A Finite Block Length Achievability Bound for Low Probability of Detection Communication

TL;DR

This paper derives a finite block length achievability bound for covert communication, providing practical insights into the limits of low probability of detection scenarios beyond asymptotic results.

Contribution

It introduces a new finite block length achievability bound for covert communication using Gallager's random coding bound, advancing understanding of non-asymptotic limits.

Findings

New finite block length bound for covert communication

Insights into non-asymptotic performance limits

Enhanced understanding of covert communication constraints

Abstract

Low probability of detection (or covert) communication refers to the scenario where information must be sent reliably to a receiver, but with low probability of detection by an adversary. Recent works on the fundamental limits of this communication problem have established achievability and converse bounds that are asymptotic in the block length of the code. This paper uses Gallager's random coding bound to derive a new achievability bound that is applicable to low probability of detection communication in the finite block length regime. Further insights are unveiled that are otherwise hidden in previous asymptotic analyses.