In telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment (DTE) usually capable of interconnection and interoperation to form an integrated whole. The components of a communications system serve a common purpose, are technically compatible, use common procedures, respond to controls, and operate in union. Telecommunications is a method of communication (e.g., for sports broadcasting, mass media, journalism, etc.). A communications subsystem is a functional unit or operational assembly that is smaller than the larger assembly under consideration.

1. COMMUNICATIONS SYSTEMS
By Ruthvik Gautham
BASIC
ELECTRONICS

2. Output
message
Input
message
Input
Transducer
Transmitter Channel Receiver
Output
Transducer
Basic Block Diagram of Communication
System

3. 5 BASIC COMPONENTS
Every communication system has 5 basic requirements
•Data Source (where the data originates)
•Transmitter (device used to transmit data)
•Transmission Medium (cables or non cable)
•Receiver (device used to receive data)
•Destination (where the data will be placed)

4. MODULATION
In electronics and telecommunications, modulation is the process of varying one
or more properties of a periodic waveform, called the carrier signal (high frequency
signal), with a modulating signal that typically contains information to be
transmitted.
In telecommunications, modulation is the process of conveying a message signal,
for example a digital bit stream or an analog audio signal, inside another signal
that can be physically transmitted. Modulation of a sine waveform transforms
a baseband message signal into a passband signal.
A modulator is a device that performs modulation.
A demodulator (sometimes detector or demod) is a
device that performsdemodulation, the inverse of
modulation.
A modem (from modulator–demodulator) can perform
both operations.

5. NEED FOR MODULATION
To overcome SHORT operating range
To overcome POOR radiation efficiency
To overcome Mutual Interference
To overcome Antenna Length Requirement

6. Amplitude Modulation
Amplitude modulation (AM) is a modulation technique used in electronic
communication, most commonly for transmitting information via
a radio carrier wave. AM works by varying the strength (amplitude) of the
carrier in proportion to the waveform being sent.

7. The equation for fAM(t) can be rearranged to look like:
EQUATIONS

8. FREQUENCY MODULATION
In telecommunications and signal processing, frequency
modulation (FM) is the encoding of information in a carrier wave by
varying the instantaneous frequency of the wave. (Compare
with amplitude modulation, in which the amplitude of the carrier wave
varies, while the frequency remains constant.)

11. Radiotelephone
A radiotelephone is a communications system for transmission of speech
over radio.

12. Radio Telegraphy
Wireless telegraphy is electric telegraphy that does not have wires
connecting the endpoints. Wireless telegraphy came to mean Morse
code transmitted with electromagnetic waves, initially called "Hertzian
waves" and by 1910 universally referred to as "radio",[3] leading to
these systems being called "radiotelegraphy".

13. Superheterodyne receiver
In electronics, a superheterodyne receiver (often shortened
to superhet), uses frequency mixing to convert a received signal to a
fixedintermediate frequency (IF), which can be more conveniently
processed than the original radio carrier frequency. It was invented by
US engineer Edwin Armstrong in 1918 during World War I.

14. THANK YOU