2ASK

[boldoo]

Dear all,

how to draw clear 2ASK ?

[Damian Marek]

Couldn’t you use a simple externally modulated laser for ASK? I don’t believe you need a coherent type setup. If not could you attach an article or explanation of 2ASK?

Thanks

[Ravil]

I agree with Damian, regular 2ASK format doesn’t require coherent detection (can’t open your scheme for some reason…)

[boldoo]

Hi

need change Receiver? then how to see 2ASK constellation map?

But if it is succeeded, I will add phase modulation, fiber and QAM receiver. My final aim is square-16QAM constellation.

[Damian Marek]

Wouldn’t a simple NRZ signal be considered 2ASK? If so I think the constellation diagram would be as simple as the one attached. The signal varies between two values 1 and 0 and the phase is always the same.

Attachments:

1. 

   2ASK.png
   

[Ravil]

NRZ and RZ format just defines the bit interval duration and in my opinion 2 of them can be used for 2ASK.

[Ravil]

The presented constellation diagram belongs to ASK, I think. For 2ASK we should have 2 different values of amplitudes on axis if I’m not mistaken…

[Damian Marek]

Ok, but then that would be exactly the same as BPSK, which is not necessarily a bad thing. Boldoo let us know what constellation diagram you want. If it is what Ravil suggested then you could simply use a 2-QAM or BPSK modulator.

[boldoo]

Dears, since I need to draw 16QAM constellation, I asked about 2ASK. then I drew attached fig.

is it 16QAM right? there is any requirement?

Attachments:

1. 

   attach.jpg
   

[Damian Marek]

Hi Boldoo,

That looks exactly like 16-QAM glad we could help. In this case you could have used our QAM components to create the constellation diagram, but nevertheless it indeed looks correct.

Cheers!

[boldoo]

thanks Damian,

now that 16QAM pass through fibers, constellation is rotated as certain phase. but i can’t fix this to correct phase. You can see another post of mine.

[Author]

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