Secrecy Performance Analysis of Keyhole MIMOME Wiretap Channels with Imperfect CSI

Abstract

This paper investigates physical layer security in multi-antenna keyhole systems with imperfect channel state information (CSI). In dense urban environments, rank-deficient channels, specifically the rank-one key-hole effect, significantly degrade secrecy performance. We derive closed-form asymptotic expressions for the secrecy outage probability (SOP) and average secrecy rate (ASR) in the high signal-to-noise ratio (SNR) regime. Based on the analytical results and Monte-Carlo simulations, the impacts of key parameters, such as Alice's antenna number and CSI error variance, are quantified and discussed, which provides insights into robust secrecy design.