Timeline for GNU Radio Companion - generating a 4-QAM constellation - how to do it?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Apr 6, 2021 at 11:33 | comment | added | Kenny | Thanks Marcus! Just for clarity - I'll add the link that discusses the setback that I was having befor - due to initially not understanding some details about the Vector Source and the Constellation Modulator ----- dsp.stackexchange.com/questions/74232/… | |
| Apr 6, 2021 at 10:59 | comment | added | Marcus Müller | yep, I did mention that in my answer, too ;) | |
| Apr 6, 2021 at 7:57 | comment | added | Kenny | Also - regarding the unexpected behaviour I noticed with the constellation plot ---- it turns out (after help from a GitHub member) that the Vector Source value of '3' requires a "Unpacked to Packed" block to be placed at the output of the Vector Source. That Unpacked to Packed block simply needs to be set at 2 bits per chunk, with 'byte' for the Type (setting). And then the output of that block can go to the Throttle block. Everything works nicely after doing that. | |
| Mar 30, 2021 at 7:38 | comment | added | Kenny | Thanks so much for your time and help Marcus! That helped tremendously. I have now gone with that nice recommendation - and downloaded/installed v3.8.2.0-57-gd71cd177 (Python 3.9.0). The graphics in the GUI appear much more advanced in the 3.8! After understanding how the 'chunks to symbols' works (after you explained it excellently) ---- I now see that the symbol table (having the four complex numbers) are tied to the values 0, 1, 2, 3. So that if I choose '3' for the vector, then the corresponding constellation symbol will be the last complex number, while '0' links to the 1st complex value. | |
| Mar 30, 2021 at 6:45 | history | answered | Marcus Müller | CC BY-SA 4.0 |