On the Compound Broadcast Channel: Multiple Description Coding and Interference Decoding

Abstract

This work investigates the general two-user Compound Broadcast Channel (BC) where an encoder wishes to transmit common and private messages to two receivers while being oblivious to two possible channel realizations controlling the communication. The focus is on the characterization of the largest achievable rate region by resorting to more evolved encoding and decoding techniques than the conventional coding for the standard BC. The role of the decoder is first explored, and an achievable rate region is derived based on the principle of "Interference Decoding" (ID) where each receiver decodes its intended message and chooses to (non-uniquely) decode or not the interfering message. This inner bound is shown to be capacity achieving for a class of non-trivial compound BEC/BSC broadcast channels while the worst-case of Marton's inner bound -based on "Non Interference Decoding" (NID)- fails to achieve the capacity region. The role of the encoder is then studied, and an achievable rate region is derived based on "Multiple Description" (MD) coding where the encoder transmits a common as well as multiple dedicated private descriptions to the many instances of the users channels. It turns out that MD coding outperforms the single description scheme -Common Description (CD) coding- for a class of compound Multiple Input Single Output Broadcast Channels (MISO BC).