Multi-channel sampling expansion in fractional Fourier domain and its application to superresolution

This paper addresses the problem of multi-channel sampling (MS) expansion for fractional bandlimited signal in the fractional Fourier domain. Firstly, the MS expansion for fractional bandlimited signals with fractional Fourier transform (FRFT) is proposed based on new multi-channel system equations, which is the generalization of classical generalized Papoulis sampling expansion. The MS expansion which is constructed by the ordinary convolution in the time domain is easy to implement. Then, by designing a type of fractional Fourier filters, the reconstruction expression for the recurrent nonuniformly sampled signal has been obtained by using the derived MS expansion. Last, the application of MS in the context of the image superresolution is also discussed. The simulation results of image superresolution are also presented.