  In this article, we investigate channel estimation for wideband
millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) under
hybrid architecture with lowprecision analog-to-digital converters (ADCs). To
design channel estimation for the hybrid structure, both analog processing
components and frequency-selective digital combiners need to be optimized. The
proposed channel estimator follows the typical linear-minimum-mean-square-error
(LMMSE) structure and applies for an arbitrary channel model. Moreover, for
sparsity channels as in mmWave, the proposed estimator performs more
efficiently by incorporating orthogonal matching pursuit (OMP) to mitigate
quantization noise caused by low-precision ADCs. Consequently, the proposed
estimator outperforms conventional ones as demonstrated by computer simulation
results.
