An Efficient 2-D DOA Estimation for a Cylindrical Conformal Array with Unknown Mutual Coupling

Chao Liu,Shunian Yin

doi:10.1155/2018/4015980

Abstract

The limited space of a conformal array may lead to a serious mutual coupling effect, which will significantly affect the performance of direction of arrival (DOA) estimation algorithms. In this paper, an efficient 2-D direction finding method is developed in the presence of unknown mutual coupling for the uniform cylindrical conformal array (CCA). To avoid the time-consuming two-dimensional spectral peak searching, the 2-D DOA estimation is decoupled and divided into two 1-D DOA estimations. Elevation is first estimated based on a subarray estimation of signal parameters via rotation invariant technique (ESPRIT), and then azimuth is estimated based on the rank reduction (RARE) method by using the elevation estimation result. Consequently, the mutual coupling coefficients can be estimated after getting the DOA estimates. The proposed method can well calibrate the mutual coupling effect of a cylindrical array with a low computational complexity. The final simulation results corroborate our analysis.

Highlights

Direction of arrival (DOA) estimation is a major research direction in array signal processing area
By taking advantages of the special structure of uniform linear array (ULA) and uniform rectangular array (URA), auxiliary elements were demonstrated to be effective for the autocalibration of mutual coupling [5,6,7]
An efficient 2-D DOA estimation method is proposed for the cylindrical conformal array in the presence of unknown mutual coupling

Summary

Introduction

Direction of arrival (DOA) estimation is a major research direction in array signal processing area. By taking advantages of the special structure of uniform linear array (ULA) and uniform rectangular array (URA), auxiliary elements were demonstrated to be effective for the autocalibration of mutual coupling [5,6,7]. This kind of method was further extended to the situation of non-Gaussian noise [8] and coherent signal condition [9] by using fourth-order cumulants (FOC) and spatial smoothing technique, respectively. Numerical experiments are provided to demonstrate the effectiveness of the proposed method

Signal Model

DOA Estimation for CCA with Unknown Mutual Coupling

Simulation Results

Conclusion