tim---/tetra-toolkit

Tools and documentation for TETRA decoding

tetra-toolkit

Tools and documentation for TETRA decoding.

The installation instructions are given for Ubuntu 15.10.

Install gnuradio and libosmosdr

sudo apt-get install gnuradio libosmosdr0 osmo-sdr gr-osmosdr

Install the library for your device

Depending on your device, you have to install a different library (see http://sdr.osmocom.org/trac/wiki/GrOsmoSDR).

If you have a RTL-SDR dongle, use :

sudo apt-get install rtl-sdr librtlsdr0

Download the GRC file

The GNU Radio Companion files are located in the grc folder.

First, you must build the TETRA Demod block :

grcc grc/tetra_demod.grc

Next, open the file grc/tetra_rx.grc in GNU Radio Companion, and execute it.

tetra-toolkit's Issues

Works but only with specific sample rate

Hi Tim,

I have run the project with a SDR RSPdx via Soapy remote.

With the default sample rate of 1M I get:

... and ...

... which look good.

But when I lower the sample rate to 384k, which should be more than enough to receive on TETRA channel I get:

... and ...

The 'coarse' looks OK, but the constellation doesn't.

I have looked at the tetra_demod block. It seems to calculate all the ratios from the input sample rate. So changing the sample rate shouldn't make any difference, as long as the bandwidth is enough.

Do you have any idea what explains the difference.

One further question, what can I do with the data coming from the udp sink?

Syntax error with tetra_demod.py

Hi Tim,
I get the following error messages with GR version 3.8.1.0 when I try to start tetra_rx.grc or tetra_demod.grc:

Traceback (most recent call last):
File "/home/adi/tetra-sdr/lime-tetra/tetra-toolkit/grc/tetra_rx.py", line 40, in
from tetra_demod import tetra_demod # grc-generated hier_block
File "/home/adi/tetra-sdr/lime-tetra/tetra-toolkit/grc/tetra_demod.py", line 124
self.mmse_resampler_xx_0 = filter.mmse_resampler_cc(, )
^
SyntaxError: invalid syntax

Done (return code 1)

Kind regards
Adi