PHY Security in MIMOME Keyhole Channels

Physical layer security (PLS) is investigated in a multiple-input multiple-output multiple-antenna eavesdropper keyhole channel over Rayleigh fading. Specifically, the secrecy performance is evaluated by two secrecy performance metrics including the secrecy outage probability (SOP) and average secrecy rate (ASR). By assuming that the transmitter has full channel state information of the main channel, the SOP and ASR are analyzed. To glean further insights, asymptotic analyses are performed to the SOP and ASR by considering an infinite amount of transmit power. It is found that the asymptotic SOP and ASR converge to some constant and the corresponding rate of convergence is determined by the diversity order and array gain.