TO COMMUNICATION SYSTEM:
is the process of establishing connection (or link) between two points for
Science of Communications involving long distances is called Telecommunication
( the world Tele standing for long distance)
The Two basic types of
communication systems are
In Analog Systems: Both
the information and the carrier are analog signals.
Digital Systems: The digital pulses are transferred between two or more points
in a communication system.
modulation systems or techniques in which one of the characteristics of the
carrier is changed in proportion with the instantaneous value of modulating
signal is called analog communication system.
Advantages of Analog
Transmitters and Receivers are simple
Low bandwidth requirement
FDM can be used
Disadvantages of analog
Noise affects the signal quality
It is not possible to separate noise and
Repeaters can‘t be used between
Coding is not possible
It is not suitable for the transmission
of secret information
Fig: Block diagram of a
general communication system
Drawbacks of Baseband
Transmission (without Modulation)
Excessively large antenna heights.
Signals get mixed up.
Short range of communication.
Multiplexing is not possible.
Poor quality of reception.
The above drawbacks can
be overcome by means of modulation techniques: