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Jul 09

Nyquist Signal Expansion with Python

Bringing it all together

I’ve put it all into one python script, resampler.py.  Below are a few figures with different resampling rates:

resampler test L1 M1Just to see what it looks like, above is the data with just the filter applied to it.

resampler test L2 M1resampler test L3 M1resampler test L3 M2resampler test L9 M5One of the things you may notice here is that the filter delay stays constant.  This is because the number of filter taps is a function of L.  The code to generate these figures is on the final page.

Final Thoughts

My initial thought is that this will be useful for getting enhanced temporal resolution of signals where we are timing it by when it crosses a voltage threshold.  Part of me is skeptical, having the Nyquist Criterion beaten into my head through many years of school.  Part of me is optimistic of what can be accomplished because engineers have been successful in squeezing many bits per Hertz of information through a channel.  Hopefully you have something to experiment with.

Permanent link to this article: http://blog.curioussystem.com/2013/07/nyquist-signal-expansion-with-python/

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