I did the following things that you suggested:
1) The gain is normalized and in the example file wifi_rx and tx it was set to 0.75. I changed the gain to a bunch of values but nothing is really changing. Also the scope plot in the receiver just shows noise and even when I get some decoded message on the console I don't see anything changing in the scope plot and the constellation plot is random as well during the transmission. At 5.89 GHz (which is default in the script when I downloaded it), it shows some packets on the console with random sequence numbers but doesn't work at all at any other frequency which I set by the frequency in the GUI.
2) I followed the instructions for testing wifi_rx with a wifi card on your page. The beacon frames are not being detected by wifi_rx and nothing gets printed on the console. I dont know whats wrong exactly. I have tested my setup with a simple script sending a single and double tone message at a frequency of 2.5 GHz and its successful so I dont think its a hardware problem.
Can you kindly tell me what could be going on ?
Thanks a lot,
Annie