Low-complexity estimator for four-dimensional parameters under a reparameterised distributed source model

The spatial character of a parametric model of a coherently distributed source signal (DSS) can be determined by four parameters: the two-dimensional direction of arrival (DOA) and the corresponding two-dimensional angular spread, associated with azimuth and elevation, respectively. The authors consider the problem of estimating these four parameters using a uniform circular array. A low-complexity estimator is proposed to alleviate the burden of calculation based on a reparameterised model of the DSS. Using the property of the reparameterised model, a two-dimensional searching method is proposed to estimate the generalised steering vectors (GSVs) of the DSS. The nominal DOA and the angular spread can be estimated using the estimated value of the GSV. The method is illustrated by some numerical examples