Physical layer secrecy performance of TAS wiretap channels with correlated main and eavesdropper channels

This letter investigates the secrecy performance of multiple-input single-output (MISO) wiretap channels when the eavesdropper channel is correlated with the main one. Assuming that the transmitter employs a transmit antenna selection (TAS) scheme, we derive a tight closed-form expression for the secrecy outage probability and analytically evaluate the secrecy performance. An asymptotic outage expression is also derived, from which a diversity analysis is carried out. We prove that correlation between channels works in favor at medium to high signal-to-noise ratio (SNR), however it degrades the performance at low SNR.