Conferences: On a Mutual Information and a Capacity Bound Gap of Pilot-Aided MIMO Channels
Pastore, Joham and J. Rodríguez Fonollosa

Abstract

For single-user MIMO channels with partial receiver CSI, we study the difference between inner and outer bounds of the mutual information achieved with Gaussian codebooks, as well as a related difference between capacity inner and outer bounds. In contrast to previous studies, we assume that the channel estimation error statistics are not given a priori, but depend on the parameters of a training routine, in which a pilot sequence is transmitted, and where the channel realization is linearly estimated. Under these conditions, we successively determine analytic upper and lower bounds on the mutual information bound gap. We further study the asymptotic behavior of said bound gaps for high SNR and a large number of antennas. This allows us to prove, for example, that for MISO channels and a certain class of semicorrelated MIMO channels, when the training and transmit power levels are equal, the capacity is approached to within min(N_Tx,N_Rx) bits by the capacity bounds, where N_Tx and N_Rx stand for the number of transmit and receive antennas, respectively.

Full document




©UPC Universitat Politècnica de Catalunya
Signal Processing and Communications group
Powered by Joomla!.