not clear 16APSK

[boldooParticipant]

Dear all,

attached pic is actually 16APSK, but it looks very bad cause of Dispersion effect. How can I fix this? is there any better way?

[Damian MarekParticipant]

Hi Boldoo,

I simulated your project again with the fibers and amplifiers off and the constellation came out properly. Although I don’t think it is a traditional 16-PSK constellation it still looks good.

The fibers and amplifiers are the agents which cause the distortion here. Try a DCF to get a better result.

Regards

Attachments:

1. 16APSKedit.osd

[RavilParticipant]

I have a question about 2dB power level sent through 16km fiber to receiver: did you consider the sensitivity limits of your detector?

+1

[boldooParticipant]

first amplifier is 0db. second amplifier is 2dB through 16km fiber. you mean it is too low?

how to set sensitivity limits?

[boldooParticipant]

Amplifier 2 db is too low. it should more than 10dB, right? what does it mean Power parameter of Receiver?

[RavilParticipant]

Not exactly. I’m suggesting you to consider the level of overload signal for your receiver. The matter is that all receivers, in general, are working in dynamic range -15-25dB and if your input power will be bigger than higher limit, your receiver will become saturated which will bring you nonlinear distortion and information quality will degrade.

[RavilParticipant]

Levels of 0dB and 2dB accordingly are used, in general, for fiber spans with length of 80-160km which gives power level at the receiver within the dynamic range…

[RavilParticipant]

For better explanation I can refer you book “Fiber optic communication” G. Agarwal…