Pulsed Multitone Signal for RFSG

[amaine]

I have tried combining the sample codes provided with NI LabVIEW 2013. I tried integrating the RFSG Pulsed Data VI and the RFSG Multitone - Uniform Spacing VI, and I seem to be producing noise. I attached the code that I've experimented on. What am I doing wrong? Or is there an better way to do it?

[Matt_L]

Hi amaine,

Can you provide a screenshot of the noise that you're observing?  I was able to run this on some of our hardware and saw the following, which is what I think we would expect (when the signal is pulsing):

 

[amaine2]

We're currently using a single RFSG (NI PXIe-5673) and a single RFSA (NI PXIe-5663) in an 18-slot PXI chassis (PXIe-1075). Since we are pulsing the Multitone signal (in this example, a dual tone), the received signal is not we're expecting. Attached are the reults and the codes that we've used. The signal was transmitted using the Pulsed_Multitone VI and was received and analyzed using the RFSA IQ Graph VI.

[Matt_L]

My apologies, I was in a rush and hadn't realized that was just the FFT of the output in the RFSG session.

After some testing it looks like the issue is in the way we're pulsing.  When I remove the repeat for the off time, the two tone signal looks right.  Looking at the RFSG Pulsed Data example, the output looks fine as well.  I expect that this has something to do with the way the pulsed two tone signal is generated vs. just a simple pulsed tone at one frequency.  I do see some signal though when I just take a look at the spectrum - can you open up the RFSA Soft Front panel and see if you get something similar? I will contine looking into this, to see if this is what we'd expect, and how else we can send a pulsed two tone signal.

[amaine2]

The code for pulsing and the code for multitone generation functions perfectly when used separately. So, the problem comes to how the two codes are being integrated. Attached are the requested result from the spectrum analyzer including the codes used.