A joint SDMA and interference suppression multiuser transmission scheme for millimeter-wave massive MIMO systems

This paper proposes a joint spatial division multiple access (SDMA) and interference suppression multiuser transmission scheme for massive multiple input multiple output (MIMO) systems working at millimeter-wave frequencies. Based on the sparsity of the beamspace channel matrix, we select several beams that capture the channel´s main lobe to approximate the original highrank channel. After judging whether the overlap exists among these selected beams, we divide the user set into two subsets, i.e., a non-interference subset or an interference subset. The non-interference subset employs an SDMA based transmission scheme, while the interference subset employs an interference suppression based scheme. This combination takes advantages of both schemes, reduces the feedback amount in frequency division duplex transmission mode, and meanwhile ensures all the users being served on a same time-frequency resource block. Simulation results demonstrate that the proposed joint scheme achieves considerable system sum-rate with a small amount of feedback.