Approximate Capacity Region of the Two-User Gaussian Interference Channel with Noisy Channel-Output Feedback

TL;DR

This paper fully characterizes the approximate capacity region of the two-user Gaussian interference channel with noisy feedback, using insights from deterministic models and advanced coding strategies, achieving a tight approximation within 4.4 bits.

Contribution

It introduces a new approximation of the capacity region for the Gaussian interference channel with noisy feedback, bridging deterministic and Gaussian models.

Findings

Capacity region approximated within 4.4 bits.

Achievability and converse regions are established.

Insights from deterministic models inform Gaussian channel analysis.

Abstract

In this paper, the capacity region of the linear deterministic interference channel with noisy channel-output feedback (LD-IC-NF) is fully characterized. The proof of achievability is based on random coding arguments and rate splitting; block-Markov superposition coding; and backward decoding. The proof of converse reuses some of the existing outer bounds and includes new ones obtained using genie-aided models. Following the insight gained from the analysis of the LD-IC-NF, an achievability region and a converse region for the two-user Gaussian interference channel with noisy channel-output feedback (GIC-NF) are presented. Finally, the achievability region and the converse region are proven to approximate the capacity region of the G-IC-NF to within 4.4 bits.