Line-Of-Sight Based Beamforming for Security Enhancements in Wiretap Channels

In this work we investigate how knowledge on a legitimate receiver´s location can enhance physical layer security in a LoS channel even when a potential eavesdropper´s location is unknown. This is achieved by defining a realistic physical-space threat model for the eavesdropper. We quantify how differing secrecy performance regions for a specific wireless system can be mapped out in terms of the generic geometric parameters defining the threat model. Our results quantify the dramatic improvement expected for the secrecy outage probability when beamforming at the transmitter, optimized on the assumed threat model, is utilized.