Detection of Chirp Signal by Combination of Kurtosis Detection and Filtering in Fractional Fourier Domain

The chirp signal has been used widely in radar signals. As a useful signal processing technique, the fractional Fourier transform (FRFT) is a way to concentrate the energy of a chirp signal. Therefore, the FRFT presents a potentially effective technique for detection of chirp signals. Compared with the common Wigner-Vill distribution (WVD) algorithm, the FRFT is a linear operator, and will not be influenced by cross-terms even if multiple components exist. Moreover, to solve the problem whereby weak components of the signal are shadowed by the sidelobes of strong ones, a new method of combination of kurtosis detection and filtering in fractional Fourier domain is proposed. In this way strong components and weak ones can be detected iteratively. The effectiveness of this combined method has been tested through simulation.