Bipolar Encoding

[Dr. Hamza M. R. Al-Khafaji]

Dear All,
In OCDMA systems, Hadamard code is used for bipolar encoding. when bit 1 is transmitted light is sent to encoder while bit 0 is encoded by the complementary of the encoder. How to implement this system ? any idea about how to switch the data bits ?, thank you.

Dr. Hamza

[Dr. Hamza M. R. Al-Khafaji]

No answer !!

[Damian Marek]

Hi Dr. Hamza,

Sorry for the wait. I’m not very familiar with Hadamard code. Do you have a scientific article you are trying to reproduce, that could help me understand your problem a bit more?

We have an example of OCDMA and we use fiber bragg gratings to emulate encoders/decoders at the following link:

OCDMA Network Design

Thanks

[Dr. Hamza M. R. Al-Khafaji]

Hi Damian Marek,
Have a nice day..

I hope you reply me faster.. In the attached file, when bit 1 is transmitted light is sent to encoder while bit 0 is encoded by the complementary of the encoder. How to implement the red colour part of this system ? any idea about how to make switching for the data bits ?, thank you.

Dr. Hamza

[Dr. Hamza M. R. Al-Khafaji]

Hi Damian Marek,
Have a nice day..

I hope you reply me faster.. In the attached file, when bit 1 is transmitted light is sent to encoder while bit 0 is encoded by the complementary of the encoder. How to implement the red colour part of this system ? any idea about how to make switching for the data bits ?, thank you.

Dr. Hamza

[Damian Marek]

Hi,

I have made an optical switch layout for you. It uses couplers and phase modulation to direct the incident light to either the first or second port of the final coupler. I am not sure how you are modulating the signal so I used a train of Gaussian pulses. Using the user defined bit sequence generator you can choose which bit is 1 and then route it accordingly.

Hope this helps!

Attachments:

1. 

   OpticalSwitchLayout.png
   

1. OpticalSwitch.zip

[Dr. Hamza M. R. Al-Khafaji]

Hi Damian Marek,
Good day..

Can you please modify the design without phase modulation ? Why you used “user defined bit sequence” ? and what is the setting of these “user defined bit sequence” components?, thank you.

Dr. Hamza

[Dr. Hamza M. R. Al-Khafaji]

Hi Damian Marek,
Good day..

Can you please modify the design without phase modulation ? Why you used “user defined bit sequence” ? and what is the setting of these “user defined bit sequence” components?, thank you.

Dr. Hamza

[Damian Marek]

Thanks for reminding me Dr. Hamza! Jaffar is correct about the use of the User Defined Bit Sequence generator, it is to control the switch, so that a binary 1 is switched up and a binary 0 is switched to the bottom port.

I have attached an amplitude modulated switch, you can replace the CW Laser with your input signal.

Hope this helps!

Attachments:

1. switch_amplitude.osd

[Jaffar Emad Kadum]

Dr.Hamza,

the first user defined bit sequence is used to modulate the light wave. the second user defined bit sequence is used to set the switching speed. i think the phase modulator is essential to perform switching function by switching the polarization of light.

[gherbi mohamed]

hi,
can anyone help me to desing a SAC OCDMA based on tow code keying

[gherbi mohamed]

hi Dr.Hamza,
can you help me because its your idea

[Author]

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