A Research On DOA Estimation Methods Of UCA

In this paper, the DOA estimation methods of uniform circular array (UCA) and the analysis of its performance are researched. In space, the UCA can search 360-degree-wide azimuth; the arrays beam of UCA has the same directional in all directions; and the array aperture can be increased with the increasing of radius in a certain range. These make the UCA having many advantages which the linear array can not catch for direction-finding.Firstly, the space structure of UCA and its data model are introduced. Then, mode-space transform is also described in detail. By using mode-space transform, the UCA can be transformed into the virtual uniform linear array.Secondly, the paper introduces the basic principles of DOA finding by phase interferometer. Based on it, the method of interferometer direction finding which based on UCA is studied; the broadband characters in DOA of UCA and the scanning ability, 360 degreed azimuths, are discussed in detail.Thirdly, MUSIC used in UCA DOA finding and beam-space methods is studied base on UCA. By using mode-space transform, high resolution DOA methods are taken into UCA, which used to fit only array with Vandermonde structure. Also, classical beamforming methods are used on virtual array. Virtual array and its beam bearing are introduced, including weigthed method for virtual array.Lastly, base on mode-space transform, DOA finding methods of coherent signals using UCA are studied, which includes spatial smoothing, matrix reconstruct, Toeplitz and other methods.