A fast Fourier transform algorithm using Hadamard transform

A fast Fourier transform (FT) algorithm using Hadamard transform (HT) is introduced, which is called HFT (Hadamard Fourier Transform). In the algorithm proposed here, a HT is used as mid-transform and the redundant calculation in the original fast FT algorithm is reduced by double transformation. The results of theoretical analysis show that the number of multiplications and additions of HFT are both decreased by 60% compared with that of traditional FFT and the executed result shows the computing speed of HFT is 1.6 to 1.7 times faster than FFT. Comparing with the similar algorithms such as WFT-II¹, RFT², it has a market improvement in computing speed and eliminates the limitatiom on the length of transform.