Data over audio transmission

this is a solution for transmitting data over audio. like dial-up modems.

methods like FSK, ASK and PSK are going to be used for modulation.

for more knowledge see this link of wikipedia

ASK modulation and demodulation

in the transmitter side, using ask.py you can modulate a data into audio.
and then in the receiver side, you can demodulate audio using de-ask.py

demodulation is done by getting mean value of absolute value of a set of samples
and then comparing it with a normalized value.

also a synchronization method is needed for this algorithm (TODO).