Unambiguous Parameter Estimation of Multiple Near-Field Sources via Rotating Uniform Circular Array
Xin Chen, Zhen Liu, Xizhang Wei · IEEE Antennas and Wireless Propagation Letters · 2016
Near-field source localization suffers from serious phase ambiguity, when the array aperture is larger than half-wavelength. In this letter, by performing adaptive rotation of uniform circular array with a center sensor, a closed-form algorithm based on phase difference is improved for estimating the source's three-dimensional (3-D) location (azimuth angle, elevation angle, and range) unambiguously. Furthermore, we also consider the case of multiple monofrequency sources that can be separated in the frequency domain, and especially, the effect of sources' frequency spacing on initial phase calibration is analyzed. Finally, the performance of the proposed algorithm under different rotation angles is demonstrated, and its superiority over the rotary 3-D multiple signal classification estimator in computational complexity is also presented.