Beamforming optimization for full-duplex MIMO multiuser system with channel estimation error

We study the beamforming optimization of full-duplex (FD) multiple-input multiple-output (MIMO) multiuser system, where full-duplex communication (FDC) is enabled at the base station (BS). The system suffers not only from self interference (SI) and co-channel interference (CCI), but also from channel estimation error. We focus on the effect of imperfect channel state information (CSI) owing to nonideal channel estimation which is an inevitable problem in practical communications. To address this issue, a beamforming optimization problem is formulated to maximize the achievable sum rate. Since the problem is non-convex, a low complexity iterative algorithm based on gradient projection (GP) is proposed. Numerical simulations demonstrate that with the proposed beamforming optimization, FD system can outperform HD system even under imperfect CSI condition.