Zhao Yuqing, Shen Feng, Xu Guanghui, Wang Guochen
School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
State Key Laboratory of Satellite Navigation System and Equipment Technology, Shijiazhuang 050081, China.
Sensors (Basel). 2021 Jan 30;21(3):929. doi: 10.3390/s21030929.
The presence of spoofing signals poses a significant threat to global navigation satellite system (GNSS)-based positioning applications, as it could cause a malfunction of the positioning service. Therefore, the main objective of this paper is to present a spatial-temporal technique that enables GNSS receivers to reliably detect and suppress spoofing. The technique, which is based on antenna array, can be divided into two consecutive stages. In the first stage, an improved eigen space spectrum is constructed for direction of arrival (DOA) estimation. To this end, a signal preprocessing scheme is provided to solve the signal model mismatch in the DOA estimation for navigation signals. In the second stage, we design an optimization problem for power estimation with the estimated DOA as support information. After that, the spoofing detection is achieved by combining power comparison and cross-correlation monitoring. Finally, we enhance the genuine signals by beamforming while the subspace oblique projection is used to suppress spoofing. The proposed technique does not depend on external hardware and can be readily implemented on raw digital baseband signal before the despreading of GNSS receivers. Crucially, the low-power spoofing attack and multipath can be distinguished and mitigated by this technique. The estimated DOA and power are both beneficial for subsequent spoofing localization. The simulation results demonstrate the effectiveness of our method.
欺骗信号的存在对基于全球导航卫星系统（GNSS）的定位应用构成了重大威胁，因为它可能导致定位服务出现故障。因此，本文的主要目的是提出一种时空技术，使GNSS接收机能够可靠地检测和抑制欺骗。该技术基于天线阵列，可分为两个连续阶段。在第一阶段，构建一种改进的特征空间谱用于到达方向（DOA）估计。为此，提供了一种信号预处理方案，以解决导航信号DOA估计中的信号模型失配问题。在第二阶段，以估计的DOA作为支持信息，设计一个用于功率估计的优化问题。之后，通过结合功率比较和互相关监测来实现欺骗检测。最后，通过波束成形增强真实信号，同时使用子空间斜投影来抑制欺骗。所提出的技术不依赖于外部硬件，并且可以在GNSS接收机解扩之前的原始数字基带信号上轻松实现。至关重要的是，该技术可以区分并减轻低功率欺骗攻击和多径。估计的DOA和功率都有利于后续的欺骗定位。仿真结果证明了我们方法的有效性。
