A fast method for direction-of-arrival estimation

In many eigenvalue-eigenvector-based direction-of-arrival estimation algorithms, one finds orthogonal basis vectors for the noise subspace. We propose a circulant basis for the noise space which can be calculated more efficiently than an orthogonal basis. The new method for high signal-to-noise ratio (SNR) has a performance similar to the well-known MUSIC algorithm but can be implemented much more efficiently.