Modulation type recognition of MIMO radar based on FrFT and instantaneous frequency extraction

In the case of low SNR, MIMO radar modulation type recognition method based on instantaneous autocorrelation spectrum has a low recognition rate of LFM MIMO radar signal and coded MIMO radar signal. To solve this problem, a recognition method based on FrFT and instantaneous frequency extraction is proposed in this paper. The method is divided into three steps. First, according to the difference of the frequency modulation slope, the linear frequency modulated MIMO radar signal is identified through the characteristic that the FrFT modulus varies with the order. Then, according to the peak state of the envelope curve in which the FrFT modulus varies with the order, the single frequency signal is identified. Finally, the frequency coded signal and the phase coded signal are identified according to the instantaneous frequency histogram. Simulation results show that the method is effective.