2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/133817A fading broadcast channel is considered where the transmitter employs two antennas and each of the two receivers employs a single receive antenna. It is demonstrated that even if the realization of the fading is precisely known to the receivers, the high signal-to-noise (SNR) throughput is greatly reduced if, rather than knowing the fading realization \emph{precisely}, the trasmitter only knows the fading realization \emph{approximately}. The results are general and are not limited to memoryless Gaussian fading.Extended version of a paper of the same title that appeared in the Proceedings of the 43rd Annual Allerton Conference on Communication, Control, and Computing, Sept. 28-30, 2005Information Theorytext