Re: [Discuss-gnuradio] Transmit Power of USRP B210

[CEL]

The process is simple: You use exactly the settings you want to use
later, send a signal of known digital power (i.e. known |x|²), measure
the output power with a spectrum analyzer. You take e.g. half that
digital power, measure again, to verify you're in the linear region.

If you are in the linear region, the ratio between your |x|² and your
measured power is your calibration factor. Be aware that you need to
know how to deal with your spectrum analyzer; we can't tell you what's
the right window, window bandwidth, sweep step width etc for your
application.

Best regards,
Marcus

On Wed, 2018-04-25 at 12:15 +0530, Prabhat Kumar Rai wrote:
> Dear Marcus & Vitt,
> 
> Thanks for your suggestion.
> As I am new in this field I don't know how to calibrate spectrum
> analyser with usrp. Is there any video tutorial or any website link
> you can provide will be helpful? I have searched on internet but
> didn't get a thing for calibration.
> 
> Suggestion from other members is also welcome.
> 
> Regards
> Prabhat
> 
> On Tue, Apr 24, 2018 at 3:03 PM, Müller, Marcus (CEL) <address@hidden> wrote:
> > You'll have to calibrate that yourself. There's no fixed formula for
> > all possible individual devices, and all possible signals (with all
> > possible PAPRs, which is especially relevant for OFDM).
> > 
> > Best regards,
> > Marcus
> > 
> > On Tue, 2018-04-24 at 13:05 +0530, Prabhat Kumar Rai wrote:
> > > Hello,
> > > 
> > > I am using tx_ofdm.grc file to transmit a signal via USRP B210. I am
> > > fixing my system as center_freq 1.8GHz, BW 20MHz, Sample rate 1.92M,
> > > Gain 20 dB, when I am checking the gain in the spectrum analyser it
> > > comes out to be -77dBm, I know that channel is giving me around 30 dBm
> > > attenuation still I am unable to compute the actual transmit power of
> > > usrp.
> > > I know that only way to know transmit power is using the combination
> > > of frequencies, sampling rates, master clock rates, analog bandwidths
> > > and gain but don't know how and where to use them, all of them are
> > > already in a usrp_sink block.
> > > 
> > > Is there any other way to compute actual transmit power of Usrp or any
> > > other formulae???
> > > 
> > > 
> > > I have to use that power for RSSI calculation.
> > > 
> > > 
> > > Regards,
> > > Prabhat
> > > 
> > > _______________________________________________
> > > Discuss-gnuradio mailing list
> > > address@hidden
> > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

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