一种水下声信号未知频率的时延差估计方法  

A time delay difference estimation method for unknown frequency of underwater acoustic signals

作　　者：郑恩明[1,2] 陈新华[1] 孙长瑜[1] 

机构地区：[1]中国科学院声学研究所,北京100190 [2]中国科学院大学,北京100190

出　　处：《振动与冲击》2014年第9期190-194,共5页Journal of Vibration and Shock

基　　金：国家海洋公益性行业科研专项经费项目(201005001)资助课题

摘　　要：针对目标辐射线谱信号频率未知时的时延差(TDD)估计问题,介绍一种基于时延差方差加权的时延差估计方法。首先对接收信号进行快速傅里叶变换(FFT)分析,然后采用引导信号对每一个频率单元进行频域互相关得到每一个频率单元时延差估计初值,最后利用噪声对应频率单元互相关谱最大值随机,目标对应频率单元互相关谱最大值基本一致的特点,统计各频率单元的时延差估计结果得到最终时延差估计值。理论分析和实验结果表明:该方法具有较好的有效性,对信噪比的宽容性远好于频域互相关法,该方法为弱线谱时延差估计提供了一个参考思路。Aiming at the problem of time delay difference（TDD）estimation of unknown frequency,a time delay difference estimation method with time delay difference variance weighted is presented.Firstly,the received signals are processed using Fast Fourier Transform（FFT）.Then,the cross-correlation of every frequency unit is conducted by using a pilot signal in frequency domain.The final TDD is obtained by calculating statistically the TDD initial values of all frequency units,when the macimum value of cross-correlation spectrum of noise frequency unit is random and the maximum values of cross-correlation spectrum of target frequency unit nearly consistent.The theoretical analysis and experimental results showed that the proposed method is valid and the signal-to-noise ratio tolerance of the method is much better than that of the cross-correlation method in frequency domain.A reference idea was provided for the time delay difference estimation of weak line spectrum target.

关 键 词：信息处理技术 频域互相关 线谱检测 时延差估计 

分 类 号：TB565[交通运输工程—水声工程]