Chip signal analysis by using adaptive short-time fractional Fourier transform

This paper proposes an adaptive short-time fractional Fourier transform. The proposed transform improves the resolution of the short-time Fourier transform for chirp signals, and avoids the cross-terms. The proposed adaptive short-time Fourier transform is based on the de-chirp effect of the fractional Fourier transform. It adaptively de-chirps the signal with time to achieve a high signal concentration in the time-frequency domain. An effective measure for local signal concentration is used to optimize the selection of the parameter of the fractional Fourier transform.