• CN:11-2187/TH
  • ISSN:0577-6686

›› 2011, Vol. 47 ›› Issue (8): 54-59.

• 论文 • 上一篇    下一篇

频散信号的窄带互相关模型及其相延迟估计

林京;吴文焘   

  1. 西安交通大学机械制造系统工程国家重点实验室;中国科学院声学研究所
  • 发布日期:2011-04-20

Narrowband Cross-correlated Model for Dispersive Signals and Its Use for Phase Delay Estimation

LIN Jing;WU Wentao   

  1. State Key Laboratory for Manufacturing System Engineering, Xi’an Jiaotong University Institute of Acoustics, Chinese Academy of Sciences
  • Published:2011-04-20

摘要: 指出已有的窄带信号互相关模型不能直接应用于频散信号的相延迟估计,尤其是在频散程度比较大的情况下。通过研究发现,导致这一结果的原因在于已有的窄带信号互相关模型中的相位量为线性假设,而频散信号互相关函数中的相位信息已包含了高阶的非线性成分,已有模型与实际情况不再匹配。为此,将二阶相位量引入已有窄带互相关模型,建立一种针对频散信号的窄带互相关模型,可以有效进行频散窄带信号的相延迟估计,通过对比发现,本方法对仿真信号的相延迟估计的误差小于原方法误差的十分之一,同时该方法在环境的适应性方面也要明显优于已有方法,如对信号带宽的变化不敏感等。

关键词: 频散信号, 相延迟估计 互相关模型 窄带信号 兰姆波

Abstract: Traditional narrowband signal cross-correlated model cannot be used directly for phase delay estimation for dispersive signals, especially when the dispersion is strong. The reason lies that the phase item in the cross-correlation function of dispersive signals contains non-linear components. However, current cross-correlation model is assumed with linear phase, which is not in accordance with the fact of dispersive signals and will lead to big error for phase delay estimation. A new cross-correlation model is established by introducing a quadratic component in the phase item. The estimation error is much smaller when the proposed model is employed for phase delay estimation for dispersive signals. At the same time, the proposed method is more robust than current model, for instance, it is insensitive to the variation of signal bandwidth.

Key words: Cross-correlation model, Dispersive signal, Lamb wave, Narrowband signal, Phase delay

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