1. Communication Systems Waseem Gulsher
BS Evening (Reg.)
10 Feb, 16
Introduction to Communication Systems
Lecture - 1
Communication Systems Waseem Gulsher

2. MS (Electronics) in progress from PAF-KIET
Waseem Gulsher
MS (Electronics) in progress from PAF-KIET
Contact:

3. Electronic Communication Systems
Recommended Text Book
Electronic Communication Systems
George Kennedy
Wyne Tomasi

4. Grading Midterm Paper Final Term Paper 25 10 5 50 100
Assignments
Quizzes
Class Participation
Attendance
Final
Total 25 10 5 50
100
Midterm Paper
Three out of five questions
Final Term Paper
Five out of Eight questions

5. Rules & Regulations
No need to take permission while entering or leaving the class during lecture.
There will be three assignments during semester and average of best two will be taken for sessional marks.
There will be five quizzes during semester and average of best four will be taken for sessional marks.
Assignments are to be submitted in a file / folder.

6. Rules & Regulations No marks will be given for copy work.
Assignments must be submitted within one week.
If assignment is submitted with one week delay, it will marked out of 5 marks instead of 10
No assignment will be accepted after 2 weeks.

7. Rules & Regulations All lectures will be delivered on multimedia.
Lectures (including assignments) will be on your addresses within 24 hours.
If not received, you can text me on my cell phone.
There will be no compromise on attendance in any case.

8. Introduction to Communication Systems

9. Significance of Human Communication
Communication is the process of exchanging information.
Main barriers are language and distance.
Contemporary society’s emphasis is now the accumulation, packaging, and exchange of information.

10. Significance of Human Communication
Methods of communication:
Face to face
Signals
Written word (letters)
Electrical innovations:
Telegraph
Telephone
Radio
Television
Internet (computer)

11. Communication Systems
Basic components:
Transmitter
Channel or medium
Receiver
Noise degrades or interferes with transmitted information.

12. Communication Systems
A general model of all communication systems.

13. Transmitter
The transmitter is a collection of electronic components and circuits that converts the electrical signal into a signal suitable for transmission over a given medium.
Transmitters are made up of oscillators, amplifiers, tuned circuits and filters, modulators, frequency mixers, frequency synthesizers, and other circuits.

14. Communication Channel
The communication channel is the medium by which the electronic signal is sent from one place to another.
Types of media include
Electrical conductors
Optical media
Free space
System-specific media (e.g., water is the medium for sonar).

15. Receiver
A receiver is a collection of electronic components and circuits that accepts the transmitted message from the channel and converts it back into a form understandable by humans.
Receivers contain amplifiers, oscillators, mixers, tuned circuits and filters, and a demodulator or detector that recovers the original intelligence signal from the modulated carrier.

16. Transceivers
A transceiver is an electronic unit that incorporates circuits that both send and receive signals.
Examples are:
Telephones
Fax machines
Handheld CB radios
Cell phones
Computer modems

17. Attenuation & Noise
Signal attenuation, or degradation, exists in all media of wireless transmission. It is proportional to the square of the distance between the transmitter and receiver.
Noise is random, undesirable electronic energy that enters the communication system via the communicating medium and interferes with the transmitted message.

18. Types of Electronic Communication
Electronic communications are classified according to whether they are
One-way (simplex) or two-way (full duplex or half duplex) transmissions
Analog or digital signals.

19. Simplex
The simplest method of electronic communication is referred to as simplex.
This type of communication is one-way. Examples are:
Radio
TV broadcasting
Beeper (personal receiver)

20. Full Duplex
Most electronic communication is two-way and is referred to as duplex.
When people can talk and listen simultaneously, it is called full duplex. The telephone is an example of this type of communication.

21. Half Duplex
The form of two-way communication in which only one party transmits at a time is known as half duplex. Examples are:
Police, military, etc. radio transmissions
Citizen band (CB)
Family radio
Amateur radio

22. Types of Electronic Communication
Analog Signals
An analog signal is a smoothly and continuously varying voltage or current. Examples are:
Sine wave
Voice
Video (TV)

23. Analog Signals Analog signals (a) Sine wave “tone.” (b) Voice.
(c) Video (TV) signal.

24. Types of Electronic Communication
Digital Signals
Digital signals change in steps or in discrete increments.
Most digital signals use binary or two-state codes. Examples are:
Telegraph (Morse code)
Continuous wave (CW) code
Serial binary code (used in computers)

25. Digital Signals
Figure 1-6: Digital signals (a) Telegraph (Morse code). (b) Continuous-wave (CW) code. (c) Serial binary code.

26. Thank You