Channel Estimation for Wideband mmWave MIMO-OFDM System with Beam Squint Effect

Millimeter-wave (mmWave) communication has been widely considered as a key enabler for the future wireless systems. To combat the high propagation loss associated with mmWave band, accurate channel state information is especially essential for achieving large beamforming gain. However, due to the influence of beam squint effect and frequency-selective fading, accurate channel estimation is challenging in a typical wideband multiple-input multiple-output system. To tackle this issue, by exploiting the structure information of the wideband channel, we first recast the channel estimation as a joint sparse signal recovery problem. Building upon this, we propose a channel estimation scheme that can effectively refine the relevant channel parameters in an iterative minimization manner. Numerical results are provided to illustrate the effectiveness of our proposed method.