Semi-Deterministic Broadcast Channels with Cooperation

The semi-deterministic broadcast channel (BC) where the decoders may cooperate via a finite-capacity one-sided link is considered. The capacity region is derived via a novel converse that uses a probabilistic construction of auxiliary random variables that depends on the distribution induced by the codebook. Achievability is established by providing a coding scheme that incorporates techniques such as rate-splitting and Marton coding with a Wyner-Ziv-like coding mechanism that optimally leverages the cooperation link. The BC is shown to be operationally equivalent to a certain class of relay-broadcast channels (RBCs) and the correspondence between their capacity regions is established.