Frequency Response Estimator - how is the frequency response computed

Using sinestream mode, the FRE block in simulink generates complex numbers for the frd data block that estimate the frequency response. Accuracy improves with more estimation periods. I need to know how FRE works under the hood so that I can justify choices for number of estimation periods for a given test frequency during the experiment. I have reasons to believe that during online estimation the FRE block is implementing some sort of synchronous demodulation. I cannot find information on how the FRE block actually computes frequency response anywhere online.

Answer 1

[Andrew Ouellette]

Hi @jacob,

You can see a description of the FRE algorithms on its documenation page.

Generally, using more estimation periods results in a better estimate (as noise is averaged out), but requires a longer simulation time.

If you want more information, you can look under the block mask (select block -> Ctrl+U) and see the implementation yourself.

[jacob]

Thank you so much, I did not know I could look under the mask. This is is perfect, thank you.