Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

This letter proposes a novel hybrid half-duplex (HD)/full-duplex (FD) relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided FD relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying strategies, namely, randomize-and-forward and decode-and-forward relaying, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between the HD and FD modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless FD relaying scheme.