[Discuss-gnuradio] GNU Radio and USRP baseband demodulation/decoding

[Einar Thorsrud]

Hi all,

I am trying to use the USRP with the LFRX daughterboard to receive a 
baseband signal coming from an external RF-frontend (the signal is 
originally 2-PSK passband). I am a GNU Radio novice, and have some 
difficulties understanding how to synchronize to and decode the 
NRZI-coded baseband signal. I suppose ones the synchronization is done 
the actual decoding will be easy.

I find it difficult to understand the process of synchronizing, what I 
would like to see is some kind of guide or feedback on how to pick 
exactly the correct number of samples for each symbol, enabling the 
decoding of the signal symbol for symbol.

What would be the correct approach to solve this problem?

(I am in fact also having similar problems understanding this using the 
OSSIE SDR system, so it may be a more general lack of understanding on 
my behalf)

--
Einar Thorsrud