Achievable rate region for three user discrete broadcast channel based on coset codes

We present an achievable rate region for the general three user discrete broadcast channel (DBC), based on coset codes. We identify an example of a three user DBC for which the proposed achievable rate region strictly enlarges that obtained by a natural extension of Marton's [1] rate region. As a step towards deriving the achievable rate region for the general three user DBC, we characterize and derive an achievable rate region for a new class - 3-to-1 DBC- of broadcast channels of which the aforementioned is an example.