Frequency estimation method of sinusoidal frequency signal based on piecewise FFT

The micro-Doppler effect on a flying spinning target, introduced by the rotation, would modulate the receiving signal with SFM (Sinusoidal Frequency Modulation), and we usually use some TF (Time-Frequency) analysis methods with complex calculation to estimate the frequency. As to the issue of the complexity of the classic TF method, a method based on the piecewise FFT was proposed in this paper. With the analysis of the local stable properties of SFM signal, the selection of the segments M and its influence on the performance of frequency estimation was discussed. Then we divided the signal into M segments with FFT, and corrected the frequency offset caused by the fence effect. And the calculated amounts of this algorithm was analysed. Finally the piecewise FFT was verified to be less calculated amounts and easy to implement with a better SNR which could be applicable to the processing of cooperative target by simulation.