Where to get fl2k_gsm.bin?

[MatejKovacic]

I tried to run fl2k_file -s 138e6 /tmp/fl2k_gsm.bin, but of course I get "Failed to open /tmp/fl2k_gsm.bin". Where can I get this file?

And after running fl2k_test -s 162e6, I get PPM reported:

real sample rate: 154004995 current PPM: -49352 cumulative PPM: -49352
real sample rate: 153975759 current PPM: -49532 cumulative PPM: -49444
real sample rate: 154063725 current PPM: -48989 cumulative PPM: -49290
real sample rate: 154012313 current PPM: -49307 cumulative PPM: -49294
real sample rate: 154000456 current PPM: -49380 cumulative PPM: -49312
real sample rate: 154221964 current PPM: -48013 cumulative PPM: -49094
real sample rate: 154045150 current PPM: -49104 cumulative PPM: -49095
real sample rate: 154155905 current PPM: -48420 cumulative PPM: -49011
real sample rate: 154172308 current PPM: -48319 cumulative PPM: -48933
real sample rate: 154348069 current PPM: -47234 cumulative PPM: -48763
real sample rate: 154399109 current PPM: -46919 cumulative PPM: -48595
real sample rate: 153913240 current PPM: -49918 cumulative PPM: -48705
real sample rate: 153992356 current PPM: -49430 cumulative PPM: -48761
real sample rate: 154236790 current PPM: -47921 cumulative PPM: -48701
real sample rate: 154146770 current PPM: -48477 cumulative PPM: -48686

How exactly can I adapt the 'ppm' variable in the flowgraphs?

[r4d10n]

Unpack gsm_osmo-trx_4sps.cf32.xz from the repo. Run the GRC flowgraph fl2k_transmit_gsm.grc with that file as input. It would generate /tmp/fl2k_gsm.bin.

You need to run fl2k_test -s 138e6 (since the ppm value is quite high at 162e6) and supply the approx average value of PPM that to the "ppm" block in the flowgraph.

[MatejKovacic]

Thanks a lot for your answer. So I should run fl2k_test -s 138e6. The result is:

real sample rate: 137996824 current PPM: -23 cumulative PPM: -23
real sample rate: 138003491 current PPM: 25 cumulative PPM: 2
real sample rate: 137997063 current PPM: -21 cumulative PPM: -6
real sample rate: 137998357 current PPM: -12 cumulative PPM: -8
real sample rate: 137985197 current PPM: -107 cumulative PPM: -28
real sample rate: 137992714 current PPM: -53 cumulative PPM: -32
real sample rate: 137997900 current PPM: -15 cumulative PPM: -29
real sample rate: 137991315 current PPM: -63 cumulative PPM: -34
real sample rate: 138004266 current PPM: 31 cumulative PPM: -26
real sample rate: 137990728 current PPM: -67 cumulative PPM: -31
real sample rate: 137995347 current PPM: -34 cumulative PPM: -31
real sample rate: 137996174 current PPM: -28 cumulative PPM: -31

So I should use ppm value -31?

[r4d10n]

Yup. Should let it stablise and use the value. On Thu, Jun 21, 2018 at 4:35 PM Matej Kovacic [email protected] wrote:

Thanks a lot for your answer. So I should run fl2k_test -s 138e6. The result is:

real sample rate: 137996824 current PPM: -23 cumulative PPM: -23 real sample rate: 138003491 current PPM: 25 cumulative PPM: 2 real sample rate: 137997063 current PPM: -21 cumulative PPM: -6 real sample rate: 137998357 current PPM: -12 cumulative PPM: -8 real sample rate: 137985197 current PPM: -107 cumulative PPM: -28 real sample rate: 137992714 current PPM: -53 cumulative PPM: -32 real sample rate: 137997900 current PPM: -15 cumulative PPM: -29 real sample rate: 137991315 current PPM: -63 cumulative PPM: -34 real sample rate: 138004266 current PPM: 31 cumulative PPM: -26 real sample rate: 137990728 current PPM: -67 cumulative PPM: -31 real sample rate: 137995347 current PPM: -34 cumulative PPM: -31 real sample rate: 137996174 current PPM: -28 cumulative PPM: -31

So I should use ppm value -31?

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[MatejKovacic]

BTW, I run the GRC and open file fl2k_transmit_gsm.grc. I correct ppm variable to a new value. How then I generate /tmp/fl2k_gsm.bin?

I already unpacked gsm_osmo-trx_4sps.cf32.xz. It creates directory gsm_osmo-trx_4sps.cf32, which contains 3.0GB file data.

Then I opened fl2k_transmit_gsm.grc and in variable File Source opened this file (/home/user/fl2k-examples/GSM/gsm_osmo-trx_4sps.cf32/data).

Then I click "Execute the flow graph" and then I close everything (GUI window GRC).

Then I run fl2k_file -s 138e6 /tmp/fl2k_gsm.bin, and it is printing out something like:

repeat 7069371
repeat 7069372
repeat 7069373
repeat 7069374
repeat 7069375
repeat 7069376
repeat 7069377
repeat 7069378
repeat 7069379
repeat 7069380
repeat 7069381

But my mobile phone does not detect any carrier...

BTW, lsusb says I have a Bus 003 Device 010: ID 1d5c:2000...

[MatejKovacic]

BTW, FM example is working.

I run: pacat -r -d alsa_output.pci-0000_00_1b.0.analog-stereo.monitor | pv -B 256k | sox -t raw -r 44100 -e signed-integer -L -b 16 -c 2 - -c 1 -e signed-integer -b 16 -t raw - biquad 4.76963 -2.98129 0 1 0.78833 0 sinc -15k loudness 5 | fl2k_fm - -s 130e6 -c 35e6 -i 44100

And with gqrx I can clearly see and hear generated signal at target frequency:

However, GSM is not working. I tried to watch the target frequency with grgsm, but there is no signal at all...

[steve-m]

How large is the file produced by GNU Radio (/tmp/fl2k_gsm.bin)? You should generate at least 5 GB or more, which can take a few minutes.

[MatejKovacic]

Hum, it is 0 bytes... Probably I am doing something wrong... In order to generate it, I need to click "Execute the flow graph" and wait for a couple of minutes? I already did that, but file is still 0 bytes...

[porrick]

Any response to MatejKovacic's last post?