基于天线阵方位变化的相位双差GNSS欺骗干扰检测算法研究*

GNSS欺骗干扰通常由单个天线发射,各个欺骗干扰信号到达接收机的角度相同,采用阵列天线接收时欺骗信号达到不同阵元的相位差包含了其角度信息,故可利用信号载波相位差进行欺骗干扰检测。相位双差检测算法通过比较不同卫星信号到达天线阵两阵元的相位差实现欺骗干扰的判别,但对于二元天线阵,其载波相位双差存在角度模糊,导致虚警概率较高,限制了算法的应用。针对这一问题,本文提出了基于天线阵方位变化的欺骗干扰检测算法,通过二元天线阵在不同方位估计信号的载波相位双差,进行多次判决,有效消除了角度模糊,降低检测的虚警概率,实现二元天线的载波相位双差检测。建立了仿真模型,并通过仿真计算分析验证了该方法的有效性。

Study of carrier phase double difference GNSS spoofing detection technique base on antenna-array direction change

GNSS spoofing signals are generally transmitted from a single antenna, so, the arrival angle of each spoofing signal is uniform, and the phase disparity at two different elements of an antenna-array receiver contains the information of the arrival angle. Thereby, the phase disparity could be used for spoofing detection. Carrier phase double difference GNSS spoofing detection technique is an effective one of those methods based on phase measurement, but high false alarm probability problem is caused by angle ambiguity for double-element antenna-array. In order to solve the problem, a technique based on antenna-array direction change is presented. The carrier phase double differences are estimated in different antenna-array directions, and then the carrier phase double differences are used to discriminate the spoofing signals. In this way, the angle ambiguity could be eliminated, and the false alarm probability is reduced. Simulation results verify the effectiveness of the proposed spoofing detection technique.