Hi Maciej,
sadly, you attached a link to a picture on
https://private-user-images.githubusercontent.com… , which is github-account-specific and
can't be used by anyone but you. But the raw URL in your Readme works,
https://github.com/user-attachments/assets/3f9eee70-811e-41be-9d43-877b2dcbb078
so I'm assuming that's the one.
What I think is wrong here is that the Polyphase Clock Sync drifts off during the pauses
between frames: it doesn't know whether it's looking at noise only or signal, and so tries
to "wildly" guess what it should do during the "noise only" periods, just to then be off
from the correct timing enough to not be able to catch up with it during the first few
symbols of each frame.
In a practical system, you'd need to first detect presence before you feed it through the
clock synchronizer.
Best regards,
Marcus
On 5/12/25 10:47 AM, Maciej Zemło wrote:
Hi everyone,
I've developed a brief demonstration project in GRC that transmits a single byte via Pluto
using BPSK modulation. The project works well when using a "Constant Source" block that
continuously sends the byte, but it completely fails to function with the "Message Strobe"
block, which sends a byte every 0.5 seconds.
The project is available on GitHub for further reference: https://github.com/yabool2001/
BPSK_test_02_3 <https://github.com/yabool2001/BPSK_test_02_3>
I've attached a screenshot illustrating the structure of the project, available here
<https://private-user-
images.githubusercontent.com/38382353/442661233-3f9eee70-811e-41be-9d43-877b2dcbb078.png?
jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.whxllXKHs55LV7wgcRfq7BPy3oQjAiGJWUoKc-J8en8>.
Could someone point me in the right direction regarding what might be going
wrong here?
Thanks in advance for your assistance!
Best regards,
Yabool2001
