Capacity bounds for a class of cognitive interference channels with state

A class of cognitive interference channels with non-causal state information is investigated, in which two transmitters (i.e., transmitters 1 and 2) communicate with two receivers (i.e., receivers 1 and 2) via an interference channel. The two transmitters jointly send one message to receivers 1 and 2, and transmitter 2 also sends a separate message to receiver 2. The channel is corrupted by an independent and identically distributed (i.i.d.) state sequence, which is noncausally known at transmitter 2 only. For the general discrete memoryless channel, inner and outer bounds on the capacity region are obtained. Bounds on degraded channels are also derived. In particular, the capacity region is established for the semideterministic degraded channel. Furthermore, for the case when the state information is also known at receiver 2, inner and outer bounds on the capacity region are obtained, and the capacity region is established for the degraded channel of this case.