Fundamental Scaling Laws of Covert Communication in the Presence of Block Fading

TL;DR

This paper establishes fundamental scaling laws for covert communication over block fading channels, analyzing the limits of undetectable information transmission and the performance of optimal adversarial detectors.

Contribution

It generalizes previous covert communication results to block fading channels, providing asymptotic bounds and characterizing detector performance.

Findings

Derived asymptotic limits for covert bits in block fading channels

Matched achievable and converse bounds for covert communication

Analyzed the impact of channel impairments on covert transmission capacity

Abstract

Covert communication is the undetected transmission of sensitive information over a communication channel. In wireless communication systems, channel impairments such as signal fading present challenges in the effective implementation and analysis of covert communication systems. This paper generalizes early work in the covert communication field by considering asymptotic results for the number of bits that can be covertly transmitted in $n$ channel uses on a block fading channel. Critical to the investigation is characterizing the performance of optimal detectors at the adversary. Matching achievable and converse results are presented.