The Signal Separation And Identification Of LFM Fuze

Due to rapid development of electronic countermeasure technology and increasingcomplexity of operational environment, new requirements emerge for the radio fuze signalseparation and identification methods. FM fuze, which is one of the most importantdevelopment of radio fuze, due to advantages such as: high precision at distance and stronganti-jamming capability, has been widely used in various applications. Its type ofmodulation signal, carrier frequency, modulation frequency, modulation frequency and soon as the characterization of the basic parameters of linear frequency modulation signal,contains a lot of important information. This paper mainly studies the signal separation andidentification methods of FM fuze modulation type and the modulation parameters. It hasimportant theoretical significance and application value on the development of fuzejamming technology and combat ability of the fuze jammer.At first, using the separation of the modulation identification method based onstatistical model, LFM is sorted the from the DSB,2ASK, FM, LFM,2FSK,2PSK,PRCPM on the base of envelope changes of signal, instantaneous frequency firmness ofsignal, nonlinear phase modulation signal in the phase of the mean and the median value ofphase average distance and the peak over threshold number of time-frequency transform.Then, analysis is made regarding the time-frequency of linear frequency modulationsignal through Short-time Fourier Transform (STFT), Wavelet Transform (WT), theWigner-Vile Distribution (WVD) and Hilbert Huang Transform (HHT). In combinationwith HHT transform time-frequency analysis method on the basis of multi-resolution andthe advantages of the adaptive sampling frequency and the improvement effect of theendpoint are realized. Finally characteristic parameters are obtained such as frequencydeviation and the modulation cycle. The simulation results show that the improved HilbertHuang Transform (HHT) is more suitable for single component and componentialcharacteristic parameters of linear frequency modulation signal identification. In identifyingdual channel superposition of double parameters of linear frequency modulation fuze signalit also can clearly recognize that the signal spectrum in time and frequency characteristics,which provides accurate identification signal characteristic parameters. Based on HilbertHuang Transform (HHT) is verified of effectiveness of the multi-component LFM fuzesignal processing. Finally, using the empirical mode decomposition (EMD) and wavelet thresholddenoising method to deal with the noise signal and to remove the strong background noise,the simulation results show that the denoising method have good denoising effect.