Suggestions for Hardware/driver WIFI combo that allows low level signal access

[Micha Feigin]

Hi All,

I'm was wondering if anyone here can recommend a hardware / driver combo 
for WIFI that allows access to the low level signal. I'm looking to do 
some non-communication related research (uni stuff) that requires 
sending custom signals over WIFI frequencies (to avoid FCC limitations), 
and I was hoping that there is some existing hardware that I can hack at 
the driver level instead of building complex hardware (which I have, but 
getting a high enough accuracy starts getting pretty expensive).

I'm not looking to bypass power/frequency limitations, just to send 
custom signals over one of the WIFI channels.

Thanks