M. Chowdhury, A. Goldsmith

We consider a multiuser single-input multiple-output multiple access channel with each user transmitting from a discrete constellation. We show that, reliable communication (with the decoding error probability per user being arbitrarily low) can be supported even with the number of antennas at the output being a vanishingly small fraction of the number of users in the system. Moreover, convex optimization-based relaxations to maximum likelihood decoder are sufficient towards achieving these results.

Prior versions of this work appeared in the 50th Annual Allerton Conference on Communication, Control, and Computing (Allerton2012), in the 2013 IEEE International Symposium on Information Theory (ISIT), and in the 2013 51st Annual Allerton Conference on Communication, Control, and Computing (Allerton2013).

This is joint work with Tsachy Weissman.