Cooperative distributed antenna systems for mobile communications [Coordinated and Distributed MIMO]

Cooperative distributed antenna systems have drawn considerable attention in recent years due to their potential to enhance both the coverage and the spectral efficiency of mobile communication systems. In this article the conceptual description of a cooperative DAS for mobile communications is presented together with key techniques for DASs, including distributed multiple- input multiple-output for single and multiple users, handover, and transmit power allocation. Furthermore, theoretical and simulation results on the spectral or transmit power efficiency of cooperative DASs are given and compared with those on conventional collocated antenna systems. It is shown that a cooperative DAS can provide very promising performance enhancements in capacity and transmit power efficiency.