Hybrid Digital-Analog Coding for Interference Broadcast Channels

We consider the transmission of bivariate Gaussian sources (V-1, V-2) over the two-user Gaussian broadcast channel in the presence of interference that is correlated to the source and known to the transmitter. Each user i is interested in estimating V-i. We study hybrid digital-analog (HDA) schemes and analyze the achievable (square-error) distortion region under matched and expansion bandwidth regimes. These schemes require proper combinations of power splitting, bandwidth splitting, rate splitting, Wyner-Ziv and HDA Costa coding. An outer bound on the distortion region is also derived by assuming knowledge of V-1 at the second user and full/partial knowledge of the interference at both users. Numerical results show that the HDA schemes outperform tandem and linear schemes and perform close to the derived bound for certain system settings.