The Capacity Region of the Gaussian Cognitive Radio Channels at High SNR

Deterministic channel models have recently proven to be powerful tools for obtaining capacity bounds for Gaussian multiuser networks that are tight in the high SNR regime. In this paper, the authors apply this technique to the Gaussian cognitive radio channel: a 2 × 2 interference channel in which one transmitter has non-causal knowledge of the message of the other, whose capacity region in general is still unknown. They approximate the Gaussian cognitive radio channel at high SNR by an underlying linear deterministic channel model for which they determine the exact capacity region, or generalized degrees of freedom region. Explicit achievable schemes and outer bounds are illustrated and future directions are discussed.