Does anyone have any experience or success using the manually written fixed-point fft provided by Mathworks in this example?

I am trying to use an fft in fixed-point within MATLAB. I have found a solution within mathworks - a page that goes through manually written functions conducting fixed-point fft. I have successfully used the example, however I am having some problems with using it in scripts and other functions. When I use the data and same model in MATLAB and Simulink. The results produced by the mathworks solution is different to the solution produced by Simulink (fixed-point fft).

Convert Fast Fourier Transform (FFT) to Fixed Point - MATLAB & Simulink - MathWorks United Kingdom

Does anyone have any experience or success using this method?

Answer 1

[Andy Bartlett]

The FFT provided by DSP System Toolbox as MATLAB callable system object dsp.FFT or as the FFT block should be consistent with each other.

The example you cited above is designed to be a sufficiently "meaty" example illustrating the conversion workflow, and is not designed to be bit true with every nuance in the FFT (object or block) shipped with DSP System Toolbox.

For developing your production embedded systems, I recommend you use the FFT from DSP System Toolbox unless you have a specific reason to customize it.