Sorting and recognition of intra-pulse modulation signals based on FRFT

As extracting the intra-pulse features of the signal is an effective method to solve the problem of the complex radar signals sorting and recognition. An algorithm to recognition of radar intrapulse modulation based on fractional Fourier transform(FRFT) was proposed in this paper. First the different modulated signals are processed by fractional Fourier transform with the order p from 0 to 4. The curve of amplitude v varying with order p is obtained. Then extract p value corresponding of the peak, peak value and kurtosis of the curve to construct a new feature vector as the complement to classical parameters. At last the cluster sorting method is used to complete the sorting work of the different modulated signals. The efficiency of extracted feature vectors for signal sorting is confirmed by computer simulation.