Feedback Capacity of the Gaussian Interference Channel to Within 1.7075 Bits: the Symmetric Case

Abstract

We characterize the symmetric capacity to within 1.7075 bits/s/Hz for the two-user Gaussian interference channel with feedback. The result makes use of a deterministic model to provide insights into the Gaussian channel. We derive a new outer bound to show that a proposed achievable scheme can achieve the symmetric capacity to within 1.7075 bits for all channel parameters. From this result, we show that feedback provides unbounded gain, i.e., the gain becomes arbitrarily large for certain channel parameters. It is a surprising result because feedback has been so far known to provide only power gain (bounded gain) in the context of multiple access channels and broadcast channels.

submitted to the International Symposium and Information Theory

References in corpus (1)

• A Deterministic Approach to Wireless Relay Networks

Cited by in corpus (4)

• Aligned Interference Neutralization and the Degrees of Freedom of the 2x2x2 Interference Channel
• On Channel Output Feedback in Deterministic Interference Channels
• Feedback Capacity of the Gaussian Interference Channel to within 2 Bits
• Interference Channel with Generalized Feedback (a.k.a. with source cooperation). Part I: Achievable Region