MISC Array: A New Sparse Array Design Achieving Increased Degrees of Freedom and Reduced Mutual Coupling Effect

• Published in: IEEE transactions on signal processing Vol. 67; no. 7; pp. 1728 - 1741
• Main Authors: Zheng, Zhi, Wang, Wen-Qin, Kong, Yangyang, Zhang, Yimin D.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Apertures; Array signal processing; Beamforming; Closed form solutions; Computer simulation; Configurations; Covariance matrices; Degrees of freedom; degrees of freedom (DOFs); Direction of arrival; direction-of-arrival estimation; Exact solutions; Linear arrays; Mathematical analysis; MISC arrays; Mutual coupling; Sensor arrays; Sensors; Sparse arrays
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2019.2897954

Recently, nested and coprime arrays have attracted considerable interest due to their capability of providing increased array aperture, enhanced degrees of freedom (DOFs), and reduced mutual coupling effect compared to uniform linear arrays (ULAs). These features are critical to improving the performance of direction-of-arrival estimation and adaptive beamforming. In this paper, a new sparse array configuration based on the maximum inter-element spacing constraint (MISC) is proposed. The MISC array configuration generally consists of three sparse ULAs plus two separate sensors that are appropriately placed. The MISC array configurations are designed based on the inter-element spacing set, which, for a given number of sensors, is uniquely determined by a closed-form expression. We also derive closed-form expressions for the number of uniform DOFs of the MISC arrays with any number of sensors. Compared with the existing sparse arrays, the MISC array enjoys two important advantages, namely, providing a higher number of DOFs and reducing the mutual coupling effects. Numerical simulations are conducted to verify the superiority of the MISC array over other sparse arrays.