Directional Localization Errors Of Eigenvector Eigenvalue (EVEV) Signal Processors

Signal-subspace processors that exploit the eigenstructures of covariance matrices have directional responses that are much more narrow than the responses of more conventional systems. EVEV methods are considered here in three specific forms that can be attributed to Pisarenko, Schmidt, and Johnson. The peaks of the processors' outputs are examined for deviation from the true direction of arrival, and variance of the results for several observations. Beamformer outputs have been computed from input data recorded from an actual array. The results demonstrate (1) that the performance of the Pisarenko processor is unsatisfactory and (2) that improved performance is achieved by the use of EVEV systems such as MUSIC at a price of some increase of computational load.