A self inversive array processing scheme for angle-of-arrival estimation

This paper proposes an improved high-resolution technique that incorporates the forward (original) array together with its complex conjugated backward version to achieve superior performance. This is in turn realized by averaging the forward covariance matrix and the backward one, and using it in conjunction with the MUSIC technique. This paper also presents the asymptotic analysis in terms of first-order approximations of the mean and variance of the null spectrum estimator. It is shown here that in an uncorrelated scene, the bias corresponding to this scheme is exactly half of that associated with the conventional one while maintaining the same variance. Furthermore, the bias expression in the new scheme is used to obtain a resolution threshold for two uncorrelated, equipowered plane waves in white noise and the result is compared with that obtained by the conventional scheme for the same source scene.