Physical layer security in MIMO wiretap channels with antenna correlation

To investigate the impact of antenna correlation on secrecy performance in MIMO wiretap channels with Nakagami-m fading, the expressions of secrecy outage probability and positive secrecy probability were derived. Diversity order and array gain were also achieved for further insight. The study was based on the information theory that physical layer security can be guaranteed when the quality of the main channel is higher than that of the eavesdropper's channel. Monte Carlo simulations well validated the numerical results of analytic expressions. It was shown that antenna correlation is detrimental to secrecy performance when average SNR of the main channel is at medium and high level. Interestingly, when average SNR of the main channel reduces to low level, the effect of antenna correlation becomes beneficial to secrecy performance.