A robust source number detection method via rotational invariance techniques

In this paper, we present an accurate robust, and computationally efficient source number detection method, for multiple narrowband far-field signals impinging on a uniform circular array (UCA). The element space manifold is transformed into the beamspace manifold via phase mode excitation for UCA. The rotational invariance techniques and the forward/back (FB) averaging can be employed in beamspace. Unlike the traditional methods that utilize the eigenvalues, the proposed method determines the number of sources by exploiting the eigenvectors. The performances of some relevant algorithms are compared via simulations, and the effectiveness of the proposed method is verified.