MSE of diagonally loaded Capon beamformer-based power spectrum estimator in snapshot deficient regime

A Capon beamformer processes the input signal such that the output power is minimized and the signal arriving from a look direction is undistorted. This paper presents a theoretical study of the estimation mean square error of a diagonally loaded Capon beamformer-based spatial power estimator in the snapshot deficient regime. The derived characterization is validated via simulations. Additionally, a strong sensitivity of the mean square estimation error to diagonal loading when beamformer is steered close to source direction has been observed.