Secrecy Analysis Based on Energy Threshold for Simultaneous Wireless Information and Power Transfer in Internet of Things

摘要

This paper studies the physical-layer secrecy performance of the downlink transmission in Simultaneous Wireless Information and Power Transfer (SWIPT) deployed in Internet of Things (IoT), where the Energy Receivers (ERs) are curious about the confidential messages of Information Receivers (IRs). Firstly, the locations of IoT users are modeled as the Poisson Point Process (PPP) to characterize the random deployment. Then, the communication model among the Resource Center (RC) and multiple IoT users is established via Time Division Multiple Access (TDMA). Furthermore, considering the energy requirements of nodes that work in "harvesting-transmitting" mode, two thresholds of eavesdropping are proposed to analyze the eavesdropping behaviors of ERs in different scenarios, based on which the curiosity probabilities are respectively obtained. Finally, the average secrecy outage probability is derived through the comprehensive analysis on different links in an entire period. The simulation results show that there exits an optimal transmitting power that can achieve the best performance and the proposed thresholds can improve the accuracy of the analysis.