Resource Allocation for Secure Gaussian Parallel Relay Channels with Finite-Length Coding and Discrete Constellations

TL;DR

This paper studies secure communication over Gaussian parallel relay channels considering practical constraints like finite-length coding and discrete constellations, proposing an optimized resource allocation algorithm to maximize secrecy rates.

Contribution

It introduces a novel power and channel allocation method using Gale-Shapley algorithms for secure relay channels with practical coding constraints and partial channel knowledge.

Findings

Practical schemes achieve near-ideal secrecy performance.

The proposed algorithm effectively maximizes secrecy rates under various CSI scenarios.

Numerical results demonstrate the robustness of the approach in Rayleigh fading channels.

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 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.