Source broadcasting with unknown amount of receiver side information

The Slepian-Wolf scheme for source coding with side information at the receiver, assures that the sender can send the source X at a rate of only the conditional entropy H(X|Y-) bits per source symbol, which is the minimal possible rate even if the sender knew the side information Y. However, the Slepian-Wolf result requires knowledge of the optimal required rate. In this paper we consider a situation where this rate is not known, possibly since the source is broadcasted to many heterogeneous receivers. The approach is based on recent results regarding sending a common information over a broadcast channel.