Marcus Müller marcus.mueller at ettus.com
Sat Jun 9 11:05:46 UTC 2018

These files just contain raw samples.

The fact that the signal then isn't around 0 Hz is simply because it 

1. (optionally/depends on example you're referring to) was mixed, in
the generating GNU Radio script, onto a carrier frequency within the
first Nyquist zone and
2. on the fact that DACs introduce *images* in spectrum at multiples of
the sampling rate, and you exploit these to have a copy of your signal,
shifted by a multiple of the sampling rate. You should filter out all
the other copies.

Terms to google for: reconstruction filter, band-pass undersampling

Best regards,

On Sat, 2018-06-09 at 00:47 +0100, Fred Neich wrote:
> Hello,
> I have a question about osmo-fl2k,
> the generated binary file using the fl2k grc transmission flow
> graphs, contains the carrier frequency,
> the fl2k_file stream the file to the device, so how the device can
> transmit these data in that frequency.
> I mean how it recognize the frequency to transmit on.
> Thank you.

More information about the osmocom-sdr mailing list