Date Added: Jun 2010
In this paper, the authors investigate transmit beamforming schemes based on artificial interference for physical layer security in a multi-antenna wiretap channel. They consider the case where no information regarding the eavesdropper is present, and they use the signal-to-interference-plus-noise-ratio of a single transmitted data stream as their performance metric. Using a second-order perturbation analysis, they quantify the degradation in performance due to imperfect CSI of the main channel at the transmitter. They then present a robust beamforming scheme that approaches the performance obtained in the perfect CSI case. Numerical simulations verify their analytical performance predictions, and illustrate the benefits of the robust beamforming scheme.