Re: [Discuss-gnuradio] OP25 FSK4 Demodulator Error

[bob wole]

Hi, Before I start working on Op25 I want to know what kind of demodulator detector is op25 using? Correlation filters or frequency discriminator (quadrature demod) ? Which algos for symbol timing and frequency offset, Equalization?

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Bob

 

 Firstly, the current gr-op25 recipe in pybombs will build a version of OP25 that's? compatible only with GNU Radio version 3.7.? (If one really wanted to build OP25 for GR3.6 he could pull the old SVN repo which is still online, but that version is no longer maintained).? However (last I knew) no one has gotten gr-baz working with the newer versions of OP25...
Second, the fsk4 module is accessible in gr-op25 - assuming gr-op25 is correctly installed you should be able successfully to do this in python, as a test-? from op25 import fsk4_demod_ff

Third, the process of getting these things more integrated generally, and ultimately into GRC, continues.? There's more work to do on this, but if you want to see a complete example py hier block that encapsulates the FSK4 demodulator, see this link: http://op25.osmocom.org/trac/wiki.png/browser/op25/gr-op25_repeater/apps/p25_demodulator.py#L71? [Note that if you pull the git repo you should checkout the 'max' branch]

Finally, last but not least, Marcus M., it was great to meet you in person at the most recent GNU Radio conference in Wash. D.C. You probably don't remember me, I was one of the few geeky looking guys there.? And thanks for pointing out, we do need to update the to do list in the wiki - the documentation always seems to lag behind :-)
73

Max Parke