Secrecy Performance of RIS-Aided Wireless Systems in the Presence of Mobile Interferers and Eavesdropper Mobility

Reconfigurable intelligent surface (RIS) recently emerged as a promising technology for beyond-$5^{\mathrm{t}\mathrm{h}}$ Generation (B5G)/$6^{\mathrm{t}\mathrm{h}}$ Generation (6G) wireless networks. In this paper, considering random waypoint (RWP) mobility model, we evaluate the secrecy performance of a RIS-aided legitimate receiver in the presence of mobile eavesdropper and mobile co-channel interferers (CCI). It is assumed that the legitimate transmitter-RIS, RIS-eavesdropper, and RIS-legitimate receiver links follow Rayleigh distributions. The links between the interferers and the legitimate receiver also follow Rayleigh distributions. The performance of the considered system is evaluated by deriving the approximated closed-form expressions for the secrecy outage probability (SOP) and probability of non-zero secrecy capacity (PNZ). It is shown through numerical results that the presence of mobile interferers and eavesdropper mobility significantly degrades the overall secrecy performance of the system considered.