Resource allocation for secure Gaussian parallel relay channels with finite-length coding and discrete constellations

Linda Senigagliesi,Stefano Tomasin,Marco Baldi

doi:10.1186/s13638-019-1603-1

Abstract

We investigate the transmission of a secret message from Alice to Bob in the presence of an eavesdropper (Eve) and many of decode-and-forward relay nodes. Each link comprises a set of parallel channels, modeling for example an orthogonal frequency division multiplexing transmission. We consider the impact of efficient implementations, including discrete constellations and finite-length coding, defining an achievable secrecy rate under a constraint on the equivocation rate at Eve. Then, we propose a power and channel allocation algorithm that maximizes the achievable secrecy rate by resorting to two coupled Gale-Shapley algorithms for stable matching problem. We consider the scenarios of both full and partial channel state information at Alice. In the latter case, we only guarantee an outage secrecy rate, i.e., the rate of a message that remains secret with a given probability. Numerical results are provided for Rayleigh fading channels in terms of average outage secrecy rate, showing that practical schemes achieve a performance quite close to that of ideal ones.

Highlights

Adding secrecy features to the physical layer is an active and promising research area [1] that complements traditional computational security approaches
In this paper we expand the results of [3] on resource allocation for confidential communications over the Gaussian parallel relay channels, as that work was limited to an ideal scenario, while we address a more realistic model by including the practical constraints of finitelength coding and discrete constellations
We show that the algorithm derived for full channel state information (CSI) can be adapted to a partial CSI

Summary

Introduction

Adding secrecy features to the physical layer is an active and promising research area [1] that complements traditional computational security approaches. A proper coding scheme can prevent an eavesdropper Eve from getting information on a message exchanged between the two legitimate users Alice and Bob [2]. In this paper we expand the results of [3] on resource allocation for confidential communications over the Gaussian parallel relay channels, as that work was limited to an ideal scenario, while we address a more realistic model by including the practical constraints of finitelength coding and discrete constellations. We first derive the achievable secrecy rate of this scheme under the assumption of full channel state information (CSI) by Alice and the relay nodes. In order to consider the impact of discrete constellations and finite-length coding, 1.1 Related works The physical layer security of messages transmitted over parallel channels with the assistance of trusted relays has already been addressed in the literature. For links comprising a single channel, early works have addressed the relay

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Conclusion