Bounds and Capacity Results for the Cognitive Z Channel

The authors study the discrete memoryless Z channel where the non-broadcasting transmitter is cognitive and knows both messages of the broadcasting transmitter. They call this the cognitive Z channel. They first propose inner and outer bounds on the capacity of the cognitive Z channel. The achievability scheme they propose consists of superposition encoding, Gel'fand-Pinsker encoding and Marton's encoding scheme for the broadcast channel. They then show that their inner and outer bounds on the capacity region is tight when the receiver without a crossover link sees a noiseless channel.