Running a gmsk test

GNU Radio
1

I’m not sure where the gmsk test went in GNU Radio, I tried following
the log and commits. So, I grabbed a gmsk test from here:
http://noether.uoregon.edu/~jl/gmsk/

Just trying to run something simple, I run it from the blksimpl
directory like this:
gnychis@monster:~/school/gr/gmsk/gnuradio-core/src/python/gnuradio/blksimpl$
./gmsk-test.py -f payload.dat
sps: 8
symbol_rate: 270833.333333
sample_rate: 2166666.66667
p_size: 1024

gr_fir_fff: using SSE
bits per symbol = 1
Gaussian filter bt = 270833.33
Modulation logging turned on.
python: gri_mmse_fir_interpolator.cc:67: float
gri_mmse_fir_interpolator::interpolate(const float*, float) const:
Assertion `imu <= NSTEPS’ failed.

Given that the test program is two years old now, I’m sure something has
changed. But does an up to date gmsk test program still exist that does
not need the USRP? I found the DECT example, but that’s USRP based.

Thanks!
George

2

George N. wrote:

Given that the test program is two years old now, I’m sure something has
changed. But does an up to date gmsk test program still exist that does
not need the USRP? I found the DECT example, but that’s USRP based.

The easiest way to test GMSK is to use the benchmark_* scripts in
examples/digital, and use the GMSK modulation.

–
Johnathan C.
Corgan Enterprises LLC
http://corganenterprises.com

3

On Sun, Oct 21, 2007 at 08:47:59AM -0400, George N. wrote:

sample_rate: 2166666.66667
changed. But does an up to date gmsk test program still exist that does
not need the USRP? I found the DECT example, but that’s USRP based.

Thanks!
George

George,

See gnuradio-examples/python/digital/benchmark_loopback.py

Try the --help option.

To select gmsk, use -m gmsk

Eric

4

Eric B. wrote:

George,

See gnuradio-examples/python/digital/benchmark_loopback.py

Try the --help option.

To select gmsk, use -m gmsk

Eric

Just to follow up on this in case anyone wanted to use the original test
script for anything, the parameters to setting up the GMSK modulation
and demodulation have changed. So, modify the lines which call
gmsk_mod() and gmsk_demod() to have proper parameters.

  • George