提出了通过特征尺度的小波系数模极大值分析线性调频信号(linear frequency modulated signal,LFM)脉内调制特征的算法,分析了怎样选取特征尺度以及探究了怎样通过特征尺度的小波系数模极大值辨识出LFM的载频变化规律；并且研究了利用改进的小波脊线法提取了LFM的瞬时频率；最后对低信噪比下的LFM利用此改进算法进行了仿真.仿真结果表明,瞬时频率估计的精度得到了提高,尤其是信号起始段频率估计的相对误差低于0.05％,有效的克服了以往的小波脊线算法对低信噪比下的信号起始段频率估计的精度不高的缺陷.%A new algorithm on extraction of in-pulse modulation characteristic for linear frequency modulated signal (LFM) using maximum of wavelet modulus is presented and analyzed on how to choose characteristic scales and explored the regulation in the carrier frequency of LFM by analyzing the feature of maximum of wavelet modulus. In order to achieve the instantaneous frequency (IF) of LFM more accurately, the improved wavelet-ridge method is also introduced . The computer simulation result shows that the proposed algorithm is more accarate in IF estimation for LFM than unproposed even in the low signal to noise ratio, especially in the starting frequency estimation of which the relative estimation error is under 0. 05 %.
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