- This topic has 9 replies, 2 voices, and was last updated 10 years, 1 month ago by
Salwa Mostafa.
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AuthorPosts
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August 17, 2014 at 10:00 pm #13276
Salwa MostafaParticipantwhen i run the project the first BER analyzer only calculated . i want the result in the rest BER analyzers
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August 18, 2014 at 2:59 pm #13352
Damian Marek
ParticipantSame problem as your other post I believe. The LED Transmitter does not have a large enough bandwidth for all your channels. Try using the white light source.
Cheers
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August 18, 2014 at 7:41 pm #13354Salwa MostafaParticipant
hi Damian
i used white light source but it didn’t work as attached. can you check it ?
in my project i use spectral width between each channel equal to .8 nm and i need 20 channel , i tried to increase the bandwidth of LED transmitter to 16 nm but it didn’t work.
thanks in advance
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August 19, 2014 at 10:13 am #13357Participant
Try changing the Sample Rate in the White Light Source to get a larger bandwidth and also center frequency at 1560 nm. I calculated that a bandwidth (sample rate) of 2.5 THz gave an appropriate range for your project.
Cheers
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August 20, 2014 at 12:31 am #13369Salwa MostafaParticipant
Hi Damian
i tried to change the sample rate in global mode but its close. also i changed the sample rate in white light to 2.5 Thz but it didn’t work.
can you tell me how you calculate the bandwidth ?
Do you mean changing the center frequency of PIN photo-detector ?
also i change the band with in LED to 2.5 THZ but it didn’t work .
if you tried and worked with you please attach the modification.
Thanks in advance
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August 20, 2014 at 10:01 am #13376Participant
Hi,
I made a few more changes. To calculate the bandwidth, I mean looking at the range of your channels ~1550nm-1570nm and converting it to THz. You can use:
df = (c/(WL)^2)*dWL
WL is the center wavelength and dWL is the bandwidth in length units. c is the speed of light and df is the bandwidth in Hz.
I didn’t change the PIN settings, but I modified the Bessel filter to have a larger bandwidth. Finally in the Global Properties check the box for Convert Noise Bins in the Noise tabs. This will convert the White Light source from a noise bin signal to a sampled signal. I also increased the power dramatically for the White Light source.
The main problem with this simulation will be the computation time (if you include SPM in the fiber). The very large bandwidth (and sample rate) makes the SPM calculation very long, but it should be possible.
Cheers
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August 20, 2014 at 9:30 pm #13383Salwa MostafaParticipant
Hi Damian
I appreciate your help.
Thank you very much indeed.
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August 21, 2014 at 3:21 am #13384Salwa MostafaParticipant
Hi Damian
i want to clarify the following points to me
1- how you increased the power dramatically for the White Light source.
2- how you determine the appropriate center frequency and band with (Bessel filter) for the project.
3-is there any simulation examples for using MIMO techniquesorry for many questions but i need to understand
Thanks in advance
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August 21, 2014 at 9:43 am #13388Participant
Hi,
1 – In the white light source component there is a parameter for power you can just change this value.
2 – This question depends on what you are trying to accomplish which to me seems like some sort of SAC-OCDMA. You will have to do some research on this topic, because I’m not really sure. It depends on the code you are using and number or users etc. Try searching the forum for other topics on Hadamard code and SAC-OCDMA.
3 – A while back there was a forum post on this subject.:
Unfortunately we do not have any pre-made examples for this application.
Regards
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August 21, 2014 at 10:45 am #13392Salwa MostafaParticipant
Thanks Damian very much.
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