BER analyzer

Hi Ranjeet,

The threshold is the value based on the received bits level compared to which the bit is detected. If the received bit amplitude is less than the threshold, the bit is detected as a logic “0”, and if the bit amplitude exceeds that of the threshold, the bit is detected as a logic “1”.

Regards

Hi ranjeet,
For this you can make it analogous to operation of a simple digital switch. Alsitu rightly mentioned about the detection. If the received bit amplitude is below the threshold, the bit is detected as a logic “0”, and if the bit amplitude exceeds the threshold, the bit is detected as a logic “1”. I hope it helps.
Regards

hi ranjeet,
threshold is very essential parameter to be set in the tranmission channel.

if threshold is smaller, then there is great possiblity of heaving eerors in system because of noise power greater than threshold.

if threshold is larger, there is possibility of loss of bits(i.e again error) in reception, because bit power can be less than threshold becauese of channel attenuation.

thus threshold is to be optimized for minimum BER.

with regards

HI RANJEET,
I THINK IT IS VERY MUCH VALID QUESTION AND COULD CONCEPT OF SETTING THE THRESHOLD FOR THE BER ANALYSIS

I GUESS WE COULD NOT SET THE THRESHOLD FOR BIT ERROR RATE ANALYSIS, THE THRESHOLD IS SET INHERENLTY BY THE ber ANALYZER.

WITH REGARDS

hi aabid,
in your comment of #32066, you are intermingling the this post query and your power threshold query of your.
and how does the threshold varies with different parameters. can we set it??
hope you will reply soon.

with regards

Hi aasif,
I guess you are not understanding the context in which i had mentioned it. I have used interrogative marks at the end of the statement that means i am asking it not stating it and if you are confused then let me put it this way for you , Which parameters decide what should be the value of threshold ???
Who does calculate the threshold value here??
I hope you got my point now.. I hope you will reply..
Regards

Hi All

Aabid i also believe that your problem of designing the component to allow certain power levels above or below the threshold is different from what Ranjeet is asking, He wants to enquire about how to set threshold for the BER analyzer. I hope i had understood it correctly. As far as what Ranjeet is asking i am attaching a link below i hope u get to know how to set threshold as it shows how to calculate BER using a test set. And Aabid in your case u have to design a component as a whole i believe.

BER Calculation Using the BER Test Set

Best Regards

Burhan

Hi All..
Well threshold is no doubt a general concept.
But for the case of BER in communication theory, I beleive it is taken to be a mid-point , because the bits are taken to be equi-probable. i.e, bits 0 and 1 have equal probability of being transmitted. And at the Rx, if the amplitude is above mid-point, it is considered as 1 and if it is less than the mid-point value, it is considered as 0.

And For Ranjeet, I would suggest you to post a screenshot of the BER Analyzer results where in there is some value. In the image you have attached, no data has been received or atleast detected. So not much can be inferred about how Optisystem has programmed the BER Analysis.

Regards.

Hello Aabid Baba

you are welcome. Productive discussions are always appreciated and discussion are overall productive i believe.
Ranjeet it seems to show the threshold values. Are u trying to ask that u want to edit this threshold value. then i believe it cannot be set in BER analyzer but it would be possible in the component ahead of that.

Regards

Burhan

Hi Ranjeet..

I appreciate that you uploaded these. Going by these images, I think the concept of having a midpoint threshold value is actually about the last option of the table ‘Decision Inst.’. And about the threshold value, I can see there’s a difference in the two imaged. I believe this has to do with adaptive thresholding, wherein going by the channel state the threshold values are set to minimise the BER. This varies with the modulation schemes as well. Eg. OOK has fixed point thresholding. Could you please tell me which modulation scheme has been employed in the system ?

Regards.

you can make it analogous to operation of a simple digital switch. Alsitu rightly mentioned about the detection. If the received bit amplitude is below the threshold, the bit is detected as a logic “0”, and if the bit amplitude exceeds the threshold, the bit is detected as a logic “1”. I hope it helps.

threshold is no doubt a general concept.
But for the case of BER in communication theory, I beleive it is taken to be a mid-point , because the bits are taken to be equi-probable. i.e, bits 0 and 1 have equal probability of being transmitted. And at the Rx, if the amplitude is above mid-point, it is considered as 1 and if it is less than the mid-point value, it is considered as 0.
And For Ranjeet, I would suggest you to post a screenshot of the BER Analyzer results where in there is some value. In the image you have attached, no data has been received or atleast detected. So not much can be inferred about how Optisystem has programmed the BER Analysis.

HI MHD
As mentioned in the other post that plz avoid copying and pasting the same comments..try adding something which maybe helpful to other members…i hope u refrain from it..
Thanks and regards

Hi All..
Well threshold is no doubt a general concept.
But for the case of BER in communication theory, I beleive it is taken to be a mid-point , because the bits are taken to be equi-probable. i.e, bits 0 and 1 have equal probability of being transmitted. And at the Rx, if the amplitude is above mid-point, it is considered as 1 and if it is less than the mid-point value, it is considered as 0.

And For Ranjeet, I would suggest you to post a screenshot of the BER Analyzer results where in there is some value. In the image you have attached, no data has been received or atleast detected. So not much can be inferred about how Optisystem has programmed the BER Analysis.

Regards