Downlink Performance Evaluation of Centralized and Distributed Antenna Systems in Multicell Multiuser Spatial Multiplexing Environment

In this paper, we compare the downlink performance of multiuser spatial multiplexing of centralized antenna system (CAS) and distributed antenna system (DAS) in interference-limited cellular scenario. We present the implementation of multiuser spatial multiplexing in a multicell system based on selection diversity. And two user scheduling strategies based on proportional fairness is proposed too. In a typical MIMO configuration (base station with 4 antennas, mobile station with 2 antenna), we achieve the evaluation of spectrum efficiency and user throughput for both CAS and DAS. The results show that compared with CAS with same number of transmit antennas, DAS can support multiuser diversity better and significantly improve the system capacity and cumulate distribution of user throughput.