Hello Debanjan,
Which version of OptiSystem do you use?
Do you have valid license? and valid maintenance and support license?
Typically, time multiplexing of 8-signals will result in multi-level signal. The Q-factor will be small due to creation of multi-levels.
We could support you once you have valid licenses.
Please contact me at:
ahmad.atieh@optiwave.com to discuss your application.
Regards,
Ahmad