A New Universal Random-Coding Bound for Average Probability Error Exponent for Multiple-Access Channels

TL;DR

This paper introduces a novel universal upper bound on the average error probability exponent for two-user discrete memoryless multiple-access channels, utilizing expurgation, and demonstrating improvements over existing bounds.

Contribution

It presents the first universal bound explicitly employing expurgation for DM MACs, enhancing the error exponent compared to prior bounds.

Findings

Bound is greater than or equal to previous bounds

Universal applicability to all DM MACs with given alphabets

First to explicitly incorporate expurgation in this context

Abstract

In this work, a new upper bound for average error probability of a two-user discrete memoryless (DM) multiple-access channel (MAC) is derived. This bound can be universally obtained for all discrete memoryless MACs with given input and output alphabets. This is the first bound of this type that explicitly uses the method of expurgation. It is shown that the exponent of this bound is greater than or equal to those of previously known bounds.