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

In this paper, the capacity region of the linear deterministic interference channel with noisy channel-output feedback (LD-IC-NOF) is fully characterized. A capacity-achieving scheme is obtained using a random coding argument and three wellknown techniques: rate splitting, superposition coding and backward decoding. The converse region is obtained using some of the existing outer bounds as well as a set of new outer bounds that are obtained by using genie-aided models of the original LD-ICNOF. Using the insights gained from the analysis of the LD-ICNOF, an achievability region and a converse region for the twouser Gaussian interference channel with noisy channel-output feedback (G-IC-NOF) are presented. Finally, the achievability region and the converse region approximate the capacity region of the G-IC-NOF to within 4.4 bits.