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!
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.