LMS equalizer

[Gaurav Rajarya]

hi, i am using electronic equalizer in my circuit but it is not showing any output .please tell me my mistake and guide me to get some better output.

Attachments:

1. lms.osd

[Damian Marek]

You have connected a null signal to the training signal input. You should connect the undistorted input signal to that input, so that the component can choose the correct coefficients.

[Gaurav Rajarya]

Thanks for your help Mr. Marek i did some changes as per your guidance but still i am not getting q-factor 1e-75 around.please check my circuit and did some required change in it.i will be very grateful to you.

Attachments:

1. lms-1.osd

[Damian Marek]

You will have to create the DP-QPSK Transmitter by yourself or copy one from the sample projects, because you need to compare the electrical M-ary signal. The output of the DSP is not in a NRZ format.

First try with a simple back-to-back system without the fiber link and see if you can get that working, only later add in the transmission section. I am sure that you are aware, but the DSP already includes an Adaptive Equalizer if that interests you, it would make the project simpler at least.

Regards

[Ravil]

Hi Gaurav,

I agree with Damian according to implementation of transmitter’s scheme. According to Damian’s second advice about Adaptive Equalizer, I just have a follow up question to you: are you planning to use two equalizers at the same time in your design or you want to replace the one from DSP with your own?

[Gaurav Rajarya]

Hi Ravil,

you are right .i want to use my own equalizer instead of the one given in DSP component.can u please suggest me something to do it in a better way?

[Gaurav Rajarya]

Hi,Mr. Damian, in previous suggestion,u told me not to use NRZ after PSK decoder.what component shoul i use at the place of it?

[Damian Marek]

Instead of the NRZ pule generator you need to use an M-ary pulse generator, however in addition you will need a Serial Parallel Converter for the dual polarization. Attached is the scheme I made which incorporates both the QAM encoder and M-ary signal generator in one component to create the necessary electrical signals.

Regards

Attachments:

1. 

   Capture1.png
   

[Author]

Posts