Successive Refinement With Decoder Cooperation and Its Channel Coding Duals

We study cooperation in multiterminal source coding models involving successive refinement. Specifically, we study the case of a single encoder and two decoders, where the encoder provides a common description to both the decoders and a private description to only one of the decoders. The decoders cooperate via cribbing, i.e., the decoder with access only to the common description is allowed to observe, in addition, a deterministic function of the reconstruction symbols produced by the other. We characterize the fundamental performance limits in the respective settings of noncausal, strictly causal, and causal cribbing. We use a coding scheme, referred to as Forward Encoding and Block Markov Decoding, which builds on one recently used by Cuff and Zhao for coordination via implicit communication. Finally, we use the insight gained to introduce and solve some dual-channel coding scenarios involving multiple-access channels with cribbing.