PHY Security of MIMO Wiretap Channels with Generalized Selection Combining

This paper investigates the secrecy outage performance of multiple-input multiple-output (MIMO) wiretap channels, where a generalized selection combining (GSC) scheme is assumed at the legitimate receiver, while the transmitter employs a transmit antenna selection (TAS) technique and the eavesdropper adopts a maximal-ratio combining (MRC) scheme. Assuming that the eavesdropper is subject to noise and jamming, a closed-form expression for the secrecy outage probability is derived, based on which the diversity and array gains are determined after performing an asymptotic analysis. The derived expression allows for arbitrary power distributed jamming signals, and are simplified to two special cases, i.e., distinct and equal power distributed jamming signals. Some representative numerical results are depicted to show the effects of the key system parameters on the secrecy performance. Finally, the proposed analysis is corroborated through Monte Carlo simulations.