[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Discuss-gnuradio] usrp_fft.py axis values and units
From: |
bjoernm |
Subject: |
[Discuss-gnuradio] usrp_fft.py axis values and units |
Date: |
Wed, 14 Jul 2010 15:30:53 +0200 |
User-agent: |
Internet Messaging Program (IMP) H3 (4.2) |
Hi,
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 Schmid to generate the signals at 2.412GHz.
My questions are the following:
1. 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)
2. 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!
best,
Björn