DOA Estimation for UCA in the Presence of Gain-Phase Errors

Abstract

In this letter, a direction-of-arrival (DOA) estimation method for the uniform-circular array (UCA) in the presence of gain-phase errors is proposed. Thanks to UCA properties, the virtual steering vector, which is constructed with the Hadamard product of the steering vector and its conjugate to eliminate phase errors, is considered to correspond to virtual 2-D sources impinging on the virtual UCA. This finding indicates that the azimuths and elevations of virtual sources, which are related to DOAs of original sources, can be decoupled and estimated via UCA-estimating-signal-parameter-via-rotational-invariance-techniques with the help of the recursive relationship of the Bessel function in the mode space of the virtual steering vector. We also propose the spatial filtering method, which is based on the linear independence of steering vectors in different directions, to eliminate one component in the virtual covariance matrix, which affects the DOA estimation of adjacent sources. This method can avoid the 2-D multiple-signal-classification search and cope with the one-component problem. Simulations verify its effectiveness.