Hi, Important and interesting update. During the testing of the BPSK_test_02_3 <https://github.com/yabool2001/BPSK_test_02_3> project, I initially believed that no valid demodulation was occurring when transmitting a packet every second. However, after accidentally leaving the transmission running for a longer duration, I observed that after approximately 95 seconds, a first burst of aggregated packets appeared. Interestingly, when repeating this experiment several times, the first occurrence of the packet burst consistently appeared after the same duration of 95 seconds. This behavior suggests a systematic delay or data accumulation occurring at a specific time interval, leading to a sudden release of aggregated data packets.
Statistics Based on log files: In the transmitter block, 470 packets containing a 1-byte payload were sent every second (01_complex_tx_bpsk_mod_log.csv - too big to view on github). In the receiver block, 306 packets were received as follows ( 06_byte_rx_log.csv <https://github.com/yabool2001/BPSK_test_02_3/blob/main/06_byte_rx_log.csv> ): - at 95.16 seconds, 23 packets were received. Then a short pause. - at 95.66 seconds, 3 packets were received. Then a long pause. - at 188.78 seconds, 7 packets were received. Then a short pause. - at 189.27 seconds, 11 packets were received. Then a long pause. - at 282.39 seconds, 32 packets were received. Then a short pause. - at 282.89 seconds, 56 packets were received. Then a long pause. - at 376.00 seconds, 6 packets were received. Then a short pause. - at 376.01 seconds, 29 packets were received. Then a short pause. - at 376.50 seconds, 54 packets were received. Then a long pause. - at 469.62 seconds, 36 packets were received. Then a short pause. - at 470.12 seconds, 49 packets were received. End of test. Link to projekt https://github.com/yabool2001/BPSK_test_02_3 Best regards, Maciek sob., 17 maj 2025 o 14:32 Maciej Zemło <mzemlo...@gmail.com> napisał(a): > Hi Marcus and Adrian, > > Apologies for the incorrect link to the private image. You are correct, > the diagram in the README.md is the proper one. Thanks a lot for your > advice. > > For now, I've tried the simplest solution — adding a "Simple Squelch" > block to feed the "Polyphase Clock Sync" only when a signal is present. The > updated schematic is now available in the README.md of the project on > GitHub: > https://github.com/yabool2001/BPSK_test_02_3 > > Unfortunately, it didn't help. In this configuration, the project only > works with a continuous source, such as "Constant Source". If there is a > better implementation for signal detection that could assist in burst > transmission, I'd be grateful for your recommendation. > > Now, I will also try Adrian’s suggestion to implement the "Correlation > Estimator" block. > > Thanks again for your support! > > Best regards, > Yabool2001 > > pon., 12 maj 2025 o 14:51 Marcus Müller <mmuel...@gnuradio.org> > napisał(a): > >> 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.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3NDcwMzkyNTIsIm5iZiI6MTc0NzAzODk1MiwicGF0aCI6Ii8zODM4MjM1My80NDI2NjEyMzMtM2Y5ZWVlNzAtODExZS00MWJlLTlkNDMtODc3YjJkY2JiMDc4LnBuZz9YLUFtei1BbGdvcml0aG09QVdTNC1ITUFDLVNIQTI1NiZYLUFtei1DcmVkZW50aWFsPUFLSUFWQ09EWUxTQTUzUFFLNFpBJTJGMjAyNTA1MTIlMkZ1cy1lYXN0LTElMkZzMyUyRmF3czRfcmVxdWVzdCZYLUFtei1EYXRlPTIwMjUwNTEyVDA4MzU1MlomWC1BbXotRXhwaXJlcz0zMDAmWC1BbXotU2lnbmF0dXJlPTg2MmQ3MjAxM2U2NDg3MmI3MzZkZGQyNGFlMzdlODdkZjlmYjRlMjc1ZDgzYzgwYmE4OGQ1ZDE5OTM2MWFjNjkmWC1BbXotU2lnbmVkSGVhZGVycz1ob3N0In0.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 >> > >> >> >>
