BER analyzer problem in Coherent detection QPSK system

[Mahmudul IslamParticipant]

I simulate the coherent detection QPSK system file from optisystem 13 samples but the min BER is 1 and Q factor is 0. Can anyone help me???

Attachments:

1. Coherent-Detection-QPSK-system.osd

[Mahmudul IslamParticipant]

Please any expert help me

[jagan padhyParticipant]

Hallo everybody,I am also finding the same problem in BER analyser.eventhough eye diagram is comming but the values of q factor and ber rate is 0 and 1.so please help,anyone experts

[Damian MarekParticipant]

You will notice that in our most recent project files we no longer use the BER Analyzer for Advanced Modulation formats. Constellation visualizers or BER Test Sets are used to calculate the BER.

The reason being the BER Analyzer approximates the BER from analyzing the noise and eye characteristics. However, in the example you attach the electrical signal is being regenerated right before the BER Analyzer creating a signal with no noise or distortion in any way, even though the signal might actually be regenerated incorrectly.

[Priti GargParticipant]

hi Damian

I read in one of the posts that there is a bug in BER test set, i am using it to find BER for an ofdm based system can u please clarify.