Research On Blind Detection Algorithm Of Multiple Communication Signals

As the electromagnetic environment becoming more complex,the electronic detection technology face new challenge.For that reason,the blind detection algorithm of multi communication signal is studied in this thesis based on time-frequency analysis technology.For Frequency hopping signal,the smoothed pseudo Wigner Vile distribution(SPWVD)is used to transform the signal into a two-dimensional time-frequency image,then the Two value morphological filter,threshold segmentation technique and OPTA thinning algorithm are used to estimate the parameters of the signal.For linear frequency modulation and binary phase shift keying(LFM-BPSK)signal,the wavelet denoising,Disceret Chirp-Fourier Transform(DCFT),Lv's Distribution(LVD)and the Fractional Fourier Transform(FRFT)are uesd to estimate the chirp rate,then some reasonable statistic is builded by using the periodic ambiguity function to estimate the code rate.For Linear Frequency Modulation Continuous Wave(LFMCW),the inter-frame correlation method,LVD and DCFT are used to estimate the period,dely,carrier frequency and the time-frequency rate of the signal.