A Low Complexity Capacity-Greedy User Selection Scheme for Zero-Forcing Beamforming

We address the user selection scheme in multi-user wireless communication system, utilizing zero-forcing beamforming for spatial division multiple access. Recently, it has been shown that multi-user scheduling can help to achieve significant throughput gain in addition to the MIMO spatial multiplexing gain. And the capacity-greedy user selection algorithm can achieve near-optimal performance with much lower complexity compared with exhaustive search, due to reduced trial times of possible user combinations. However the computational complexity may be still too high for feasible applications, which depends on the system bandwidth, the number of active users and the number of antennas. In this paper, a novel capacity-greedy user selection scheme is proposed for the multi-user zero-forcing beamforming system, which involves low-complexity approximation for multi-user zero-forcing beamforming capacity. Simulation results verify that the proposed scheme can reduce the computational complexity of user selection greatly, with slightly performance loss.