基于聚焦预处理的累量域空间平滑算法

针对传统累量域波达方向估计算法对各重复位置处虚拟阵元利用不充分的问题,提出了一种基于聚焦预处理的累量域相干信号波达方向估计算法。首先分析了直接平滑原物理阵列和四阶累积量产生的虚拟阵列不能解相干的原因;然后推导了基于累量域聚焦技术解相干的原理;最后提出了直接累量域聚焦、前后向累量域聚焦和二次前后向累量域聚焦算法,并对其进行了性能分析,指出聚焦预处理技术不但不损失阵列孔径,而且充分利用了累量域各虚拟阵列的数据,提高了角度估计精度。理论分析和仿真结果都表明了算法的有效性。

Spatial smoothing algorithm in cumulant domain based on focusing preprocessing

Considering that the traditional direction of arrival (DOA) algorithms in the cumulant domain discard the repeated virtual array elements, a new algorithm for estimating the DOA of coherent signals based on focusing preprocessing in the fourth order cumulant domain is proposed. First, the reasons for the failure of decorrelation are analyzed from the lost of shift-invariant characteristics in the virtual arrays. Then, the principle of decorrelation and DOA estimation of coherent sources is deduced by using the focusing technology. Finally, algorithms of direct focusing, forward/backward focusing and quadratic forward/backward focusing in the cumulant domain are proposed and their performances are analyzed. The analysis shows that, the new algorithms not only avoid the reduction of the array effective aperture but also make full use of the data of the virtual array, they have higher resolution of DOA estimation than similar algorithms. Theoretical analysis and simulation results demonstrate the merits of the new algorithm.