Duobinary Modulation format

[karanveer singh bansal]

Respected Sir/Madam
I am using the duobinary modulation format for my thesis research work and I designed the duobinary system layout according to the tutorial ” advance modulation format ” given on optiwave website. The min BER I got is 0 and quality factor is 42.
But when I check the transmitted sequence from PRBS and the received binary sequence from the first port of 3R regenerator with the help of MATLAB component, I found that the both sequences are different. This shows that the quality factor and BER of the system is very poor.
But the results I got are quite good. I can’t understand why this happens.
Help me out to resolve this problem.
Thank You.

Attachments:

1. DB-format.zip

[Ahmad Atieh]

Dear Karaveer,
I’ve checked your project, everything is correct. There is a delay of two bits in the sequence as shown in the image attached. Please place a View Signal Visualizer as shown in the image and check the bits. Move two bits at the RX output and compare the bits. They match very well and that is why you have very good QF and BER.
By the way, you don’t need to use the Matlab component because the View Signal Visualizer does the job.
Regards,
Ahmad

Attachments:

1. 

   TX-and-RX-data.png
   

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