关键词: 来波角度估计, 稀疏阵列, 互耦效应

Abstract:

In the field of array signal processing, existing improved arrays have significant performance limitations: although the improved coprime array has a sparse structure, its ability to fill holes is weak, resulting in a limited number of identifiable incoming signals. Although the improved nested array can fill most of the array holes to support the identification of more incoming signals, the densely distributed array elements cause strong coupling effects, which seriously restrict the angle estimation accuracy. To address the above contradictions, this paper proposes an Optimal Weight function Sparse Array (OWSA) based on a newly improved array configuration. By optimizing the array element layout and weight allocation, this array further improves the sparsity of array elements on the basis of ensuring a long uniform degree of freedom, thereby effectively alleviating the electromagnetic coupling effect between array elements and achieving the synergistic improvement of the ability to identify multiple incoming wave angles and the coupling suppression performance. Experimental results show that the OWSA array successfully balances the core problem that it is difficult for the uniform degree of freedom and coupling effect to be taken into account in traditional array configurations. In complex scenarios such as a low signal-to-noise ratio, a small number of snapshots, and high coupling, its direction-of-arrival angle estimation accuracy is significantly better than that of the improved coprime array and nested array, which verifies the feasibility and superiority of this new array in high-precision angle estimation in complex electromagnetic environments.

Key words: DOA estimation, sparse array, mutual coupling