Transmit Antenna Subset Selection for Downlink MIMO Systems

This paper discusses transmit antenna subset selection schemes for downlink closed-loop multiple-input multiple-output (MIMO) systems in multicell environments. A simplified cooperative scheme is proposed to increase the sum of the mutual information of the links in all cells. The proposed simplified-cooperative scheme is realistic in that it only utilizes a limited amount of information from adjacent links, while the conventional cooperative scheme requires a large amount of information such as channel state information and MIMO transmit configurations of adjacent links. In spite of the use of a limited amount of information, the proposed scheme provides almost 90 percent of the average mutual information provided by the cooperative scheme. Furthermore, the proposed scheme shows significant enhancements over the competitive scheme which does not consider the effects of antenna subset selection on the performance of adjacent links.