复解析小波变换的圆阵波达方向估计方法

Circular Array DOA Estimation Based on Complex Analytical Wavelet Transform

针对多重信号分类的圆阵高分辨波达方向估计方法不稳定问题,提出了复解析小波变换的圆阵波达方向估计方法。该方法通过复解析小波变换将圆阵拾取数据转换为一定频带复解析数据,在时域对复解析数据进行时延补偿,并采用多采样点累积处理方式对时延补偿后复解析数据构造协方差矩阵,对协方差矩阵进行特征分解,并对分解所得各子空间特征向量进行累积求和,获得各子空间获空间谱,对各子空间合成空间谱进行极大值判决处理,提高目标子空间空间谱在最终合成空间谱中的比重。数值仿真及实测数据处理结果均表明,相比频域多重信号分类方法,通过时域多点累积处理和极大值判决处理,最低信噪比的宽容性得到了5 dB以上的改善。

To solve the instability of direction of arrival(DOA)estimation based on multiple signal classification(MUSIC)method in circular array,a DOA estimation method based on complex analytical wavelet transform was proposed.Firstly,the complex analytical form with certain frequency band of received data was obtained via complex analytical wavelet transform,and the covariance matrix was constructed through complex analytical data after time delay compensation via multi-point accumulation in time-domain.Secondly,the spatial spectrum of every subspace was obtained by accumulating the eigenvector,that was obtained by eigen-decomposition.Finally,the final synthetic spatial spectrum through the judgment of maximum value,and the proportion of target subspace on synthetic spatial spectrum was increased.The results of numerical simulation and measured data processing showed that,compared to the frequency domain multiple signal classification method,this method could reduce the demand of multiple signal classification for minimum input signal-to-noise ratio more than 5 dB by the processing of nonlinear weighting and multi-point accumulation in time domain.