Hi Doug
It appears that more extensive changes (than just the tiny patch I sent
yesterday) would be needed to gz-baz to make it compatible with the latest
(3.7) versions of GR and of op25. Also (AFAIK) there is no support for P25
Phase II in gr-baz.
The version of op25 (the GR-3.7.x compatible one) that you currently have
installed *does* have full RX support for P25 Phase II (but not TX).
Unfortunately there is "some assembly required"; the P25 phase II RX support
has not been integrated into the GUI app scope.py - so at this stage of the
project the phase II support is primarily oriented to other developers and
system builders. If you're willing to roll up your sleeves, however, you can
decode Phase II audio with it. Below is a sketch of the commands you'd need to
run (once you have captured a complex I/Q sample of the signal, that is). The
sampling rate (2M in this example), relative signal frequency (706.3 KHz), NAC,
SYSID, WACN, and TDMA slot ID are all variables that you would need to set
properly for your own local environment.
Note that you may need to set the proper git branch in the gr-op25 repo to
access the py scripts detailed below.
You also should have the scope.py app installed - you should be able to use
that to acquire the trunk control channel and extract the pieces that you'll
need (NAC/SYSID/WACN). The site seems to be having problems, but the URL for
that is http://op25.osmocom.org/trac/wiki.png/wiki/SignalScopePage
Best
Max
#! /bin/sh
# resample from 2M rate to 96K rate, translating frequency by +706.3 Kc
python arb-resample.py -i ~/20130605-774mhz-2mhz -s 2000000 -r 96000 -g 10 -c
706300 -o 2013-96k.dat
# demodulate
python cqpsk-demod-file.py -i 2013-96k.dat -a -6 -r dbit.dat
# process the demodulated file of dibits (dbit.dat) into audio
tdma_audio.py -i dbit.dat -n 0x4a1 -s 0x4a2 -w 0xbee00 -t 1
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
