Can I ask a silly question
Can you use gnu radio as a filter sweeper
Perhaps hack rf sig gen in harmony with rtl sdr to sweep a filter or preamp for gain response
Since gnu radio is like a spectrum analyser
Andrew
Sent from my iPhone
If you want to first manually correct, add a Qt GUI Range block,
give it the ID "dopplercorrection", and allow a start and stop of
+- what you expect. Set the default value to zero.
Then, add a "rotator" block, and put in the "Phase Increment"
field the value you want to advance the phase of every sample. In
fact, that means that you want to put in
"-dopplercorrection/sampling rate" there.
I made a quick toy example:
<dopplercorrection.grc.png>
In fact, the correcting part of a PLL pretty much does the same,
mathematically, ideally.
Now, I'm not 100% familiar with the nature of packet radio, but in
the end, you want automatic doppler tracking – so, you typically do
stuff like using a "band-edge FLL" block to roughly bring the
signal's spectral power to the center of your baseband, then –if
necessary– you'd probably try to use the structure of the packet to
get finer frequency information, to correct the rest.
Best regards,
Marcus
On 2017-10-27 16:04, Andrew Rich wrote:
I am up to the stage of adding fft and scope sinks and resamplers and sliders
Need to explore the blocks
Curious about doppler correction
Andrew
Sent from my iPhone
On 27 Oct 2017, at 11:35 pm, Marcus Müller <address@hidden> wrote:
Glad you're getting engaged with SDR, and especially GNU Radio!
So, if you're completely new to GNU Radio, I'd recommend the "official Guided Tutorials":
http://tutorials.gnuradio.org
They start out rather smooth, and you can "stop" at any point (e.g. if you don't actually want to learn how to write your own C++ block, read only the chapters before that happens), and you'll get a pretty good idea of how things fall into place. Generally, feel free to ask here, or on IRC, or Slack, whatever feels nicest to you :)
Best regards,
Marcus
On 2017-10-27 14:19, Andrew Rich wrote:
Thanks Marcus
I can now start learning gnu radio
Andrew
Sent from my iPhone
On 27 Oct 2017, at 10:09 pm, Marcus Müller <address@hidden> wrote:
Hi Andrew,
most SDR devices are most easily usable in GNU Radio with the "Osmocom Source" block, contained in gr-osmosdr.
BUT: to get an gr-osmosdr with the AirSpy driver, you need to, in this order
1. Install GNU Radio and libairspy
2. build gr-osmosdr from source (Do NOT install it as binary package)
You get libairspy from [1].
Best regards,
Marcus
[1] https://github.com/airspy/airspyone_host
On 2017-10-27 11:16, Andrew Rich wrote:
Hello
Can some one tell me please what I need to do to use my AirSpy Mini as a source in GRC.
What do I need to install ?
The only other SDR I have is RTL-SDR and HackRF and Funcube Dongle
Want to start learning packet radio
Andrew Rich VK4TEC
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