Demodulation of KiwiSDR

[danielcjacobs]

Hi!
I am wanting to measure the modulation data such as the envelop and modulation index, and I was wondering if that's possible to do with the kiwiclient even if I had to modify the code myself to get it to work.
Would that be possible? Does the kiwiclient perform demodulation or does it simply read sound data from the KiwiSDR?

[UgoPoddine]

Hello Daniel, I'm often use kiwiclient to easily link to a remote, well located and equipped, online kiwi SDR receiver, and downloading locally the IQ data stream that the remote received from my on air transmission. After this, I'm able to analyze off line the IQ file, for example feeding it to GnuRadio, to Octave or also to some SDR software for demodulation. It runs fantastically well, without any code modification Best regards Ugo Il giorno 4 Giu 2020, 20:22, alle ore 20:22, Daniel Jacobs <[email protected]> ha scritto:

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Hi! I am wanting to measure the modulation data such as the envelop and modulation index, and I was wondering if that's possible to do with the kiwiclient even if I had to modify the code myself to get it to work. Does the kiwiclient perform demodulation or does it simply read sound data from the KiwiSDR? -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #58

[danielcjacobs]

Hello Daniel, I'm often use kiwiclient to easily link to a remote, well located and equipped, online kiwi SDR receiver, and downloading locally the IQ data stream that the remote received from my on air transmission. After this, I'm able to analyze off line the IQ file, for example feeding it to GnuRadio, to Octave or also to some SDR software for demodulation. It runs fantastically well, without any code modification Best regards Ugo Il giorno 4 Giu 2020, 20:22, alle ore 20:22, Daniel Jacobs [email protected] ha scritto:
…
Hi! I am wanting to measure the modulation data such as the envelop and modulation index, and I was wondering if that's possible to do with the kiwiclient even if I had to modify the code myself to get it to work. Does the kiwiclient perform demodulation or does it simply read sound data from the KiwiSDR? -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #58

Do you download this data stream using kiwirecorder.py? If so could you provide an example of what you might run on the command line?
If this is the approach you use, I'm guessing it would be quite complicated to measure the modulation envelope by modifying the kiwiclient code...

I'm quite new to signal processing, I've played around a bit with GNURadio and if I can get sufficient data using the kiwiclient it seems that GNURadio could be a viable solution. I'm just not sure how I would go about getting the proper data and then accessing that data from GNURadio.

[jks-prv]

The file "Makefile" in the kiwiclient/kiwirecorder directory shows many examples of how to run it with the proper arguments to record the types of signals you want.

I think it's probably much easier to be processing signals in files recorded from kiwirecorder with other software to get what you want. Adding Python code to kiwirecorder itself may not be ideal. Remember also there is a record function in the Kiwi user interface itself: the red circle on the main control panel between the "spec" button and speaker (mute) icon. That's another way you can get files created (real-mode or IQ files).

[UgoPoddine]

Hello Daniel,

this is a simple statement that can be used, of course with kiwirecorder.py :

python3 /home/pi/kiwiclient/kiwirecorder.py -s kiwisdr.briata.org -p 8073 -f 3549 -m iq -u Daniel --time-limit=30 --station=CASSINE -r 8000

... where -f is the received frequency in KHz and -s and -p the url of your preferred receiver,
Passband filtter(s) can be added if necessary.

Be aware of the sample rate of the received IQfile : the -r 8000 option force it to a more standard sample rate than the standard kiwiclient one.
GnuRadio is a very good longlasting solution for fast, no coding, standard SDR data games.

Cheer
Ugo