Dear Mr. Alessandro,
Thank you very much for kind help and suggestion. I put the BER analyzer in the 100 Gbps DP-QPSK System, (File attached). However, I could not find consistency in the output of EYE diagram and constellation diagram got at the receiver end of the system. If circuit connection is wrong, requested to help for rectification if any.
I would request, if anybody can explain the reason for inconsistency in Eye diagram and constellation diagram. File is attached for ready reference.
Thanking you all in advance.