EE 551451, Fall, 2006 Communication Systems

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EE 551/451, Fall, 2006Communication Systems

• Zhu Han
• Department of Electrical and Computer Engineering
• Class 1
• Aug. 22nd, 2006

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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
• Chapter 1

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Instructor Information

• Office location MEC 202B
• Office hours Wed. 130pm -400pm
• Email zhuhan_at_boisestate.edu
• Phone ??
• Course website ??
• Research interests
• Wireless Networking and Resource Allocation

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Motivations

• Recent Development
• Satellite Communications
• Telecommunication Internet boom at the end of
  last decade
• Wireless Communication next boom?
• Job Market
• Probably one of most easy and high paid majors
  recently
• Intel changes to wireless, Micron will follow?
  Cypress
• Research Potential
• One to one communication has less room to go, but
  multiuser communication is still an open issue.

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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?

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Textbook and Software

• Require textbook
• B.P. Lathi, Modern Digital and Analog
  Communication Systems, 3rd edition, Oxford
  University Press, 1998
• 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

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Schedule

• Analog communication systems
• 8/229/28 chapter 2,3,4,5,6,12
• Theory for communications (minimal depth, not
  required)
• Theory of probability, random process chapter
  10, 11
• Estimation and detection chapter 14
• Information theory chapter 15
• Error correct coding chapter 16
• Technique of digital communications
• Principle of digital transmission 10/311/16
  chapter 7,8,13
• Digital communication standards 11/28, 11/30
  (video)
• Recent development 12/5, 12/7 chapter 9 and
  others

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Homework, Project, and Exam

• Homework
• 2 questions per week for undergraduate, 34 for
  graduate
• Projects simple MATLAB programs
• AM/FM Modulation
• BPSK Modulation (undergraduate), BPSK/MQAM
  (graduate)
• Term paper
• If interviewed for a xxx company, what should you
  know (under)
• For research on xxx, what is the state-of-art
  (graduate)
• Exams
• Two exams for analog and digital parts,
  respectively, Free questions
• Votes for the percentages for homework, projects,
  and exams
• Participations
• Attendance and Feedback

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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, English,

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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

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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

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Questions?
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Chapter 1 Communication System
History and fact of communication
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Telecommunication

• 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 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

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Analog 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

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A/D and D/A

• Analog to Digital conversion Digital to Analog
  conversion
• Gateway from the communication device to the
  channel
• Nyquist Sampling theorem
• From time domain If the highest frequency in the
  signal is B Hz, the signal can be reconstructed
  from its samples, taken at a rate not less than
  2B samples per second

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A/D and D/A

• Quantization
• From amplitude domain
• N bit quantization, L intervals L2N
• Usually 8 to 16 bits
• Error Performance Signal to noise ratio, 6 dB
  per bit

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Communication System Components
transmitter
Source Coder
Channel Coder
Modulation
D/A
Source input

Distortion and noise
channel
Reconstructed Signal output
Source decoder
Channel decoder
demodulation
A/D
receiver
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Source Coder

• Examples
• Digital camera encoder TV/computer decoder
• Camcorder
• Phone
• Theorem
• How much information is measured by Entropy
• More randomness, high entropy and more
  information

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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, Distortion, 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)

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Shannon Capacity

• Shannon Theory
• It establishes that given a noisy channel with
  information capacity C and information
  transmitted at a rate R, then if RltC, 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 RgtC, 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

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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)

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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

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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

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Summary

• Course Descriptions
• Communication System Structure
• Basic Block Diagram
• Analog or Digital
• Nyguist Theorem, AD/DA
• Entropy to measure the quantity of information
• Shannon Capacity
• Spectrum Allocation
• Homework
• Identify the frequencies of the wireless devices
  around you.
• Name the communication companies that you want to
  work with. What are they doing and why you think
  they will success
• Check the industry expo exhibitions websites for
  more information
• 2 page paper due in two weeks due 9/5/06

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OSI Model
Open Systems Interconnections Course offered
next semester