Primary Rate-Splitting Achieves Capacity for the Gaussian Cognitive Interference Channel

TL;DR

This paper demonstrates that primary rate-splitting achieves the capacity of the Gaussian cognitive interference channel by generalizing existing regimes and highlighting the importance of cooperation levels.

Contribution

It introduces a novel capacity result using rate-splitting of the primary user's message, extending known regimes and emphasizing cooperation's role.

Findings

Capacity achieved by primary rate-splitting in Gaussian cognitive interference channel

Generalizes 'very strong interference' and 'primary decodes cognitive' regimes

Shows capacity depends on channel conditions and cooperation level

Abstract

The cognitive interference channel models cognitive overlay radio systems, where cognitive radios overhear the transmission of neighboring nodes. Capacity for this channel is not known in general. For the Gaussian case capacity is known in three regimes, usually denoted as the "weak interference", "very strong interference" and "primary decodes cognitive". This paper provides a new capacity result, based on rate-splitting of the primary user's message into a public and private part and that generalizes the capacity results in the "very strong interference" and "primary decodes cognitive" regimes. This result indicates that capacity of the cognitive interference channel not only depends on channel conditions but also the level of cooperation with the primary user.