Help required on Dispersion Compensation by DSP

[UMAR FAROOQ]

Hi,

I am working on millimeter wave radio over fiber converged network and now I want to compensate dispersion with DSP. The problem is the dispersion because from back to back the setup works fine but when I include fiber the constellation is not good. I am using 16 QAM OFDM modulated on 60 GHz mmWave carriers. Can you help me regarding this and which steps are required to form a DSP code to compensate CD. Now I am using digital filters method to compensate it but it’s not working. Also my setup is a direct detection system. Thanks

Best regards,

Umar Farooq

[Ahmad Atieh]

Dear Umar,
thanks for your enquiry.
I am not sure what the cause of bad constellation after you include the fiber. I need to know the length of the fiber, bit rate, number of OFDM tones, etc. to provide feedback.
Could you please send me your project as a zip file to ahmad.atieh@optiwave.com and I’ll try to provide some feedback and recommendations?
Regards,
Ahmad

[UMAR FAROOQ]

Hi,

Thanks for your reply.
Here are the main Parameters.
Length of fiber= 25 Km
Bit Rate= 5 G Bits/s
No of OFDM Carriers =16
Each carrier has 16 QAM Modulation
This setup is converged with 60 GHz millimeter wave carriers and then after fiber these carriers are detected on OFDM receiver. Its a direct detection system.
The setup works fine for btb and upto 5 Km but when I increase the fiber I got the very bad constellation.
Now I want to compensate this dispersion with DSP code file.

Best regards,
Umar Fraooq

[Ahmad Atieh]

Hello,
unfortunately, I can’t help you without the project layout. I’ve asked you to email me your project to ahmad.atieh@optiwave.com as a zip file. I need to check the whole system to be able to provide feedback.
Please communicate with me on my email to discuss further.
Regards,
Ahmad

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