Home Forums SYSTEM Chromatic dispersion effect

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    • #27403
      Prarthana Kashyap
      Participant

      Hi everyone,
      in case of mm-wave signal transmission in Radio over Fiber (RoF) technology, the control and processing of the mm-wave wireless signals is done at the central station thereby allowing the central exchange to remotely monitor the mm-wave signal transmission. the fiber chromatic dispersion can have a severe effect on the achievable carrier-to-noise ratio (CNR) of the recovered radio signals in such systems, So my question is how to get rid of this. I am looking for solution or hint.

      Thanks in advance

      Regards,
      Preathana

    • #27405
      Dr. Dhiman Kakati
      Participant

      Dear Prarthana,
      you can go for adopting advanced modulation schemes such as QAM, DQPSK. I am also working on the same kind of projects. In contrast to mm-wave signal transmission over fiber, the effect of fiber chromatic dispersion on the distribution of lower frequency intermediate frequency (IF) signals is less severe and the signals can be transmitted over longer fiber distances. This is also true for fiber transmission of digital baseband data signals where chromatic dispersion has a minimal effect on the delivery of few gigabits per second data streams over fiber links less than 100 km in length. In addition, both IF and baseband over fiber techniques have the advantage that they can exploit the use of mature microwave and digital hardware at the remote base station.
      This will be much helpful in case of full duplex design.

      Regards

      +2
    • #27408
      alistu
      Participant

      Hi Prarthana,

      After you adopted the suitable modulation scheme in your work, you may use the DSP component in OptiSystem in “Signal Processing Library” to compensate for the dispersion. Another way of compensating the dispersion is to use DCF in your fiber link, if it is possible to use it in your work.

      Regards

      +2
    • #27412
      Prarthana Kashyap
      Participant

      Thank you both Dhiman and Alistu for the reply, it is really helpful, so i have to 1st follow the steps what Dhiman has explained and the go for techniques as Alistu has mentioned, it is really nice to get instant help from the forum.

      regards

    • #27429
      Dr. Dhiman Kakati
      Participant

      You are welcome Prarthana.

      Regards

    • #27434
      MHD NA
      Participant

      you should note that dispersion of fiber gives a gain equals 6 dB in the strength of the generated harmonics for lengths of fiber between 8-35 Km.

      Regards

    • #27438
      Prarthana Kashyap
      Participant

      Hi MHD, I am not getting, will you please elaborate.

      Regards

    • #27439
      MHD NA
      Participant

      this attached diagram may be helpful.
      For any question, you are welcome

      Attachments:
    • #27447
      Prarthana Kashyap
      Participant

      Hi MHD,
      I am not getting why it is so for 8-35 km as you have mentioned. What is the meaning of OFM, I mean full form.

      Regards

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