Ergodic capacity of antenna selection aided massive multi‐user MIMO systems with imperfect CSI in correlated time‐varying channels

Abstract

In this study, the authors address antenna selection (AS)-aided massive multi-user multiple-input-multiple-output (MU-MIMO) system based on maximum signal-to-noise ratio, where imperfect channel state information (CSI), time-varying channel and antenna spatial correlation are considered. More explicitly, a computationally simple training-based channel estimator is firstly employed for obtaining the imperfect down-link CSI. Channel quantisation (CQ) is subsequently introduced by the feedback link which is used for feeding back so-obtained CSI to base station. Time varying coefficient is utilised to characterise channel time variety and antenna spatial correlation is modelled by Kronecker model. Furthermore, the authors derive closed-form ergodic channel capacity of the AS-aided MU-MIMO system with channel estimation error, CQ error and delay feedback, which has not yet been addressed in the state-of-the-art approaches. Simulation results are provided to demonstrate the tightness of their theoretical computations of the ergodic channel capacity.