New signal subspace direction-of-arrival estimator for wideband sources

Wideband direction finding is one of the difficult tasks in signal processing.The classical rotational signal subspace transform algorithm requires initial values which are close enough to the true values.The preprocessing procedure should be carefully done lest it introduce some distortion.Failure to find proper initial values may prevent convergence of the estimator or cause biases in the estimator,consequently influence the estimation precision.The proposed method educes the relation of the different frequency and direction bearing vector,then constructs an especial matrix by use of the connection of signal subspace,noise subspace and array manifold,finally estimates DOA via condition number.Therefore it does not require any initial values,thus can improve the steadiness of new algorithm and reduce the calculation cost.By use of the signal subspace and the noise subspace of decomposed wideband signals,the influence of noise subspace disturbance on estimation precision is reduced.Simulation results verified the efficiency of the new method.