Physical Layer Security in Relay Networks with Outdated Relay Selection

TL;DR

This paper analyzes the impact of outdated relay selection on the physical layer security of cooperative relay networks, deriving analytical expressions for key secrecy metrics and validating them through numerical results.

Contribution

It provides the first comprehensive analytical framework for secrecy performance considering outdated relay selection in cooperative networks.

Findings

Outdated relay selection degrades secrecy performance.

Closed-form expressions for secrecy capacity metrics are derived.

Numerical results confirm the analytical models.

Abstract

In this paper, the secrecy performance of a cooperative relay network with outdated relay selection is investigated where an eavesdropper intercepts the channels between the source and the destination. The best relay is chosen among N relays based on the opportunistic relay selection algorithm, which may not be the best relay at the time of transmission because of the outdated channel state information. We derive closed-form analytical expressions for the non-zero secrecy capacity, the secrecy outage probability, and the ergodic secrecy capacity. Finally, our theoretical analysis is validated by the numerical results, and detailed discussions and insights are given.