基于GNSS多通道跟踪接收机的阵列反欺骗方法

An Anti-spoofing Method Based on GNSS Multi-channel Tracking Receiver

近年来,基于阵列天线的空域处理方法被认为是最有效的欺骗检测和抑制手段之一。提出了一种基于卫星导航接收机多通道跟踪能力的阵列反欺骗方法。多通道跟踪接收机对每一个捕获到的导航信号在所有阵元通道后均进行跟踪处理并提取信号幅度和载波相位观测量,首先计算载波相位双差平方和进行欺骗检测,然后利用载波相位单差和信号幅度比估计信号导引矢量,从而进行基于子空间投影的欺骗信号抑制或基于波束形成的真实卫星信噪比提升。理论分析和仿真试验证明,该方法可有效检测并消除同一来向的欺骗信号且不影响真实卫星信号质量。由于前端非理想因素带来的幅度和相位偏移都已包含在接收机跟踪通道提取的观测量内,实际应用时对阵列天线校准和射频通道均衡的要求明显降低。

In recent research,spatial processing technique based on antenna array has been considered as one of the most effective spoofing detection and mitigation methods.This paper provides a novel anti-spoofing scheme based on the multi-channel tracking capability of Global Navigation Satellite System(GNSS)receiver.In this method,all the navigation signals received by each antenna are processed and the signal amplitude and carrier phase observations are extracted in tracking channels.Then,the square sum of carrier phase double differences is computed as the spoofing detection metric,and the amplitude ratio and the carrier phase single differences are used to estimate the signal steering vectors.Finally,the subspace projection is adopted to eliminate the spoofing signals and the beam-forming is used to enhance the signal-to-noise ratio of the authentic signals.The theoretical analysis and simulation results show that this method can detect and mitigate spoofing signals from the same incoming direction without attenuating satellite signal quality.Due to the extracted observations contain the amplitude and phase offsets brought by the un-ideal factors in front-ends,the accuracy requirements to array calibrating and channel proportionating in application are reduced evidently.