[Discuss-gnuradio] 802.11g

[Thomas Nitsche]

Hi,
we are doing some research here on decoding 802.11g using GNURadio. As 
far as i know there is code available for transmission of 802.11g frames 
on CGRAN but no receiver code. Is there any work going on for the 
receiver side right now? Is it theoretically possible to decode a signal 
received with the USRP N210? The bandwidth provided by the gigabit 
ethernet connection should be sufficient in contrast to the USRP1 USB 
connection, or am i wrong?

I had a look at the (generic) GNURadio OFDM mod/demod code but its kind 
of hard to understand whats going on there. I have reused the 
ofdm-sync-pm code to generate seemingly helpful frequency offset values 
from the 802.11 short training sequence. I also extracted timing 
information by correlating with the known short sequence. However i am 
not sure if this synchronization is accurate enough for at least a few 
fft blocks.

Is there anything like:

fine timing/frequency correction,
sampling offset correction,
channel estimation or
code for using pilot tone subcarriers

in the generic GNURadio ofdm implementation that could be reused for a 
802.11g receiver? What is with the code for extracting infos from the 
subcarriers? Would it be easier to rewrite it from scratch or can some 
of the gnuradio code be reused?

Thanks for any information you can provide,
Thomas