S. Mandayam/ ECOMMS/ECE Dept./Rowan University Electrical Communications Systems Spring 2005 Shreekanth Mandayam ECE Department Rowan University Lecture 1a January 18, 2005

S. Mandayam/ ECOMMS/ECE Dept./Rowan UniversityPlan 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!

S. Mandayam/ ECOMMS/ECE Dept./Rowan University Telecomm Trends arkets/yir_bigwinners03/index.htm rkets/yir_biglosers03/index.htm

S. Mandayam/ ECOMMS/ECE Dept./Rowan University Telecomm Trends (continued)

S. Mandayam/ ECOMMS/ECE Dept./Rowan University Motorola V710 Basic Features 1.2 megapixel camera with flash Record and Send 15 second videos Connectivity via BluetoothBluetooth 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.SAR Supported Optional Features Video & PIX Messaging GET IT NOW TXT Messaging Picture Messaging Internet Ready NationalAccess Tech Success Tech Success

S. Mandayam/ ECOMMS/ECE Dept./Rowan University

S. Mandayam/ ECOMMS/ECE Dept./Rowan University Decisions, decisions….. I live in the Philadelphia metro area. What cell-phone carrier should I choose? Verizon wireless, Cingular, Spring PCS, AT&T……? 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?

S. Mandayam/ ECOMMS/ECE Dept./Rowan University What is a communications system? Communications Systems: Systems designed to transmit and receive information Info Source Info Source Info Sink Info Sink Comm System

S. Mandayam/ ECOMMS/ECE Dept./Rowan University Block Diagram Receiver Rx received message to sink Transmitter Tx s(t) transmitted signal Channel r(t) received signal m(t) message from source Info Source Info Source Info Sink Info Sink n(t) noise

S. Mandayam/ ECOMMS/ECE Dept./Rowan University 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

S. Mandayam/ ECOMMS/ECE Dept./Rowan University 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 log 2 (1 + S/N) [bits/sec] R < C: No Error!!!

S. Mandayam/ ECOMMS/ECE Dept./Rowan University

Wireless Comm Evolution: UMTS (3G)

S. Mandayam/ ECOMMS/ECE Dept./Rowan UniversityEvolution TECHNOLOGYFEATURES 1-G Late 1970’s, early 1980’s AMPS Advanced Mobile Phone Service -Analog voice service - No data service 2-G 1990’s 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

S. Mandayam/ ECOMMS/ECE Dept./Rowan University And there’s more…. Joseph M. Nowack,

S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: What are we studying? Electrical Communications Systems Measures of information and noise Capacities for information transmission Design of communications systems Measures of performance Communications circuits Communications protocols Hardware INdependent Hardware dependent

S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: Topics Receiver Rx Transmitter Tx s(t) Channel r(t) m(t) Modulation circuits and systems DSP Demodulation circuits and systems DSP Noise Wire/wireless Antennas/ Coupling Antennas/ Coupling Analog/digital Protocols Fundamental limits

S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: Details

S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: Course Logistics

S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS Readiness Quiz NEXT MONDAY, Jan 24, 12:40 PM Room 204/206 CLOSED Book and Notes Topics: Complex algebra, Phasors, Fourier Series, AC Circuits BRING YOUR CALCULATOR!

S. Mandayam/ ECOMMS/ECE Dept./Rowan UniversitySummary