[SOLVED] Demodulation of noisy Amplitude Shift Keying modulated signal

[stani]

Hello,

I'm intersetd to find out more about the demodulation of noisy Amplitude Shift Keying (ASK) modulated signal.
If I have singal that is modulated using ASK and I'm sending it over the channel with very high white noise (making the SNR at the receiver very low ~ 0dB), how should I perform demodulation? I'm learning about ASK and I read about the coherent detector, but I'm not sure if this is the right way to do the demodulation.
Thank you!

 

[MHanif]

Hi Stani

The optimum detector of ASK is the average filter. If you are using Binary ASK and your levels are say 0 and 1. Then what will you do is to perform average on the received 'symbol' (which means you have done synchronization and you have multiple samples representing one symbol either 1 or 0). After averaging you will get an answer for each symbol All you have to do is to compare that value with a threshold. If your bits are equally likely, then you will have to compare the average result with 0.5=(0+1)/2.

MHanif