Issues with decoding hopping EFR and using GR 3.7

[domi007]

Hi,
I have been trying to get this code working for me for more than a month now, so I'm pretty confident I know my way around it, so I would like to give some input and get some help:

1. I captured many files using a USRP B200, and I was able to figure out what parameters to give to the channelize2.py script, so now I have all the channels split up for me in files. I checked how the cell works, and I distinguished between single hop (change to a different frequency for voice, but only once) and multiple hop (keeps changing frequency for each frame) cells. I know the code is for multiple hop, so I tried to decode such traffic, but it fails to give me voice data. The cell uses EFR, so the configuration of the receiver is TE, not T, but other than that it is just a hopping cell, so I really don't know why it doesn't work. I can maybe give you my capture files so you can give it a try maybe.
   I also tried to patch the code for single hop cells, (by specifying the cai value by hand instead of calculating it using the calculate_ca_sfh function), but also that fails. I'm always getting parity errors, so I tried disabling parity checks, but that resulted simply in a garbage speech file of course.
2. For GnuRadio 3.7 you need to change the center frequency in gsm_receive100_channelize.py to look like this:
   self.top_block.set_center_frequency(-freq_offset)
   (notice the negative sign in front of freq_offset)

If you don't do that the code will simply not work at all (not even with the broadcast channel) according to my experiments.

I would really like to get your ideas and opinion on these issues if possible. Thanks.

[alex0500]

hi. can you provide original cfile? i wil try run on grc 3.7