Subspace-based estimation of Direction-Of-Arrival with known directions

Estimation of Directions-Of-Arrival is an important problem in various applications. A priori knowledge on the signal location is sometimes available and previous works have exploited this prior-knowledge. The principle is to “orthogonally” deflate the signal subspace and therefor to cancel the known part of the steering matrix. Our solution is based on a simple modification of the well-known MUSIC criterion by substituting the classical Moore-Penrose pseudo-inverse by the obliquely weighted pseudo-inverse. The later is in fact an efficient way to introduce prior-knowledge into subspace fitting techniques.