Adaptive time-varying filter for linear FM signal in fractional Fourier domain

The aim of the paper is to propose an adaptive method for filtering the linear FM signal embedded in white Gaussian noise. The proposed approach is based on the idea that the fractional Fourier transform for a signal is equivalent to rotating the signal on the time-frequency plane. The performance of the method is evaluated in terms of computational complexity and SNR improvement factor. Some theoretic analysis and simulation results are included to demonstrate the validity of the method. The results show that remarkable SNR improvement and tolerable signal distortion are obtained and, compared with two other dimension time-frequency filtering algorithms, the method is easy in computation and simple in implementation.