ROF bidirectional with RSOA

[gulkaran bajwa]

hello everyone, i need a simulation setup of ROF bidirectional transmission system with RSOA using DPSK(optisystem 7). i don’t understand how can i use RSOA for my uplink transmission (OOK). please guys help me out.

[alistu]

Hi Gulkaran,

There is a sample OptiSystem file which shows how to properly use reflective SOA to modulate data generated by pseudo random bit sequence generator component. Please go to the “optical” folder in “amplifiers library”. There you can see the “reflective SOA” example. I hope it will help you.

Regards

[aasif bashir dar]

are you using the licensed version of optiwave or not?

i could provide you the simulation step from my sample files from optiwave 14, but it would not open unless you are using the licensed version.

[gulkaran bajwa]

aasif# BRo, can you attach screenshots of a simulation model that would be helpful for me
if you can??

[alistu]

Here I am attaching the “Reflecting SOA” OptiSystem sample file screen shot that I recommended in my previous comment. In this implementation, the is also a bidirectional system. I think it would be helpful as well.

Regards

[gulkaran bajwa]

hi alistu,
thanks for help, please find out attachment of my project below and i am not getting any signal in upstream. So, please kindly tell me where i am wrong

[aasif bashir dar]

hi bajwa,
this file is not opening in optisystem 14.

with regards

[gulkaran bajwa]

hello aasif,
i am using optisystem 7 i am attaching screenshot if you can tell me where i am wrong in simulation or might be my parameters wrong. i shall be very thankful to you i really need it i m stuck.

[gulkaran bajwa]

i am getting downstream but not upstream signal (OOK)

[aasif bashir dar]

well the .osd file as per me correct.
but you have to iteration because you are using optical for bidirectional fiber.
i suggest u to go through this, and then re-simulate your file . i hope you will get the results.

Lesson 5: Bidirectional Simulation — Working with Multiple Iterations

look in practical case the delay element never exists. but for simulation purposes we need to add it there

with regards

[Aabid Baba]

Hello bajwa,

This is a common problem that everyone faces initially with bidirectionality. I know you may be getting a downstream response though not the upstream response. I faced the same problem.
Well you need to add delay component in both downstream and upstream in your design and on the layout simulation parameters just make the iteration number to 3 to 4. I ll attach the screenshot of the layout parameter. When checking the results keep on changing the signal index until you get a result. Signal index is present on the right top corner.
Hope it helps.
best regards!

[gulkaran bajwa]

Hi Aabid,
I have used delay in downstream but not in upstream because i think there is no need to add delay in uplink and i have also done iteration but still not getting results in upstream and as per your attachment i have done it with initial delay too but then i am out of both upstream and downstream.if you were facing same problem then please let me out from this one. thanks for your efforts

[Aabid Baba]

please check the attached screenshot for having some idea about where you need to change the iteration value.

[alistu]

Hi Aabid,

I believe Gulkaran has already used delay components in his current system implemetation. Can you please make the necessary changes and modifications to the current .osd file he has attached and upload it in the way you think your point could be helpful? Thank you very much.

Regards

[Aabid Baba]

Hello alistu.
i can do it only in lab time. shall do it tomorrow only for sure.
Hi bajwa, i had also mentioned signal index. it is very important factor for getting an upstream response. I will have a look to your osd file tomorrow morning hopefully. One thing you can do is just number the iterations to 4 and simulate. When analyzing the response , just look at the top right corner of the analyzer ( it displays signal index). Increase the signal index until you get response. It surely will work.

[alistu]

Thank you very much for the consideration. I will wait for the practical help.

Regards

[gulkaran bajwa]

Hi Aabid,
I am changing signal index too as per you said but i am not getting any signal in my upstream BER analyzer.I am waiting for your practical consideration thanks for your efforts and also for tutorials.

[Aabid Baba]

Bajwa please go through lesson 5 of the attachment. It will make your concepts clear about bidirectional thing. And let me add one more thing here. Delays have no physical significance. These are here just for sake of simulation. In practical scenario you can remove all delays. Hope it may prove helpful. Just go through Lesson 5 of the attachment.

best regards.

[aasif bashir dar]

hi bajwa
i firmly believe what aabid have suggested you ,will work.I also recommended you same previously in reply #30161.lesson 5 of above attached does contain every you need for remedying your .osd design.

with regards

[Aabid Baba]

Hello bajwa,
just tried your circuit. I am not familiar with many components but i could see that you have kept other ports of many bidirectional components floating. I suggest you to connect them to either ground or optical null. For circulatory primarily you need to connect them properly in the design. Any bidirectional component won’t provide you any response until it has some input at other ports too. It gives you null response every time.
regards

[gulkaran bajwa]

i have used optical null and ground null to close every floating ports but still no positive results in upstream thanks aabid for your efforts
is there any alternative for this?

[Aabid Baba]

you are welcome.
i tried few times but i could only get downstream RF spectrum. I am unfamiliar with many components you have used in your design which i couldn’t modify.
Anyways i would try my best to make some useful changes.
regards

[gulkaran bajwa]

Thanks Aabid

[Aabid Baba]

you are welcome

[Priti Garg]

Hi Gulkaran
I am also facing similar problem,but i am not even able to change the signal index in bidirectional components. Were you able to solve this problem. Please help. Regards

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