基于局部多项式傅里叶变换的多分量线性调频信号瞬时频率估计*

针对多分量线性调频信号的瞬时频率估计问题,把局部多项式傅里叶变换应用到求多分量线性调频信号瞬时频率估计中,提出了一种不受分量间交叉项干扰的新方法,该方法对多分量线性调频信号进行局部多项式傅里叶变换,把每一个线性调频信号分离出来,根据每一个线性调频信号的局部多项式傅里叶变换谱,通过搜索找到谱的峰值所在的位置,从而找到峰值所对应的频率,准确地估计出了多分量线性调频信号的瞬时频率。仿真实验中与多分量信号的Wigner-Hough变换进行了对比,验证了该方法的有效性。

Instantaneous frequency estimation of multi-component LFM signals based on local polynomial Fourier transform

For the problem of the instantaneous frequency estimation of multi-component linear frequency-modulated(LFM) signals,this paper presented a new method for overcoming cross-terms interference.And the local polynomial Fourier transform(LPFT) method was applied to estimate instantaneous frequency of multi-component LFM signals.By means of doing local polynomial Fourier transform on multi-component LFM signals,could separate each LFM signal,and then searched the ridge peaks of the spectrum to find the corresponding frequency according to the local polynomial periodogram of the each LFM signal,so accurately estimate the instantaneous frequency of the multi-component LFM signal.Compared with Wigner-Hough transform,the simulation results verify the availability of the proposed method.