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    • #21077
      seda yılmaz
      Participant

      hello everybody
      ı have to make optical cdma. I did circuit of optical cdma and it is run but I don’ understand what I did.I don’t understand it has one or two channel.I will share my source. Please, you search my source. İs it wireless cdma or cable cdma? I think I did cable cdma but I don’t sure.I don’t understand what I did.Can you help me? I have to understand this week.
      Best

    • #21094
      Ravil
      Participant

      Hi Seda,

      Since you are asking most of your questions about the scheme you made, can you, please, upload it? Did you make your scheme in the exact accordance with the source that you have uploaded?

    • #21097
      seda yılmaz
      Participant

      I did my scheme in the exact accordance with the my source.Only I change frequency.

    • #21222
      Ravil
      Participant

      Hi Seda,

      In my opinion, you have two channels in your scheme. Each branch (represented by decoder, PIN-photodiode and subtractor) of the balance detector in your scheme defines a channel of the group signal. However, it wasn’t specified in the implementation scheme, it’s highlighted in your attached paper that designed method is applicable for cable (fiber optical CDMA) network.

    • #21224
      Ravil
      Participant

      Taking a look at the attached simulation scheme, you can notice that there is an optical fiber (with the length of 5km) is used as the transmission medium. At the same time, this technique can be implemented for wireless as well.
      Sorry for the delay. For some reason my answer has not been sent before! Let me know if you have any more question about the scheme!

    • #21242
      seda yılmaz
      Participant

      Hi Ravil
      Thank you very much for helping. I will ask about shape of eye diagram. I will sent shape eye diagram of its in the tomorrow. My teacher is that your shape is wrong. But I think it is true. Anyway, I will ask you in detail.Thank you again.
      Best

    • #21244
      Ravil
      Participant

      Hi Seda,

      You are welcome! I am glad to help you with what I can. Please, feel free to send your eye diagram and I (as well as the other forum memebers) will try to help you.

    • #21252
      Abhishek Shrama
      Participant

      Hello Seda
      I am agree with Ravil,in this paper(you have attached) comparison of performance of different coding techniques and detection has been studied.Modified Double-Weight and double weight schemes used in this paper due to the advantage of less MAI and PIIN.FBG’s used to implement these code with specific chip.Rest for your eye diagram ,upload your system to better understand results.Rest Ravil explained well about fiber and wireless system.

    • #21267
      seda yılmaz
      Participant

      Hi Ravil
      I share my eye diagram. My teacher said that there should not be interference signals in the upper part of the eye diagrams but she said that there should not be interference signals in the side of the eye diagrams.Do you think my eye diagram is true?

    • #21269
      seda yılmaz
      Participant

      Hello Abhishek
      Thank you for helping.

    • #21303
      Ravil
      Participant

      Hi Seda,

      According to the question that your teacher asks you, does he/she mean that that “amount” of interference doesn’t correspond to your quality characteristics, i.e. Q-factor and BER? From my point of view, it looks like you should have less interference in accordance with your quality characteristics. However, I think that the threshold value might needs to be adjusted… How did you set it up? Did you just use the auto settings?

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