ECE 4371, Fall, 2009

Introduction to Telecommunication Introduction to Telecommunication EngineeringEngineering

Zhu Han

Department of Electrical and Computer Engineering

Class 1

Aug. 25nd, 2009

                                                           

                                                           

ECE 4371

OutlineOutline

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 InformationInstructor Information

Office location: Engineering 1 N324 Office hours: Mon. 2:00pm-5:00pm, Other time including

weekend by appointment Email: zhan2@mail.uh.edu Phone: 713-743-4437(o), 301-996-2011(c) Course website:

http://www.egr.uh.edu/Courses/ECE/ECE4371/ECE4371.htmlhttp://www.egr.uh.edu/Courses/ECE/ECE4371/ECE4117.html

TA: Zhou Yuan, talentyz@gmail.com Research interests:

Wireless Networking, Signal Processing, and Security

http://wireless.egr.uh.edu/

                                                           

ECE 4371

MotivationsMotivations

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 DescriptionsCourse 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 SoftwareTextbook and Software

Require textbook:

Simon Haykin, Communication Systems, 4th edition, John Wiley and Sons, Inc.

Require Software: MATLABhttp://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

ScheduleSchedule

•8/22: background and preview•8/28 ~9/2: Chapter 1•9/4-9/18: Chapter 2•9/23-10/2: Chapter 3•10/7: Midterm 1 (Chapter 0-Chapter 3)•10/9-10/21: Chapter 4•10/23-10/30: Chapter 5•11/4-11/9: Chapter 6•11/13-11/25: Chapter 7•11/27: Midterm 2 (Chapter 4-Chapter 6)•12/2-12/4: Chapter 8•12/9-12/11: Chapter 10•Final Exam (Chapter 7, 8, 10)

                                                           

ECE 4371

Homework, Project, and ExamHomework, Project, and Exam

Homework 2 questions per week for undergraduate, 3~4 for graduate

Projects: simple MATLAB programs AM/FM Modulation BPSK Modulation (undergraduate), BPSK/MQAM (graduate) USRP2/GnuRadio if the hardware will be ready.

Exams Three independent exams Votes for the percentages for homework, projects, and exams

Participations Attendance and Feedback Quiz if the attendance is low

                                                           

ECE 4371

Teaching StylesTeaching 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 PoliciesOther 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 studentsReasons 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

                                                           

ECE 4371

Communication SystemCommunication System

A B

Engineering System

Genetic System

Social System

History and fact of communication

                                                           

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Communication System ComponentsCommunication System Components

SourceCoder

ChannelCoder

Modulation

+

Sourcedecoder

Channeldecoder

demodulation

Distortion and noise

transmitter

channel

receiver

Source input

ReconstructedSignal output

D/A

A/D

                                                           

ECE 4371

Communication ProcessCommunication Process Message Signal

Symbol

Encoding

Transmission

Decoding

Re-creation

Broadcast

Point to Point

                                                           

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TelecommunicationTelecommunication Telegraph

Fixed line telephone

Cable

Wired networks

Internet

Fiber communications

Communication bus inside computers to communicate between CPU and memory

                                                           

ECE 4371

Wireless CommunicationsWireless 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 DigitalAnalog or Digital Common Misunderstanding: Any transmitted signals are

ANALOG. NO DIGITAL SIGNAL CAN BE TRANSMITTED Analog Message: continuous in amplitude and over time

– AM, FM for voice sound– Traditional TV for analog video– First generation cellular phone (analog mode)– Record player

Digital message: 0 or 1, or discrete value– VCD, DVD– 2G/3G cellular phone– Data on your disk– Your grade

Digital age: why digital communication will prevail

                                                           

ECE 4371

Source CoderSource 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, SpectrumChannel, Bandwidth, Spectrum Bandwidth: the number of bits per second is proportional to B

http://www.ntia.doc.gov/osmhome/allochrt.pdf

                                                           

ECE 4371

Power, Channel, NoisePower, Channel, Noise 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 CapacityShannon 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

sbitSNRBC /)1(log2

                                                           

ECE 4371

ModulationModulation 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

ExampleExample Figure 10

Modulation over carrier fc

s(t)=Accos(2fct) for symbol 1; -Accos(2fct) for symbol 0

Transmission from channel

x(t)=s(t)+w(t)

Correlator

Decoding– If the correlator output yT is greater than 0, the receiver output

symbol 1; otherwise it outputs symbol 0.

0,5.0

1,5.0)2cos()(

0symbolforwA

symbolforwAdttftxy

Tc

TcT

cT

                                                           

ECE 4371

Channel CodingChannel 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)Quality of a Link (service, QoS) Mean Square Error

Signal to noise ratio (SNR)

– Bit error rate

– Frame error rate

– Packet drop rate

– Peak SNR (PSNR)

– SINR/SNIR: signal to noise plus interference ratio

Human factor

N

iii XX

NMSE

1

2|ˆ|1

22 GPP txrec

                                                           

ECE 4371

Communication NetworksCommunication Networks

Connection of 2 or more distinct (possibly dissimilar) networks.

Requires some kind of network device to facilitate the connection.

Internet

Net A Net B

                                                           

ECE 4371

Broadband CommunicationBroadband Communication

                                                           

ECE 4371

OSI ModelOSI Model

Open Systems Interconnections; Course offered next semester

                                                           

ECE 4371

TCP/IP ArchitectureTCP/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

SummarySummary Course Descriptions

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