Re: [Discuss-gnuradio] Question on acquiring 802.11b signals

[Eric Blossom]

On Mon, Aug 21, 2006 at 11:50:50PM -0700, Swapneel S. Ukhalkar wrote:
> I posted on a similar topic about two weeks ago but it really didn't 
> help me. I am new to the world of GNU radio and have been fiddling with 
> my USRP and RFX2400 daughterboard to acquire 802.11b signals. At this 
> point, I just would like to take the fft of a chunk of spectrum so that 
> I may see all of the wireless signals in the vicinity and their 
> strengths (much like Eric Blossom did for the FM stations in Figure 3 of 
> his "Listening to FM Radio in Software" article at 
> http://www.linuxjournal.com/article/7505). I have been going over the 
> basic FM receiver code in the GNU radio tutorials. I can see how easy it 
> is to see different FM signals in a spectrum chunk. However, one of the 
> things that I'm having trouble understanding is how each 802.11 signal 
> is differentiated from one another (apart from the spectral mask). Could 
> you give me some insight into what I have to do to acquire and display 
> the appropriate signals. Maybe if I looked at the code which was used to 
> generate Figure 3 in that article it might help. Thanks in advance.
> 
> --
> Swapneel S. Ukhalkar
> BSEE UC Santa Barbara
> address@hidden

I think using the spectral mask is the simplest thing to start with.
Other than that, you'll need to use/build a real demodulator for the
signals of interest.

BBN's been working on this:

http://www.mail-archive.com/address@hidden/msg05060.html

Eric