Structures of space-time codes and multipath MIMO channels

In a wireless system with multipath multiple-input multiple-output (MIMO) channels using antenna arrays, the delay spread of the multipaths results in intersymbol interference (ISI) and channel frequency selectivity. In contrast with the channel frequency selectivity, spatial gains at the multipath angles also naturally result in channel angle selectivity. Based on the channel selectivity structures characterized by the path delays and the path directions-of-departure/arrival, we seek new insights into the matching of space-time codes and multipath MIMO channels in their angle-frequency (AF) structures.