WDM System

[Jaffar Emad Kadum]

Dear Optisystem team

I trying to design optical OFDM/UWB system, I designed each system alone and both of them are working fully functional. The bit rate of UWB is 625 Mb/s and bite rate of OFDM system is 50 Gb/s. but when I connected them in WDM system they are not working. I attached the system and I hope you can help me to modify and change the system and simulation layout parameters to make the system working.

I use OPTISYSEM 12.0

Regards

[Damian Marek]

Hi Jaffar,

The problem here is a number of your filters are not set with the correct bandwidth. I set the WDM Demux/Mux to Rectangular filters and 50 GHz bandwidth. The problem was the two signals were too close and the Gaussian filter was not completely getting rid of the other signal.

I got the OFDM part to 0 BER. I’m not sure how the transceiver is working for the UWB part, have you looked at the time domain output after that signal multiplication? There is no electrical signal.

Cheers

[Jaffar Emad Kadum]

Dear Damian,

The problem now is with the tow different bit rates ( 625 Mb/s and 50 Gb/s) I hope you can modify the layout parameters to make the system working in both UWB and OFDM. It is clear from the attached eye diagram of UWB.

[Damian Marek]

Hi,

How did you fix the UWB trans/rec components, is that working for you? Could you attach your project file?

Note: You cannot attach bmp files in these posts, try jpeg or png.

Thanks

[Jaffar Emad Kadum]

Dear Damian

I attach you the UWB over fiber project, it is working at 625 Mb/s, please not that I am setting the bite rate parameter of the layout at 625 Mb/s and the system is working.

[Damian Marek]

Hi Jaffar,

I found the problem. When working on projects with multiple bit rates it is important to make sure that components use the right bit rate. As default there is only one bit rate and filters and modulators use it to calculate bandwidth and other parameters.

In your file I created another parameter named bitrate2 and changed all the components in the OFDM system that were calling Bit rate.

Cheers

[Jaffar Emad Kadum]

Thank you Damian, the WDM system is now working, but when using any length of optical fiber the OFDM will stop working for example I used 30 km SMF with dispersion and loss compensation and the BER became (0.3), what do you think the problem?

[Damian Marek]

Hi Jaffar,

This seems to be the same problem as we discussed earlier with the OFDM component. We are coming out with an update for OptiSystem later this fall that will solve this issue. Sorry for the inconvenience.

Regards

[Jaffar Emad Kadum]

Thank you Damian, we look forward for these updates.

Regards

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