Achievable rates for transmission of discrete constellations over the Gaussian MAC channe

TL;DR

This paper analyzes the achievable rate region for a two-user Gaussian MAC using uncoded PAM, deriving a pentagon-shaped region and proposing a strategy to achieve it, with comparisons to bounds and orthogonal methods.

Contribution

It introduces a new achievable rate region for uncoded PAM in the two-user Gaussian MAC and a strategy to attain it, expanding understanding of non-orthogonal transmission schemes.

Findings

Derived a pentagon-shaped achievable rate region for uncoded PAM.

Proposed a strategy to achieve the derived rate region.

Compared the region with outer bounds and orthogonal transmission methods.

Abstract

In this paper we consider the achievable rate region of the Gaussian Multiple Access Channel (MAC) when suboptimal transmission schemes are employed. Focusing on the two-user MAC and assuming uncoded Pulse Amplitude Modulation (PAM), we derive a rate region that is a pentagon, and propose a strategy with which it can be achieved. We also compare the region with outer bounds and with orthogonal transmission.