两级滤波结构的导航卫星天线阵抗干扰算法

摘要

干扰和多径是影响接收机导航定位性能的两个主要因素。针对卫星导航接收机的抗干扰问题，提出了一种基于两级滤波结构的卫星导航天线阵抗干扰算法。第一级滤波采用功率倒置算法抑制干扰，通过相关解扩提高卫星信号的信噪比，并估计出其空间特征矢量。第二级滤波用估计得到的卫星信号空间特征矢量对第一级滤波输出信号进行加权处理，从而形成指向卫星信号方向的主波束来进一步提高信噪比。仿真结果表明，该算法的性能明显优于功率倒置算法，且非常接近传统的波束形成算法，不需要阵列校正以及姿态测量单元辅助，其实现代价远小于传统的波束形成算法。%Interference and multipath were the two dominant factors that affect the guidance and positioning performance of GNSS (Global Navigation Satellite System).According to the problem of anti-interference,a two-stage anti-jamming algorithm was proposed for GNSS antenna array.In the first stage,the PI (power inversion)algorithm was applied to suppress the interference.Then,the SNR (Signal-to-Noise-Ratio)of GNSS signal was improved by dispreading processing,and the spatial signature vector was estimated.In the second stage,the estimated spatial signature vector was used to weight and sum the output signal of the first stage.The proposed algorithm could null the interference and steer beams in the direction of GNSS signals simultaneously.Simulation results show that the performance of the proposed algorithm is better than PI algorithm, and it is similar to MVDR (Minimum Variance Distortionless Response)algorithm.The proposed algorithm requires no array calibration and aided altitude measurement unit,which has less implementation cost than MVDR algorithm.