基于功率估计的高动态GNSS抗干扰零陷展宽算法

Null widening algorithm for GNSS using a novel signal power estimation in high speed environment

摘要:

全球卫星导航系统(GNSS)接收机在高速运动状态下时，干扰来向的快速变化会导致阵列抗干扰算法性能下降，为此，提出一种基于功率估计的抗干扰零陷展宽算法。根据特征值将采样协方差矩阵划分为信号子空间与噪声子空间，通过子空间投影确立信号导向矢量与功率的线性关系；利用线性关系估计干扰功率，并根据零陷展宽需求重新设定干扰区域内的信号功率；最后，以干扰区域内功率的估计值为基础重构干扰加噪声协方差矩阵，求解阵列权矢量。仿真表明，相比其他零陷展宽算法，所提算法在相同展宽下具有更深的零陷，阵列输出信干噪比也有所提升。

Abstract:

When Global Navigation Satellite System(GNSS) receivers move in high dynamic environment, the Directions Of Arrival(DOAs) corresponding to interferences may change rapidly, which will reduce the performance of anti-jamming algorithm. A novel null widening algorithm based on signal power estimation is proposed. Firstly, according to the eigenvalues, the Sampling Covariance Matrix(SCM) is divided into signal subspace and noise subspace, and a set of linear equations is established based the signal subspace projection. Then, the signal powers around interferences are reset according to the required null width based on the linear equations. Finally, the Interference-plus-Noise Covariance(INC) matrix can be reconstructed with the reset signal power, based on which the weight vector is solved. Simulation shows that the proposed algorithm has a deeper null than other algorithms when the null width keeps the same, and the Signal to Interference Noise Ratio(SINR) of array output is also improved.