Bearing estimation in the unknown noise fields

In most algorithms of estimation of the direction of arrival (DOA) of the sources, the additive noise term is assumed to be spatially white or known to within a multiplicative scalar. When the noise is nonwhite but has a known spectral, we can still handle the problem through pre-whitening. However there are no techniques presently available to deal with completely unknown noise fields. In this paper, a proposed algorithm is used at each frequency to estimate the noise spectral matrix, which is used for whitening the received spectral matrix. A fast focusing operator is used to construct coherent source subspace. To illustrate the performances of the proposed algorithm, the problem of the localization of the sources is studied, without and with pre-whitening pre-processing. The simulation results show the improvement of the DOA when the perfect modelisation of the noise spectral matrix is used