High Accuracy Near-Field Localization Algorithm at Low SNR Using Fourth-Order Cumulant

Source localization is a key technology in array signal processing. However, it has a serious problem that the direction of arrival (DOA) estimation accuracy is reduced at low signal-to-noise ratio (SNR). Thus, this Letter proposes an improved near-field multiple signal classification (INF-MUSIC) algorithm to improve DOA estimation accuracy at low SNR. Firstly, the fourth-order cumulant is used to construct a Hermitian matrix with only DOA information. Secondly, the spatial spectrum has physical property that is a breakpoint and approaches a larger value at the DOA, thus first derivative of spatial spectrum is used to improve DOA estimation accuracy at low SNR. Finally, the corresponding ranges are estimated one by one by the one-dimensional MUSIC algorithm. The simulation results show that the INF-MUSIC algorithm makes the DOA estimation accuracy improved by 2° at low SNR.