On the Optimality of Decode and Forward for Some Cooperative Broadcast Channels

This article characterizes new boundary points on the capacity region of certain classes of more capable broadcast channels (BC) with uni-directional cooperation from the stronger to the weaker receiver. The new boundary points are achieved by a simple coding scheme that employs superposition coding at the transmitter with decode and forward at the stronger receiver. We evaluate our general result for Gaussian BCs and for a BC consisting of a binary erasure channel (BEC) to the stronger receiver and a binary symmetric channel (BSC) to the weaker receiver.