11 Sep
2019
11 Sep
'19
5:48 p.m.
Hi,
I'm interested in intercepting L band up-link RACH
channel
I found the BCCH channel of the spot beam I'm currently in then scan the same ARFCN
but in uplink
I had a cfile and I tried to read it using gr-gmr1 in the branch sylvain/gr
but i have no results , may be I don't know how to use the read utility in sylvain/gr
Although the method should work to detect the RACH burst on L-band, it
has only ever been tested on C-band wideband captures, so YMMV.
Note that the example .grc graph that's provided does an IQ swap
because usually when you get samples from a C-band LNB they underwent
a spectrum inversion due to the high-side LO mixing inside the LNB. If
you're working off a direct capture off L-band you need to remove that
swap from the graph.
Also, are you sure you actually _have_ RACH requests in your file and
they don't saturate your receiver ?
If you have an example capture to post, put it online somewhere and
post the link.
I also have another question about the file test.pcap
in http://people.osmocom.org/tnt/gmr/
how can I have a file like it and is it l band RACH data or C band.
This was captured on C-band.
Cheers,
Sylvain Munaut