Capacity theorems for three-user cooperative relay broadcast channels

This paper investigates the rate regions of three-user cooperative relay broadcast channels which are based on a three-user broadcast channel. We consider three basic models, the single relay broadcast channel, the parallel relay broadcast channel, and the multi-layer relay broadcast channel. Achievable rate regions are derived by using the decode-and-forward scheme and the compress-and-forward scheme. Furthermore, two-sided cooperative relay broadcast channels based on these three basic models are studied. Outer bounds on the rate regions of the three-user cooperative relay broadcast channels are also obtained. The outer bounds are tighter than the cut-set bounds.