Novel Nonuniformly Sampled Method Based on Fractional Fourier Transform
Feng Liu · Modern Electronics Technique · 2009
Because of confination of the sampling equipments and the sampled signals,complete uniform sampling can not be realized,so the signals must be sampled nonuniformly.According to the signal′s time-variant feature,the signal is sampled by low sampling frequency in the signal′s low-frequency part and by high sampling frequency in the signal′s high-frequency part.The nonuniformly sampled Chirp signal is analyzed by fractional Fourier transform.The spectral expression of nonuniformly sampled Chirp signal in the fractional Fourier domain has been derived,and its fractional spectral property has been analyzed.This method solves the problem of redundant data because of over-sampling in the whole sampling period,meets the real-time request and has better ability to resist noise.The innovation of this paper is that the proposed nonuniform sampling method meets the sampling theorem request,and the spectral expression of nonuniformly sampled signal in the fractional Fourier domain has been obtained.