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ECE 4371, Fall, 2014
Introduction to Telecommunication Introduction to Telecommunication EngineeringEngineering
Zhu Han
Department of Electrical and Computer Engineering
Class 1
Aug. 25nd, 2014
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 2 W302 Office hours: Mon. 10am-2:00pm, Other time including
weekend by appointment Email: [email protected] or [email protected] 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
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:
Modern Digital and Analog Communication Systems, Lathi and Ding
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
Homework, Project, and ExamHomework, Project, and Exam
Homework 3-4 questions per week
Projects: simple MATLAB programs Based on the simulation at the end of each chapter
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 REU
ECE 4371
Chapter 1: Communication SystemChapter 1: Communication System
A B
Engineering System
Genetic System
Social System
History and fact of communication
ECE 4371
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
ECE 4371
TelecommunicationTelecommunication Telegraph
Fixed line telephone
Cable
Wired networks
Internet
Fiber communications
Communication bus inside computers to communicate between CPU and memory
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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
ADC/DACADC/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 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 1.6 page 12
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
MultiplexingMultiplexing Space-division multiplexing
Frequency-division multiplexing
Time-division multiplexing
Code-division multiplexing
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
History of TelecommunicationHistory 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 TelecommunicationHistory 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
SummarySummary 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
