Song Yi, Yang Weiwei, Xiang Zhongwu, Wang Biao, Cai Yueming
School of Physics and Electronic Electrical Engineering, Huaiyin Normal University, Huai'an 223300, China.
College of Communications Engineering, Army Engineering University of PLA, No. 88 Houbiaoying, Qinhuai District, Nanjing 210007, China.
Sensors (Basel). 2019 Jul 19;19(14):3184. doi: 10.3390/s19143184.
This paper investigates the secrecy performance of a cognitive millimeter wave (mmWave) wiretap sensor network, where the secondary transmitter (SU-Tx) intends to communicate with a secondary sensor node under the interference temperature constraint of the primary sensor node. We consider that the random-location eavesdroppers may reside in the signal beam of the secondary network, so that confidential information can still be intercepted. Also, the interference to the primary network is one of the critical issues when the signal beam of the secondary network is aligned with the primary sensor node. Key features of mmWave networks, such as large number of antennas, variable propagation law and sensitivity to blockages, are taken into consideration. Moreover, an eavesdropper-exclusion sector guard zone around SU-Tx is introduced to improve the secrecy performance of the secondary network. By using stochastic geometry, closed-form expression for secrecy throughput (ST) achieved by the secondary sensor node is obtained to investigate secrecy performance. We also carry out the asymptotic analysis to facilitate the performance evaluation in the high transmit power region. Numerical results demonstrate that the interference temperature constraint of the primary sensor node enables us to balance secrecy performance of the secondary network, and provides interesting insights into how the system performance of the secondary network that is influenced by various system parameters: eavesdropper density, antenna gain and sector guard zone radius. Furthermore, blockages are beneficial to improve ST of the secondary sensor node under certain conditions.
本文研究了认知毫米波（mmWave）窃听传感器网络的保密性能，其中次级发射机（SU-Tx）打算在主传感器节点的干扰温度约束下与次级传感器节点进行通信。我们认为随机位置的窃听者可能存在于次级网络的信号波束中，从而使机密信息仍可被截获。此外，当次级网络的信号波束与主传感器节点对准时，对主网络的干扰是关键问题之一。考虑了毫米波网络的关键特性，如大量天线、可变传播规律和对阻塞的敏感性。此外，在SU-Tx周围引入了一个窃听者排除扇区保护区域，以提高次级网络的保密性能。通过使用随机几何方法，获得了次级传感器节点实现的保密吞吐量（ST）的闭式表达式，以研究保密性能。我们还进行了渐近分析，以促进在高发射功率区域的性能评估。数值结果表明，主传感器节点的干扰温度约束使我们能够平衡次级网络的保密性能，并为次级网络的系统性能如何受到各种系统参数（窃听者密度、天线增益和扇区保护区域半径）的影响提供了有趣的见解。此外，在某些条件下，阻塞有利于提高次级传感器节点的ST。
