Re: Fw: Help Feedback with GNURadio Companion

[Chris Gorman]

Hi Tom,

Marcus outlined some good resources, but if you're like me and need a
little bit more hand holding in order to use gnuradio-companion to
build flowgraphs using blocks like the costas loop, etc., there is an
excellent course at Harvey Mudd College by Jason Gallicchio[1].  The
course is online and free to watch off youtube.  In the course, you
build a QPSK modem and GPS receiver, using gnuradio and a PlutoSDR and
an RTL-SDR.

I'm not finished the course yet, but I have enjoyed the material so
far.  Prof. Jason also has the flowgraphs online[2].

Best regards,
Chris

[1] https://gallicchio.github.io/learnSDR/
[2] https://github.com/gallicchio/learnSDR/



On Tue, Aug 8, 2023 at 8:31 AM Marcus Müller <mmueller@gnuradio.org> wrote:
>
> Hi Tom,
>
> GNU Radio, the way it's currently written, does not allow you to build a loop 
> with sample
> streams – that's why you can't build a proper PLL from components in GRC :)
>
> But: there's ready-made PLLs for some use cases, namely for automatically 
> locking onto a
> carrier (and mixing down with it) [1], for detecting the frequency of a 
> carrier [2] and
> for detecting a carrier and generating a "clean" version of it [3].
>
> Now, these blocks do the PLL "block-internally", so if these PLLs don't 
> fulfill your phase
> locking purposes, then you'd need to implement that yourself (for example, in 
> a Python
> block, or in C++).
>
> So, maybe we should talk about what you need your PLL for? It's quite 
> possible we already
> have something like that ready-made or easy to modify.
>
> Best,
> Marcus
>
> [1] https://wiki.gnuradio.org/index.php?title=PLL_Carrier_Tracking
> [2] https://wiki.gnuradio.org/index.php?title=PLL_Frequency_Detector
> [3] https://wiki.gnuradio.org/index.php?title=PLL_Carrier_Regeneration
>
> On 08.08.23 13:12, tom sutherland wrote:
> > Is there a tutorial, example or guide to creating feedback loop (PLL, 
> > Costas, etc...)
> > using Companion/python?
> > Thanks...Tom
>