by Modulation is a process of conversion of one form of signal to another form such that the modulated signal is suitable for transmission.
There are three types of modulation.
- AM
- FM
- PM
A signal has three main properties: Amplitude, Frequency, and Phase.
Modulation is the process of changing the properties of the carrier signal with the help of modulating signal (Message signal).
The resulting signal after the modulation is called modulated signal.
Following are the reason to require modulation.
To reduce the size of the Antenna ( λ = c/f )
To reduce interference ( by separating same frequency message to different frequencies)
To allow Multiplexing of a signal. (example Dish Home, one wire has many channels)
