波达方向估计中的宽带信号个数检测新方法

A new method for determining number of wideband signals in direction of arrival estimation

在进行波达方向估计时,往往要对信号个数进行判断,传统的宽带信号个数检测方法需要在每个频点上进行多次采样,否则无法正确完成测向.针对此问题,提出了一种基于Bootstrap准则实现的宽带信号个数检测新方法.将宽带信号划分为若干个互不重叠的子带部分,之后对每个子带信号进行特征分解,利用特征值对相应的特征向量进行加权,再通过Bootstrap准则构造新的信号重采样矩阵,用聚类的方法判断出该子带上的信号个数,最后将各个子带上的结果进行综合判断出宽带信号个数.所提方法回避了聚焦的过程,且在非高斯噪声背景下也有较高的估计成功概率,尤其是在小快拍数下有着较好的估计性能,仿真结果证明了该方法的性能.

Since the number of signals needs to be determined when we perform direction of arrival（DOA）estimation algorithms,wideband signals have to be sampled many times in every frequency for traditional methods,otherwise,it can＇t be judged correctly.To this question,the paper proposes a new method for determining the number of wideband signals based on Bootstrap criterion.First,the wideband signals are divided into several non-overlapping subbands,eigen decomposition is performed to every part of the data,and the eigenvectors are weighted by corresponding eigenvalues in every frequency.Furthermore,Bootstrap criterion is employed to construct resampling matrix,then the number of signals in these frequencies is estimated by some clustering techniques.Finally,the results of every frequency are integrated to derive the number of wideband signals.The method avoids the process of focusing,and it has a high probability of success under the circumstance of non-Gaussian noise,especially when the snapshots is small.The performance is proved by simulation results at last.