时频联合分析法线性调频信号脉内特征提取

Extracting the In-pulse Characteristics of LMF Signal Based on the Joint Time-frequency Analysis Method

针对小波变换法在提取线性调频信号脉内特征中的不足,提出了将时频重排和时频脊线相结合的时频联合分析方法。首先通过Morlet小波计算信号的小波谱,再对小波谱进行时频重排,由重排后的时频图提取时频脊线,得到线性调频信号的脉内调制特征。该方法在低信噪比下,能准确提取线性调频信号脉内特征信息。最后利用计算机仿真验证了该方法的可行性。

Aiming at the lack of wavelet transform in extracting the in-pulse characteristics of LMF, we combine timefrequency reassignment with time-frequency ridge and propose a joint time-frequency analysis method. Gain the wavelet spectrum of signals by continuum Morlet wavelet transform at first; then reassign the spectrum; gain the in-pulse characteristics of LMF by extracting the ridgc of the spectrum at last. In low SNR condition. the method can extract the in-pulse characteristics of LMF exactly. Simulations approve the feasibility of the method.