  Terahertz (THz)-band has been envisioned for the sixth generation wireless
networks thanks to its ultra-wide bandwidth and very narrow beamwidth.
Nevertheless, THz-band transmission faces several unique challenges, one of
which is beam-split which occurs due to the usage of subcarrier-independent
analog beamformers and causes the generated beams at different subcarriers
split, and point to different directions. Unlike the prior works dealing with
beam-split by employing additional complex hardware components, e.g.,
time-delayer networks, a beam-split-aware orthogonal matching pursuit (BSA-OMP)
approach is introduced to efficiently estimate the THz channel and beamformer
design without any additional hardware. Specifically, we design a BSA
dictionary comprised of beam-split-corrected steering vectors which inherently
include the effect of beam-split so that the proposed BSA-OMP solution
automatically yields the beam-split-corrected physical channel directions.
Numerical results demonstrate the superior performance of BSA-OMP approach
against the existing state-of-the-art techniques.
