Hi, I have created another version, BPSK_test_02_4 <https://github.com/yabool2001/BPSK_test_02_4>, which transmits a packet containing a pair of random bytes every second. I log the generated pairs ( 01_byte_tx_log.csv <https://github.com/yabool2001/BPSK_test_02_4/blob/main/01_byte_tx_log.csv>) and the received pairs (06_byte_rx_log.csv <https://github.com/yabool2001/BPSK_test_02_4/blob/main/06_byte_rx_log.csv>) and add CRC. This allows me to match pairs and accurately identify the delay and buffering of my packets in the receiver block (matched_bytes.csv <https://github.com/yabool2001/BPSK_test_02_4/blob/main/matched_bytes.csv>). I assume that I lost many pairs due to imperfections in my project, but the delay and data buffering are noticeable and interesting.
Main github link: https://github.com/yabool2001/BPSK_test_02_4/ Best regards, Yabool2001 niedz., 18 maj 2025 o 13:35 Maciej Zemło <mzemlo...@gmail.com> napisał(a): > 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.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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 >>> > >>> >>> >>>
