Enhanced DOA Estimation Exploiting Multi-Frequency Sparse Array

• Published in: IEEE transactions on signal processing Vol. 69; pp. 5935 - 5946
• Main Authors: Zhang, Shuimei, Ahmed, Ammar, Zhang, Yimin D., Sun, Shunqiao
• Format: Journal Article
• Language: English
• Published: New York IEEE 2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Array interpolation; Array signal processing; Arrays; Correlation; Correlation analysis; Direction of arrival; Direction-of-arrival estimation; Estimation; group sparsity; Interpolation; multi-frequency sparse array; Redundancy; Sensor arrays; Sparse matrices; zero lag redundancy
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2021.3122292

In this paper, we develop a general framework of multi-frequency sparse array to estimate the direction-of-arrival (DOA) of a significantly higher number of targets than the number of physical sensors. The multi-frequency sparse arrays are designed to offer zero lag redundancy in the rendered difference coarray so that the available degrees of freedom are fully utilized to enable high-resolution DOA estimation. A modified sensor interpolation technique is developed to accurately estimate the signal correlation matrix so that the effect of holes in the difference coarray is mitigated. The proposed technique accounts for both self-lags between signals corresponding to the same frequencies and the cross-lags between signals corresponding to different frequencies. As such, it enhances the DOA estimation performance compared to existing methods that either perform array interpolation utilizing only the self-lags or carry out group sparse reconstruction without exploiting array interpolation. Simulation results verify the offerings of the multi-frequency sparse arrays.