  Terahertz (THz) communication is considered one of the most critical
technologies for 6G because of its abundant bandwidth. To compensate the high
propagation of THz, analog/digital hybrid precoding for THz massive multiple
input multiple output (MIMO) is proposed to focus signals and extend
communication range. Notably, considering hardware cost and power consumption,
infinite and high-resolution phase shifters (PSs) are difficult to implement in
THz massive MIMO and low-resolution PSs are typically adopted in practice.
However, low-resolution PSs cause severe performance degradation. Moreover, the
beam squint in wideband THz massive MIMO increases the performance degradation
because of the frequency independence of the analog PSs. Motivated by the above
factors, in this paper, we firstly propose a heuristic algorithm under fully
connected (FC) structure, which optimize the digital precoder and the analog
precoder alternately. Then we migrate the proposed heuristic algorithm to the
partially-connected (PC) architecture. To further improve the performance, we
extend our design to dynamic subarrays in which each RF chain is connected to
any antenna that does not duplicate. The numerical results demonstrate that our
proposed wideband hybrid precoding with low-resolution PSs achieves better
performance to the comparisons for both FC structure and PC structure.
