The phase difference method using sub array and phase unwrapping(SUPDM)is presented to improve the arrival direction estimation of the phase difference method(PDM). The sensor outputs are transformed into the frequency domain
and the array is divided into several sub arrays. The coherent average is calculated on the spectra at the center frequency bin in each sub array
and phase angles of the resulting spectra are obtained. Then the transverse phase unwrapping is applied to these phase angles. The reciprocal of the phase difference between the maximum phase and the minimum phase is taken as the DOA estimator
and the peak locations of the spatial spectrum give the DOA estimation. The SUPDM has better performance than that of the PDM under different signal to noise ratios and source separations. The resolution capability of the SUPDM is superior to that of both the PDM and the conventional beam-former when there exists spectrum leakage. The simulation results show that
the root mean square error of the SUPDM estimation has 0.03 degree smaller than that of the PDM when there is single source and the signal to noise ratio is -5 dB.
GONG Xiangyi, YUAN Junquan, SU Linghua. A multi-pare unwrap ambiguity of interferometer array for estimation of direction of arrival [J]. Journal of Electronics and Information Technology, 2006,28(1):55-59.
SHIEH Ching-Sung, LIN Chin-Teng. Direction of arrival estimation based on phase differences using neural fuzzy network [J]. IEEE Transactions on Antennas and Propagation, 2000,48(7):1115-1124.
KRIM H, VIBERG M. Two decades of array signal processing research: the parametric approach [J]. IEEE Signal Processing Magazine, 1996, 13(4):67-94.
NIU Yilong, SUN Jincai, WANG Yi, et al. Immune memory based quantum clone algorithm for joint estimation of 3-dimensional parameters [J]. Journal of Xi'an Jiaotong University, 2009,43(4):75-79.
PAWULA R F. Distribution of the phase angle between two vectors perturbed by Gaussian noise II [J]. IEEE Transactions on Vehicular Technology, 2001, 50(2):576-583.
STOICA P, JIAN L, HAO H. Spectral analysis of nonuniformly sampled data: a new approach versus the periodogram [J]. IEEE Transactions on Signal Processing, 2009,57(3):843-858.
WANG Zhaohua, HUANG Xiangdong. Principle of phase measurement and its application based on all-phase spectral analysis [J]. Journal of Data Acquisition and Processing, 2009, 24(6):777-782.