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I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
1
ECE-321
INTRODUCTION 2 TELECOMMUNICATION
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
2
CONTENT
1
RF wave propagation.
Antennas for HF, VHF, UHF and
microwaves.
Noise in Communication Systems.
Link Budget Analysis.
Fundamentals of Radar Systems.
Fundamentals of Satellite Communications.
Fundamentals of Wireless Communications.
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
3
Weekly Calendar
1
Weekly Calendar of Lectures
Week Topics Remarks
1, 2 RF wave propagation
2, 3 Antennas for HF, VHF, UHF and microwaves
4 Noise in Communication Systems
5 Link Budget Analysis
6, 7, 8 Fundamentals of Radar Systems
9, 10, 11 Fundamentals of Satellite Communications
12 -15 Fundamentals of Wireless Communications
Final Exam
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
4
MARK DISTRIBUTION
1
LAB(SIM) LAB(EXP) HWs Attendance+ Participation Quiz Midterm Final Exam
10 10 10 10 10 20 30
Mark Distribution EE321
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
5
CHAP1
COMMUNICATION SYSTEM
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
6
source: originates a message
transmitter: converts the message into a signal that can be transmitted over a channel
Channel: transport of the signal over a certain medium (e.g. wire, optical fiber or a radio link)
Receiver: converts the received signal back into a readable message
destination: end user
I-THE BLOCK DIAGRAM
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
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Sources of Information
1. Voice Microphone
2. Image Camera
3. Data Computer
Electrical
Signal
Types of Channels
1. Free space wireless comm.
2. Cables
3. Optical fibers Wire Comm.
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
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2) Transmitter : Modifies the baseband signal for efficient
transmision. The transmitter consists on preamphizer, sampler,
Encoder, modulator and Amplifier
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
9
4) Transmission Medium Channel
Pair of copper wires
Coaxial cable
Radio link
Light in optical fiber
Light in air
Waveguide
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
10
1
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
11
II Transmission Impairments
The transmission signal is subjected to the following
undesirable effects created by the transmission channel
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
12
1. Noise
Is defined as random and unpredictable electrical signals
produced by natural processes both internal and external
to the system
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
13
External Noise
Man-made noise generated by contact
switches
Automobile ignition Radiation
Flurescent lights
Electrical Storms
Solar radiation
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
14
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
15
Internal Noise
Thermal motion of electrons in conductors
Random Emission diffusion or recombination of
charged carriers in electronic devices
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
16
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
17
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
18
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
19
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
20
Signal to Noise Ratio (SNR)
Signal Power
By definition SNR = -------------------------
Noise Power
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
21
2. Attenuation
Attenuation is defined as the reduction in the signal strength
as it travels along the transmission medium. It is also called
“ Transmission Loss”.
Attenuation is directly proportional to distance and frequecy
Rain and snow also increases attenuation where the atmosphere
used as a transmission medium.
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
22
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
23
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
24
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
25
3. Distortion
The waveform perturbation caused by the imperfect response
of the system is called distortion.
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
26
4. Interference
Interference results from the combination of or two or more signals
In the same frequency band.
As a result of interference, the signals sometimes add up to create a
more powerful signal and sometimes canal each other to create a
weaker signal
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
27
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
28
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
29
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
30
5) Receiver Reponses the signal from the channel by undoing
the signal modification made at the transmitter and the channel.
The receiver may consists on a Demodulator, a decoder a filter
a deemphasizer and an amplifier
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
31
6) destination The unit to which the message is communicated.
It can be the user , a computer .
The output signal is similar to the original input message.m
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
32
III -TRANSMISSION MODES
1. Baseband Transmission Mode
2. Passband (BroadBand)Transmission Mode
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
33
1. Baseband Transmission Mode
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
34
2. Passband (BroadBand)Transmission Mode
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
35
IV MODULATION Baseband signal produced by various information sources
are not always suitable for direct transmission over a given channel .
Therefore the baseband signal is used to modify some parameter
Of a high frequency carrier signal. This process is known as
Modulation
At the receiver the modulated signal must pass through a
receive process called “Demodulation” in order to obtain
The baseband signal
I – term 2013-2014 INTRO 2 TELECOM (EE321)
Prepared by : Dr. Lotfi LADHAR
36
Questions
TOGETHER WE CAN MAKE THE DIFFERENCE
KNOWLEGE IS A POWER
1