A visible light communication broadcast channel is considered, in which a transmitter luminaire communicates with two legitimate receivers in the presence of an external eavesdropper. A number of trusted cooperative half-duplex relay luminaires are deployed to aid with securing the transmitted data. Transmitters are equipped with single light fixtures, containing multiple light emitting diodes, and receiving nodes are equipped with single photo-detectors, rendering the considered setting as a single-input single-output system. Transmission is amplitude-constrained to maintain operation within the light emitting diodes' dynamic range. Achievable secrecy rate regions are derived under such amplitude constraints for this multi-receiver wiretap channel, first for direct transmission without the relays, and then for multiple relaying schemes: cooperative jamming, decode-and-forward, and amplify-and-forward. Superposition coding with uniform signaling is used at the transmitter and the relays. Further, for each relaying scheme, secure beamforming vectors are carefully designed at the relay nodes in order to hurt the eavesdropper and/or benefit the legitimate receivers. Superiority of the proposed relaying schemes, with secure beamforming, is shown over direct transmission. It is also shown that the best relaying scheme depends on how far the eavesdropper is located from the transmitter and the relays, the number of relays, and their geometric layout.
Bibliographical noteKAUST Repository Item: Exported on 2021-03-12
Acknowledged KAUST grant number(s): OSR-2016-CRG5-2958-02
Acknowledgements: This research was supported in part by the U.S. National Science Foundation under Grant CCF-093970 and Grant CCF1513915. Erdal Panayirci has been supported by the Turkish Scientific and Research Council (TUBITAK) under the 1003 Primary Subjects R&D Funding
Program, and in part by KAUST under Grant No. OSR-2016-CRG5-2958-02. This paper was presented in part at the IEEE Global Conference on Signal and Information Processing, Anaheim, CA, USA, November, 2018 . The associate editor coordinating the review of this paper and approving it for publication was W. Xu
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Electrical and Electronic Engineering