Study of Opportunistic Cooperation Techniques using Jamming and Relays for Physical-Layer Security in Buffer-aided Relay Networks

TL;DR

This paper explores opportunistic relay and jammer cooperation in MIMO buffer-aided relay networks to enhance physical-layer security, proposing algorithms for relay selection and interference management that significantly improve secrecy rates.

Contribution

It introduces novel algorithms for relay and jammer selection, incorporating interference cancellation and hybrid storage strategies to boost security in buffer-aided relay networks.

Findings

Significant increase in secrecy rate compared to existing algorithms.

Effective use of inter-relay interference for security enhancement.

Hybrid relay strategy improves signal delivery and jamming efficiency.

Abstract

In this paper, we investigate opportunistic relay and jammer cooperation schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks. The network consists of one source, an arbitrary number of relay nodes, legitimate users and eavesdroppers, with the constraints of physical layer security. We propose an algorithm to select a set of relay nodes to enhance the legitimate users' transmission and another set of relay nodes to perform jamming of the eavesdroppers. With Inter-Relay interference (IRI) taken into account, interference cancellation can be implemented to assist the transmission of the legitimate users. Secondly, IRI can also be used to further increase the level of harm of the jamming signal to the eavesdroppers. By exploiting the fact that the jamming signal can be stored at the relay nodes, we also propose a hybrid algorithm to set a signal-to-interference and noise ratio (SINR) threshold at the node to determine the type of signal stored at the relay node. With this separation, the signals with high SINR are delivered to the users as conventional relay systems and the low SINR performance signals are stored as potential jamming signals. Simulation results show that the proposed techniques obtain a significant improvement in secrecy rate over previously reported algorithms.