Secrecy Enhancement for SSK-Based Communications in Wireless Sensing Systems

Reliability and security are the main concerns in modern industrial wireless sensing systems because of the nature property of the industrial wireless sensing environment. Therefore, how to enhance the secrecy and make the industrial wireless sensing systems smart attract a lot of attention. In order to address the secrecy problem in industrial wireless sensing systems, this article proposes a secrecy enhancement mechanism based on space shift keying (SSK) communication in industrial wireless sensing systems where a transmitting node, a receiving node, and an eavesdropper are considered. To prevent the valid information from being attacked by the eavesdropper, the technologies of antenna selection (AS) and the artificial noise (AN) are jointly used in the proposed scheme to enhance the physical layer security (PLS). Eventually, the designed AN is canceled at the receiving node and remains at the eavesdropper. In addition, two kinds of AS methods, namely, signal-to-leakage-noise ratio (SLNR)-based method and Euclidean distance AS (EDAS)-based method are proposed for the proposed secrecy enhancement scheme. Specifically, the SLNR and EDAS methods are designed for the known eavesdropper channel case and the unknown eavesdropper channel case, respectively. Moreover, to make the scenario practical, the channel estimation error is fully considered in the sensing data transmission stage since the perfect channel state information (CSI) is rarely available in the actual sensing environment. The results from simulations demonstrate that the proposed scheme can enhance the system performances of secrecy rate (SR) and bit error rate (BER) when compared with the traditional random selection method.