Description:
<jats:p xml:lang="en">Modified transmit antenna selection (M-TAS)/Alamouti orthogonal space-time
block coding (STBC) schemes have been shown to achieve superior error
performance together with a reduced-rate feedback channel in the presence of
feedback imperfections when compared to the conventional TAS/Alamouti-STBC
schemes. By shifting the focus of the investigation, this paper answers the
query on whether the modified schemes provide enhancements in also the secrecy
outage probability (SOP) performance of multi-antenna schemes in wiretap
channels. The exact expressions of the SOP for the modified TAS/Alamouti-STBC
schemes in Rayleigh fading channels have been derived and validated via Monte
Carlo simulations. Additionally, the deteriorating effects of active
eavesdropping has been demonstrated by simulating the pilot contamination
attacks (PCAs) on the feedback channel. The extensive investigation and
comparisons to the conventional schemes have shown that M-TAS/Alamouti-STBC schemes employed at the transmission end of the
legitimate link provide considerable enhancements in the secrecy rates of
wireless communications systems in the presence of PCAs.</jats:p>