Elbir, Ahmet M.2024-08-232024-08-2320230018-95451939-9359https://doi.org/10.1109/TVT.2023.3265395https://hdl.handle.net/20.500.12684/14136The sixth generation networks envision the deployment of terahertz (THz) band as one of the key enabling property thanks to its abundant bandwidth. However, the ultra-wide bandwidth in THz causes beam-split phenomenon due to the use of a single analog beamformer (AB). Specifically, beam-split makes different subcarriers to observe distinct directions since the same AB is adopted for all subcarriers. Previous works mostly employ additional hardware components, e.g., time-delayer networks to mitigate beam-split by realizing virtual subcarrier-dependent ABs. This article introduces an efficient and unified approach, called beam-split-aware (BSA) hybrid beamforming. In particular, instead of virtually generating subcarrier-dependent ABs, a single AB is used and the effect of beam-split is computed and passed into the digital beamformers, which are subcarrier-dependent while maximizing spectral efficiency. Hence, the proposed BSA approach effectively mitigates the impact of beam-split and it can be applied to any hybrid beamforming architecture. Manifold optimization and orthogonal matching pursuit techniques are considered for the evaluation of the proposed approach in multi-user scenario. Numerical simulations show that significant performance improvement can be achieved as compared to the conventional techniques.en10.1109/TVT.2023.3265395info:eu-repo/semantics/openAccessTerahertzbeam splitbeam-squint hybrid beamformingmulti-usermassive MIMOWireless CommunicationsChannel EstimationMimo SystemsSquintArticle72912355123602-s2.0-85153353469WOS:001103676800100Q1Q1