Essential Elements of a Communication System

A communication system allows people to send/receive data and information. Examples of a communication system are telephone, radio, television and computer. Nowadays, communication systems are much depended on through out the world.
Communication systems generally consist of 5 basic components:
*Data source - Produces data being sent.
*Transmitter - Encodes data in to a signal compatible with a 'transmission medium'.
*Transmission Medium - Channel which the signal transmits to the destination.
*Receiver - Decodes the signal back to its original data.
*Destination - Receiver of the information.
The purpose of a communication system is to transmit intelligence signal from a source to a destination at some point away from the source.

Before we can send a message signal over the communication channel, we need to modify the message signal into a form that is suitable for transmission over a channel. We called this process of modifying message signal as modulation. This modulation process involves changing some parameters of a carrier wave in accordance with the message signal so the resultant wave will match the communication channel's bandwidth. In order to recover the message signal, the receiver of the communication system will have to go through the demodulation process, which is the inverse of the modulation process.

Here is an example of a communication system: