Node Selection for Physical Layer Security Using Graph-Based Vertex-Frequency Representation

In multi-hop multi-relay cooperative wireless communication systems, node selection for physical layer security (PLS) is an important problem. By defining secrecy capacity based on localized vertex spectrum (LVS), three optimization problems namely i) the best destination for a given eavesdropper, ii) the upper and lower bounds of secrecy capacity for a given destination and iii) the joint optimal destination-eavesdropper pair which maximizes the secrecy capacity are proposed. The performance of the proposed methods have been shown in terms of secrecy outage probability (SOP) by performing simulations and the enhanced PLS is benchmarked with existing literature.