Marcus, You find attached my flow graph with Tx and Rx. I know that it is not recommended to have TX and RX in the same flow graph but i did it just to obtain one view for my Tx and Rx.
Thanks, 2017-07-04 11:23 GMT+02:00 Marcus Müller <marcus.muel...@ettus.com>: > Dear Rafik, > > I think we're approaching this from the wrong side: I don't think that I > should be explaining why you get a good BER and SNR estimate, it is you who > should explain why you're expecting something different, and then we can > discuss! I'm not quite sure what I could be explaining at this point :) > > Best regards, > > Marcus > > On 07/04/2017 11:20 AM, Rafik ZITOUNI wrote: > > Thank you Marcus for your answer ! > > My BER and SNR are calculated and obtained using MPSK SNR Estimator Probe > and Error Rate blocks. I obtained two points, which rotate in the qt gui > constellation sink despite the BER and SNR have been obtained as expected. > Could you give me an explanation how it was possible to obtain a good snr > and ber with a wrong constellation with good SNR and BER? > > I found the presentation of Tom Rondeau useful, since he explained the > function of the costas loop block. https://static.squares > pace.com/static/543ae9afe4b0c3b808d72acd/543aee1fe4b09162d08 > 633fc/543aee1fe4b09162d0863402/1392309732018/mpsk.pdf > > > This morning I add a Costas loop after a Polyphase Clock Syncronisation > block, and it s going well. You find attached a screenshot of my > constellation for a DBPSK of my receiver/transmitter. I propose to add a > grc to gnuradio/gr-digital for MPSK since grc is more easy to understand > than python source code. > > > Now I am trying to send and receive data files such as videos or images > (bmp). Do you have an example with a file exchange implemented in .py or > grc? > > Best, > > > 2017-07-04 9:44 GMT+02:00 Marcus Müller <marcus.muel...@ettus.com>: > >> Hi Rafik! >> >> So, what's wrong with the BER and the SNR estimate? >> >> Best regards, >> >> Marcus >> >> On 07/03/2017 11:29 PM, Rafik ZITOUNI wrote: >> >> Dear all, >> >> I translate the /gr-digital/examples/narrowband/digital_bert_tx.py and >> the /gr-digital/examples/narrowband/digital_bert_rx.py python source >> codes to GRC flow graphs. The objective is to get more graphical >> possibilities with a GRC. My flow graph gives a fine result of BER and SNR >> for DBPSK modulation. >> The problem is with the rotating points of my constellation. I think that >> the rotation of my view comes from a lack of frequency synchronization, but >> why I obtained a correct BER and SNR? >> >> You find attached to this message a constellation view obtained by my >> flow graph. >> >> Please could you explain me this result or give an advice to improve the >> obtained result? >> >> Regards, >> >> >> -- >> <http://www.ece.fr/>Rafik >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> _______________________________________________ Discuss-gnuradio mailing >> list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/ >> listinfo/discuss-gnuradio > > -- > <http://www.ece.fr/>Rafik > > -- <http://www.ece.fr/>Rafik
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