Secrecy Performance of Backscatter Communication Networks with Multiple Reader and Tag Selection Schemes

This paper investigates the secrecy performance of optimal tag selection (OTS) and random tag selection (RTS) schemes of a passive backscatter communication network comprising multiple tags, multiple readers, and an eavesdropper with a practical non-linear energy harvesting model. The exhaustive search-based OTS scheme requires the complete channel state information (CSI) to provide the secrecy to the reader. In contrast, RTS schemes deploy the arbitrary search-based selection without any CSI. The secrecy outage probability (SOP) is evaluated as the secrecy performance metric for the BackCom network. The exact closed-form expressions for SOP are obtained for both selection schemes. We also derive the exact closed-form expressions for asymptotic SOP for OTS and RTS schemes, which gives a better understanding of the SOP concerning different parameters. Furthermore, we demonstrated the effect of the number of tags, number of readers, and path loss parameters on the SOP performance for the adapted BackCom network.