Converse bound for Gaussian Multiple Access Channel with Feedback

EDIC candidacy exam
Exam president: Prof. Olivier Lévêque
Thesis advisor: Prof. Michael Gastpar
Co-examiner: Prof. Rüdiger Urbanke

Abstract
A converse bound is derived for the Gaussian multiple-access channel (MAC) with feedback. The bound is based on dependence-balance constraint. An essential ingredient to prove the bound is the method known in the literature as "doubling trick'' which is used to prove optimality of Gaussian auxiliary random variables. For the Gaussian MAC with equal transmitter powers, the bound promises to be the feedback sum-rate capacity.

Bacground papers
Feedback Can at Most Double Gaussian Multiple Access Channel Capacity, Thomas, J., G. IEEE Xplore paper.
On Noisy Feedback for Interference Channels, Gastpar M, Kramer , G. IEEE Xplore paper.
The Capacity Region of the Two-Receiver Gaussian Vector Broadcast Channel With Private and Common Messages, by Geng Y., Nair C.G. IEEE Xplore paper.