[Discuss-gnuradio] Editing usrp_spectrum_sense.py

2016-03-21 Thread Fikrat Al-Kazimi
Hi guys, I hope you're all doing well. I'm been searching a lot and I read that if I want to measure the absolute power ( in W or dBm ) using the usrp_spectrum_sense.py, then I must calibrate the USRP by injecting a signal of known physical power. Can someone please walk me through the calibrati

Re: [Discuss-gnuradio] Editing usrp_spectrum_sense.py

2016-03-21 Thread Marcus Müller
Dear Fikrat, Feed in a known power, note down the digital power, repeat for another known power. You'll get three input power->digital power mappings. Now, assume the power transfer function is a linear one: $P_{digital} = G\cdot P_{analog} + P_{noise}$ With the two $(P_{digital}, P_{analog})$

Re: [Discuss-gnuradio] Editing usrp_spectrum_sense.py

2016-03-22 Thread Marcus Müller
Dear Fikrat, the physical power depends on your waveform. Generally, the power is always $P(t) = U(t)\cdot I(t)$, which, thanks to Ohm's law ($U=R\cdot I\rightarrow I = \frac UR$) is $P(t) = \frac{U^2(t)}{R}$. As you might know from the basics of electrical engineering, one can represent harmonic

Re: [Discuss-gnuradio] Editing usrp_spectrum_sense.py

2016-03-23 Thread Marcus Müller
Hi Fikrat, no need to apologize :) Just keep the list in CC:, as I did now. In fact, we're usually pretty happy to meet a few software engineers in the GNU Radio community. We've got our own experience in writing efficient algorithms, and our own experts in making things highly accelerated on dif