未知相关噪声环境下相干宽带源波达方向宽容估计算法

A robust direction of arrival estimation algorithm of coherent wideband sources in unknown correlated noise fields

提出了一种未知相关噪声环境下,相干宽带源波达方向宽容估计算法。在实际应用中,尤其当阵列的孔径相对较小时,环境噪声通常是空间相关的,这引起了相干子空间类算法聚焦误差的增加和波达方向估计性能的严重下降。为此,提出了一种基于差分矩阵的聚焦变换算法,该算法抵消了未知相关噪声,从而减小了聚焦误差。仿真和实验结果表明,提出的方法能适用于低信噪比环境下的方位估计,宽容性及分辨率得到明显提高。

A robust Direction of Arrival （DOA） estimation algorithm for coherent wideband sources in unknown correlated noise fields is investigated in this paper. In practical applications, the additive noise is usually unknown and correlated among sensors, especially for arrays with comparatively small apertures. The spatially correlated noise incurs an increase in focusing error and a severe degradation in the DOA estimation. To deal with the problem, a new method of focusing transformation based on differentiating covariance matrix is proposed to eliminate noise, and hence reduce the focusing error. The simulation and experiment are carried out to demonstrate that the robustness and resolution are significantly improved at low SNR levels.