Fixed-point high dynamic range fast Fourier transform

摘要

A method for generating a Fast Fourier Transform (FFT) is disclosed. The method includes providing an input signal to two or more fixed-point FFT algorithms that apply different scaling to reduce the increase in output, so that each FFT algorithm is characterized by a different gain. Create an array of values. The method further includes determining, for each FFT output value, whether the output value of the FFT algorithm having a relatively high gain has been clipped due to saturation. Otherwise, the output value of the FFT algorithm is included in the final FFT. Alternatively, the output value of the FFT algorithm having a low gain is included in the final FFT. By reconstructing the final FFT with such combinations of values from different FFTs, it is possible to benefit from the advantages of both high gain and low gain FFTs while avoiding or minimizing their drawbacks To do.