  In this paper, an achievability region and a converse region for the two-user
Gaussian interference channel with noisy channel-output feedback (G-IC-NOF) are
presented. The achievability region is obtained using a random coding argument
and three well-known techniques: rate splitting, superposition coding and
backward decoding. The converse region is obtained using some of the existing
perfect-output feedback outer-bounds as well as a set of new outer-bounds that
are obtained by using genie-aided models of the original G-IC-NOF. Finally, it
is shown that the achievability region and the converse region approximate the
capacity region of the G-IC-NOF to within a constant gap in bits per channel
use.
