A new achievable rate region for the cognitive radio channel

The cognitive radio channel (CRC) refers to a communication model in which two senders attempt to communicate with their respective receivers simultaneously through a common medium, and one of the senders has complete and a priori (non-causal) knowledge about the message being transmitted by the other. A coding scheme that collectively has advantages of cooperative coding, collaborative coding, and dirty paper coding, is developed for such a channel. With resorting to this coding scheme, a new achievable rate region for the CRC is derived, which includes several previously known rate regions. Furthermore, it is demonstrated by Gaussian numerical examples that the new achievable rate region offers strict improvements over the existing results in the high-interference-gain regime.