基于自适应滤波与倒谱联合分析的时延估计方法

Time delay estimation based on adaptive filtering and cepstrum analysis method

为了加强倒谱分析方法在窄带信号多途时延估计的抗噪声性能,该文在自适应滤波的基础上,提出了一种基于自适应陷波滤波与波形修正的信号预处理方法。该方法首先对回波信号进行自适应陷波滤波,有效减少噪声分量,然后对输出波形的包络进行调整,恢复信号的边沿信息,在保留信号中信道信息的前提下有效提高输入信噪比。仿真结果证明,该预处理方法提高信噪比效果明显,并不破坏时延分量,与倒谱分析相结合,能够有效提取线谱信号中的信道信息。

In order to strengthen its anti-noise performance when using cepstrum to estimate the multipath time-delay of narrowband signals,a pre-processing method by adaptive Notch filtering and envelop modification is proposed based on the adaptive filtering. This method improves the signal-to-noise ratio（ SNR） by adaptive Notch filtering,modifies its envelope and preserves the time-delay in-formation. Simulation results show that this method can improve the SNR effectively and do not destroy the delay component. The channel information can be extracted effectively in combination with the cepstrum method.