Then, a 3D hybrid beamforming architecture is proposed by leveraging two-tier true time delay (TTD), which is able to combat the beam squint effect from the horizontal and vertical directions. To further reduce hardware cost and power consumption, a low-cost 3D hybrid beamforming architecture with a two-tier TTD and phase shifter combination (TPC) is designed. Simulation results are shown that the performance of the proposed 3D hybrid beamforming architectures is capable of approaching that of the full-digital beamforming counterpart in the face of beam squint, despite relying on reduced implementation cost.