Shang Xiaohui, Yin Hao, Wang Yida, Li Mu, Wang Yong
College of Communications Engineering, Army Engineering University of PLA, Nanjing 210007, China.
Institute of Systems Engineering, AMS, Beijing 100039, China.
Sensors (Basel). 2020 Mar 14;20(6):1632. doi: 10.3390/s20061632.
In this paper, we investigate the impact of saturation nonlinear energy harvesting (EH) and activation threshold on the multiuser wireless powered sensor networks (WPSNs) from the physical layer security (PLS) perspective. In particular, for improving the secrecy performance, the generalized multiuser scheduling (GMS) scheme is exploited, in which the th strongest sensor is chosen based on the legitimate link. For evaluating the impact of various key parameters on the security of system, we obtain the exact closed-form expressions for secrecy outage probability (SOP) under linear EH (LEH), saturation nonlinear EH (SNEH) and saturation nonlinear EH with activation threshold (SNAT), respectively, and solve the maximization problem of secure energy efficiency (SEE). Simulation results demonstrate that: (1) the number of source sensors, the EH efficiency and the transmit power of power beacon (PB) all have positive impact on SOP, and the smaller generalized selection coefficient is advantageous for secrecy performance; (2) LEH is an ideal situation for SNEH when the saturation threshold is large enough and SNEH is a special situation for SNAT when the activation threshold is low enough; (3) the time-switching factor and the activation threshold both have an important impact on the secrecy performance, which are worth considering carefully.
在本文中，我们从物理层安全（PLS）的角度研究饱和非线性能量收集（EH）和激活阈值对多用户无线供电传感器网络（WPSN）的影响。具体而言，为了提高保密性能，采用了广义多用户调度（GMS）方案，其中根据合法链路选择第(t)强的传感器。为了评估各种关键参数对系统安全性的影响，我们分别得到了线性EH（LEH）、饱和非线性能量收集（SNEH）和具有激活阈值的饱和非线性能量收集（SNAT）下保密中断概率（SOP）的精确闭式表达式，并解决了安全能量效率（SEE）的最大化问题。仿真结果表明：（1）源传感器的数量、EH效率和功率信标（PB）的发射功率均对SOP有正向影响，广义选择系数越小对保密性能越有利；（2）当饱和阈值足够大时，LEH是SNEH的理想情况，当激活阈值足够低时，SNEH是SNAT的特殊情况；（3）时间切换因子和激活阈值均对保密性能有重要影响，值得仔细考虑。
