Amplitude Shift Keying
START
STOP
MODULATE
DEMODULATE
Message Signal
m(t)
Message Signal Amplitude
10
Volts
Message Signal Frequency
3000
Hz
Carrier Signal
c(t)=A
c
cos(2πf
c
t)
Carrier Signal Amplitude
10
Volts
Carrier Signal Frequency
20
KHz
Amplitude Shifted Signal
Result
s(t)=A
c
cos(2πf
c
t) if m(t)>0
s(t)=0 if m(t) < 0
Amplitude Shifted Signal
Message Signal
m(t)
Message Signal Amplitude
10
Volts
Message Signal Frequency
3000
Hz
Carrier Signal Amplitude
10
Volts
Carrier Signal Frequency
20
KHz
Result
s(t)=A
c
cos(2πf
c
t) if m(t)>0
s(t)=0 if m(t) < 0