Elements of Communication System

• Communication is the act of transmission of information.

• Communication system has three essential elements − transmitter, medium/channel, and receiver.

• Receiver and transmitter are located at different places and the channels connect them.

• Transmitter converts the message signal produced by the source of information into a form suitable for transmission through the channel.

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Some important terms

• Transducer − It converts one form of energy into another.

• Signal − It is information converted into electrical forms, which is suitable for transmission.

• Noise − It refers to the unwanted signal that tends to disturb the transmission and processing of message signal in a communication system.

• Transmitter − It processes the incoming message signal and makes it suitable for transmission through a channel to the receiver.

• Receiver − It extracts the desired message signal from the received signal at the output of the channel.

• Attenuation − It is the loss of strength of a signal while propagating through a medium.

• Amplification − It is the process of increasing the amplitude of a signal using an electronic circuit called the amplifier.

• Range − It is the largest distance between a source and a destination up to which the signal is received with sufficient strength.

• Bandwidth − It is the portion of the spectrum occupied by the signal.

• Modulation − It is a process of superimposing a high frequency wave (carrier) on the low frequency message/ information signal, which cannot be transmitted to long distance without the help of the carrier.

• Demodulation − It is the process of retrieval of information from the carrier wave at the receiver.

• Repeater − It is a combination of receiver and a transmitter. It is used to extend the range of a communication system.