Fft monitoring of more than one channel

Hello list,

I modified the usrp_spectrum_sense.py to work as an energy
detector based on the Neyman-Pearson Theorem. So basically
the algorithm is supposed to tell me if a certain part of
the spectrum is occupied or not.

I simply wrote the output into a text file to see I it is
working at all, but right now I am trying to find a way to
somehow monitor the it in a large plot, that dynamically
changes with the current detection results.
That means that if I am sensing the spectrum for example
between 2.4 and 2.5GHz in steps of 20MHz, I want the the
whole bandwidth to be graphically displayed in some kind
of plot (x-Axis = frequency, y-Axis = “0”/“1”), which is
divided into parts of 20MHz.
The channel states are supposed to get updated every time
the channel is sensed again, just like the output is
already doing.

I first thought that gtgui_sink_x might be the right
thing, but since I am peridically changing the frequency
and the sink is designed to look at a single center
frequency, I don know how to append several frequency
windows to a large one.
I dont know if what I am planning to do is even possible
using gnu radio only.

I higly appreciate any suggestions.
Thanks in advance.

-Sebastian

On Wed, Feb 8, 2012 at 8:19 AM, Sebastian D.
[email protected]wrote:

2.5GHz in steps of 20MHz, I want the the whole bandwidth to be graphically
only.

I higly appreciate any suggestions.
Thanks in advance.

-Sebastian

If you want to show the whole spectrum in one qtgui window, it’s going
to
take a bit of hacking.

On the other hand, you can probably just use the qtgui right now. The
block
just takes in the data sent to it and plots it, regardless of where it
came
from. The center frequency of the plot is just for reference and doesn’t
have any real meaning for the data planned. This will only show a
section
of the full bandwidth at a time, but it might be enough to get you
started.

Tom