Orthogonal modulation formats in Optisystem

[Ina Singh]

I read few papers in which authors have implemented orthogonal modulation formats such as NRZ/DQPSK/PolSK using which the authors have transmitted different data streams simultaneously using the three modulation schemes over a single wavelength channel to improve the bandwidth efficiency of the system. I tried implementing the same in Optisystem v.14 but the results are not coming as expected. Can someone please tell me how we can simulate orthogonal modulation formats in Optisystem? Is there any example project file for it?
Also, i am attaching the above mentioned papers for reference….

Thanks in advance

[Mohamed A. A. Abouseif]

Hi Ina,
I have went carefully through the paper you have attached.
first of all, I do believe OptiSystem can model the proposed system. All the required components are there in OptiSystem.
just make sure to mimic the all components correctly in the paper to get similar behaviour of the output curves. I see it is written the three hybrid modulation techniques is reported in [5, 6] and then the author call the output signal orthogonal modulated signal. So the three data; Data1, Data2, and Data3 could be extracted in the output port.
you can try and also send us your design to try to check it with you.
Hope that helps,
good luck
Mohamed

[Ina Singh]

Sir, I have tried to duplicate the project file as described by the authors, but the results are not as expected. I tried to run back-to-back transmission simulation. Even then the output shows no signal (Q Factor=0). I think there is some issue with the simulation/component parameters I have considered.

Sir, I am attaching the project file along this mail. Kindly, look into it and suggest me further improvements. I shall be very thankful..

[Ina Singh]

Sorry, I think I forgot to attach the project files..Please find attachment

[Ina Singh]

Sir, I am trying to attach my project file along the mail, but due to some reason, the file is not being transferred along the mail. Can you please tell me your mail id so that I can forward you the project file.

[Mohamed A. A. Abouseif]

Hi Ina,
I have been checking your project.
I recommend you to start by dividing your projects into sub parts.
so start first with Data1 only in the system. then check the output and match it with Data1.
afterwards, add Data2. then try to check the output matched with Data1 and Data2.
At this point, you can add Data3 and get the output of Data1 and Data2 and Data3.
by this procedure, you will be able to minimize the source of errors.
hope that helps you move forward.
let us know if we can help in anything else.

thanks
Mohamed

[Mohamed A. A. Abouseif]

Also, I suggest you can build a three separated projects with Data1 and Data2 and Data3.
and make sure each project is running properly before you build the total project sequentially as explained in my last email.
thanks
Mohamed

[Ina Singh]

Hello sir,

Thank you for your worthy advice. As per your suggestion, I separated simulation projects for data 1 (NRZ), data 2 (DQPSK) and data 3 (PolSK) each transmitting at 40 Gbps datarate. After making some changes the individual projects are working as expected. The individual simulation projects are located in separate layouts in attached file.

Now when I tried to combine data 1 and data 2 (Layout 2 in the attached .osd file), the data 1 (NRZ) is received correctly but BER analyzer at receiver side of data 2 (DQPSK) shows Quality factor=0 dB. I have tried to locate the source of error, but couldn’t find one.

Sir it would be great help if you could look into it and suggest me the solution.

Ina

[Ina Singh]

Project file

[Mohamed A. A. Abouseif]

Hi Ina,
It nice to hear first step for individual projects is running well.

I have tried layout2 and I found Q factor 0.626 not zero as you have in your program.
could you try again and run it in your side.

thanks
Mohamed

[Ina Singh]

Sir,

I tried simulating layout 2 again and yes Q Factor came out to be 0.626. But I believe that the Q Factor of the received signal should be better since we are using a back to back simulation. In case of data 1 the Q factor came out to be 221.613 whereas for data 2 it is only 0.626.

[Mohamed A. A. Abouseif]

Ina,
if you compare layout2 and the Data2 QPSK, you might notice the difference is only that the input to the MZ is CW.
So based on this notice, I have replaced the input of MZ of the data2 by a combination of output of Data1 and another CW laser.
you will find that in the attached project for you. another important point based on this notice is that, the higher the power of the CW laser, the higher the Q factor of Data2.
I think this would help you the problem. just try to adjust the CW laser power to have acceptable Q factor for Data1 and Data2.
I think also the same Scenario will be used to add Data3 as well.

It is an interesting example
please update me on the progress if there is anything else we can help.

thanks
Mohamed

[Mohamed A. A. Abouseif]

sorry here is the project,

Mohamed

Attachments:

1. Orthogonal-Modulation-Revised_MohamedAbouseif.zip

[Ina Singh]

Sir,

I tried open the project file you designed but it won’t open (Failed to load document from the storage). Can you please upload the file again (also it would be nice if you can upload the snapshot of the modified design in case the file fails to reopen again)

Thanks
Ina

[Ina Singh]

Sir,

Kindly send me the project file and the screen shot of the revised project again as the previous one failed to open.

Ina

[Mohamed A. A. Abouseif]

Hi Ina
here is the screen shoot and the program itself just in case you can open it this time.

good luck
thanks
Mohamed

Attachments:

1. SceenShot.docx

[Mohamed A. A. Abouseif]

Ina,
here is the project again.

Mohamed

Attachments:

1. Orthogonal-Modulation-Revised_MohamedAbouseif-1.zip

[Ina Singh]

Sir,

The project file failed to open this time too. I am using a licensed version of Optisystem v.14. I also tried running it on Optisystem V.15 evaluation version but it failed to open on it too.

Sir, it would be a great help if u could send me the screenshots of the modified project file.

Ina

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