3R Regenerator

[Ranjeet Kumar]

Hi,
Could anyone explain The significance of 3R Regenerator ? Whether it has benefit of using instead of NRZ/RZ and PBRS with BER analyzer.
Is it any difference in results of Min. BER and Q-factor and other parameters on using 3R Regenerator instead of PBRS in combination with Electrical pulse generator keeping all parameter same?

Attachments:

1. 

   Capture13.jpg
   

[ZULKARNAIN]

hi ranjeet…
as already discussed by Damian in one of the previous post, the purpose of the 3R Regenerator is to simplify the connections in a design. Normally you would need the original bit sequence and generated electrical signal along with the output transmitted signal to generate a realistic eye diagram. This component removes the need to make multiple forks and connections from the input. However, sometimes it can fail for very noisy systems or in some other cases where the global bit rate does not match the received bit rate. In these cases I generally use the input signals for the Eye Diagram Visualizer.

Protocol implementation using Optiwave

with regards

[ZULKARNAIN]

So we use a 3R generator mostly for simplification of the layout. As for as its advantage is concerned regarding BER, the Min. BER using a 3R Generator was much higher than that without a 3R Generator, e.g., 10^-5 as against 10^-8 respectively.
Hope this may help you.
with regards

[Ranjeet Kumar]

Thank you ZULKARNAIN,
I am not pretty sure about the things you are explaining is wright or wrong, But i appreciate your efforts to explain the problems.
I will try to implement your suggestions in design and will see what is correct.

[Ranjeet Kumar]

ZULKARNAIN,
As you have said that mostly we can’t use 3R Regenerator for noisy system because it gives more BER value than than system with PBRS and NRZ/RZ , I don’t know why it happens as it should give less BER because it uses default values of parameters.

[FAYIQA NAQSHBANDI]

Hi ranjeet

If you use a combination of PBRS and pulse generator in place of 3R regenerator,i don’t think there should be a strong variation in the values of BER and quality factor.Significance of using 3R regenerator is simply to reduce the system complexity.
Still to verify the same you can simulate your system using both the cases and compare the performance.

Regards

[Ranjeet Kumar]

Hi FAYIQA NAQSHBANDI ma’m
There is some difference between results which depends upon type of system for both cases as ZULKARNAIN have also said. We will not get same results in both cases.
Here i am uploading resuts of same system with or without 3R regenerator: Left side Image – with 3R regenerator , Right side Image – without 3R regenerator for OFDM system with 4 user.
Here we can see a large difference between Q-factor in both cases for same system.

Attachments:

1. 

   Capture14.jpg
   

[Ranjeet Kumar]

hi,
I am uploading Osd file of OFDM system of which results has been considered on 2nd user.
we can see the difference in results.

Attachments:

1. OFDM-PON8.osd

[Aabid Baba]

Hello ranjeet,
Zulkarnain is right when mentioning that the purpose of the 3R Regenerator is to simplify the connections in a design. Usually , we need the original bit sequence and generated electrical signal along with the output transmitted signal to generate an eye diagram.
However, BER using a 3R Generator is much higher than that without a 3R Generator as far as i am concerned.

regards

[FAYIQA NAQSHBANDI]

Hi ranjeet

In the images you have attached.The output of the case whr 3R regenerator is used is better than the other one.
Did you check the different parameters you are using in the other case.I don’t still think there should be a strong variation in the results provided the parameters are properly defined.

Regards

[Aabid Baba]

Hello fayiqa,
Thanks for the reply. Well there is a difference. If you visit the link posted by zulkarnain you will find that there the person has implemented it and found results varying but you can be right in your case too. It is matter of implementation in different scenarios.
Regards

[FAYIQA NAQSHBANDI]

HI AABID
It was a presumption based reply because what we actually do is just use 3R Regenerator Regenerator to simplify our system design by reducing the number of connections in a design….The performance should not vary to this extent because either way we are logically same and to our ease we use 3R regenerator instead of all three connections to be connected to the analyzer.. proper analysis is required in this case.
thanks

[Naazira Badar]

Hi all..

I’m surprised how results get bad in the case of employing the 3R Generator. That’s because I believed we make use of it to recover the original data and hence a reference signal is provided by it. In this regard, 3R Generator should always help in improving the results. I might have to check my results without employing it as well.

Regards.

[FAYIQA NAQSHBANDI]

HI Naazira
I am myself surprised to see such a huge difference in the results which in my opinion should not be the case because either way we are logically same and to our ease we use 3R regenerator instead of all three connections to be connected to the analyzer..As i said it needs proper analysis.. I strongly believe that there should not be such a huge variation in the results.
Thanks and regards

[burhan num mina llah]

Hi All

Well Naazira thats really a fact that 3R regenerator as the name suggests is for improving and not meant to degrade the signal. I have myself used it many a times and found to function like regeneting the siganl and hence improving it.

Regards

Burhan

[FAYIQA NAQSHBANDI]

HELLO BURHAN
You are right it should logically regenerate the original signal in its true form and the results should get improved. However i am surprised to see such a huge variation in various system performance parameters as suggested by the screenhots posted by Ranjeet. I don’t think it should happen. Have you ever compared the results that you got by using both the methods..?
Thanks and regards

[Aabid Baba]

Hi everyone,
Well i feel it is a worthy topic to discuss. I too find it very strange that the results to such an extent. I could see quality factor to be varying very much.
I hope someone analyzes it on his/her system design and compares the results by using/not using 3R Regenerator.
Regards

[Naazira Badar]

Hi Fayiqa, Aabid and Burhan..

Yes, I genuinely believe proper analysis is needed to be done before concluding that 3R Generator degrades the performance, as its only point is to help detect the original signal as accurately as possible.

Regards.

[burhan num mina llah]

Hi All

Yeah thats what we expect a regenerator to do.
Fayiqa and Aabid i have not really compared the results but always used it with an intention to improve the signal and get a better improved signal to be analysed further.

Regards

Burhan

[FAYIQA NAQSHBANDI]

HI BURHAN
I agree with you. Indeed it should do it but i don’t understand what’s the logic behind all this.
Thanks and regards

[Naazira Badar]

Indeed, Burhan.

[Ranjeet Kumar]

Hi FAYIQA NAQSHBANDI ma’m
i have checked all parameters as per standard but left image which is of 3R regenerator shows high Q-factor than that with PBRS and NRZ/RZ.
I am confused about so much difference, i think 3R regenerator shows ideal characteristics so it shows good Q-factor.

[FAYIQA NAQSHBANDI]

HELLO RANJEET
Well now what i understand from the comparison is that in my opinion , in 3R regenerator scenario the signal quality is improved because as the name suggests ‘regenerate’ . I believe it is the improvement of signal in 3R regenerator that the quality factor is so high compared to case when you directly connect the signal to the BER analyzer. But i still believe this much variation should not have been there. It quite strange.
Anyway thanks for conveying it.
Regards

[burhan num mina llah]

Hi Fayiqa Naqshbandi

Your are indeed correct and i am also confused.
Anways you are welcome.

Regards

Burhan

[FAYIQA NAQSHBANDI]

HELLO BURHAN
Indeed it is rather confusing..it would have been better if someone from optiwave itself explains why such a variation in results occurs..Maybe we are logically doing and thinking wrongly and if they correct us here our doubts and confusions will go..Anyways discussions are always productive..
Thanks and regards

[Naazira Badar]

Hi Fayiqa. .
I believe there must be some other implementation/logical error.

Regards.

[FAYIQA NAQSHBANDI]

HI NAAZIRA
I too think so but if you check the post whose link had been posted damian has clearly mentioned that using 3R regenerator gives you simplification rather than connecting PRBS and pulse generator we have to just connect 3R Regenerator to the visualizer…i hope it gets clear..
thanks and regards

[Ranjeet Kumar]

Thanks all,
for considering this topic as valuable and important , thank you for sharing your knowledge through discussions.

[Sanjeev kumar]

I think there may be some change of value of the BER measurement done in these two ways. if we set PRBS generator to use layout bit rate then PRBS and pulse generator will provide same result as we get by using 3R regenerator. whereas if we set PRBS bit rate with some defined rate then result would vary from 3R regenator. I have noticed in many cases 3R regenartor calculates on the basis of layout sample rate. so we can differentiate the response ofthese two on basis of its analysing parameters such as bit rate.

[FAYIQA NAQSHBANDI]

HELLO SANJEEV KUMAR..
Well your post is rather a bit confusing..if you check the previous comments you will get that he has kept the bit rate same and the he has checked it for the same system which is clear from the screenshots that ranjeet has shared…i think it has to do with the logic and underlying operation which leads to this variation which naazira has mentioned..
Thanks and regards

[Naazira Badar]

Hi Fayiqa Naqshbandi

I know what you are saying. But No doubt it makes the system design simple, but the underlying reason and logic behind using still remains the same, i.e. reshaping and regenerating.

Regards.

[FAYIQA NAQSHBANDI]

HI NAAZIRA..
yes i completely agree with your statement that the underlying reason and logic behind using still remains the same which is reshaping and regenerating.. i hope this confusion is clear very soon..
Thanks and regards

[MHD NA]

its advantage is concerned regarding BER, the Min. BER using a 3R Generator was much higher than that without a 3R Generator.

[Naazira Badar]

Yes Fayiqa Naqshbandi..

I agree with you as well. All the best.

Regards.

[Ranjeet Kumar]

hi FAYIQA NAQSHBANDI ma’m

In this images which i have attached,the output of the case where 3R regenerator is used is better than the other one.
I have tried to check the different parameters i am using in the different cases, but found the same. I think there should be a strong variation in the results provided the parameters are properly defined, I will try to improve the design and will seek for some good results.

Regards

[FAYIQA NAQSHBANDI]

HI RANJEET
i see it means you have uploaded the screenshots for two different scenarios..but in that case it would definitely show some variation in the results because you are using it in two different cases here…it would be more convenient if u choose same design and check the results using the two case:
one in which you directly use 3r regenerator
two in which you connect sequence and pulses directly to the eye diagram analyser.
I hope it will be more clear that way..
Thanks & regards

[Ranjeet Kumar]

Hi all,
I am also surprised to see huge difference between the BER and Q-factor for above two cases.
I don’t know why it occurs.
May be some fault in the design which i trying to find but not succeed till date.
If anyone will find some such remarkable errors in the design of osd file in being uploaded please explain it.
As you all have consider it as worthy , so it is necessary to find such errors and would get free from such confusion as 3R regenerator is frequently used in design.

[MHD NA]

the purpose of the 3R Regenerator is to simplify the connections in a design. Normally you would need the original bit sequence and generated electrical signal along with the output transmitted signal to generate a realistic eye diagram. This component removes the need to make multiple forks and connections from the input. However, sometimes it can fail for very noisy systems or in some other cases where the global bit rate does not match the received bit rate

[Ranjeet Kumar]

Hi,
This component regenerates an electrical signal. It generates the original bit sequence, and a modulated electrical signal to be used for BER analysis. It is a subsystem based on the Data Recovery component and a NRZ Pulse Generator.
This first output port is the bit sequence, the second one is a modulated NRZ signal and the last output is a copy of the input signal. These three signals can be connected directly to the BER Analyzer, avoiding additional connections between transmitter and the receiver stage.
By using the 3R Regenerator, there is no need for connections between the transmitter and the BER Analyzer. This is especially important for WDM systems, where you have with multiple transmitters, receivers and BER Analyzers. For more information, see “Spatial CW Laser”.

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