Performance of Transmit Precoding in Time-Varying Point-to-Point and Multi-User MIMO Channels

Transmit precoding strategies in multiple-input multiple-output (MIMO) systems provide a mechanism for increasing the performance of point-to-point links and enable spatial division multiple access in multi-user networks. However, communication node mobility in such systems can lead to rapid channel variation which limits the quality of attainable channel state information (CSI). This paper explores the performance of point-to-point and multi-user precoding strategies based on CSI which goes out of date and channel distribution information which provides a more average channel representation. Results based on experimentally obtained MIMO channels in outdoor environments are presented.