Analytical Derivation and Simulation Analysis of Spatial Resolution for Adaptive Filtering

ABSTRACT

Adaptive filtering uses the difference between the interfering and useful signal in the incoming direction to achieve anti‐jamming, and the spatial resolution is particularly important when the difference is small. In this paper, the spatial resolution of adaptive filtering is characterised by the quantitative relationship between the signal‐to‐noise loss and the angle between the main beam direction of the array and the incoming direction of the interfering signal through the mathematical induction method. The theoretical derivation shows that, similar to the definition of antenna resolution, the resolution of adaptive filtering is mainly related to the effective aperture of the array and has less correlation with the number of array elements. We also use the Wiener solution of adaptive filtering to simulate and analyse the anti‐jamming performance of ternary linear arrays and circular arrays. The results show that the change in the direction of the incoming wave of the useful signal induces a change in the effective aperture of the array in the direction of the incoming wave of the interference, which in turn leads to a change in the spatial resolution of the array. In addition, as the array element spacing increases, the statistical blind zone of the cancellation becomes smaller while the grating lobe becomes larger.