The QT GUI Frequency Sink does have a option to hide the other side of
the spectrum. When float input is selected, an additional parameter
"Spectrum Width" is available. Options are "Full" and "Half".
Ron
On 4/19/21 12:03, Kevin Reid wrote:
On Mon, Apr 19, 2021 at 11:44 AM Alberto <alberto_gnura...@libero.it
<mailto:alberto_gnura...@libero.it>> wrote:
To obtain a real FFT i can use Float to Complex block ?
Float to Complex will do the same thing you're seeing now — it just
writes a zero imaginary component into the stream.
If you need a signal with an actually one-sided spectrum you can use
the Hilbert block, which uses the Hilbert transform to generate a 90°
phase shifted quadrature component. But that is just wasted compute
cycles unless your next signal processing step actually needs that
result. For viewing purposes, just ignore the other side of the
spectrum. (It would be nice if the QT GUI Frequency Sink had an option
to hide it when given float input, but as far as I know, it doesn't.)