In this paper, the η-Nash equilibrium (η-NE) region of the two-user
Gaussian interference channel (IC) with perfect output feedback is approximated
to within 1 bit/s/Hz and η arbitrarily close to 1 bit/s/Hz. The
relevance of the η-NE region is that it provides the set of rate-pairs
that are achievable and stable in the IC when both transmitter-receiver pairs
autonomously tune their own transmit-receive configurations seeking an
η-optimal individual transmission rate. Therefore, any rate tuple outside
the η-NE region is not stable as there always exists one link able to
increase by at least η bits/s/Hz its own transmission rate by updating its
own transmit-receive configuration. The main insights that arise from this work
are: (i) The η-NE region achieved with feedback is larger than or equal
to the η-NE region without feedback. More importantly, for each rate pair
achievable at an η-NE without feedback, there exists at least one rate
pair achievable at an η-NE with feedback that is weakly Pareto superior.
(ii) There always exists an η-NE transmit-receive configuration that
achieves a rate pair that is at most 1 bit/s/Hz per user away from the outer
bound of the capacity region.Comment: Revised version (Aug. 2015