New Results on the Capacity of the Gaussian Cognitive Interference Channel

The capacity of the two-user Gaussian cognitive interference channel, a variation of the classical interference channel where one of the transmitters has knowledge of both messages, is known in several parameter regimes but remains unknown in general. In this paper, we consider the following achievable scheme: the cognitive transmitter pre-codes its message against the interference created at its intended receiver by the primary user, and the cognitive receiver only decodes its intended message, similar to the optimal scheme for "weak interference"; the primary decoder decodes both messages, similar to the optimal scheme for "very strong interference". Although the cognitive message is pre-coded against the primary message, by decoding it, the primary receiver obtains information about its own message, thereby improving its rate. We show: (1) that this proposed scheme achieves capacity in what we term the "primary decodes cognitive" regime, i.e., a subset ...

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Stefano Rini, Daniela Tuninetti, Natasha Devroye
• Keywords: Cognitive, CORR 2010, Education, Interference Channel, Strong Interference