A Novel Beam Tracking Scheme in RIS for Wideband THz Communication Systems

Terahertz (THz) massive multiple-input multiple-output (mMIMO) has recently gained significant attention because of its ability to deliver a high data rate and offer a high capacity. In this letter, a novel sub-surface of sub-arrays (SSoSA)-based beam tracking scheme is proposed to track mobile users in reconfigurable intelligent surface (RIS)-aided wideband THz mMIMO systems. By considering the sub-connected phase-delay-phase architecture, the proposed scheme can simultaneously track the physical directions of users, unlike traditional schemes that generate one frequency-independent beam in each time slot. Simulation results show that the proposed scheme offers near-optimal achievable rate performance with low training overhead.