一种基于空域滤波的空间临近相干源角度估计方法

Direction of Arrival Estimation Method for Spatially Adjacent Coherent Sources Based on Spatial Filtering

相干源常见于存在多径的场景,如何解相干历来是阵列信号处理领域亟待解决的难题之一,特别针对空间临近相干源,其角度估计精度尚有待提高。针对空间临近相干源该文提出一种基于空域滤波的角度估计方法。首先利用空域滤波技术将多个相干源分离,再对滤波分离后的各个信号分别进行角度估计,并通过对滤波器系数和相干源角度的迭代优化提高测角精度。针对非均匀线阵,该方法采用虚拟阵列技术扩展其适用范围。计算机仿真结果表明该方法的测角精度较现有方法更高,信噪比较高时其测角的均方根误差可达克拉美罗界,验证了该方法的有效性和在空间临近相干源场景的优越性。

Coherent sources commonly exist in scenarios with multipath effect. How to decorrelate coherent sources is traditionally a problem urgently to be solved in the array signal processing domain. Especially for spatially adjacent coherent sources, the performance of the estimation of Direction Of Arrival （DOA） remains to be improved. A DOA estimation method based on spatial filtering is proposed for spatially adjacent coherent sources. Multiple coherent sources are separated by spatial filtering and the DOAs are estimated respectively afterwards. The performance of the DOA estimation is enhanced by refining the filter parameters and the DOAs of the coherent sources iteratively. To extend its application to non-uniform linear array, the virtual array technique is adopted. The computer simulation results indicate that the proposed algorithm has better DOA estimation performance than the existing methods. In the scenario of sufficiently high Signal to Noise Ratio （SNR）, the Root Mean Square Error （RMSE） could achieve Cramer-Rao Bound （CRB）. The effectiveness and the superiority of the proposed method for spatially adjacent coherent sources are validated by the simulation results.