ECE 3770: Communication SystemsLecture 1: Introduction

Mojtaba Vaezi

Lecture 1: Introduction EE 3770: Communication Systems

Lecture 1Introduction

Course Information

History of Communication

Communication Process

Mojtaba Vaezi 1-1

Contents

Course Information

History of Communication

Communication Process

Lecture 1: Introduction 1-2

Course Logistics

Instructors

Instructor: Mojtaba VaeziE-mail: mvaezi at villanova dot eduOffice: Tolentine 433AOffice Hours: TW 10:00am-11:00am or by appointment

Teaching Assistant Amro Lulu (alulu01 at villanova.edu)

Time and LocationTime Location

Lectures MWF 11:30-12:20 Tolentine 427ALabs M 14:30-16:30 Tolentine 314A

Course Homepage: http://www.princeton.edu/~mvaezi/ece3770

Please often visit the course website for course information, specialannouncements, and course materials (lecture notes, slides,assignments, supplementary documents, etc.)

Lecture 1: Introduction 1-3

Objectives

This course provides broad knowledge of how communication systems workfrom a system engineering point of view and how to apply it to real-worldproblems.

Course Objectives

Introduce the basic building blocks of communication systems

Introduce communication channel and discuss how signals are shapedfor transmission and reception over channel

Develop and compare the performance of analog and digitalmodulation/demodulation schemes

Introduce sampling, quantization and pulse code modulation

Introduce and analyze the noise effect in communication systems

Lecture 1: Introduction 1-4

References

Textbook

Simon Haykin and Michael Moher, Communication Systems, 5thEdition, John Wiley & Sons, 2009. (ISBN: 978-0-471-69790-9)

ReferencesB. P. Lathi and Zhi Ding, Modern Digital and Analog CommunicationSystems, 4th Edition, Oxford University Press. (ISBN 978-0-19-533145-5)Proakis and Salehi, Fundamentals of Communication Systems,(2nd Edition) Pearson, 2013.

Lecture 1: Introduction 1-5

Outline

Section 1: Introduction/Mathematical Foundational (Chapters 1 &2)

An overview of early and current communication systems/historyReview of frequency domain analysis of signals and systemsReview of signal classification and operations

Section 2: Analog Communications (Chapters 3, 4 & 6)Amplitude modulation schemesAngle modulation schemesFrequency division multiplexing

Section 3: Digital Communications (Chapters 7 & 8)Sampling theorem and the basis for digital communicationsQuantization, PCM, line coding, and reducing ISIDigital carrier modulation

Lecture 1: Introduction 1-6

Assessment

Assessment

Weight RemarksHomework 20% 7–8 homework; each due in 1 week

Labs 25% A total of 10 lab assignmentsMidterm 1 15% Monday, February 26, 2018 (in class)Midterm 2 15% Wednesday, April 4, 2018 (in class)Final Exam 25% According to the university schedule

Homework Policy

Assigned on Mondays, due the following Monday at 5pm

25% penalty for late assignments

No assignment is accepted more than a week later

Everyone should turn in their own write up

Lecture 1: Introduction 1-7

Feedback and Comments

Comment on

Lectures, homework, labs, exams, etc.

What did you like most about this course?

What would you change?

Other comments?

Tell us what you think (while we can still do something about it!)- Regular feedbacks- Mid-semester survey

Lecture 1: Introduction 1-8

Contents

Course Information

History of Communication

Communication Process

Lecture 1: Introduction 1-9

Early Communication Methods

(a) smoke signal (b) carrier pigeon

(c) semaphore telegraph

Lecture 1: Introduction 1-10

Modern Communication Systems

Telegraph1830, Joseph Henry1837, Samuel B. Morse, Morse code

Telephone1876, Alexander G. Bell (“Watson come here; I need you”)1915, US transcontinental service (requires amplifiers)

Wireless telegraphy1895, Jagadish Chandra Bose builds radio transmitter1896, Marconi patents radio telegraphy1901, Marconi, first transatlantic transmission

Radio1906, first broadcast (Reginald Fessendend)1920, first commercial AM radio station (Montreal XWA → CINW)1935, FM radio (Edwin Howard Armstrong)

Lecture 1: Introduction 1-11

Contents

Course Information

History of Communication

Communication Process

Lecture 1: Introduction 1-12

Electrical Communication SystemIn its simplest form, a telecommunication system consists of atransmitter , a channel , and a receiver .

Lectures No. 1 and 2: Introduction to Digital Communications Engineering I

Communications System

In its simplest form a telecommunications system consists of

a transmitter, a channel, a receiver and two transducers.

Channel

Transmitter

Messageand inputtransducer

Estimateof messageand outputtransducer

Receiver

DT008/2 Digital Communications Engineering I Slide: 19Examples of channelsWired (copper wire: 1 MHz, coaxial cable: 100 MHz)Wireless (microwave: GHz)Optical fibre (uses light as the signal carrier, THz)

Lecture 1: Introduction 1-13

(Analog) Communication SystemElectrical Communication System

Mai Vu 5

ChannelTransmitterInformation

SourceReceiver Destination

Noise and Distortion

Input

message

Transmitted

signal

Received

signal

Output

message

Same

information?

Early communication systems were all analog: examples includeAM and FM radio, analog TV, audio cassettesFirst generation cellular phone technology (based on FM)

Analog communication getting obsolete

Lecture 1: Introduction 1-14

Communication Resources

Bandwidth: the range of frequencies a channel can transmit withreasonable fidelity

A precious and very expensive resourceAn example of FCC auctions in 2017:84 MHz of wireless spectrum for about $20 B

Power: Signal power P is related to the quality of transmissionOften measured in terms of signal-to-noise ratio (SNR)Limited by availability and/or regulation

Why are these important?Shannon’s channel capacity equation

C =W log2(1 + SNR) bit/s

That is, data rate (C ) depends on bandwidth (W ) and SNR

Lecture 1: Introduction 1-15

Objectives of System Design

To transmit the message both efficiently and reliably, subject to certaindesign constraints: power, bandwidth, and cost.

Efficiency: is usually measured by the amount of messages sent in unitpower, unit time and unit bandwidthReliability: is expressed in terms of SNR or probability of error

Shannon capacity formula says zero error rate is possible as long as actualsignaling rate is less than C

Lecture 1: Introduction 1-16