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calculate SNR from Power spectrum (Urgent)

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Hi. I have used simple blocks like PSK modulator,white noise,phase noise,tone interference, up and down converter and demodulator in a chain to simulate a noisy channel and also perform modulation in  LabVIEW. I would like to know is it possible to calculate SNR from the power spectrum live for this channel? Is there any function avaiable in Modulation toolkit to calculate SNR from Power spectrum?


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Accepted by topic author ethen99

Hello en99,


The Spectral Measurements Toolkit provides VIs to calculate the 'Power in Band'.  By taking the ration of this VI and the apparent noise level, I believe you should be able to calculate the SNR.


The screenshot shows where this VI can be found:




George T.
Senior Applications Engineer
National Instruments UK and Ireland
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I try use it. It calculated parameter SFDR, not SNR.

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@Valentin87 wrote:

I try use it. It calculated parameter SFDR, not SNR.

You must have bad math if you have the dynamic range instead of SNR. 


How about posting a snippet of your code?  That would help us find your mistake a lot quicker.  


Are you using RFmx? Why not? SNR is a basic measurement and easy to find.  Did you check the shipping examples? SMTK and RFmx examples are pretty good. 


Any one of those actions would solve your problem more ("Urgent"ly.)

Although I suspect, it's not that time critical for the rest of us.

"Should be" isn't "Is" -Jay
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