Integer discrete Fourier transform and its extension to integer trigonometric transforms

摘要

DFT has good quality of performance and fast algorithms. But when we implement the DFT, we require the floating-point multiplication. In this paper, we introduce the integer Fourier transform (ITFT). ITFT is approximated to the DFT, but all the entries in the transform matrix are integer numbers. So it only requires fixed-point multiplication, and the implementation can be much simplified, especially for VLSI. This new transform will work similarly to the original DFT, for example, the transform results are similar and the shifting-invariant property is also preserved for ITFT. We also introduce the general method to derive the integer transform. By this approach, we can derive many types of integer transforms (such as integer cosine, sine, and Hartley transforms).