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Calculation/Simulation Error

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(joined April 2016)
Participant

Hi everyone,

This is my final project on 3 user SAC-OCDMA project. My college work is due in a few days .. However, it is not running/cannot be calculated.

Can somebody please be kind enough to solve it for me?

Why cannot it be calculated? Everything is alright here apparently.

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Responses (19):

    • #38661
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      Irfan Morshed
      Participant

      Hi everyone,

      This is my final project on 3 user SAC-OCDMA project. My college work is due in a few days .. However, it is not running/cannot be calculated.

      Can somebody please be kind enough to solve it for me?

      Why cannot it be calculated? Everything is alright here apparently.

      Attachments:
    • #38666
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      alistu
      Participant

      Hi Irfan,

      This file is OptiSystem SAC-OCDM sample as far as I am concerned (so you can find it in OptiSystem samples). I ran the simulation and it went smoothly with acceptable results except for the third user (which you should first enable in the simulation BTW). If you cannot open the file or do the calculation, this is a technical issue and you should contact Optiwave, which will probably answer after the weekend.

      I suspect something might be wrong with the way the third code is generated by FBGs. I haven’t worked much on SAC-OCDMA, but if you are interested to know how the codes should be generated, I suggest you thoroughly go through the related comprehensive discussion in the link below:

      how to implement sac ocdma?

      Regards

    • #38667
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      Irfan Morshed
      Participant

      Sample file? I got that file from the discussion link you shared, and it seemed to be Miss Kaurs completed thesis work.

      Anyway, my project basically is for 3 users, sending 1010, 1100 and 1001. Can u check my encoding and decoding algorithm? I used complementary/balanced detection.

      So we have 4 wavelength values –

      lamda 1 = 1550 nm
      lamda 2 = 1550.8 nm
      lamda 3 = 1551.6 nm
      lamda 4 = 1552.4 nm

      Walsh code for Encoding :

      User 1 (1010) : 2 FBGs at encoder coded with lamba 1 and lamda 3 (lamda 2,4 are cut off)
      User 2 (1100) : 2 FBGs at encoder coded with lamba 1 and lamda 2
      User 3 (1001) : 2 FBGs at encoder coded with lamba 1 and lamda 4

      Walsh code for decoding using complementary/balanced detection :

      User 1 (1010) : 2 top FBGs at decoder coded with lamba 1 and lamda 3, 2 bottom FBGs at decoder coded with lamba 2 and lamda 4
      User 2 (1100) : 2 top FBGs at decoder coded with lamba 1 and lamda 2, 2 bottom FBGs at decoder coded with lamba 3 and lamda 4
      User 3 (1001) : 2 top FBGs at decoder coded with lamba 1 and lamda 4, 2 bottom FBGs at decoder coded with lamba 2 and lamda 3

      That sounds logical?

    • #38668
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      Irfan Morshed
      Participant

      Brother, I will only get access to optisystems on tuesday.

      I checked with others. For my project with 3 users, the algorithm that I wrote above is correct.

      So for each user, I will have 2 FBGs at encoder side, and 4 FBGs at decoder side (for complementary detection/ 2 Top and 2 bottom FBG arrays). If possible, could you please be kind enough to just edit that osd file and instead use 2 FBGs for each user at encoder side, and 4 FBGs for each user at decoder side using the wavelength values that I mentioned? And white light source frequency should probably be the center frequency (1550.8 nm).

      If it runs after this work, then my project will be successful. Its due in a few days and I have no access till tuesday.

      Its just 5 minutes work for u.

      Please be kind enough to help this little brother out.

    • #38669
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      Irfan Morshed
      Participant

      I am entirely helpless and I have nobody to help me.

      My work is due in a few days and I am already having panick attacks.

    • #38670
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      Irfan Morshed
      Participant

      User 1 FBG connection attached below.

    • #38672
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      Irfan Morshed
      Participant

      Or if u want, u can make user 3 work somehow in that osd file.

      But if u use my coding as mentioned above, it should give the right result. I do not have access till tuesday.

      Please help out.

    • #38673
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      alistu
      Participant

      Here are screen shots from each of the 3 users BER analyzer. The third user signal is probably corrupted, so the BEr analyzer does not show anything. I will let you know in case any progress will be made in making it work.

    • #38677
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      Irfan Morshed
      Participant

      Okay thanks. Could u please tick the checkbox : “Show Eye Diagram”, and send me eye diagram for user 1 or user 2 please.

      I needed the eye diagram actually more.

    • #38680
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      Irfan Morshed
      Participant

      Thanks a lot. Which version are u using bro? v 13?

      The file does not open from version 14 for some weird reason.

      I thought optisystems was backward compatible!

    • #38681
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      Irfan Morshed
      Participant

      I installed version 14 from online.

      And it gives me this error on calculating entire project.

      What the hell .. how can version 14 be this screwed up!

      Attachments:
    • #38683
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      Irfan Morshed
      Participant

      I think this is the final solution.

      Bro, kindly run this one and hopefully this should give us the expected results.

      Does it run and give the proper results for the 3 users?

      Attachments:
    • #38685
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      Irfan Morshed
      Participant

      final one.

    • #38687
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      alistu
      Participant

      Yes, here’s the screen shot from all users.

      BTW, did you try to change the FBG frequencies to make it work?

    • #38688
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      Irfan Morshed
      Participant

      Bro,

      I cannot access it because it does not open from optisystems version 14! That is why I requested you to kindly change the FBG wavelength and make it same as the one I gave above.

      For each user – 2 FBGs for encoder, 4 FBGS (2 top, 2 bottom for complementary subtraction) at decoder.

      This is the file. I think you helped Miss Kaur with it already.

      And if you cannot change it, can you please let me know if the attached file works/runs or not?

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