Distortion bounds for broadcasting a Gaussian source in the presence of interference

We consider the transmission of a Gaussian source over the two-user Gaussian broadcast channel in the presence of interference that is known to the transmitter. The interference is assumed to be correlated to the source and each user is interested in estimating the source signal. We propose a hybrid digital-analog (HDA) scheme based on proper combinations of power splitting, Wyner-Ziv and HDA Costa coding. The achievable (square-error) distortion region (inner bound) of this scheme is analyzed under source-channel bandwidth expansion; the matched bandwidth is treated as a special case. An outer bound on the distortion region is also derived by assuming full/partial knowledge of the interference at both users and by adapting the approach of Reznic et al. (2006). This outer bound can be tighter than the “trivial” outer bound found by assuming point-to-point communication.