Date Added: Apr 2012
A multi-antenna multiuser broadcast channel with transmitter beamforming and user selection is considered. Different from the conventional works, the authors consider imperfect Channel State Information (CSI) which is a practical scenario for multiuser broadcast channels. They propose a Robust Regularized Zero-Forcing (RRZF) beamforming at the base station. Then, they show that the RRZF outperforms Zero-Forcing (ZF) and Regularized ZF (RZF) beamforming even as the number of users grows to infinity. Simulation results validate the advantage of the proposed robust RZF beamforming.