Oblique projections for direction-of-arrival estimation with prior knowledge

Remy Boyer (1) , Guillaume Bouleux (2)

1 L2S - Laboratoire des signaux et systèmes
2 LASPI - Laboratoire d'Analyse des Signaux et des Processus Industriels

Abstract—Estimation of directions-of-arrival (DOA) is an important problem in various applications and a priori knowledge on the source location is sometimes available. To exploit this information, standard methods are based on the orthogonal projection of the steering manifold onto the noise subspace associated with the a priori known DOA. In this paper, we derive and analyze the Cramér-Rao bound associated with this model and in particular we point out the limitations of this approach when the known and unknown DOA are closely spaced and the associated sources are uncorrelated (block-diagonal source covariance). To fill this need, we propose to integrate a priori known locations of several sources into the MUSIC algorithm based on oblique projection of the steering manifold. Finally, we show that the proposed approach is able to almost completely cancel the influence of the known DOA on the unknown ones for block-diagonal source covariance and for sufficient signal-to-noise ratio (SNR).

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Remy Boyer, Guillaume Bouleux. Oblique projections for direction-of-arrival estimation with prior knowledge. IEEE Transactions on Signal Processing, 2008, 56 (4), 14 p. ⟨hal-00575873⟩