Rapid Change of Sample Rate - IQ Power Spectrum

#1 · 30/11/2022, 21:36

Hi,

I see a rapid change of the FFT rate and sampling rate GHz/s in IQ power spectrum menu. Why is it changing and is it related to the actual data sample rate? I assume that data sample rate should be fixed for a certain frequency span.

Thanks

#2 · 30/11/2022, 21:42

You have 4 main sample rates (select under IQ rate).

All other rates are based on additional/selected decimation e.g., smaller span, demodulator block etc.

#3 · 30/11/2022, 23:41

Thank you for your quick reply.

In the attached screenshots, in the IQ power spectrum's legend you can see two rates e.g. 39.1 FFT/s / 3.98GHZ/s. What do these numbers represent? and why are they changing? 39.1FFT/s -->24.4FFT/s .....

Thanks

Uploaded files:

#4 · 01/12/2022, 09:03

Likely because you are at almost 100% CPU saturation, so your system can't handle the incoming data fast enough (also see the yellow Rx warning) and is dropping samples. Try to lower the FFT and/or V6 settings until the CPU saturation indicator is no longer red and the Rx indicator is green.