Simplified Semi-Orthogonal User Selection for MU-MIMO Systems with ZFBF

In this letter, we simplify the well-known semi-orthogonal user selection (SUS) algorithm for the multi-user multiple-input multiple-output (MU-MIMO) system with zero-forcing beamforming (ZFBF). Compared with the original SUS algorithm, the proposed user selection algorithm achieves the same performance, but with significantly less complexity. Simulation results show that the proposed algorithm can make a good tradeoff between performance and complexity for the MU-MIMO system with ZFBF.