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.squarespace.com/static/ 543ae9afe4b0c3b808d72acd/543aee1fe4b09162d08633fc/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
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