Direction-of-Arrival Estimation of M-1 Signals Based on Unitary-ESPRIT and Successive-Selection Technique with an M-Element Hexagonal Array
Eddy Taillefer, J. Cheng, Yoichiro Watanabe · 2008
A method for full-azimuth DoA estimation of multiple signals with a hexagonal array is proposed. The DoA estimation is performed in two steps. In the first, a set of estimate candidates is constructed by gathering the estimates that are obtained from applying the Unitary-ESPRIT algorithm to several translational invariances designed into a hexagonal array. In the second step, the DoA estimates are successively selected from the estimate candidate set by using a selection function. The proposed method removes the north-or-south signal membership ambiguity and the limitation on the number of estimable sources, problems common to any ESPRIT-based algorithm used with one translational invariance. Therefore, up to M - 1 signal DoA estimations can be expected with an M-element hexagonal array in the full azimuth. The successive-selection approach is based on a selection function that uses an estimate of the signal's spatial correlation matrix to successively select the DoA estimates. For each DoA estimate selection, the already estimated signal components are removed from the correlation matrix. The method's DoA estimation and resolution capabilities are demonstrated by computer simulation.