采用方向域滤波的非圆信号测向方法

针对实际应用中多个非圆信号从某一先验已知角度范围内入射的情况，提出了一种采用方向域滤波的非圆信号测向算法。新算法首先利用非圆信号测向MUSIC(NC-MUISC)算法得到入射信号的空间谱，再利用信号先验入射角度范围将其空间谱函数在方向域进行滤波，得到虚拟扩展协方差矩阵，然后仿照NC-MUISC算法求得信号入射方向。仿真结果表明，新算法保持了NC-MUISC算法的阵列扩展能力，同时在分辨力和测向精度方面进一步提高，且先验角度范围越准确则算法性能越好，具有良好的实用价值。 

Direction-finding Algorithm for Noncircular Signals through Direction Domain Filtering

In some practical applications, the directions of arrival (DOAs) of impinging noncircular signals are in a roughly known range. A new algorithm based on direction domain filtering is proposed to improve the resolution and accuracy of the traditional MUSIC (multiple signal classification) algorithm for noncircular signals (NC-MUSIC). Firstly, get the spatial spectrum of NC-MUSIC algorithm and filter it by the roughly known range. Secondly, use the filtered spatial spectrum to reconstruct the extended covariance. Thirdly, find DOAs of impinging noncircular signals followed the steps of traditional NC-MUSIC algorithm based on the reconstructed extended covariance. Simulation results show that the proposed algorithm holds the ability of array extension that the traditional NC-MUSIC algorithm already has, improves the resolution and the accuracy which are inversely proportional to the magnitude of the roughly known range. The proposed algorithm is of practical value.