discuss-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Help with Airspy Mini


From: Marcus Müller
Subject: Re: [Discuss-gnuradio] Help with Airspy Mini
Date: Fri, 27 Oct 2017 17:15:22 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0

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:

Doppler correction
      Flow graph

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
_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio


    

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature


reply via email to

[Prev in Thread] Current Thread [Next in Thread]