Achievable rate-region for $3-$User Classical-Quantum Interference Channel using Structured Codes

TL;DR

This paper develops coset code techniques for a subclass of 3-user classical-quantum interference channels, resulting in a new inner bound that surpasses existing bounds and enhances communication efficiency.

Contribution

It introduces coset code methods for 3-to-1 CQICs, improving the known capacity region bounds over traditional unstructured coding schemes.

Findings

New inner bound for 3-to-1 CQICs capacity region

Coset codes outperform unstructured codes in this setting

Enlarged capacity bounds for specific examples

Abstract

We consider the problem of characterizing an inner bound to the capacity region of a $3-$user classical-quantum interference channel ($3-$CQIC). The best known coding scheme for communicating over CQICs is based on unstructured random codes and employs the techniques of message splitting and superposition coding. For classical $3-$user interference channels (ICs), it has been proven that coding techniques based on coset codes - codes possessing algebraic closure properties - strictly outperform all coding techniques based on unstructured codes. In this work, we develop analogous techniques based on coset codes for $3$to$1-$CQICs - a subclass of $3-$user CQICs. We analyze its performance and derive a new inner bound to the capacity region of $3$to$1-$CQICs that subsume the current known largest and strictly enlarges the same for identified examples.