[Dhananjay PatelParticipant]

Hi Priti,

Working with bidirectional fiber with the new OFDM modulator and demod block may not help in correct results because there is a bug in the BER testset tool, which calculates the BER.

Bidirectional design requires you to have number of iterations equal to the amount of bidirectional devices used in the design (for Eg: circulators, fiber etc). But the BER test set block does not work in the iteration mode.

Hope this helps

[Dhananjay PatelParticipant]

I am using BER test set for bidirectional OFDM system. When I try to replace BER test Set with PRBS generator, the results are not correct. The New OFDM design works fine only with BER test set.

How to proceed furthur?

Thanks

[Dhananjay PatelParticipant]

Thanks for the reply. I have gone through the tutorial which aasif has mentioned.

I have few doubts in Reflective SOA example given in the samples.

Why the iteration value in global parameters have been choosen ‘5’?

Thts the reason that RSOA is executed 5 times, but in that design we have only three delay elements.

Also the output BER value for both the transmission is not the same. One is excellent (the modulation done with MZM) while the other BER value is poor (The one modulated with RSOA).

Please let me know.

[Dhananjay PatelParticipant]

Please provide us with the help.

[Dhananjay PatelParticipant]

Dear Damian,

Please help

[Dhananjay PatelParticipant]

Please find attached the .osd file for the same. Let me know if I have done some design error

Attachments:

1. OFDM-DSBFC-with-DFB-laser.osd

[Dhananjay PatelParticipant]

Hi Alitsu,

I understood the need of delay component. Now my question is how to or what value of delay component should be used for the design. How to choose the value of delay in the delay component block of optisystem?

[Dhananjay PatelParticipant]

Hello All,

I am still not able to figure out why we need to connect the delay components with the bidiectional fiber. I am using the same design from the samples Radio over Fiber SCM ASK.

[Dhananjay PatelParticipant]

Integrating the matlab and optiwave is a tedious and time consuming job. I would rather suggest you to use the OFDM component block available with optiwave and set the parameters ap per your need.

I think you cannot integrate the simulink and optiwave as I have not come accross any reading which says both can work together. Use the sample designs available in the samples folder

[Dhananjay PatelParticipant]

Dear Farhad Hagh Panah Shirvan,

I have found lot of problems with your circuit. Kindly modify it as per the sample programs given in optiwave samples folder. Besdes there is no output from the pohot diode and hence the signal is not demodulated. The real problem is with the gaussian filter. remove or disable it and try anagin. I guess you will get the output.

The bandwidth chosen for the gaussian filter is inappropriate and thus at the output of the filter there is no signal.

I hope then it works

[Dhananjay PatelParticipant]

LiNb MZM, is a dual electrode MZM, usally biased at quadrature. For your analysis, you can keep the vlotage of switching equal to 4 volts and bias voltage equal to 2 volts. this will make MZM perform in linear region.

Besides, try reading more papers on MZM. This will give you an insight of the parameters and their values to be choosen depending upon your application.

[Dhananjay PatelParticipant]

I would like to inform that, when I am trying to execute the design of bidirectional system, its taking lot of time in execution. (More than 40 mins) and after that the system hangs (not responding).

Does it usually takes lot of time when executing with bidirectional fiber?

[Dhananjay PatelParticipant]

Also in the above examples what Sam has given, I am not able to understand the concept of optical delay. Can anyone provide some information in order to understand its significance of optical delay in the process

[Dhananjay PatelParticipant]

Can anyone tell me for designing a bidirectional optical system, do i need to use a single mode fiber or bidirectional fiber available in the component library.

[Dhananjay PatelParticipant]

Hi Sasha,

Can you please tell us, how are you measuring the attenuation.

Besides, I hope you are changing the laser wavelength and the fiber reference wavelength at the same time. I agree with Alessandro, in the sense that in first and second window of wavelengths the attenuation should be maximum. Instead you are getting best results there. Lets us know about it?