Home Forums GENERAL DESIGN 0FDM-QAM-VLC-.LOS

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    • #79885
      Rajat kumar
      Member

      Respected sir,
      I was sharing design for OFDM -QAM using LOS model for VLC . Problem arising in receiver constellation. Can we directly Drive LED after electrical rescale as frequency is in range of GHZ . can White LED transmit power of 1 watt or 2 can be changed by changing slope efficiency?.

    • #80879
      Ahmad Atieh
      Moderator

      Dear Rajat,
      The problem of LED is producing non-coherent light which cause the QAM signal to face lots of distortion as it uses in-phase and quadrature components to carry the OFDM signal.
      please note that you can’t load OptiSystem projects to the forum. You need to send them as zip files.
      Regards,
      Ahmad

    • #83483
      Ahmad Atieh
      Moderator

      Dear Rajat,
      The problem of LED is producing non-coherent light which cause the QAM signal to face lots of distortion as it uses in-phase and quadrature components to carry the OFDM signal.
      please note that you can’t load OptiSystem projects to the forum. You need to send them as zip files.
      Regards,
      Ahmad

    • #80887

      Respected sir,
      I have referred few research articles where they have simulated and received OFDM QAM using white LED . How to decide the filter at receiver after PIN for receiving OFDM Qam . In shared design what changes I need to implement to get required constellation .
      thanks. Sorry for uploading Project to forum. Sharing zip file for reference .

    • #83491

      Respected sir,
      I have referred few research articles where they have simulated and received OFDM QAM using white LED . How to decide the filter at receiver after PIN for receiving OFDM Qam . In shared design what changes I need to implement to get required constellation .
      thanks. Sorry for uploading Project to forum. Sharing zip file for reference .

    • #80889
      Ahmad Atieh
      Moderator

      Dear Rajat,
      could you please email me the articles that describe using LED with OFDM/QAM to my email at ahmad.atieh@optiwave.com?
      Regards,
      Ahmad

    • #83493
      Ahmad Atieh
      Moderator

      Dear Rajat,
      could you please email me the articles that describe using LED with OFDM/QAM to my email at ahmad.atieh@optiwave.com?
      Regards,
      Ahmad

    • #80891

      Respected sir I have emailed the article on ahmed.atieh@optiwave.com which was published in wireless personal communication in 2019. thanks and regards

    • #83495

      Respected sir I have emailed the article on ahmed.atieh@optiwave.com which was published in wireless personal communication in 2019. thanks and regards

    • #80893
      Ahmad Atieh
      Moderator

      I did receive the paper. I am not fully convinced that the results are correct.
      The range of the FSO channel used in the paper is 1m, which is not possible in this component. in addition to my original point about coherence of light produced by LED would not support QAM where phase between in-phase and quadrature is very important. Algorithms in the DSP are used to correct for that.
      Could you please communicate with me through my email ahmad.atieh@optiwave.com?
      Regards,
      Ahmad

    • #83497
      Ahmad Atieh
      Moderator

      I did receive the paper. I am not fully convinced that the results are correct.
      The range of the FSO channel used in the paper is 1m, which is not possible in this component. in addition to my original point about coherence of light produced by LED would not support QAM where phase between in-phase and quadrature is very important. Algorithms in the DSP are used to correct for that.
      Could you please communicate with me through my email ahmad.atieh@optiwave.com?
      Regards,
      Ahmad

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