Abstract:
We consider compound multiple-antenna broadcast channels with M transmit antennas and K single-antenna receivers, where the channel of receiver r takes one of Jr complex ...Show MoreMetadata
Abstract:
We consider compound multiple-antenna broadcast channels with M transmit antennas and K single-antenna receivers, where the channel of receiver r takes one of Jr complex vectors. We show that for any finite Jr, the degrees of freedom (DoF) of MK/M+K-1 is achievable. It is in contrary to the commonly believed conjecture that the DoF collapses to one for large Jr's. We also establish the optimality of this result, where Jr ≥ M, r = 1, ..., K. The achievable scheme relies on using a number theoretic approach of interference alignment, and ignoring the possibility of cooperation among the transmit antennas. Moreover, we show that if Jr's for some of the users are relatively small, then both transmit cooperation and interference alignment are needed. Unlike the conventional schemes, here the transmit precoders are not full rank.
Published in: 2010 IEEE International Symposium on Information Theory
Date of Conference: 13-18 June 2010
Date Added to IEEE Xplore: 23 July 2010
ISBN Information: