gr-gsm should be a good project for you and for the community. I wish
you success.
You may want to look at the slow frequency hopping implementation of
airprobe that is placed here: https://github.com/BogdanDIA/airprobe-hopping.
It uses PFB to split a 20mhz band received with USRP-N210 into GSM
channels and then use all of them according to the hopping algorithm
decoded on the Immediate Assignment message and SI 1. It is not a
perfect implementation as airprobe is not perfect too, that is why I
think this will be a good project.
The hopping patch has been done two years ago and has API for
gnuradio3.6 era. I did not update it yet on 3.7. Here is small paper I
wrote at the moment of creating a patch. It may be of help to you.
Bogdan
On Tuesday, March 11, 2014 5:40 AM, zhenhua han [email protected]
wrote:
Hi all,
As Martin B. noticed in the mail list yesterday, I haven’t open my
proposal here.
There’s also some code for this somewhere… can’t find it right now.
A CEL student wrote a highly optimized MLSE, specifically for GSM, a
while back (a long while back, it still uses autotools). Still, the
code is very good, and there’s a lot to be taken out of this. He tried
out a lot of compiler switches, too, so check out lib/Makefile.am.
It assumes frame synchronization (i.e. post-SCCH sync), but you just
drop in a frame, and it returns the equalized result.