一种低信噪比下的信号源数检测新方法

摘要

The detection of the number of space signals is one of the key issues in array signal processing. In view of the poor performance of traditional detection methods at low signal-to-noise ratios, a new method called Detection Technique based on Approximate Eigenvectors (DTAE) is proposed to improve the detection performance of sensor arrays at low signal-to-noise ratios. In the proposed method the direction of the centroid of the cluster of signals is first estimated by some kind of beamform scanning in the space, next the approximate eigenvectors of the data covariance matrix is calculated according to the centroid estimate, then the array output data are weighted by the approximate eigenvectors, finally the estimate of the number of signals is acquired by some kind of manipulating of the peak-to-average power ratio of the weighted data in frequency domain.Simulations show the proposed method DTAE demonstrates much better performance than Akaike Information Criterion (AIC) and other methods at low signal-to-noise ratios, which is valuable in engineering practice.%空间信号源数检测是阵列信号处理的关键问题之一,该文针对低信噪比下传统检测方法的性能差的问题,提出了一种基于近似特征向量的检测新方法DTAE(Detection Technique based on Approximate Eigenvectors)来改善低信噪比下传感器阵列的信源数检测性能.该方法首先利用波束形成器在空间做预扫描来估计信号群中心的位置,以这些位置作为参考方向计算接收数据协方差矩阵的特征向量的近似值,然后使用特征向量的近似值对阵列输出数据加权,最后计算加权输出数据的频域峰值-平均功率比值从而估计信号源的个数.仿真结果表明,提出的新方法在低信噪比下的检测性能显著优于AIC(AkaikeInformation Criterion)等方法,有一定的工程应用价值.