  We propose a MIMO channel estimation method for millimeter-wave (mmWave) and
terahertz (THz) systems based on frequency-selective atomic norm minimization
(FS-ANM). For the strong line-of-sight property of the channel in such
high-frequency bands, prior knowledge on the ranges of angles of
departure/arrival (AoD/AoA) can be obtained as the prior knowledge, which can
be exploited by the proposed channel estimator to improve the estimation
accuracy. Simulation results show that the proposed method can achieve
considerable performance gain when compared with the existing approaches
without incorporating the the strong line-of-sight property.
