Physical Layer Security in MIMO OSTBC Line-of-Sight Wiretap Channels with Arbitrary Transmit/Receive Antenna Correlation

In this paper, the physical layer security of multiple-input multiple-output (MIMO) wiretap channels with orthogonal space-time block codes (OSTBCs) and arbitrary antenna correlation is investigated. In our analysis, we consider general correlation matrices with arbitrary eigenvalue distributions. Also, in order to study the impact of the line-of-sight condition on the secrecy performance, the main channel is assumed to undergo Rician fading, while the eavesdropper one experiences Rayleigh fading. An easy-to-evaluate, closed-form expression for the secrecy outage probability is derived, from which an asymptotic analysis is carried out. Representative numerical results are plotted and validated through Monte Carlo simulations. Insightful discussions regarding the impact of the multiple antennas, correlation, and Rician factor on the secrecy outage performance are provided.