Digital signals are used in communication processes to minimize the effects of noise. In an analog communication system, noise can distort the transmitted signal, but digital signals represent information as discrete values so that noise only causes errors if it is large enough to be misinterpreted as a different value. Digital signals work by assigning multiple voltage levels to represent bits, so even if noise adds to the signal voltage, it is less likely to cause the wrong value to be detected at the receiver.
2. What is the need for Digital Signal?
Digital signal is used in communication process to minimize the effect of noise (unwanted signal).
Transmitter Receiver
wired communication
t10
5v
2.5v
t
Noise of 0.2v is added
Analog Communication
2.7v
Digital Communication
V(t)
tt10
5v
2.5v
2.75v
1.25v
increasing the levels to 4, so(
5/4=1.25)
At time t1, voltage is equal to
2v, whereas allowed signal
voltages are 1.25v, 2.5v ,3.75v
& 5v
Therefore V(t1)=2.5v, so error
voltage=0v
