Efficient Uplink User Selection Algorithm in Distributed Antenna Systems

An efficient uplink user selection algorithm for distributed antenna systems (DAS) is proposed in this paper. Previous user selection algorithms in multiple-input-multiple-output (MIMO) systems are designed for conventional MIMO systems where antennas are located together. Since DAS can be thought as a variation of MIMO systems, the user selection algorithms which are originally designed for conventional MIMO systems can also be applied to DAS. However, the channel characteristics of DAS are different from those of conventional MIMO systems. Thus there should be specific user selection algorithm for DAS environments which utilizes the channel characteristics of DAS. This paper proposes an efficient uplink user selection algorithm specified for DAS. Simulation results show that the proposed algorithm gives near optimal performance which reaches up to 98.5% of the optimal spectral efficiency. Furthermore, the complexity of the proposed algorithm is also examined and the results show that it is easy to implement in practical systems.