Feedback in interference channels and other multi-user networks

An acheivable rate region for the Gaussian interference channel with feedback is derived. An outer bound on the capacity region of this channel is also derived. The achievable rate region is optimal at the corner points, and shows that there exist channels with an arbitrary increase in capacity due to feedback. A general outer bound on the capacity region of networks with feedback is derived and is used to interpret the role of feedback in increasing the capacity region of multiple access, broadcast and interference channels.