[Ubaid BhatParticipant]

hi all…
i really appreciate the efforts put by manoj to solve the querey…
best regards

[Ubaid BhatParticipant]

HI pooja rawat…
you have rightly mentioned that the sensitivity of an electronic device is the minimum magnitude of input signal required to produce a specified output signal having a specified signal-to-noise ratio, or other specified criteria. Receiver sensitivity parameter is an important factor.Also the value of this parameter should be as much low as possible which means that the receiver requires less power to detect a signal.
I hope you find it helpful.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi ranjeet kumar….
indeed a very good explanation of the relation between dispersion parameter of SMF and DCF and their length.it is very helpful.
but i am confused with the explanation of the Khadija omran for taking the length of SMF as 5 times than that of DCF.Anyone please explain that if it is correct.But i think it is not necessary.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi sahil singh….
as already mentioned by dhiman kakati the BER of the system should not change very much by enabling the random seed in prbs generator.if your system design is good then there should not be any change in BER with changing the bit sequence. we simulate the design for different bit sequences because in practicality there will always be different bit sequences that will go down the system.so i think you should look into your design for this.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi Remo De Suza,
well as already mentioned by dhamin kakti that with the help of random seed we are able to find the flexibility of the system.Well because of random seed the results may change slightly everytime because everytime a different bit sequence is generated. So for constant results you should uncheck the parameter.thus consistency of the results can be ensured after unchecking the random seed option no matter haw many times you simulate the design.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

HI Atul sharma…
Well i think you have already used the delay components and still you are not getting any response for the upstream. i think it might be because of the noise in the system. You can use a filter to get the signal and filter the noise.hope your problem gets solved by using the filter.
with regards
ubaid bhat

[Ubaid BhatParticipant]

As far as the slowing of system is concerned,well definitely the simulation time is going to increase because of delay elements.But in optiwave you require the time delay element to view both upstream and down stream data transmission. I think the optiwave has no other provision for simulating bidirectional fibers. however for practical proposes there is no such need.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi atul sharma…
i am glad to know that you got the use of delay concepts. Well talking about the physical significance of the delay components they are only used for simulation purposes for the bidirectional fiber to work.In actual fiber transmission they are not used and the upstream/downstream frequencies occur simultaneously without any delay element.hope you got my point
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi rahul tiwari…
well by increasing the number of sequence length generated from bit sequence generator gives you good eye diagram but the increasing length will also increase the simulation time many folds. So your system configuration should be good enough for such a large simulation time. So better is to take an appropriate sequence length to avoid such an error.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

HI ATUL SHARMA..
dhiman kakati correctly mentioned the difference between the parameters of the two.in optisystem for simulation purposes of the bidirectional fibers you have to introduce some delay so that both waves travel simultaneously in opposite direction.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

Also the noise which gets introduced into the system are usually high frequencies needed to be filtered can be done with low pass filter only. so the low pass filter is a very important device on the receiver side for better reception of the signal.hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi naazira badar…
well the name itself suggests that the filter will allow the frequencies which are within the passband of the low pass filter and will filter the frequencies which are above the cutoff frequency. As the information is available only on lower frequencies which are used to modulate the carrier which is a very high frequency, so we need to filter the high frequencies and only pass the low frequencies at the receiver side.hope you got my point
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi dhiman kakati..
So if you want to filter some of the frequencies from the input frequecy then you have to use a filter with less cutoff and in this case below 20Ghz. But i think usually the information is available only for few Ghz so we need lpf with cutoff only for few Ghz. i hope you got my point.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi dhiman kakati…
well indeed a very good question …
well you have already mentioned in the question that the low pass filter will pass only those frequencies which lie in it’s pass band and will reject those which lie outside of the passband. Since the input frequency is only 20Ghz which is well in the passband of the filter,so it will be passed as it is.
with regards
ubaid bhat

[Ubaid BhatParticipant]

hi ranjeet kumar..
i agree with in saying that ome of the signal light may be coupled out of the core into the pump cladding, e.g. as a result of bending or by a fiber Bragg grating. That light will then remain in the pump cladding and will not (as for other fibers) get lost via the coating.
but you have mentioned active fiber in your comment.can you explain please this active fiber related to double clad fibers.
with regards
ubaid bhat