Uniform circular array in the parameter estimation of coherently distributed sources

We consider the problem of two-dimensional (azimuth and elevation) direction-of-arrival estimation for coherently distributed sources using a pair of uniform circular arrays. We propose a low-complexity estimation algorithm, the sequential one-dimensional searching algorithm. The proposed algorithm has a basis on the eigenstructure between the steering matrix and signal subspace, and utilizes a preliminary estimate obtained by the total least square estimation of signal parameters via the rotational invariance technique as a pre-processing stage. The proposed algorithm exhibits as good estimation performance as the maximum likelihood method for coherently distributed sources. Some simulation results are included to show the performance of the proposed method.