I’m currently using USRP, GNU Radio and the file usrp_fft.py to find
the Signal-to-noise ratio, Noise- and Signal-power.
I use the ZigBee PHY from Thomas S. to generate the signals at
My questions are the following:
In usrp_fft.py are the axis denoted as “amplitude [db]” and of
course “frequency”. Now in order to deduce the signal strength or the
noise strength respectively, I need the reference amplitude used to
compute the db value. In the code there is the setting “–ref-scale”
and it’s default value is 13490.0. Now is this reference Amplitude
13490.0 mV? (look at units -> milli-volts)
How can I get from here to the signal-power and noise-power? Or
maybe the signal-strength isn’t bad either… (I need those values to
find the transmitting power of the USRP, I guess it could be 1mW, but
don’t know how to check that)
Thanks a lot for your help!