“…To cope with these shortcomings, numerous works have been conducted on the applications of mmWave massive MIMO time-varying channels (Kabaoglu, 2009;Fernandez et al, 2010;Bourdoux et al, 2011;Gu et al, 2014;Awad et al, 2015;Choi et al, 2016;Gao et al, 2017a;Ma et al, 2018;Wu et al, 2019). Although the complexity of transceivers is reduced by hybrid analog/digital structures, the high cost of hardware prevents the transceivers from exploiting one dedicated radio frequency (RF) chain for each equipped antenna (Awad et al, 2015;Ma et al, 2018;Wu et al, 2019;Brighente et al, 2020), and hybrid beamforming schemes require more pilot overhead for fast time-varying channels (Garcia et al, 2016;Kong et al, 2017). Although many channel tracking schemes have been researched in the applications of mmWave V2I communication (Bourdoux et al, 2011;Gu et al, 2014;Awad et al, 2015;Gao et al, 2017a;Mehrabi et al, 2020), however, those schemes are suitable only for the terahertz frequency band and cannot be applied to fast timevarying mmWave channels.…”