Amplitude De-Modulator

[Jamal]

How to set the threshold value after Amplitude Modulator to set the output levels ?
Is there any criteria or we just set the threshold depending on the output of Amplitude Demodulator ?

[alistu]

Hi Jamal,

The amplitude modulator, as it can be seen in the help section of the component in the technical background section, multiplies the bit sequence with a carrier. So for a ‘1’ you would see a signal and for ‘0’, you would have a zero sginal at the output. I haven’t seen threshold detector being used for it. Have you seen so?

Regards

[Jamal]

Oh sorry
I meant amplitude DEMODULATOR

[alistu]

I am aware of that. However, the same thing should be done in the demodulator to demodulate the signal and you can see this in amplitude demodulator technical background in the help section. But if you are asking about PAM coding component and PAM modulation which gives multi-level output signal, you can use a visualizer at the output of the modulator to see the signal levels of the modulated signal and then use these levels to determine the threshold for the demodulator. For example, if the output signal from the modulator has two values of 1 and -1, the threshold at the receiver can be 0.

Regards

[Dr. Dhiman Kakati]

Dear Jamal,
are you asking for m-ary ASK then accordingly you have to select the threshold depending on your design. I have attached here the waveform please have a look.

with Regards

[Dr. Dhiman Kakati]

please find here the attached image.

Regards

Attachments:

1. 

   introduction-to-modulation-and-demodulation-24-638.jpg
   

[Jamal]

Yes Dhiman, you got me right
Ok,so it is design dependent.
Thanks

[Dr. Dhiman Kakati]

You are most welcome Jamal.

Regards

[Jamal]

Can you have a look at this osd file, I am having trouble setting the threshold. I want to have oscilloscope-visualiser3 and oscilloscope-visualiser8 same.

[Jamal]

Attached is the osd. file

Attachments:

1. MZM-Sudebands-with-ASK-signal-oversampled-without-SMF.osd

[Author]

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