Home Forums SYSTEM Frequency in RoF

Frequency in RoF

Profile Photo
(joined April 2021)
Participant

Hello everyone,

What is the difference between the frequency in the sine generator and the frequency in the quadrature modulator? if the frequency of the sine generator is the radio frequency that we specify, then what is the function of the frequency in the quadrature modulator? is that carrier frequency? and how to determine the frequency of the quadrature modulator?
Why in the sample used 11 GHz as radio frequency in sine generator and 2 GHz in quadrature modulator?

Here i attached sample from optisystem sample

Attachments:

Responses (6):

    • #69590
      Profile Photo
      Agatha Binka
      Participant

      Hello everyone,

      What is the difference between the frequency in the sine generator and the frequency in the quadrature modulator? if the frequency of the sine generator is the radio frequency that we specify, then what is the function of the frequency in the quadrature modulator? is that carrier frequency? and how to determine the frequency of the quadrature modulator?
      Why in the sample used 11 GHz as radio frequency in sine generator and 2 GHz in quadrature modulator?

      Here i attached sample from optisystem sample

      Attachments:
    • #69592
      Profile Photo
      Ahmad Atieh
      Moderator

      Dear Agatha,
      the sine wave provides the RoF frequency. However, the Quadrature modulator offer an intermediate frequency for the OFDM subcarriers. You may check the RF spectrum analyzer to view the spectrum of the OFDM signal. The designer chooses these frequencies. There was limitation on the available equipment to conduct the experimental realization of this design. That is why those frequencies were chosen based on the equipment.
      Attached is a paper that summaries the work presented at CLEO2021.
      Regards,
      Ahmad

      • #69594
        Profile Photo
        Agatha Binka
        Participant

        Thank your Mr. Ahmad for the answer

        Mr. Ahmad, do you know how to measure whether it is good or bad the BER results from the BER Test component? Because the BER results from the BER test are not the same as the minimum BER results from the BER analyzer. Where the minimum BER analyzer result can be said it is good if the BER value is less than 10^-12.

    • #69595
      Profile Photo
      Ahmad Atieh
      Moderator

      Hello Agatha,
      typically with advanced modulation systems, the target for FEC operational system is around 1E-3 depending. There is a standard parameter used in the industry for these communication systems. The 1E-12 is typically used for 10G system with no FEC. This is mainly for old systems.
      Regards,
      Ahmad

    • #69596
      Profile Photo
      Agatha Binka
      Participant

      Is there any reference that I can read about the target for FEC operational system 1E-3?

    • #69597
      Profile Photo
      Ahmad Atieh
      Moderator
    • #69600
      Profile Photo
      Agatha Binka
      Participant

      Thank you very much Mr. Ahmad for your answers and the references.

Login You must be logged in to reply to this topic.