Method of direction-of-arrival estimation for uncorrelated, partially correlated and coherent sources

A new direction-of-arrival estimation method is proposed when uncorrelated, partially correlated and coherent sources coexist. These sources are estimated at two different stages. The uncorrelated and partially correlated sources are first estimated using conventional subspace methods. By exploiting the property of oblique projection, the contributions of uncorrelated and partially correlated sources are then eliminated from the covariance matrix and only the coherent sources remain. Finally, the coherent sources are estimated by the technique of spatial smoothing. The new method need not estimate the partially correlated sources repeatedly but can resolve more sources than the array elements. Simulation results demonstrate the effectiveness and efficiency of the new method.