Secrecy performance of MIMO wiretap channels with Nakagami-m antenna correlation

Secrecy performance based on TAS/MRC scheme with Nakagami-m antenna correlation was investigated in MIMO wiretap channels. New closed-form expressions of the exact secrecy outage probability and the probability of positive secrecy were presented. For further insights, the asymptotic secrecy outage probability in the high SNR region was also derived. It is confirmed that antenna correlation has no effects on diversity order. Most importantly, we concluded that higher antenna correlation at receiver offers more beneficial effects on secrecy performance when average SNR of the main channel is at low level, but it imposes more detrimental effects when average SNR of the main channel is at medium and high level. Finally, we provide Monte Carlo simulations to verify the analytical results.