Artificial-Noise-Aided Secure Transmission over Finite-Input Intersymbol Interference Channels

Abstract

We propose an artificial noise (AN) injection strategy for securing communication over finite-input intersymbol interference (ISI) channels. The technique relies on injection of colored noise whose power spectral density has the least match with the spectrum of the main channel in a certain sense. By evaluation of an achievable secrecy rate, we demonstrate that the proposed AN injection based solution results in a considerable improvement over the existing approaches, especially when the eavesdropper works at high signal-to-noise ratios (SNRs).Index Terms-Physical layer security, finite-state wiretap channel, artificial noise, inter-symbol interference.

Constrained Secrecy Capacity of Finite-Input Intersymbol Interference Wiretap Channels

“…It is shown in [21] that such feedback can enlarge the rate-equivocation region for finite-state Markov wiretap channels compared with the case without feedback. It is also known that higher secure rates can be achieved by introducing artificial noise matched to the spectrum of Bob's channel [23]. Although these enhancements are certainly interesting, in this paper we focus on the standard version of the PR-WTC model (with neither feedback nor additional artificial noise) as it requires few assumptions and consequently is more practically relevant.…”