SDR Complex Mixing, Sampling, Fourier, Zero IF Quadrature Direct Conversion

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  • čas přidán 21. 08. 2024
  • GNUradio files available from github.com/gal...
    See also
    gallicchio.git...
    --- Learn SDR with Professor Jason Gallicchio

Komentáře • 21

  • @yashodhansatellite1
    @yashodhansatellite1 Před měsícem

    Excellent contribution to the society

  • @joedegs123
    @joedegs123 Před měsícem

    Awesome videos. I finally understand what a negative frequency is.

  • @stevehageman6785
    @stevehageman6785 Před 5 měsíci +1

    Wonderful, thanks. 45 Years ago in 'my' school (when we didn't have these software tools to visualize everything) - it was a lot harder to grasp what is really happening from just the math. You did a great job with the step, by step visualization. :-)

  • @yuvaviva5619
    @yuvaviva5619 Před rokem +2

    Very nicely explained.

  • @dyna8996
    @dyna8996 Před rokem

    Great Job. Thank You very much for your sharing sir!

  • @kraftrad7840
    @kraftrad7840 Před rokem

    Great explanations

  • @elijahsmith7552
    @elijahsmith7552 Před 11 měsíci

    At 1:11:34 I think it should be a ySin(2wt) term. It's written that way under the gnu block as well, so perhaps I'm mistaken. Anyway, thanks for this excellent video.

  • @klewisjohnson
    @klewisjohnson Před 2 lety

    Very good stuff thanks

  • @yilin-dt4de
    @yilin-dt4de Před 3 měsíci

    Got a question @26min: how can you show a complex signal in Im and Re part as 2 separate signal while only 1 output from the source block? does this mean actually there are 2 signals to achieve complex signal?

  • @paulmaine6433
    @paulmaine6433 Před 2 lety +2

    Very good! How can we get a copy of all of your flow graphs?
    Thank you!

    • @HarveyMuddPhysicsElectronics
      @HarveyMuddPhysicsElectronics  Před 2 lety +3

      All GNUradio files are available from github.com/gallicchio/basicSDR If you don't want to check out the repository, you can click on each file, click "raw" and then save it.

    • @paulmaine6433
      @paulmaine6433 Před 2 lety +1

      @@HarveyMuddPhysicsElectronics I really appreciate you sharing your flowgraphs! Thank you!!!

  • @franzschoning6529
    @franzschoning6529 Před rokem

    I have some questions about the trick to use both sides of the spectrum by varying both the x and y components please. Non SDR radios, for eg analogo AM radio, duplicates the spectrum. A) is it possible to build a non-SDR radio to also use both the x and y components or is this trick limited to SDR? And B) how would this more spectrum efficient non-symmetric signal be used in practice? You mentioned that the x and y could be for example stereo audio. Is this an actual use case? I would have thought that with imperfectly matched oscillators, the left and right channels would smear across each other. Are there other more concrete examples of how this spectrum could be efficiently used, either for digital signals or amalogue audio signals. Thanks for the great video series.

    • @hashhoomy
      @hashhoomy Před rokem

      Single side band (SSB) is an AM signal with half the spectrum.

  • @pilotlanding
    @pilotlanding Před 2 lety

    Very good explanation. The only thing I am not sure is your multiplication of a complex number by it's complex conjugate. If z = x + iy, shouldn't z*conj(z) = x^2 + y^2 ?The product of a complex number and its conjugate is a real number.

    • @HarveyMuddPhysicsElectronics
      @HarveyMuddPhysicsElectronics  Před 2 lety +1

      You're right about that. Where in the video did I say something different? I could try to add a correction to the description. I couldn't find it when I quickly looked at the math on the board.

    • @pilotlanding
      @pilotlanding Před 2 lety

      @@HarveyMuddPhysicsElectronics It starts at 1:07:05 ... when you explained about how to extract the real component of a complex signal by using the complex conjugate.ohhhhhhhh my bad .... you said sum not multiplication !!!

  • @bulldogbrower6732
    @bulldogbrower6732 Před 10 měsíci

    Why hasn’t anyone used the SDR to derive the ATSC video signal and display it on the screen yet ?

  • @user-bg7rj4mo4p
    @user-bg7rj4mo4p Před měsícem

    how you write this? what is the screen that yoy used

  • @keylanoslokj1806
    @keylanoslokj1806 Před 8 měsíci

    How does he write on the board with a mirror direction?

    • @watts-jake
      @watts-jake Před 6 měsíci +1

      The camera is mirrored , so he writes like normal which would be mirrored for those who look at the board but if you look at it through a camera it reverses it so it's the right way