Direction-of-Arrival Estimation for Near-Field Sources with Multiple Symmetric Subarrays

Tomoyuki KITADA  Jun CHENG  Yoichiro WATANABE  

IEICE TRANSACTIONS on Communications   Vol.E96-B   No.2   pp.553-560
Publication Date: 2013/02/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E96.B.553
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Antennas and Propagation
array antenna,  direction of arrival,  spherical sources,  near-field source,  

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A direction-of-arrival estimation (DoA) scheme that uses a uniform circular array (UCA) is proposed for near-field sources, where multiple pairs-of-subarrays exist with central symmetry. First, multiple generalized ESPRIT (G-ESPRIT) spectrums are obtained by applying the conventional G-ESPRIT algorithm to each of multiple pairs-of-subarrays. Second, a parallel spectrum is found by adding up the reciprocals of these G-ESPRIT spectrums and taking the reciprocal of the total. The locations of peaks in the parallel spectrum give the DoAs being estimated. When a DoA approaches the translation direction of two subarrays, the conventional G-ESPRIT spectrum is broken by a false peak. Since the translation directions of pairs-of-subarrays are different from each other, the false peak, due to the DoA approaching one of translation directions, does not exist simultaneously in all G-ESPRIT spectrums. The parallel concatenation of the spectrums suppresses the false peak and enhances the true DoA peaks. Simulation shows that the proposed scheme reduces the root mean square error of the DoA estimation, compared with the conventional G-ESPRIT algorithm.