Rate Region Combining in Multiuser MIMO

The concept of "information combing" is extended to multiple access schemes, where the receiver is equipped with multiple receive antennas. In particular, the connection of the respective rate region to that of the scalar MACs, which are present if the receive antennas are treated separately, is derived. This interpretation leads to new, expedient insights and the gains over "scalar combing", i.e., the synergy available in MIMO channels, are quantified from a new point of view. The theoretical results are illustrated by numerical examples