Mimicking Full-Duplex Secure Communications for Buffer-Aided Multi-Relay Systems

TL;DR

This paper introduces a novel relay selection protocol for buffer-aided cooperative wireless networks that enhances secure communication by mimicking full-duplex operation and improving secrecy throughput against eavesdroppers.

Contribution

It proposes a max-ratio relaying protocol with a randomize-and-forward strategy, providing theoretical analysis and closed-form expressions for secrecy throughput, verified by simulations.

Findings

Significant improvement in secrecy throughput over existing policies

Effective relay selection based on channel ratios

Theoretical analysis matches simulation results

Abstract

This paper considers secure communication in buffer-aided cooperative wireless networks in the presence of one eavesdropper, which can intercept the data transmission from both the source and relay nodes. A new max-ratio relaying protocol is proposed, in which different relays are chosen for reception and transmission according to the ratio of the legitimate channels to the eavesdropper channels, so that the relay selected for reception and the relay selected for transmission can receive and transmit at the same time. It is worth noting that the relay employs a randomize-and-forward (RF) strategy such that the eavesdropper can only decode the signals received in the two hops independently. Theoretical analysis of the secrecy throughput of the proposed scheme is provided and the approximate closed-form expressions are derived, which are verified by simulations. Through numerical results, it is shown that the proposed scheme achieves a significant improvement in secrecy throughput compared with existing relay selection policies.