Secrecy performance analysis of AF relaying with relay selection scheme over Nakagami‐m fading channels

This paper investigates the secrecy outage probability (SOP) and intercept behavior for the amplify‐and‐forward network over Nakagami‐m fading channels. Relay selection schemes are evaluated. The optimal and suboptimal criterions require the instantaneous and statistical channel state information of the eavesdroppers' channels, respectively. The enhanced 2‐hop criterion needs the additional information of the target secrecy rate for relay selection. Theoretical analysis reveals that the diversity order of the SOP is dominated by the minimum fading figures of the source‐relay and relay‐destination channels, while that of the intercept probability depends on the fading figure of the relay‐destination channel. In the multirelay scenario, the optimal, suboptimal, and enhanced 2‐hop scheme achieve the same diversity orders of the SOP. For the intercept probability, the optimal and second‐hop relay selection schemes provide the same diversity order, while the diversity orders of the suboptimal and enhanced 2‐hop schemes are the same. Simulation results finally substantiate the accuracy of the theoretical analysis.