Re: [Discuss-gnuradio] 802.11 and Bluetooth

[Shravan Rayanchu]

Hi Thomas,

I have put the code at http://www.cs.wisc.edu/~shravan/specsense.txt

It has some small modifications to the original
usrp_spectrum_sense.py. The output is a set of samples (freq, power);
This is done 1 Mhz at a time in steps of 0.5 Mhz.

Let me know in case you make some modifications to this and get a
better output. I am just curious, are the units of log10 block output
in dB ?

Thanks,

Shravan


On 12/6/06, Thomas Schmid <address@hidden> wrote:
> Hi Shravan,
>
> That is really cool. Can you share with us your modifications to the
> script and the command line you used? I would like to try this at my
> home where I see like 20 APs from my neighbors and compare it to the
> plot of the wi-spy.
>
> Thomas
> >
> > Actually, you get a reasonable plot. Although you can only sense a
> > maximum of ~6 Mhz at once, doing so in steps of frequency gives a fair
> > idea. I made some changes to the spectrum_sense example, so as to a
> > fftshift and remove outer 25% of the bins. I used a frequency step of
> > 0.5 Mhz and also passed it through the log10 block. Attached are the
> > plots for entire spectrum (spec.pdf) and channel 1 (0.5m.pdf).
> >
> > Although, I am not sure what the "UNITS" are, they should give a sense
> > of the relative powers at different frequencies.  (Would they end up
> > in dB as I passed it through the log10 block? I couldnt particularly
> > understand Eric's code i.e. what is passed to the log10 block)
> >
> > Thanks,
> >
> > Shravan