Improved unfolded coprime array subject to motion for DOA estimation: augmented consecutive synthetic difference co-array

• Published in: IET signal processing Vol. 14; no. 10; pp. 823 - 836
• Main Authors: Ma, Penghui, Li, Jianfeng, Zhang, Xiaofei, Zhao, Gaofeng
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 18.12.2020
• Subjects: array aperture; array motion; array signal processing; augmented consecutive synthetic difference co‐array; closed‐form expression; coprime element numbers; DCA synthesis; direction of arrival estimation; DOA estimation performance; dominant consecutive DCA segments; existing coprime array configurations; improved unfolded coprime array; inter‐element distances; IUFCA motion; negative virtual arrays; physical elements; positive virtual arrays; Research Article; synthetic DCA; uDOF; UFCA motion; uniform degree of freedom; uniform linear subarrays; negative virtual arrays; synthetic DCA; IUFCA motion; positive virtual arrays; dominant consecutive DCA segments; existing coprime array configurations; coprime element numbers; improved unfolded coprime array; augmented consecutive synthetic difference co-array; direction-of-arrival estimation; physical elements; array motion; DOA estimation performance; uDOF; UFCA motion; closed-form expression; uniform degree of freedom; uniform linear subarrays; DCA synthesis; inter-element distances; direction of arrival estimation; array aperture; array signal processing
• DOI: 10.1049/iet-spr.2020.0200
• ISSN: 1751-9675

Direction of arrival (DOA) estimation using the improved unfolded coprime array (IUFCA) subject to array motion isdiscussed in this study. Unfolded coprime array (UFCA) consists of two uniform linear subarrays, and the two subarrays are arranged at different sides of theaxis, which leads to a large number of holes in the difference co-array (DCA). With array motion and DCA synthesis,part of the holes can be filled, but there are still holes in the center which lead to the virtual arrays separated.By analyzing the hole positions in the synthetic DCA generated by UFCA motion, the authors improve the originalUFCA by relocating some physical elements, then the two dominantconsecutive DCA segments in the positive and negative sides can be connected. The expression of synthetic DCA is analyzed, and the closed-form expression of theuniform degree of freedom (uDOF) subject to IUFCA motion is studied. Simulation results show that IUFCA motion can obtain a largenumber of uDOFs, which leads to better DOA estimation performance and more identifiable signals compared with existingcoprime array configurations.