IntFFT

Implementation of 6 FFTs - Radix 2, Radix 4, Split Radix - each one decimated in time and frequency and their according integer approximations implemented according to this paper: https://www.researchgate.net/publication/3908291_Integer_fast_Fourier_transform_IntFFT

Essentialy, the complex product $x_k \cdot e^{i \theta}$ in the FFT is replaced with a lifting scheme (function lift in intfft.h). It's using a quantizator (the Q template) which converts floats to integers. Functions like round, floor or ceil could be used as quantizators.