ANALOG COMMUNICATION BASICS

The word communication arises from the Latin word commūnicāre, which means “to share”. Communication is the basic step for exchange of information.

For example, a baby in a cradle, communicates with a cry when she needs her mother. A cow moos loudly when it is in danger. A person communicates with the help of a language. Communication is the bridge to share.

Communication can be defined as the process of exchange of information through means such as words, actions, signs, etc., between two or more individuals.

Parts of a Communication System

Any system, which provides communication consists of the three important and basic parts as shown in the following figure.

• Sender is the person who sends a message. It could be a transmitting station from where the signal is transmitted.
• Channel is the medium through which the message signals travel to reach the destination.
• Receiver is the person who receives the message. It could be a receiving station where the transmitted signal is being received.

Types of Signals

Conveying an information by some means such as gestures, sounds, actions, etc., can be termed as signaling. Hence, a signal can be a source of energy which transmits some information. This signal helps to establish a communication between the sender and the receiver.

An electrical impulse or an electromagnetic wave which travels a distance to convey a message, can be termed as a signal in communication systems.

Depending on their characteristics, signals are mainly classified into two types: Analog and Digital. Analog and Digital signals are further classified, as shown in the following figure.

Analog Signal

A continuous time varying signal, which represents a time varying quantity can be termed as an Analog Signal. This signal keeps on varying with respect to time, according to the instantaneous values of the quantity, which represents it.