Antenna group selection based user scheduling for massive MIMO systems

Accurate transmit-side channel state information (CSI) is essential for achieving optimal performance of large-scale multiple-input multiple-output (MIMO) systems. However, due to high dimensionality of the massive MIMO systems, large overhead of the uplink CSI feedback is a big concern for frequency division duplexing (FDD) systems. In this paper, we propose antenna group scheduling (AGS) algorithm that combines antenna selection and user scheduling for pursuing further reduction in feedback overhead. The AGS method selects the antenna group with the maximum channel gain to reduce the dimension of channel vector and schedules users in the group maximizing the sum rate. Simulation results demonstrate that the proposed technique achieves significant feedback overhead reduction over the conventional beamforming techniques (33%~50%) under the same target sum rate requirement.