> > From: Marcus D. Leech <[email protected]> > > > > Let's say I have an FFT output that's many, many, bins wide, and I want > > to compress that information into a narrower display (let's say from 4M > > > bins down to 1024 bins). > > > > My approach has been to sum up each set of [4M/1024] bins, and use that > > as the final output. > > > > Marcus Leech > > I think adding FFT bins is the correct way. But, for me I always select the > maximum in these bins. I'm not sure that this is right but it gives me a good > look over my spectrum data.
Spectrum Estimation is not trivial - I highly recommend having a look at "Introduction to Spectral Analysis" by Stoica and Moses. A mathematical yet readable introduction. To solve you problem in a mathematically way, you can use windowing in the time domain with subsequent overlapping block averaging (Welch's method). Gives a good practical estimate. Code for GNU Radio is here: https://www.cgran.org/wiki/SpecEst Integrating the FFT bins is just fine, but you probably loose frequency resolution that way (if that doesn't matter, just leave it). Best regards, Jens _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
