[Discuss-gnuradio] OFDM with noise - lost packets

[Mateusz]

Hello, I have been evaluating the OFDM examples (at the beginning of my 
Bachelor Thesis)
In ofdm_rx I have added noise source and file sinks to plot BER(SNR) in 
matlab. I added a Tag Debug on the output.
The result is disappointing, I observe plenty of lost packets already at 
the SNR of about 13dB and below (noise amplitude about 1.5 in an 
unmodified ofdm_rx).
So are those examples useful, with such a performance, to utilize with 
USRP and antennas?
Which part of a synchronization process fails, that causes missing 
indexes of data packets (observed in a Tag Debug) in a noisy channel)?
I think it's at the loop of 'header recognition', so it's the 'coarse 
frequency offset' that is too big for 'channel estimator'.

I mainly want to know if it's only possible to use ofdm_rx with a low 
noise, with SNR over about 13 dB.

Mateusz Loch