WDM DP-QPSK system

[Monika MehraParticipant]

I made 4 channel 112Gb/s WDM Dp-QPSK system usnig inbuilt DSP component with disabling dispersion and nonlinear effect.
My question is what value of reference wavelength of SMF and DCF should be taken If I use the frequencies of 193.1THz,193.2THz,193.3THz and 193.4THz. Or should i disable the reference wavelength as it is given in introductory tutorials of optisystem.
2) I have taken bit rate in global parameters as 112Gb/s. How much bit rate should i take for all the 4 channels . Should they all be same or different
2) If I take same bit rate for each DP-QPSK transmitter , the BER r not same in all the channels there is little bit difference in all the channels ,so how can I study the relation between BER and Input power of WDM system.Should I check the relation for all the channel or only one channel
Kindly reply

[alistuParticipant]

Hi Monika,

You’d better choose the center wavelength as the reference wavelength and if it is hard to calculate it, you can simply disable it as you have mentioned, so that the center wavelength would be chosen as the reference.

The bit rate for each channel depends on what is defined in its PRBS generator. Since it is usually defined the same as the layout bit rate value, each of your channels would have 112Gbps bit rate in your case (It would be more helpful if you please upload your osd file).

Regards

[Alessandro FestaParticipant]

Regarding question #2, you need to consider that noise and non-linear effects are not the same for all channels in a WDM system, and this is why BER is different for all of them. I think that, to study the relations you mention, you should try to balance them as much as possible and then use the worst BER.

[Monika MehraParticipant]

thanks alistu for ur reply. I am attaching my file. Kindly check it

[alistuParticipant]

Thank you for the file (I strongly suggest that you use subsystems in your layout). As I told you, the bit rate in all channels is set the same as the global bit rate. So your overall system bit rate would be 4×112=448Gbps for this 4-channel system. I have attached an image of where you determine the bit rate for each channel in script mode.

Attachments:

1. 

   bitrate.jpg
   

[Monika MehraParticipant]

thanks alitsu. so if to make the global bit rate same as overall bit rate i should divide the bitrate by the no of channels. I made a ckt with dcf. kindly check this and suggest me any changes in it. u send one file 112Gb/s dp-qpsk with dsp changed to dhiman i am not able to open this. can u tell me which version is required to open that. i am attaching the files. can u suugest me some papers or examples or osd filles on WDM-DP-QPSK which i can refer.
regards

[alistuParticipant]

You’re welcome Monika. Since Dhiman is using the latest version, you must use version 13.0.3 to be able to open the files.

If you choose the bit rate in PRBS the same as the global bit rate, then the bit rate is NOT divided; Please have a look at my former reply again.

I simply suggest that you start a new file based on the Optisystem sample (which works fine and you can see the correct constellation diagram as the one in Dhiman’s file) and use subsystems to separate the users. The current implementation is really hard to follow. Also, I omitted all users but one and could not get the proper result.

[Monika MehraParticipant]

I am having opti system version 13.0.2.121.kindly send me the link from where i can download optisystem version 13.0.3

[alistuParticipant]

After you sign in, go to your profile and you’ll see the option “Evaluation license download”. Click on it and you’ll see the links to download trial versions. You should just notice ANY files you create using OptiSystem 13.0.3 you will not be able to open using older OptiSystem versions (including the one you are using now).

[SashaParticipant]

Hello Monika,

In community forum page, you can see the download option nearby, just click that option and you will be directed to download page. There you can see the list of optiwave softwares with version. There you can download it.

Regards,
Sasha

[Monika MehraParticipant]

I download the software as per ur instructions but the downloaded software is of version 13.0.2 but not 13.0.3. kindly suggest me how to download optisystem version 13.0.3

[alistuParticipant]

Re you using 32-bit or 64-bit version? I asked Optiwave about this a few days ago and they implied that the last version is there to download. However, after you install the software, when you go to the help section in the menu bar and choose “about OptiSystem”, which version is shown there?

[Monika MehraParticipant]

i am using 32 bit version. after installation the version shown is 13.0.2.163

[alistuParticipant]

I have downloaded the 64-bit version and it was the last version (which is version 13.0.3) about two months ago, while I had formerly downloaded the 32-bit version and it was not the latest version. And when I asked about this from Optiwave, I did not receive an assured reply about both versions being v13.0.3. So you could either download the 64-bit version or ask Optiwave about this. Maybe it will be fixed.

[Monika MehraParticipant]

thanks alitsu for ur reply.i will download 64 bit version