Forum Replies Created

    April 13, 2015 at 6:22 am #19624
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    Liju Mohan
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    Thank you Damian. I did have to try an alternate setup for it since there are no components that acts as FBG arrays.

    April 5, 2015 at 2:38 am #19287
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    Liju Mohan
    Participant

    Hi, I managed to clear out the issues with the MD codes project. I used a different encoder and decoder scheme. Would you have any references on FBG arrays in optisystem? OH, and Happy Easter!

    April 1, 2015 at 12:52 pm #19211
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    Liju Mohan
    Participant

    Hi,

    Opening Optisystem and then opening the file always works, but the issue i mentioned is not something that happens all the time. The error pops up rather unexpectedly at times, and yes it is always set to open with “run as administrator”.

    Sometimes, restarting the laptop would also get rid of that issue.

    April 1, 2015 at 12:44 pm #19210
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    Liju Mohan
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    Hi,

    I did attempt that method at first, but i did not manage to get an acceptable output for it and hence moved on to try using the technique employed for the sample. Would you perhaps be able to make a sample using just one user based on that?

    March 31, 2015 at 3:36 pm #19179
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    Liju Mohan
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    I am truly sorry, I did know that. I’ll make sure i do not do that again. IF you haven’t yet, this is the paper “Modified Quadratic Congruence Codes for Fiber Bragg-Grating-Based Spectral-Amplitude-Coding Optical CDMA Systems” – Zou Wei and H. Ghafouri-Shiraz. It is an IEEE journal paper.

    March 31, 2015 at 3:24 pm #19174
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    Liju Mohan
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    It is not a very recent paper, but it is the most descriptive paper i have read on MQC codes. The other main reference i use is a book “Optical CDMA Networks Principles, Analysis and Applications by Hooshang and Massoud.

    March 31, 2015 at 2:04 pm #19161
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    Liju Mohan
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    Thank you for taking the time to look into it. Would you perhaps still happen to have the file where in you have fixed the bandwidth issue? I will check out the project with the MD codes as you have suggested. As for the reference paper on MQC, i have the main paper i have referred, to learn the construction of the code. The link for the paper is http://115.248.50.245:7777/jlf/search/generalredirect?rurl=http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=948274&queryText%3Dmodified+quadratic+congruence

    March 31, 2015 at 6:28 am #19142
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    Liju Mohan
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    Hi Damian,

    I have just tried the SAC OCDMA structure using another set of codes, more specifically using Multi-Diagonal codes for 3 Users. Here again i seem to be facing a similar issue, only this time it doesnt work with even 2 users simultaneously ON. Perhaps it is an issue with my set up?

    March 27, 2015 at 12:02 pm #19055
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    Liju Mohan
    Participant

    Hi Heitor,

    Maybe this article could be of use to you.

    Regards,

    March 27, 2015 at 11:54 am #19054
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    Liju Mohan
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    Thank you for taking the time to respond to my problem. I shall look forward to hearing from you on Monday.

    March 25, 2015 at 1:39 pm #19006
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    Liju Mohan
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    I had that doubt myself, so i changed the codes for the 2nd user and the 3rd user (just to be sure) and tried again. The result was the same. When they are ON together, it simply doesnt produce the required output.

    March 24, 2015 at 11:10 pm #18991
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    Liju Mohan
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    Hi Damian,

    Thank you for responding to my issue. I believe the issue begins at the power combining stage before the transmission via the optical fiber. Or it could be an issue faced because of the code. I generated the code manually using Matlab, and have based the encoding and decoding sections based on this code. The codes are mentioned on the respective encoders. I hope the issue is a rather simple one i seem to be overlooking. I have attached the initial osd project.

    Regards

    March 24, 2015 at 1:36 am #18949
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    Liju Mohan
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    Any help would be appreciated..

    March 18, 2015 at 2:18 am #18830
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    Liju Mohan
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    Hi.. I have tried to create a 3 user Sac-OCDMA system using the MQC coding scheme and have accordingly created the FBGs based on the codes for the encoding and decoding sections. However, i still happen to be experiencing some issues. When any user is turned ON individually, i get a clear output, as in acceptable BER values. But if i were to turn ON all the 3 users simultaneously, i got not output what-so-ever. Any suggestion as to why that might be?

    March 18, 2015 at 2:06 am #18826
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    Liju Mohan
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    I am using windows 8.1 for optisystem on my laptop, and windows 7 for optisystem in the lab. If i were to compare the both with regards to optisystem performance, then windows 7 is more smoothly functioning (It seems to experience unexpected crashes/issues more often in windows 8.1). But all in all i would prefer windows 8.1 to windows 7 considering everything i use the OS for.