Optical Receiver in version 13

[Javier Mateo Gascón]

I think something is wrong in the module Optical Receiver in the Optisystem version 13. I test the same project with versions 12 and 13. It is a very simple project with only the fiber atenuation needed to reach the receiver with the same optical power that the aproximate sensitivity of the receiver.
In version 13 the obtained Q is more than 47 and in version 12 is the expected value of 6.
I attach two screenshots with the results obtained with the two versions.
Thank you for your support.

Attachments:

1. 

   OptiSystem13vs12.jpg
   

[Damian Marek]

Hi Javier,

Could you please attach your project file for the OptiSystem 13 version?

Thanks

[Javier Mateo Gascón]

Hi Damian,
This is the osd in 12 version. This file can be opened with both versions. However, if you want, I can make a new one from scratch with the version 13.
Best regards.

Attachments:

1. ReceiverTest.osd

[Javier Mateo Gascón]

I send you the same file in version 13 from scratch.
May be that the origin of the problem is that in version 13 the default filter cutoff was 0.75*symbol rate but I think the correct choice should be 0.75*Bit rate as in version 12. If you filter to 0.75*symbolrate, you lose the signal.
Thanks Damian!

Attachments:

1. ReceiverTestv13.osd

[Damian Marek]

Thank you for these files! I am not sure what is causing this behavior and although you are right about the filter needed 0.75*Bit rate that doesn’t fix the discrepancy.

I’ll ask the OptiSystem team what they make of these results, maybe I am missing something!

Regards

[Damian Marek]

I got an answer back from the System team. Apparently a decision was made to change the effective noise bandwidth from a default value of the sample rate to the bit rate. From customer feedback it will revert back to the value of the sample rate in the next release (13.0.2). For now try changing the effective noise bandwidth from bit rate to the sample rate.

I tried this and got a Q factor of around 5.9.

Cheers!

[Javier Mateo Gascón]

Efectively this is the expected behavior. Thank you!

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