My question is: How Is it possible to get a good estimation of the BER without a costas loop?
2017-07-04 11:39 GMT+02:00 Marcus Müller <marcus.muel...@ettus.com>: > You're still not explaining what your question is – I really don't know > what to answer. > > What is wrong? > > On 07/04/2017 11:31 AM, Rafik ZITOUNI wrote: > > Sorry I missed to add the flow graph. > Here is attached. > > 2017-07-04 11:29 GMT+02:00 Rafik ZITOUNI <rzito...@gmail.com>: > >> 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 >> > -- > <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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