On the Secrecy Performance of MIMOME Keyhole Channels Aided with Artificial Noise

Multiple antennas aided wireless communications under dense urban environments often suffer from keyhole effect, which leads to rank deficiency. Secrecy performance of artificial noise (AN) aided multiple-input multiple-output multiple-antenna eavesdropper (MIMOME) keyhole channels is investigated in this paper. Expressions of the asymptotic lines of some vital secrecy metrics are obtained in terms of secrecy outage probability (SOP) and average secrecy rate (ASR) in the high signal-to-noise ratio (SNR) regime, and are verified by Monte-Carlo simulations. It is shown that the secrecy performance is influenced by the antenna numbers at the transceiver and the eavesdropper. Most importantly, by comparing the scheme aided with AN to that without AN, it is found that AN plays a great role in enhancing security of MIMOME keyhole channels.