[Discuss-gnuradio] gr-ieee802-11

[Stefano Banti]

Hi all,

I would like to overcome a limitation of gr-ieee802-11, which is due to 
the fact it must copy a fixed amount of samples in the ofdm_sync_short 
block; the consequence of this is that is non possible to capture all of 
the wifi frame on the air; if you copy 40 sym and there was a frame 
start after 35 sym you lose it. At the moment I have failed to overcome 
this limitation, so I'm asking if someone can point me in the right 
direction.

I'm experimenting with this great work, in the area of 802.11a rtx using 
my B200 at 20Msps and my home 802.11a modem. For experimenting purpose, 
I have implemented 2 blocks, one for frequency offset estimation and 
correction, and one for equalization based on pilot carriers. I have 
also modified ofdm_sync_long to add LT frequency correction. My work is 
based on paper "Frequency Offset Estimation and correction in the 
802.11a WLAN (2004)", wich you can find on the web. I can see a lot of 
traffic at 6Mbit bpsk, but not all of the frames, and frequency offset 
correction can reach 200khz of cfo with correct decoding.

thanks in advance

Stefano