有色噪声下GNSS空时抗干扰算法的性能分析和改进

在全球卫星导航(GNSS)阵列天线抗干扰理论中,系统噪声通常被视为理想白噪声(AWGN).但在实际工程中发现系统噪声通常是有色噪声且会影响空时自适应处理(STAP)算法的性能.该文首先推导得出了有色噪声功率谱与空时抗干扰后卫星导航信号相关峰的理论关系,然后通过仿真实验验证了该理论关系的正确性,同时分析了噪声功率谱的等效...

Effect of Colored Noise on STAP Algorithm for GNSS Anti-jamming and Algorithm Improvement

In adaptive array processing for Global Navigation Satellite System (GNSS) anti-jamming, system noise is usually modeled as AWGN(Additive White Gauss Noise). But in engineering, system noise is generally non-white and colored noise has a great impact on the performance of STAP (Space-Time Adaptive Processing) algorithm. Firstly, the theoretical relationship between the power spectrum of noise and the correlation peak of GNSS signal after space-time anti-jamming is derived, then the theoretical relationship is verified by simulation experiment which simultaneously analyzes the effect of equivalent bandwidth and spectrum peak shift of noise on GNSS signal’s correlation peak. Experimental results show the more the noise power spectrum energy is concentrated at the peak of the power spectrum of GNSS signal, the lower the correlation peak of the GNSS signal after space-time anti-jamming. For the above problem, diagonal loading and subspace projection methods are proposed in this paper, and the two methods achieve the whitening of colored noise by consistent processing of the eigenvalues of the noise covariance matrix, so that the effect of colored noise is eliminated. Finally, method is verified by experiments.