On the Throughput of Secure Hybrid-ARQ Protocols for Gaussian Block-Fading Channels

—The focus of this paper is an information-theoretic study of retransmission protocols for reliable packet communication under a secrecy constraint. The hybrid automatic retransmission request (HARQ) protocol is revisited for a blockfading wire-tap channel. Here, two legitimate users communicate over a block-fading channel in the presence of a passive eavesdropper who intercepts the transmissions through an independent block-fading channel. In this model, the transmitter obtains a 1-bit ACK/NACK feedback from the legitimate receiver via an error-free public channel. Both reliability and confidentiality of secure HARQ protocols are studied by the joint consideration of channel coding, secrecy coding, and retransmission protocols. In particular, the error and secrecy performance of repetition time diversity (RTD) and incremental redundancy (INR) protocols are investigated based on Wyner code sequences. These protocols ensure that the confidential message is decoded successfully by th...

• Type: Journal
• Year: 2007
• Where: CORR
• Authors: Xiaojun Tang, Ruoheng Liu, Predrag Spasojevic, H. Vincent Poor
• Keywords: CORR 2007, Education, Retransmission Protocols, Secrecy, Secure Harq Protocols