Some Discussions on PHY Security in DF Relay

TL;DR

This paper analyzes the physical layer security of decode-and-forward relay systems, providing rigorous derivations of secrecy capacity and outage probability, with insights from asymptotic analysis validated by simulations.

Contribution

It offers the first rigorous derivations of secrecy channel capacity and closed-form SOP expressions for secure DF relay models from an information-theoretic perspective.

Findings

Analytical expressions for secrecy capacity and SOP are derived.

Asymptotic analysis reveals system behavior at high SNR.

Simulation results confirm the accuracy of the analytical models.

Abstract

Physical layer (PHY) security in decode-and-forward (DF) relay systems is discussed. Based on the types of wiretap links, the secrecy performance of three typical secure DF relay models is analyzed. Different from conventional works in this field, rigorous derivations of the secrecy channel capacity are provided from an information-theoretic perspective. Meanwhile, closed-form expressions are derived to characterize the secrecy outage probability (SOP). For the sake of unveiling more system insights, asymptotic analyses are performed on the SOP for a sufficiently large signal-to-noise ratio (SNR). The analytical results are validated by computer simulations and are in excellent agreement.