Effective Direction-of-Arrival Estimation Algorithm by Exploiting Fourier Transform for Sparse Array

Zhenyu WEI  Wei WANG  Ben WANG  Ping LIU  Linshu GONG  

IEICE TRANSACTIONS on Communications   Vol.E102-B   No.11   pp.2159-2166
Publication Date: 2019/11/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2018EBP3265
Type of Manuscript: PAPER
Category: Antennas and Propagation
direction-of-arrival (DOA) estimation,  fast Fourier transform (FFT),  low-complexity,  sparse arrays,  spatial smoothing,  

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Sparse arrays can usually achieve larger array apertures than uniform linear arrays (ULA) with the same number of physical antennas. However, the conventional direction-of-arrival (DOA) estimation algorithms for sparse arrays usually require the spatial smoothing operation to recover the matrix rank which inevitably involves heavy computational complexity and leads to a reduction in the degrees-of-freedom (DOFs). In this paper, a low-complex DOA estimation algorithm by exploiting the discrete Fourier transform (DFT) is proposed. Firstly, the spatial spectrum of the virtual array constructed from the sparse array is established by exploiting the DFT operation. The initial DOA estimation can obtain directly by searching the peaks in the DFT spectrum. However, since the number of array antennas is finite, there exists spectrum power leakage which will cause the performance degradation. To further improve the angle resolution, an iterative process is developed to suppress the spectrum power leakage. Thus, the proposed algorithm does not require the spatial smoothing operation and the computational complexity is reduced effectively. In addition, due to the extention of DOF with the application of the sparse arrays, the proposed algorithm can resolve the underdetermined DOA estimation problems. The superiority of the proposed algorithm is demonstrated by simulation results.