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BER in OFDM

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(joined August 2016)
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dear colleges,
I am trying to simulate QAM4-OFDM WDM PON system.
BER tester is utilized in the OFDM part .
the system shows the EVM but always it shows BER=zero and it doesn’t realistic.
the input signals are CW 193.1 THz 193.16, 193.2, 193.26 THz, line width is 0.1 MHz.
the system speed is 10 Gb/s. is the line width of the CW laser source has the effect on the BER appearance? or what?
your help is highly appreciated.

Responses (4):

    • #66937
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      shaymaa Tahhan
      Participant

      dear colleges,
      I am trying to simulate QAM4-OFDM WDM PON system.
      BER tester is utilized in the OFDM part .
      the system shows the EVM but always it shows BER=zero and it doesn’t realistic.
      the input signals are CW 193.1 THz 193.16, 193.2, 193.26 THz, line width is 0.1 MHz.
      the system speed is 10 Gb/s. is the line width of the CW laser source has the effect on the BER appearance? or what?
      your help is highly appreciated.

    • #66965
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      Ahmad Atieh
      Moderator

      Hello,
      You may have some EVM value while the BER is zero. You may check the SER, it should be zero too.
      Regards,
      Ahmad

      +1
    • #66967
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      shaymaa Tahhan
      Participant

      Yes SER is zero also whenever BER is zero.
      1- what is the best bitrate to configure and evaluate the OFDM QAM4 system based on?
      because when I increase the bitrate the BER is increasing with SMF distance (take the symbol rate half of the bitrate because I am using QAM 4)
      2- if I took the one span (10km SMF, 2km DCF) should I include the length of the DCF in the OFDM demodulator or just the SMF?
      if NO, then if I increase the span to 20 the DCF will be 40km is it ok to not include its length?!

    • #66979
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      shaymaa Tahhan
      Participant

      Should I put a value in the OFDM POWER in the OFDM modulator?

    • #66985
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      Ahmad Atieh
      Moderator

      Yes, you need to specify the power in the OFDM Modulator. This will affect the transmission characteristics.
      Regards,

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