It's all about the Software

Hi, could anyone give me an explanation suitable for dummies please?

Some systems, like RFSPACE receivers with SpectraVue, somehow manage to create a very high resolution real time spectrum (say RBW better than 1 Hz) at a reasonable refresh rate (say at least 1 Hz). That's really handy for measuring carrier offsets from nominal frequency - and maybe tuning. What I don't understand is how it can be done in real time. Most SDR software gives much poorer resolution than that.

It's possible to get this resolution by re-processing an IQ recording - Console Analyser can do it. But my amateur attempts with Gnu Radio (lots of decimation) never worked properly.

Thanks for any help.

Paul,

The magic words you're looking for are probably FFT Overlap, this is what I do when the resolution is increased.

You could have an update rate of 10 / second and a RBW of 2Hz by using this approach, it's really the only true solution.

GNU Radio is something I've never played with so can't help, sorry.

https://dsp.stackexchange.com/questions ... ap-and-fft

Simon, Hi, and thanks for that quick response. Never heard of FFT overlap before.
Quickly checked the reference you gave me. Not sure if it's doable in GRC (or Pothos), and I don't know MatLab.
Very sure, though, I'm not going to try wading in those deep waters .
Just keep my head down and use whatever features the experts are generous enough to offer!

Shout here when you have any DSP-related questions.