A statistical analysis of MUSIC null-spectrum via decomposition of estimation error

A statistical performance analysis of the multiple signal classification (MUSIC) method is addressed in this paper. To obtain the first and second order statistics of the sample MUSIC null-spectrum at the directions of arrival, a method which does not require the eigendecomposition is considered for the two signal sources case. From this result we obtain a more exact expression of the resolution threshold which is then used to evaluate the resolution capability for two closely located signal sources.