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Opendigitalradio / ODR-DabMod

ODR-DabMod is a DAB (Digital Audio Broadcasting) modulator, part of the ODR-mmbTools.
https://www.opendigitalradio.org
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QUESTION: multiple MUX's on one hackrf one #57

Closed LaneaLucy closed 5 months ago

LaneaLucy commented 5 months ago

hi, is it possible to send multiple MUX's with one hackrf one? it should be possible if i understand everything right, the question is just can dabmod accept multiple inputs or do i need to run multiple instances of dabmod and add the IQ streams togethere somewehere else? and then the next question is for a example for it.

thx in advance

andimik commented 5 months ago

Oh, very interesting question. Let's see if there is a solution for this.

mpbraendli commented 5 months ago

Hi! There was a similar question on the old crc-mmbtools google groups (we're not using that anymore, discussion is on https://groups.io/g/odr-mmbtools now) about using a single B200. My answer was:

If you want to walk the "modulate several ensembles with one B200" path: ODR-DabMod has a ZMQ output. You can connect that to a ZMQ source in GNURadio.

So you could do a GNURadio flowgraph that takes two modulated ensembles from two odr-dabmod instances, does interpolation, frequency translation, addition, and transmits this with a single B200.

The sample rate required might be quite high, and you'll get into difficulties once you want to amplify the resulting signal, but for tinkering and learning, it's a fun exercise.

This is not a usage scenario we want to cover inside ODR-DabMod itself, so I'll close the issue, but please let us know if you get something working. Ideally in the groups.io, that reaches more users.

Cheers mpb

LaneaLucy commented 5 months ago

Why you not want to cover this? I mean a little example flow graph for people how know how to tinker with it would be great to be included

mpbraendli commented 5 months ago

I'd love such ideas to be part of the Opendigitalradio project, and that's why there's the discussion forum and the wiki.

I'm not willing to maintain it myself for lack of time. But please try, tinker, and share your findings!