Research progress on discretization of linear canonical transform

Linear canonical transformation (LCT) is a generalization of the Fourier transform and fractional Fourier transform. The recent studies have shown that LCT is widely used in optics, signal processing and applied mathematics, and the discretization of the LCT becomes vital for the applications of LCT. Since the discretization of LCT cannot be obtained by directly sampling in time domain and LCT domain, the discretization of the LCT becomes the focus of investigation recently. Based on the development history of LCT discretization, a review of important research progress and current situation of discretization of the LCT is presented in this paper. Meanwhile, the connection among different discretization algorithms and the future development direction are given. It is of great reference value for researchers to fully understand the LCT discretization method and can further promote its engineering applications.