Rate Adaptation for Secure HARQ Protocols

Mael Le Treust (1) , Leszek Szczecinski (2) , Fabrice Labeau (3)

1 ETIS - UMR 8051 - Equipes Traitement de l'Information et Systèmes
2 INRS - Institut National de la Recherche Scientifique [Québec]
3 McGill University = Université McGill [Montréal, Canada]

This paper investigates secure transmission using HARQ protocol when the encoder only knows the statistics of the channel-state. We analyze the tradeoff between reliability and secrecy probabilistic guarantees. The conventional approach of ensuring the secrecy via introduction of dummy-message is followed. However, unlike the previous works on this subject, we design a coding strategy tailored to HARQ by splitting the dummy-message rate over several rate parameters. These additional degrees of freedom improve the matching between the dummy-message rates and the realizations of the eavesdropper channels. We evaluate the performance in terms of secrecy outage probability, connection outage probability and secrecy throughput. For Rayleigh fading channel, the splitting of the dummy-message rate provides higher secrecy throughput and lower expected duration/average delay.

Mots clés: Hybrid automatic repeat request; physical layer security; state-dependent wiretap channel; channel state information; secrecy outage probability and secrecy throughput.

Domaines: Sciences de l'information et de la communication

Mael Le Treust, Leszek Szczecinski, Fabrice Labeau. Rate Adaptation for Secure HARQ Protocols. 2017. ⟨hal-01404320v2⟩