ECE4371_class1

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ECE 4371, Fall, 2014
Introduction to Telecommunication
Engineering
Zhu Han
Department of Electrical and Computer Engineering
Class 1
Aug. 25nd, 2014
Outline

Instructor information

Motivation to study communication systems

Course descriptions and textbooks

What you will study from this course

Objectives

Coverage and schedule

Homework, projects, and exams

Other policies

Reasons to be my students

Background and Preview
ECE 4371
Instructor Information

Office location: Engineering 2 W302

Office hours: Mon. 10am-2:00pm, Other time including
weekend by appointment

Email: zhan2@uh.edu or hanzhu22@gmail.com


Phone: 713-743-4437(o), 301-996-2011(c)
Course website:
http://www2.egr.uh.edu/~zhan2/ECE4371/ECE4371_4117.html

No TA for 4117. My students and I will be your TA 

Research interests:
Wireless Networking, Signal Processing, and Security
http://wireless.egr.uh.edu/
ECE 4371
Motivations

Recent Development
– Satellite Communications
– Telecommunication: Internet boom at the end of last decade
– Wireless Communication: next boom? iPhone

Job Market
– Probably one of most easy and high paid majors recently
– Intel changes to wireless,
– Qualcom, Broadcom, TI, Marvell, Cypress

Research Potential
– One to one communication has less room to go, but
multiuser communication is still an open issue.
– Wimax, 3G, next generation WLAN
ECE 4371
Course Descriptions

What is the communication system?

What are the major types?

Analog or Digital

Satellite, Fiber, Wireless…

What are the theorems?

What are the major components?

How is the information transmitted?

What are the current industrial standards?

What are the state-of-art research?

Can I find a job by studying this course?

Can I find research topics?
ECE 4371
Textbook and Software

Require textbook:
Modern Digital and Analog Communication Systems, Lathi and Ding

Require Software: MATLAB
http://www.mathworks.com/ or type helpwin in Matlab environment

Recommended readings

Digital communications: J. Proakis, Digital Communications

Random process: G.R. Grimmett and D.R. Stirzaker, Probability and
Random Processes

Estimation and detection: H.V. Poor, An introduction to Signal
Detection and Estimation

Information theory: T. M. Cover and J. A. Thomas, Elements of
Information Theory

Error correct coding: P. Sweeney, Error Control Coding
ECE 4371
Homework, Project, and Exam

Homework


Projects: simple MATLAB programs



3-4 questions per week
Based on the simulation at the end of each chapter
Exams
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Three independent exams
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Votes for the percentages for homework, projects, and exams
Participations

Attendance and Feedback

Quiz if the attendance is low
ECE 4371
Teaching Styles



Slides plus black board

Slides can convey more information in an organized way

Blackboard is better for equations and prevents you from
not coming.
Course Website

Print handouts with 3 slides per page before you come

Homework assignment and solutions

Project descriptions and preliminary codes
Feedback

Too fast, too slow

Presentation, Writing, English, …
ECE 4371
Other Policies
Any violation of academic integrity will receive academic and
possibly disciplinary sanctions, including the possible awarding
of an XF grade which is recorded on the transcript and states that
failure of the course was due to an act of academic dishonesty.
All acts of academic dishonesty are recorded so repeat offenders
can be sanctioned accordingly.
• CHEATING
• COPYING ON A TEST
• PLAGIARISM
• ACTS OF AIDING OR ABETTING
• UNAUTHORIZED POSSESSION
• SUBMITTING PREVIOUS WORK
• TAMPERING WITH WORK
• GHOSTING or MISREPRESENTATION
• ALTERING EXAMS
• COMPUTER THEFT
ECE 4371
Reasons to be my students

Wireless Communication and Networking have great market

Usually highly paid and have potential to retire overnight

Highly interdisciplinary

Do not need to find research topics which are the most difficult
part.

Research Assistant

Free trips to conferences in Alaska, Hawaii, Europe, Asia…

A kind of nice (at least looks like)

Work with hope and happiness

Graduate fast

REU
ECE 4371
Chapter 1: Communication System
B
A
Engineering System
Social System
Genetic System
History and fact of communication
ECE 4371
Communication System Components
transmitter
Source
Coder
Source
input
channel
Reconstructed
Signal
output
Source
decoder
receiver
ECE 4371
Channel
Coder
Modulation
Distortion and noise
Channel
decoder
demodulation
D/A
+
A/D
Communication Process

Message Signal

Symbol

Encoding

Transmission

Decoding

Re-creation

Broadcast

Point to Point
ECE 4371
Telecommunication

Telegraph

Fixed line telephone

Cable

Wired networks

Internet

Fiber communications

Communication bus inside computers to communicate
between CPU and memory
ECE 4371
Wireless Communications

Satellite

TV

Cordless phone

Cellular phone

Wireless LAN, WIFI

Wireless MAN, WIMAX

Bluetooth

Ultra Wide Band

Wireless Laser

Microwave

GPS

Ad hoc/Sensor Networks
ECE 4371
Analog or Digital


Common Misunderstanding: Any transmitted signals are
ANALOG. NO DIGITAL SIGNAL CAN BE TRANSMITTED
Analog Message: continuous in amplitude and over time
–
–
–
–

Digital message: 0 or 1, or discrete value
–
–
–
–

AM, FM for voice sound
Traditional TV for analog video
First generation cellular phone (analog mode)
Record player
VCD, DVD
2G/3G cellular phone
Data on your disk
Your grade
Digital age: why digital communication will prevail
ECE 4371
ADC/DAC

Analog-to-Digital Conversion (ADC) and Digital-to-Analog
Conversion (DAC) are the processes that allow digital
computers to interact with these everyday signals.

Digital information is different from its continuous counterpart
in two important respects: it is sampled, and it is quantized
ECE 4371
Source Coder

Examples
– Digital camera: encoder;
TV/computer: decoder
– Camcorder
– Phone
– Read the book

Theorem
– How much information is
measured by Entropy
– More randomness, high
entropy and more information
ECE 4371
Channel, Bandwidth, Spectrum

Bandwidth: the number of bits per second is proportional to B
http://www.ntia.doc.gov/osmhome/allochrt.pdf
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Power, Channel, Noise
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Transmit power
– Constrained by device, battery, health issue, etc.

Channel responses to different frequency and different time
– Satellite: almost flat over frequency, change slightly over time
– Cable or line: response very different over frequency, change
slightly over time.
– Fiber: perfect
– Wireless: worst. Multipath reflection causes fluctuation in
frequency response. Doppler shift causes fluctuation over time

Noise and interference
– AWGN: Additive White Gaussian noise
– Interferences: power line, microwave, other users (CDMA phone)
ECE 4371
Shannon Capacity

Shannon Theory
– It establishes that given a noisy channel with information capacity C and
information transmitted at a rate R, then if R<C, there exists a coding
technique which allows the probability of error at the receiver to be made
arbitrarily small. This means that theoretically, it is possible to transmit
information without error up to a limit, C.
– The converse is also important. If R>C, the probability of error at the
receiver increases without bound as the rate is increased. So no useful
information can be transmitted beyond the channel capacity. The theorem
does not address the rare situation in which rate and capacity are equal.

Shannon Capacity
C  B log2 (1  SNR) bit / s
ECE 4371
Modulation

Process of varying a carrier signal
in order to use that signal to
convey information
– Carrier signal can transmit far
away, but information cannot
– Modem: amplitude, phase, and
frequency
– Analog: AM, amplitude, FM,
frequency, Vestigial sideband
modulation, TV
– Digital: mapping digital
information to different
constellation: Frequency-shift
key (FSK)
ECE 4371
Example
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Figure 1.6 page 12

Modulation over carrier fc
s(t)=Accos(2fct) for symbol 1; -Accos(2fct) for symbol 0

Transmission from channel
x(t)=s(t)+w(t)

Correlator
 0.5 Ac  wT , for sym bol1
yT   x(t ) cos(2f ct )dt  
 0.5 Ac  wT , for sym bol0
0
T

Decoding
– If the correlator output yT is greater than 0, the receiver output
symbol 1; otherwise it outputs symbol 0.
ECE 4371
Channel Coding

Purpose
– Deliberately add redundancy to the transmitted information, so
that if the error occurs, the receiver can either detect or correct it.

Source-channel separation theorem
– If the delay is not an issue, the source coder and channel coder can
be designed separately, i.e. the source coder tries to pack the
information as hard as possible and the channel coder tries to
protect the packet information.

Popular coder
–
–
–
–
Linear block code
Cyclic codes (CRC)
Convolutional code (Viterbi, Qualcom)
LDPC codes, Turbo code, 0.1 dB to Channel Capacity
ECE 4371
Quality of a Link (service, QoS)

Mean Square Error
1 N ˆ
MSE   | X i  X i |2
N i 1

Signal to noise ratio (SNR)

–
–
–
–
–

Prec

2

PtxG
2
Bit error rate
Frame error rate
Packet drop rate
Peak SNR (PSNR)
SINR/SNIR: signal to noise plus interference ratio
Human factor
ECE 4371
Multiplexing

Space-division multiplexing

Frequency-division multiplexing
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Time-division multiplexing

Code-division multiplexing
ECE 4371
Communication Networks

Connection of 2 or more distinct (possibly dissimilar) networks.

Requires some kind of network device to facilitate the
connection.

Internet
Net A
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Net B
Broadband Communication
ECE 4371
OSI Model
Open Systems Interconnections; Course offered next semester
ECE 4371
TCP/IP Architecture
• TCP/IP is the de facto
global data
communications standard.
• It has a lean 3-layer
protocol stack that can be
mapped to five of the
seven in the OSI model.
• TCP/IP can be used with
any type of network, even
different types of networks
within a single session.
ECE 4371
History of Telecommunication

Table 1.1 page 17
– Prehistoric: Fires, Beacons, Smoke signals
– 6th century BC: Mail
–
–
–
–
5th century BC: Pigeon post
4th century BC: Hydraulic semaphores
490 BC: Heliographs
15th century AD: Maritime flags
– 1790 AD: Semaphore lines
– 19th century AD: Signal lamps
ECE 4371
History of Telecommunication

Audio signals:
– Prehistoric: Communication drums, Horns
– 1838 AD: Electrical telegraph. See: Telegraph history.
– 1876: Telephone. See: Invention of the telephone, History of the telephone,
Timeline of the telephone
– 1880: Photophone
– 1896: Radio. See: History of radio.

Advanced electrical/electronic signals:
–
–
–
–
–
1927: Television. See: History of television
1930: Videophone
1964: Fiber optical telecommunications
1969: Computer networking
1981: Analog cellular mobile phones
– 1982: SMTP email
– 1983: Internet. See: History of Internet
– 1998: Satellite phones
ECE 4371
Summary

Course Descriptions

Chapter 1: Communication System Structure
– Basic Block Diagram
– Typical Communication systems
– Analog or Digital
– Entropy to Measure the Quantity of Information
– Channels
– Shannon Capacity
– Spectrum Allocation
– Modulation
– Communication Networks

Question on Chapter 2: Signals and signal space
ECE 4371
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