The Capacity Region of the Three Receiver Less Noisy Broadcast Channel

We determine the capacity region of a 3-receiver less noisy broadcast channel. The difficulty in extending the two-receiver result to three-receivers involves extending the Csiszar-sum lemma to three or more sequences, a standard difficulty in this area. In this work we bypass the difficulty by using a new information inequality, for less noisy receivers, that is employed in the converse. We also generalize our result to obtain the capacity region for a class of less noisy receivers.