Compressed Sensing for Physical Layer Security in Single Relay Cooperative System

In this paper, we investigate the physical layer security of single amplify-and-forward (AF) relay communication system based on compressed sensing (CS). Different to the traditional method by compressing the source data with a specific measurement matrix (e.g. Gaussian matrix)to achieve security, we first demonstrate that the combination matrix of the compression measurement matrix and cooperative AF channel matrix between legitimate nodes (source, relay, and destination) can be considered as a secure measurement matrix for physical layer security. Compared with CS scenario without AF (CS Non-AF), the eavesdropper in the proposed scheme can hardly decode the original data correctly even when it has a perfect knowledge of eavesdropper channel state information (ECSI). The robustness of the scheme in the presence of one eavesdropper is also investigated.