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| Full Name | Dr Rk Sethi |
| Organization | |
| Job Title | Researcher |
| Country |
Forum Replies Created
Gaurav Rajarya Hi,
The integration of PDM with QPSK seems to be reliable solutions to achieve longer reach, larger capacity, and higher spectral efficiency. QPSK can be generated with comparatively low complexity. Please have a look at the following forum link:
The following application link shows design of a 100 Gbps DP-QPSK transmission system using coherent detection with DSP:
What components are you searching?
Regards.
Sethi Rk
Hi Abhishek Shrama,
Please have a look at:
Start Writing Research Paper on Radio over Fiber. Which format should i Follow?
Hi Deepanshu Sharma,
Downloaded the article from the link.
From the article:
New speed for the signal
We now effectively deal with two different speeds.
First is the bit rate ftx, measured in bits per second, also referred to as “transmission rate.”
Second, we define the symbol rate S that quantifies the number of symbols transmitted per second,
With the coding efficiency in bits/symbol: e = log2 (number of symbols in alphabet),
the symbol rate calculates as: the bit rate ftx measured in bits per second / the coding efficiency in bits/symbol
The minimum optical bandwidth required by the signal (in Hz) is determined by dividing the symbol rate by 2.
Therefore, the bandwidth required by complex modulated signals doesn’t depend on the data rate but only on the symbol rate.
That also means the more bits encoded into one symbol at a given data rate, the greater the reduction in occupied optical bandwidth.
So, there is not any affect of DD method on the spectral efficiency.
Regards.
Sethi Rk
Welcome Anamika Basnotra, Sam Sung and Abdullah Baig.
Please don’t forget to inform through Forum or e-mail whenever paper published.
Best of luck.
Regards.
Sethi Rk
drsethirk@gmail.com
Esakkimuthu Hi,
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Hi Mohamed Ajina,
You can use Multi-mode fiber. It depends on the application.
Normally, Multimode fiber will permit short transmission distances of up to about 10 miles and will permit the use of comparatively inexpensive fiber optic communication transmitters and receivers. It will be bandwidth limitations of a few hundred MHz per Km of length. On the other hand, SMF may be used for the transmission distance in excess of 10 miles but will need the use of Laser transmitters. The equipment for single mode transmission more expensive as compared to multimode equipment.
Information carrying capacity = BW *Length
MMSI 20MHz.Km
MMGI 1GHz.Km
SMSI 100GH.Km
For more information you can refer:
Fiber-Optic Communication Systems, 4th Edition. Govind P. Agrawal
Hi Abhishek,
Welcome Dear.
Regards.
Abhishek Shrama Hi,
The X – axis parameters are not readable in the attached plots.
Hi Anamika Basnotra,
Providing a list of suggested or preferred reviewers will definitely quicken the process, because Journals are always short of reviewers.
Some authors send names of friends, who they think may be favourable as reviewers from the list of people with sufficient expertise. But these people are unlikely to be chosen to review the manuscript. Finally the editor has to choose the reviews obtained for any given manuscript and determine whether or not they are fair and thorough. The best suggestion is to not avoid mentioning names but pick names that in your opinion can provide good constructive review on your work and not just favourable. Our goal should not be to get our work published; instead it should be to make sure that whatever publishes is the best. If we adopt that approach, then only we will suggest reviewers who have the requisite expertise, regardless of what bias they might hold.
There are three types of editors:
– Some editors may be busy / sluggish people just take names and send the paper to them for review.
– Others think that you provide the list of the favourable people who will likely endorse your paper for non-existent merits, and never send requests to these people.
– These people rely less and less on these suggestions and look upon them with suspicion and make selections from their own wisdom, understanding and research on the topic.
Deepanshu sharma Hi,
Can you attach complete paper. From the snap shot it is showing coding efficient 1 bit / symbol, spectral efficiency .5 bits/sec/Hz.
The spectral efficiency of a digital communication system is measured in bit/s/Hz. It is the net bitrate (useful information rate excluding error-correcting codes) or maximum throughput divided by the bandwidth in hertz of a communication channel.
It can also be measured in bit/symbol, showing the net bit rate divided by the symbol rate.
Arunima Sharma Hi,
We are unable to see the attachment of your project, please resend it.
mean while, you can go through the tutorial at:
Regards.
How are you using DSP component for PS-QPSK, for increase fiber length. Can you attach the screen shot of the same. which version are you using? The new version of OptiSystem 13.0 has a new Universal DSP component with a complete suite of DSP algorithms (including a new nonlinear compensation model) for analysing various modulation formats.
Regards.
Abhishek Shrama Hi,
As you mentioned that you are working on FWM erbium doped fiber, Can you please tell me exactly what is your research objective? Are you following some reference paper? Four-wave mixing is a nonlinear effect. It takes place when two waves of different wavelengths are injected into an SOA, resulting in to a new optical field with new frequency is generated at the output. can you please attach a screen shot of the compressed optical power spectrum when bit rate increases?
Mohammadmahdi Aariannejad Hi,
The fundamental properties of the fiber are that they have some degree of birefringence and have the core that is not exactly circular over the entire length. Consequently the signals transmitted get split into two perpendicular polarization modes. These different polarizations arrive at the receiver with different delays.
Polarization mode dispersion occurs due to birefringence along the length of the fiber that causes different polarization modes to travel at different speeds which will lead to rotation of polarization orientation along the fiber.
Though normally much smaller than Group Velocity Dispersion effects, this Polarization Mode Dispersion effect can become a major link design concern in Group Velocity Dispersion compensated systems operating at bit rates of 10 Gbps and higher.
For more detail you can refer:
“G.P. Agrawal, “Fiber Optic Communication Systems”, second edition , John Wiley @ Sons, Inc., 1997.”
Abhishek Hi,
Welcome. Your are also one of the active participant of the Forum. Actively asking questions and solving problems / difficulties of the members.
Regards.