An approach to physical layer security in MIMO wireless via vector perturbation precoding.

In this paper, we investigate the application of vector perturbation (VP) precoding for physical layer security. We propose the notion of practical secrecy leakage to measure the performance of practical secrecy schemes which aims to maximize eavesdropper's error probability. We show that practical secrecy leakage can be avoided with modified VP scheme under specified restrictions of perturbation vector. A new sphere decoder is developed to satisfy these limitations with a cost of legitimate receiver's error performance. We show that the proposed scheme can avoid practical secrecy leakage although the number of receiver's antenna is small while obtaining a better performance at the legitimate receiver compared with artificial noise based schemes.