奇异值分解的HB加权广义互相关时延估计

Time Delay Estimation of Generalized Cross Correlation with Hassab-Boucher Weighted Function Based on Singular Value Decomposition

  • 摘要: 传统广义互相关时延估计技术是直接基于测量数据,其精度受环境噪声及异常值波动影响显著下降。针对上述问题,提出了一种新的时延估计算法,即奇异值分解的HB(Hassab-Boucher)加权广义互相关法。首先,将接收到的信号进行奇异值分解处理,抑制环境噪声的影响并提高信号的信噪比;其次,采用降噪后的信号进行互功率谱计算时引入HB加权函数,达到锐化互相关函数峰值的目的;最后,在时延初值未知的情况下,提出了一种基于中位数与平均数结合的时延后处理方案,去除时延估计结果中的异常值波动,得到最优时延估计值。仿真实验结果表明,在低信噪比条件下,与传统的广义互相关和基于奇异值分解的广义互相关参考方法相比,本文提出方法的异常点百分比和均方根误差更低,时延估计正确率更高。

     

    Abstract: Traditional time delay estimation technology of generalized cross correlation based on direct data, without the impacts of various environment noises and fluctuation of outlier, results the greatly attenuated of its accuracy. A novel time delay estimation (TDE) method is proposed to solve the problem. This method is called generalized cross correlation method with Hassab-Boucher (HB) based on singular value decomposition (SVDHB-GCC). Firstly, adopting the singular value decomposition (SVD) is not only to reduce the effect of environmental noise, but improve the SNR of received signals. Secondly, the peak of GCC function can be sharped by introducing the Hassab-Boucher weighted function into the calculation of the power spectral density. Finally, the post processing approach based on mean and median is exploited, which can obtain the optimal estimation of TDE by revising its abnormal fluctuation with the unknown initial value of time delay. Simulation results show that the proposed method has lower percentage of abnormal points (PAP) and root mean square error (RMSE), and the reverse is true in the accurate ratio (AR) of TDE, compared with other methods in low signal-noise ratio (SNR).

     

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