Physical layer security performance of MF relay selection systems

Abstract

Aimed at the poor security performance of single antenna multi-relay modify-and-forward (MF) cooperative wireless systems in collusion eavesdropping scenario, MF cooperative physical layer security systems combining source node transmit antenna selection (TAS) and multi-relay selection in collusion eavesdropping scenario were proposed.Two relay selection schemes were considered, namely, the optimal maximization of the main channel signal-to-noise ratio (SNR) and the suboptimal maximization of the source-relay link SNR.The closed-form expressions of the secrecy outage probability (SOP) and ergodic secure capacity (ESC) for the above MF cooperative wireless systems were derived.The numerical results of SOP and ESC of MF secure relay systems with optimal or suboptimal relay selection were consistent with the simulation results, which verifies the correctness of the above theoretical analysis.It also shows that the more the number of transmit antennas at the source node and relay nodes, and the less the number of eavesdropping nodes, the better the physical layer security performance of MF secure relay systems with optimal or suboptimal relay selection.

Keywords

• transmit antenna selection;relay selection;physical layer security;modify-and-forward;secrecy outage probability;ergodic secrecy capacity