A Fast Nyström-based DOA Estimation Approach for Coherent Signals

This paper presents a fast approach for Direction of arrival (DOA) estimation based on the Nyström method, specifically designed for coherent signals. In coherent signals, the rank of the covariance matrix is affected by signal coherence, resulting in the rank being less than the real source number. Traditional DOA estimation methods are unable to accurately estimate DOA in such scenarios. To address this problem, we propose an approach that utilizes the Nyström method to decrease the complexity of obtaining the signal subspace. And to decohere the signal, we construct a new data matrix by utilizing the signal subspace. Finally, the QR decomposition-based method is used to obtain DOA estimation. We conduct simulations to compare the efficiency of our proposed approach with some existing DOA estimators. The results verify the effectiveness of our method.