A DOA Estimation Method for Sparse Array Based on DFT Spectrum of Received Signals

In the direction of arrival (DOA) estimation of sparse array received signals, the estimation accuracy of the grid search method in compressed sensing is improved with the increase of over-complete redundant dictionary elements. However, the increase of over-complete redundant dictionary elements will lead to a significant increase in the computational complexity of this method. In order to reduce the computational complexity caused by over-complete redundant dictionary division, based on the equivalent received signal of large aperture continuous difference co-array generated by sparse array, a DOA estimation method using discrete Fourier transform (DFT) spectrum of signal for initial estimation is proposed in this paper. After obtaining the DFT spectrum of the equivalent signal, based on the correspondence between the DFT spectrum and the actual angle value, this paper proposes a new strategy for dividing the over-complete redundant dictionary. In the process of fine angle search, this paper applies Taylor expansion to orthogonal matching pursuit (OMP) algorithm to obtain higher estimation accuracy. Numerical simulation results demonstrate the advantages of the proposed estimation method over the other methods.

Automated summary

This paper proposes a new method for DOA estimation of sparse array received signals, utilizing DFT spectrum for initial estimation, optimizing estimation accuracy through a new strategy for dividing the over-complete redundant dictionary, and applying Taylor expansion to OMP algorithm in fine angle search process.