Loading in 2 Seconds...
Loading in 2 Seconds...
Electrical Communications Systems ECE.09.331 Spring 2007. Lecture 1a January 16, 2007. Shreekanth Mandayam ECE Department Rowan University http://users.rowan.edu/~shreek/spring07/ecomms/. Plan. Why are we studying ECOMMS? Technology successes, Trends and Decisions
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Electrical Communications SystemsECE.09.331Spring 2007 Lecture 1aJanuary 16, 2007 Shreekanth Mandayam ECE Department Rowan University http://users.rowan.edu/~shreek/spring07/ecomms/
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 - Shannon’s Theorem • Wireless comm evolution • What are we studying in this course? • Course logistics • ECOMMS Readiness QUIZ, next Monday!
Telecomm Trends (2003) http://money.cnn.com/2003/12/12/markets/yir_biglosers03/index.htm http://money.cnn.com/2003/12/23/markets/yir_bigwinners03/index.htm
Telecomm Trends (2004) http://money.cnn.com/2004/12/17/markets/yir04_markets/
Telecomm Trends (2005) http://money.cnn.com/2005/06/20/markets/halfyear/index.htm
Telecomm Trends (2006) 2006: Tech winners and losers The best and worst tech performers in the S&P 500 this year. By Grace Wong, CNNMoney.com staff writer December 14 2006: 12:02 PM EST NEW YORK (CNNMoney.com) -- Nvidia tops the list for best performing tech stock in the S&P 500 this year. With a gain of 98 percent as of Wednesday, the graphics chip maker led the winners in 2006. More on tech's biggest winners and losers Software companies Cognizant Technology Solutions (Charts) and BMC Software (Charts) are also among the top 5 performing stocks - as is heavyweight Cisco Systems (Charts), which has climbed 59 percent so far this year. On the other end of the spectrum, chipmaker AMD (Charts) has struggled as has Internet giant Yahoo (Charts). The worst performing tech stock of the year? ADC Telecommunications (Charts), which is down 35 percent in 2006. http://money.cnn.com/2006/12/14/technology/winners_losers/index.htm?postversion=2006121412
Communications: Where are we? 4GW? 1975 2007
Video/Camera 1.3 Megapixel Camera 2.2" 176 x 220 internal screen 65K TFT color display 1.0" 9 6 x 80 external 65K CSTN color display Video Resolution: 176x144 Camera Resolutions: 160x120, 320x240, 640x480, 1280x1024 Mobile Media VCAST Music and Video Service Mobile Web 2.0 Mobile Instant Messaging (IM) Picture and Video Messaging Service (MMS) Two-Way Text Messaging Service (SMS)Data & Text Up to 11 lines text Voice/Audio Advanced Speech Recognition Integrated speakerphone General Bluetooth Capable (v1.1) Supports the Headset, Handsfree Serial Port and Dial Up Networking Profiles. BroadbandAccess Connect microSD removable memory aGPS capable for E911 emergency location Specifications 1.9 GHz CDMA PCS I 800 MHz CDMA Dimensions: 3.86 x 2.08 x 0.57 inches Weight: 3.49 oz Battery: 780 mAH Li-Ion SAR: Ear-1.14 , Body - 1.56 Usage Time: Up to 200 Minutes OR Standby Time: Up to 325 Hours For the consumer Motorola Razr V325i
Decisions, decisions….. • I live in the Philadelphia metro area. What cell-phone carrier should I choose? • Verizon, Cingular, T-Mobile, ……? • I’m designing the next generation microprocessor. It’s going to be connected to Internet2. How do I design the right size the memory buffer? • I’m designing the remote navigation for the Mars Rover. What’s the right bandwidth/data rate for control signal transmission?
Info Sink Info Source Comm System What is a communications system? • Communications Systems: Systems designed to transmit and receive information
Info Source m(t) message from source n(t) noise Receiver Rx Transmitter Tx Channel received message to sink s(t) transmitted signal r(t) received signal Block Diagram Info Sink
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
Fundamental Limit: Shannon’s 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 < C: No Error!!!
Mars Orbiter (Odyssey/Mars Global Surveyer) 12k – 3.5k bps DSN Antenna (on Earth) X-Band 128 kbps Mars Rover (Spirit/Opportunity)
Wireless Comm Evolution: UMTS (3G) http://www.3g-generation.com/ http://www.nttdocomo.com/reports/010902_ir_presentation_january.pdf
And there’s more…. Joseph M. Nowack, http://www.jacksons.net/~tac/
Hardware dependent Hardware INdependent 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
Receiver Rx Transmitter Tx Channel m(t) s(t) r(t) ECOMMS: Topics Noise Wire/wireless Antennas/ Coupling Demodulation circuits and systems DSP Antennas/ Coupling Modulation circuits and systems DSP Analog/digital Protocols Fundamental limits
ECOMMS: Course Logistics http://users.rowan.edu/~shreek/spring07/ecomms/
ECOMMS Readiness Quiz NEXT MONDAY, Jan 22, 12:40 PM Room 204/206 CLOSED Book and Notes Topics: Complex algebra, Phasors, Fourier Series, AC Circuits BRING YOUR CALCULATOR!