Unitary root-MUSIC with a real-valued eigendecomposition: a theoretical and experimental performance study

A real-valued (unitary) formulation of the popular root-MUSIC direction-of-arrival (DOA) estimation technique is considered. This Unitary root-MUSIC algorithm reduces the computational complexity in the eigenanalysis stage of root-MUSIC because it exploits the eigendecomposition of a real-valued covariance matrix. The asymptotic performance of Unitary root-MUSIC is analyzed and compared with that of conventional root-MUSIC. The results of this comparison show identical asymptotic properties of both algorithms in the case of uncorrelated sources and a better performance of Unitary root-MUSIC in scenarios with partially correlated or fully coherent sources. Additionally, our simulations and the results of sonar and ultrasonic real data processing demonstrate an improved threshold performance of Unitary root-MUSIC relative to conventional root-MUSIC. It can be then recommended that, as a rule, the Unitary root-MUSIC technique should be preferred by the user to the conventional root-MUSIC algorithm.