Secrecy Performance of Energy-Harvesting Backscatter Communication Network Under Different Tag Selection Schemes

This paper investigates the secrecy performance of a Backscatter communication (BackCom) network considering a practical non-linear energy harvesting model with various tag selection schemes. The tag circuit reflects the signal by finding the optimal dynamic reflection coefficient that maximizes the backscattered signal power while satisfying the tag energy constraint. The channel gains of all links follow Rayleigh fading model. Accounting performance and complexity trade-offs, two computationally efficient sub-optimal and a random selection schemes are proposed and analyzed. The performance is analyzed by obtaining the secrecy outage probability (SOP) and probability of intercept (POI) in closed-form. To gain further insights, expressions for the asymptotic SOP and POI are also derived for all selection schemes. We compare the proposed selection schemes with optimal selection scheme and conclude that proposed schemes significantly reduce the complexity and performs satisfactorily in terms of SOP and POI.