Fast Direction of Arrival Estimation Using a Sensor-Saving Coprime Array with Enlarged Inter-Element Spacing

Direction of arrival (DOA) estimation using coprime array is discussed, and a fast method using a sensor-saving coprime array with enlarged inter-element spacing is proposed. Original coprime array combines the results obtained from two coprime subarrays to uniquely determine the DOA estimation, and it is shown in this paper that one subarray actually only requires half of its original sensor number and can achieve enlarged inter-element spacing based on the array compensation from the cross correlation matrix. Thereafter, a fast DOA estimation method, which extracts the noise subspace without eigenvalue decomposition, is proposed to obtain coprime DOA estimations based on one dimensional root finding technique. Final unique DOA is estimated from the coincide results of the coprime estimations. Simulation results verify that the proposed method can achieve almost the same estimation performance as conventional methods while requiring less sensors.