Coordinated multi-cell MU-MIMO downlink transmission with adaptive beam deactivation

In this paper, we propose an adaptive beam deactivation scheme for the coordinated multi-cell multiuser multiple-input multiple-output (MU-MIMO) downlink system with limited feedback. In the proposed scheme, each user feeds back the indices of a desired beam and multiple undesired beams from its codebook and some channel quality indicators to its base station (BS). Based on the feedback information and the proposed transmitting user set selection algorithm, the coordinating BSs select one user for each BS to serve. Through the numerical example, we show that the proposed scheme achieves comparable sum rate gain compared to the conventional zeroforcing based coordinated multi-cell system with reduced feedback load.