[Fauza KhairParticipant]

HI Nadzreen,
Could I have your email address, please ?

[Fauza KhairParticipant]

Hi Nadzreen, please try this scheme if you want to know about the characteristic of direct detection mechanism.

Based on this simulation, you can find that The direct detection mechanism is not appropiate for high modulation e.g 16-QAM. The constellation is not good and have the High BER. You also using the high power for CW Laser, and you cand find the effect of the phase set and quadrature demodulator.

[Fauza KhairParticipant]

I’m sorry, I don’t know why i cannot attcah the .osd file in this reply.

would you like to give me the your email address ?

[Fauza KhairParticipant]

I think, you must try this project.

I Hope this project can give you the solution. But this project not give us the BER Value.

On this project, we must change the configuration of the phase value on the Quadrature Demodulator for the variation of optical launch power (CW Laser) and optical fiber length so that we can the good constellation.

[Fauza KhairParticipant]

Hi Nadzreen, can you attach the your optisystem project file.osd ?

if you run the OFDM system with QAM modulation, you must configure the symbol rate and reference bit rate, not only on the QAM Modulator, but also on OFDM Modulator. After that, When you used the BER TEST set, there are many parameter sets that must changed.

[Fauza KhairParticipant]

I can see the new example of QAM folder, 128 QAM.. What is new component which is offered by OptiSystem 14 ?

[Fauza KhairParticipant]

Hi Gokul Boro,, can you attach your .osd file design or block diagram OFDM with 16 QAM ?? Please check example in OptiSystem 13 about OFDM with single polarization or dual polarization,, run and go to project browser,..

[Fauza KhairParticipant]

Investigation of Optical Modulators in Optimized Nonlinear Compensated LTE RoF System

i will attach this paper.

[Fauza KhairParticipant]

Thank you alistu,,

Is impossible if I give some dithering in Optical Link ??
I want know effect on linearity parameters if we inject the dithering input like as local oscillator or other laser ??

[Fauza KhairParticipant]

OK… Thank
The title of that paper is Direct and External Intensity Modulation in OFDM RoF Links. You can see in ieeexplore.. ^_^

For external modulation, LiNB MZM and CW Laser are used in simulation. In this case, I have get same result. I Think the main parameters almost same with the example of OptiSystem13.

But, I can’t get same result for direct intesity. Electrical rescale and VCSEL are used in simulation.

[Fauza KhairParticipant]

Thank you alistu…^_^

Please give me your advice about the VCSEL Laser parameters and other parameters in this project. I can’t get the same result according to my reference paper.
I’m going to compare the constellation visualizer results for before and after elecrical rescale is used..

I have attached .osd file and .png block diagram and visualizer results from that paper too.

Thank you so much

[Fauza KhairParticipant]

Thank you Mr Alessandro Festa..
Please try if bits per symbol = 2 or 4 bits.

Regard,

Fauza

[Fauza KhairParticipant]

Thank Mr Alessandro Festa.. So, PRBS only generates the bit sequences, the value is true (1) or false (0), isn’t it ?

When the output PRBS is connected to QAM Sequence generator and then both of QAM Sequence outputs are connected to OFDM, we can measurement the electrical power in output of OFDM.. I have some difference power value if i use 4 QAM and 16 QAM. Please give me explanation, where the power in step could be present ? from QAM or OFDM ?

Thank you before,

[Fauza KhairParticipant]

Thank you Mr Damien Marek..

Ok, i am very happy if that is not about licence key…

you can ignore this error command..

Cheers !

[Fauza KhairParticipant]

Mr Feras,

Could I have your design system model, before ?