On Fri, 15 Dec 2017 10:08:29 -0700 Mark Goldberg <marklgoldb...@gmail.com> wrote:
> > The approach using FFT works, but just using the peak frequency, you throw > > away half of the data (the phase) and also limit yourself in precision > > to the bin width. It's not 100% clear that estimating the frequency > > using an FFT is unbiased in this case, thus you might get worse (or better) > > results than what the oscillator actually does. > > > > Since I do not know the exact algorithm used to interpolate peak frequency, > I don't know the effect on precision. They do claim that the peak frequency > determination precision is much smaller than the bin width, which seems to > be shown by the data. > > The results are good enough to discern between "bad" and "good" units under > test, but I have no way to compare my results to any other method of > measurement. This is all I have access to. If all you want is to discern good and bad units, this is good enough. > > [1] "Oscillator metrology with software defined radio", > > by Sherman and Jördens, 2016 > > https://arxiv.org/abs/1605.03505 > > > > I have seen this paper before. Unfortunately, it is a lot more work to > implement than what I have already done. I am really a hardware engineer, > with decades old education in control systems that has not been used in a > long time. It would take getting my brain back in gear and re-studying, not > a bad thing actually! > > The other issue is the Perseus drivers have issues under Windows 10 that > may or may not be solved. I was able to get it to work with Spectrum Lab, > but it does not work with many other tools that would be able to implement > this algorithm. > > That said, I may look into it further in the future. Apparently the Perseus is supported by GnuRadio[1]. Which means you can just click your control system together (similar to LabView). According to [2] the driver uses libusb and works on windows as well. If you want to use GnuRadio, I suggest you go to one of the many Hackfests[3] they have and let them jump-start you (I started this way years ago). Attila Kinali [1] https://gnuradio.org/ [2] https://github.com/Microtelecom/libperseus-sdr [3] https://www.gnuradio.org/event-type/hackfest/ -- <JaberWorky> The bad part of Zurich is where the degenerates throw DARK chocolate at you. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
