Low Complexity Scheduling for Downlink Multiuser MIMO Systems in Correlated Channels

Many successive scheduling schemes associated with linear transmit beamforming have been proposed which can asymptotically achieve the sum rate of dirty paper coding (DPC) in Ltd. channels. In this paper, the performance of the successive scheduling in spatially correlated channels is studied. Then we propose a low complexity alternating user scheduling (AUS), which can be applied to both zero-forcing beamforming (ZFBF) and regularized ZFBF (R-ZFBF). The new scheduling algorithm can achieve a comparable sum rate with that of the exhaustive searching in both i.i.d. and spatially correlated channels with the same order of complexity as the successive scheduling.