Hi,
please keep mailinglist in cc, for others to find out.
in tetrapol_dump is implemented SCR detector. It tries all 128 possible values and finds out wich one works. By design SCR is system constant for controll channels (CCH) and for transport channels (TCH) is broadcasted on CCH.
I have attached small file with demodulated data and example outputs, hope this help a bit. It is CCH with system_info and few other messages.
With best regards, JS
On Fri, 10 Mar 2017 10:22:52 +0200 Evgenii Royzman dzhudzhan@gmail.com wrote:
Hi,
Very sad.
But in plan I want to realize it and ready for reverse.
Yet have several question:
- do you have records with known parameters.
This need me for debug my decoder subsystem. I use the same sequence (descrambling, diffdec(UHF, VHF), deinterleaving(UHF, VHF), ch.decoding (based on Viterbi described in https://www.amazon.com/Digital-Communications-Fundamentals-Applications-2nd/...), crc, descr), but unknown parameters of my records confusing me, especially metrics after Viterbi (no zero values for every SCR [0,127]).
- can i get bitstream from your system after ch.decoder by tee,
cose i use something like "./tetrapol_dump -i /myPath/1.bin -b UHF -t TCH -d DOWN | tee /myPath/output.bin" and in result have only part of terminal info after "Exiting."(you can see it in previous attaches). Or even better get bitstream from different parts, after deinterleaving for example. Or is this real only after change source code and recompile it? If true, back to question from previous letter about IDE (i think about Eclipse CDT with switch to your makefile).
Will be thank for any feedback.
Regards,
Evgenii
2017-03-09 18:36 GMT+02:00 JS jiri.svoboda@yandex.com:
vocoder is not producing anithing listenable, need a lot of work (and a bit of reverseingeneering).
JS
On Thu, 9 Mar 2017 17:39:46 +0200 Evgenii Royzman dzhudzhan@gmail.com wrote:
Hi,
Thank for advice, now I can see some results during decoding and some tee. Will try vocoder.
P.S. If you interesting in attach examples of my tests.
Regards,
Evgenii
2017-03-09 14:40 GMT+02:00 Evgenii Royzman dzhudzhan@gmail.com:
Sorry sent press Send instead attach)
One more file in attach.
I also wanted to know what IDE you use to debug your project, and maybe you have some example of records I/Q or binary after demodulation with known parameters (SCR, -b, -t, -d) I would be very pleasure!
I try my own system in java and this sources very imported for me.
P.S. attached records from http://www.sigidwiki.com/wiki/Tetrapol
Sorry for separate letters)
Regards,
Evgenii
2017-03-09 14:29 GMT+02:00 Evgenii Royzman dzhudzhan@gmail.com:
HI, thank for quick response!
As I understood, tetrapol_detector.sh set parameters for receive signal from air via sdr and demodulate it. My binary file already demodulated by another demodulator (file in attach).
My question about, can I decode my record with you decoder (tetrapol_dump) and which extension, reverse, invert e.t.c? Or I anyway need to install tetrapol_detector.sh?
I have tried to use command like: "./tetrapol_dump -i /myPath/1.bin -b UHF(and VHF) -t TCH(and CCH ) -d DOWN(and UP) | tee /myPath/output.bin" but at once had "Exiting." on next line with no any info in terminal and zero output.bin.
2017-03-09 13:33 GMT+02:00 JS jiri.svoboda@yandex.com:
Hi,
after demodulation you should use tetrapol_dump. I suggest you to study tetrapol_detector.sh which shows what tools are used and what they do.
With best regards, JS
On Thu, 9 Mar 2017 12:21:10 +0200 Evgenii Royzman dzhudzhan@gmail.com wrote:
> Hi guys! > > You did really cool work with tpol. > > I'm also trying something with this one and you results is > absolutely find for my! > > I have already demodulated signal and would decode it with > your app/tetrapol_dump, is it real or i have to use binary > only after your demod? > > Regards, > > Evgenii
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JS