PAM4 Link with MZM

[Shuang Yin]

Hi,

I am trying to simulate a MZM based PAM4 link. I have two issues as following,

1. As you can see in the attached figure, the PAM4 signal after modulation is unequally spaced due to nonlinearity in MZM transfer curve, is it possible to pre-distort the PAM4 pulse and make the modulated signal equally spaced?

2. There is an electronic equalizer module which helps in electronic dispersion compensation. Can this equalizer module work for multi-level signal, i.e., PAM4? It looks like the module can only accept binary sequence as reference, which prevents it to be used in multi-level signal.

Thanks~

Michael

Attachments:

1. 

   PAM4_Eye_Diagram.bmp
   

[Damian Marek]

Hello,

You can use the Predistortion component in the Pulse Generator library to compensate for the nonlinearity of the MZM. Unfortunately you are correct the electrical equalizers are only to be used with binary signals (RZ/NRZ).

Regards

[Aadil Raza]

Dear Damian,

In electrical equalizers help, it is mentioned that It can be used to equalize PAM signal formats (including PAM-2 (OOK), PAM-4, PAM-8, etc.). This is not correct?

[Jamal]

Damian, is there any example that shows the working of the pre-distortion component ?

[Aadil Raza]

Dear Damian Marek

Please share some snapshot of working of predistortion component…

Regards

[Author]

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