高速运动环境下GNSS接收机阵列抗干扰算法

全球卫星导航系统(global navigation satellite system, GNSS)接收机高速运动状态下,干扰信号来向快速变化将导致阵列抗干扰算法性能下降,为此提出了基于干扰加噪声协方差(interference-plus-noise covariance, INC)矩阵重构的零陷加宽算法。首先,依据采样协方差矩阵相邻特征值之比估算干扰信号数目。然后,利用空间谱估计值粗略判定干扰信号来向,并根据零陷展宽需求重新设定干扰区域空间谱估计值。最后,以干扰区域谱估计值为基础重构INC矩阵,求解阵列权矢量。仿真实验表明,相比于其他零陷加宽算法,所提算法在相同展宽下的零陷更深,阵列输出载噪比(carrier to noise ratio, C/N₀)也高出5 dBHz以上。

Anti-jamming algorithm for GNSS receivers with array antenna in high speed environment

When global navigation satellite system (GNSS) receivers move at a high speed, the directions of arrival (DOAs) corresponding to interferences may change rapidly, which will cause a performance degradation of array antenna. A null widening algorithm based on the interference-plus-noise covariance (INC) matrix reconstruction is proposed. Firstly, the number of interferences is estimated via the ratio between adjacent eigenvalues of the sample covariance matrix. Then, the interference DOAs are estimated roughly using the spatial spectrum estimates and the spatial spectrum estimates around interferences are reset according to the required null width. Finally, the INC matrix can be reconstructed with the reset spatial spectrum estimates, based on which the weight vector is sloved. Simulation results show that the proposed algorithm performs better than the other null widening algorithms in the carrier to noise ratio (C/N₀), by at least 5 dBHz. Meanwhile, the proposed algorithm has a deeper null when the null width keeps the same.