The Two-User Gaussian Fading Broadcast Channel

TL;DR

This paper derives outer bounds for the capacity region of the two-user Gaussian fading broadcast channel using Costa's entropy power inequality, and characterizes conditions where inner and outer bounds coincide.

Contribution

It introduces a new outerbound framework based on Costa-EPI and identifies cases where capacity bounds meet, advancing understanding of the Gaussian fading broadcast channel.

Findings

Outer bounds formulated as a feasibility problem

Conditions identified for inner and outer bounds to meet

Partial capacity region characterization achieved

Abstract

This paper presents outerbounds for the two-user Gaussian fading broadcast channel. These outerbounds are based on Costa's entropy power inequality (Costa-EPI) and are formulated mathematically as a feasibility problem. For classes of the two-user Gaussian fading broadcast channel where the outerbound is found to have a feasible solution, we find conditions under which a suitable inner and outer bound meet. For all such cases, this paper provides a partial characterization of the capacity region of the Gaussian two-user fading broadcast channel.