Performance analysis of wideband direction finding using interpolated arrays

A new direction finding algorithm is derived for multiple wideband signals received by an arbitrary array, and its performance is analyzed. Using an interpolation technique, a set of virtual arrays is generated, each for a direct frequency band, having the same array manifold. The covariance matrices of these arrays are added up to produce a composite covariance matrix. Direction of arrival estimates are obtained by eigendecomposition of this composite covariance matrix using the narrowband MUSIC algorithm or its variants. By choosing the virtual arrays to be linear and equally spaced, one can apply the root-MUSIC algorithm to this problem. Closed-form expressions for the asymptotic covariance matrix of the direction of arrival (DOA) estimation errors are derived using a perturbation analysis.<
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