Threshold level in BER

[Abhishek Shrama]

Greetings
I am just wanted to know why sometimes threshold value and graph in BER analyzer comes out to be like as i am attaching in these files

Attachments:

1. 

   1apture.png
   

[Damian Marek]

It looks like it is functioning properly, but the scale might be confusing. On one of the y axii there should be a scale for the threshold value, and this scaling of the axis which is probably a very small range of values, because of the very good quality of the eye diagram. Those very small ripples in the eye diagram at the top and bottom are responsible for this interesting shape!

Regards

[Abhishek Shrama]

Thank you Damian, I have a query ,I want to know BER diagram is for one bit or one sequence?
If it is for one bit then it would be single 1 or 0.But it shows both one and zero .

[Ravil]

Hi Abhishek,

According to your first question, your eye diagram looks fine (functioning properly as Damian said) and very clear. The only thing which is confusing me are the axii. As far as I know, you should have a threshold value oon one of the axii and the other should express the distribution function for “1s” and “0s”.

[Ravil]

According to your second question, usually the eye diagram describes a statistical distribution of informational bits (“1s” and “0s”) with the presence of noise. Therefore, you have your diagram for one sequence of bits (theoretically this sequence can be measured based on time interval of your observation). It always shows “1s” and “0s” and related noise. If you are not sure about the obtained results of your threshold, you can compare them with the theory.

[Author]

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