Home Forums SYSTEM Orthogonal modulation formats in Optisystem

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    • #49842
      Ina Singh
      Participant

      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

    • #49855

      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

    • #49867
      Ina Singh
      Participant

      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..

    • #49868
      Ina Singh
      Participant

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

    • #49869
      Ina Singh
      Participant

      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.

    • #49892

      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

    • #49893

      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

    • #49898
      Ina Singh
      Participant

      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

    • #49899
      Ina Singh
      Participant

      Project file

    • #49901

      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

    • #49902
      Ina Singh
      Participant

      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.

    • #49905

      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

    • #49906

      sorry here is the project,

      Mohamed

    • #49909
      Ina Singh
      Participant

      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

    • #49922
      Ina Singh
      Participant

      Sir,

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

      Ina

    • #49925

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

      good luck
      thanks
      Mohamed

    • #49927

      Ina,
      here is the project again.

      Mohamed

    • #49932
      Ina Singh
      Participant

      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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