Home Forums SYSTEM not clear 16APSK

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    • #15324
      boldoo
      Participant

      Dear all,

      attached pic is actually 16APSK, but it looks very bad cause of Dispersion effect. How can I fix this? is there any better way?

    • #15422
      Damian Marek
      Participant

      Hi Boldoo,

      I simulated your project again with the fibers and amplifiers off and the constellation came out properly. Although I don’t think it is a traditional 16-PSK constellation it still looks good.

      The fibers and amplifiers are the agents which cause the distortion here. Try a DCF to get a better result.

      Regards

      Attachments:
    • #15558
      Ravil
      Participant

      I have a question about 2dB power level sent through 16km fiber to receiver: did you consider the sensitivity limits of your detector?

      +1
    • #15578
      boldoo
      Participant

      first amplifier is 0db. second amplifier is 2dB through 16km fiber. you mean it is too low?

      how to set sensitivity limits?

    • #15580
      boldoo
      Participant

      Amplifier 2 db is too low. it should more than 10dB, right? what does it mean Power parameter of Receiver?

    • #15610
      Ravil
      Participant

      Not exactly. I’m suggesting you to consider the level of overload signal for your receiver. The matter is that all receivers, in general, are working in dynamic range -15-25dB and if your input power will be bigger than higher limit, your receiver will become saturated which will bring you nonlinear distortion and information quality will degrade.

    • #15611
      Ravil
      Participant

      Levels of 0dB and 2dB accordingly are used, in general, for fiber spans with length of 80-160km which gives power level at the receiver within the dynamic range…

    • #15612
      Ravil
      Participant

      For better explanation I can refer you book “Fiber optic communication” G. Agarwal…

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