Is Gaussian signalling optimal for covert communications?

Shihao Yan, Yirui Cong, Stephen V. Hanly, Xiangyun Zhou

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

Abstract

While Gaussian signalling is assumed in many studies on covert communications, its optimality has not been carefully investigated. In this work, we examine this optimality by considering the approach of upper bounding D(p 0 (y)∥p 1 (y)) as the covert communication constraint, where D(p 0 (y)∥p 1 (y)) is the Kullback-Leibler divergence from p 0 (y) to p 1 (y), p 0 (y) and p 1 (y) are the likelihood functions of the observation y at the warden under the null hypothesis (no covert transmission) and alternative hypothesis (a covert transmission occurs), respectively. Considering additive white Gaussian noise at both the receiver and the warden, we prove that Gaussian signalling is not optimal in terms of maximizing the mutual information of transmitted and received signals for covert communications with D(p 0 (y)∥p 1 (y)) ≤ 2ϵ 2 as the constraint. We also explicitly show a skew-normal signalling can outperform Gaussian signalling in terms of achieving higher mutual information subject to the same covertness constraint D(p 0 (y)∥p 1 (y)) ≤ 2ϵ 2 .

Original languageEnglish
Title of host publication2019 IEEE International Conference on Communications (ICC)
Subtitle of host publicationproceedings
Place of PublicationPiscataway, NJ
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Pages1-6
Number of pages6
ISBN (Electronic)9781538680889
ISBN (Print)9781538680896
DOIs
Publication statusPublished - 2019
Event2019 IEEE International Conference on Communications, ICC 2019 - Shanghai, China
Duration: 20 May 201924 May 2019

Publication series

Name
ISSN (Print)1550-3607
ISSN (Electronic)1938-1883

Conference

Conference2019 IEEE International Conference on Communications, ICC 2019
CountryChina
CityShanghai
Period20/05/1924/05/19

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Cite this

Yan, S., Cong, Y., Hanly, S. V., & Zhou, X. (2019). Is Gaussian signalling optimal for covert communications? In 2019 IEEE International Conference on Communications (ICC): proceedings (pp. 1-6). Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE). https://doi.org/10.1109/ICC.2019.8761750