DAB Single Frequency Network transmission

Hello,

For your information, here’s an application for DAB (Digital Audio
Broadcasting) Single Frequency Network transmission using newest USRP
with external synchronisation:

It’s working well in the lab but we have not been able to test on the
field yet because one of the just ordered used Thunderbolt clock has a
problem.
The student (in copy) had built his own GPS clock based on ublox module
but the jitter is too important when tuning it at 10MHz (check his
report).
He’s considered sending the base frequency directly but this would
require some modifications in the USRP.

The other thing we noticed is that with a DAB signal, there’s a periodic
null symbol (around 100ms without any power) and some of the WBX/USRP
have problem with that, when the signal returns it peaks and then
decreases again. It looks like an AGC problem. Have some of you already
experienced this ?

Regards

Mathias C.