SDR Complex Mixing, Sampling, Fourier, Zero IF Quadrature Direct Conversion
ฝัง
- เผยแพร่เมื่อ 23 ก.พ. 2021
- GNUradio files available from github.com/gallicchio/basicSDR
See also
gallicchio.github.io/learnSDR
--- Learn SDR with Professor Jason Gallicchio
![[TH] VCT Pacific Stage 2 - Week 4 Day 3 // GEN vs TS | PRX vs ZETA](http://i.ytimg.com/vi/nspkjQuZve0/mqdefault.jpg)
Awesome videos. I finally understand what a negative frequency is.
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. :-)
Very nicely explained.
Great Job. Thank You very much for your sharing sir!
Great explanations
Very good stuff thanks
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.
how you write this? what is the screen that yoy used
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?
Very good! How can we get a copy of all of your flow graphs?
Thank you!
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.
@@HarveyMuddPhysicsElectronics I really appreciate you sharing your flowgraphs! Thank you!!!
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.
Single side band (SSB) is an AM signal with half the spectrum.
Why hasn’t anyone used the SDR to derive the ATSC video signal and display it on the screen yet ?
How does he write on the board with a mirror direction?
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
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.
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.
@@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 !!!