Electrical Communications Systems 0909.331.01 Spring 2005

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Electrical Communications Systems0909.331.01
Spring 2005
Lecture 1aJanuary 18, 2005

• Shreekanth Mandayam
• ECE Department
• Rowan University
• http//engineering.rowan.edu/shreek/spring05/ecom
  ms/

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Plan

• Why are we studying ECOMMS?
• Technology successes, Trends and Decisions
• What is a communications system?
• Objectives
• Block diagram
• What limits our ability to communicate?
• Fundamental limits - Shannons Theorem
• Wireless comm evolution
• What are we studying in this course?
• Course logistics
• ECOMMS Readiness QUIZ, next Monday!

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Telecomm Trends
http//money.cnn.com/2003/12/12/markets/yir_biglos
ers03/index.htm
http//money.cnn.com/2003/12/23/markets/yir_bigwin
ners03/index.htm
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Telecomm Trends (continued)
http//money.cnn.com/2004/12/17/markets/yir04_mark
ets/
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Tech Success
Basic Features 1.2 megapixel camera with flash
Record and Send 15 second videos Connectivity
via Bluetooth 500 Phone Book Entries
Speakerphone Personal Organizer Voice
Activated Dialing Meets FCC SAR limit.
Manufacturer's highest FCC reported SAR 1.40 at
ear, 1.07 on body. Actual SAR may vary.
Supported Optional Features Video PIX
Messaging GET IT NOW TXT Messaging Picture
Messaging Internet Ready NationalAccess
Motorola V710
http//www.verizonwireless.com/
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(No Transcript)
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http//www.esa.int/SPECIALS/Cassini-Huygens/
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Decisions, decisions..

• I live in the Philadelphia metro area. What
  cell-phone carrier should I choose?
• Verizon wireless, Cingular, Spring PCS, ATT?
• Im designing the next generation microprocessor.
  Its going to be connected to Internet2. How do I
  design the right size the memory buffer?
• Im designing the remote navigation for the Mars
  Rover. Whats the right bandwidth/data rate for
  control signal transmission?

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What is a communications system?

• Communications Systems Systems designed to
  transmit and receive information

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Block Diagram
Info Sink
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What limits our ability to communicate?

• NOISE!!!!!
• Noise an unwanted, random fluctuation in the
  signal
• Without the effects of noise, a message with
  infinitesimally small power could be transmitted
  over infinitely large distances
• ALL advances in communications technology are
  advances to combat the effects of noise

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Fundamental Limit Shannons Theorem (1948,1949)

• Theoretical limit for error-free transmission in
  a communications system in the presence of noise
• Source Data Rate R bits/sec
• Channel Capacity
• C B log2(1 S/N) bits/sec
• R lt C No Error!!!

http//www.bell-labs.com/news/2001/february/26/1.h
tml
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Wireless Comm Evolution UMTS (3G)
http//www.3g-generation.com/ http//www.nttdocomo
.com/reports/010902_ir_presentation_january.pdf
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Evolution
TECHNOLOGY FEATURES
1-G Late 1970s, early 1980s AMPS Advanced Mobile Phone Service -Analog voice service - No data service
2-G 1990s CDMA Code Division Multiple Access TDMA Time Division Multiple Access GSM Global System for Mobile Communications PDC Personal digital cellular Digital voice service - 9.6K to 14.4K bit/sec. - CDMA, TDMA and PDC offer one-way data transmissions only - Enhanced calling features like caller ID - No always-on data connection
3-G 2000 and beyond W-CDMA Wide-band Code Division Multiple Access CDMA-2000 Based on the Interim Standard-95 CDMA standard TD-SCDMA Time-division synchronous CDMA - Superior voice quality - Up to 2M bit/sec. always-on data - Broadband data services like video and multimedia - Enhanced roaming
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And theres more.
Joseph M. Nowack, http//www.jacksons.net/tac/
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ECOMMS What are we studying?
Electrical Communications Systems

• Communications protocols

• Measures of information and noise
• Capacities for information transmission

• Design of communications systems
• Measures of performance

• Communications circuits

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ECOMMS Topics
Noise
Wire/wireless
Antennas/ Coupling
Demodulation circuits and systems DSP
Antennas/ Coupling
Modulation circuits and systems DSP
Analog/digital
Protocols
Fundamental limits
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ECOMMS Details
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ECOMMS Course Logistics
http//engineering.rowan.edu/shreek/spring05/ecom
ms/
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ECOMMS Readiness Quiz

• NEXT MONDAY, Jan 24, 1240 PM
• Room 204/206
• CLOSED Book and Notes
• Topics
• Complex algebra, Phasors, Fourier Series, AC
  Circuits
• BRING YOUR CALCULATOR!

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Summary