Communication System Icontents.kocw.net/KOCW/document/2014/hanyang/namhaeun/1.pdf · 2016-09-09 ·...

ECC1015 Communication System I

Communication System I

Electronics and Communication EngineeringHanyang University

Haewoon Nam

Lecture 1

(ECC1015)

1


Course Outline

• Lecture Time and Room:– Mon. 02:30pm - 04:00pm, Eng. Bldg 1, Room 502 (Y05-502)– Thu. 09:00am - 10:30am, Eng. Bldg 1, Room 205 (Y05-205)

• Office Hours: Wed. 01:00pm - 03:00pm or email for appointment

• Instructor: Haewoon Nam• Email: [email protected]• Office: Engineering Building 3, Room 304

2


Course Outline

• Textbook:1. “Communication Systems Engineering”” by John G. Proakis and M. Salehi,

Pearson/Prentice Hall2. “Introduction to Analog and Digital Communications”, by Simon Haykin and

Michael Moher, Wiley

3


Course Outline

• Prerequisites: – ECE308 Signals and Systems– ECC304 Theory of Random Variables– Students who have not completed the prerequisites may still take this course.

Please discuss it with the instructor.

• Homeworks– Tools: Matlab and Simulink

• Grading:– Midterm exam 30%– Final exam 30%– Attendance and participation 10%– Quizzes 10%– Homework 20%

4


Course Schedule

• Week 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Course introduction• Week 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of signals and systems• Week 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Amplitude modulation• Week 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Amplitude modulation• Week 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle modulation• Week 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle modulation• Week 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle modulation• Week 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mid-term exam• Week 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pulse modulations• Week 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Digital modulations• Week 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Digital modulations• Week 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Random variables• Week 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Random variables• Week 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effect of noise• Week 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver design• Week 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Final exam

5


Historical Background

• Telegraph– 1844, Samuel Morse,

• “What hath God wrought” transmitted by Morse’s electric telegraph• Washington D.C ~ Baltimore, Maryland• Morse code : variable-length code (a dot, a dash, a letter space, a word

space)

• Radio– 1864, James Clerk Maxwell

• Formulated the electromagnetic theory of light • Predicted the existence of radio waves

– 1887, Heinrich Hertz• The existence of radio waves was confirmed experimentally

– 1894, Oliver Lodge• Demo : wireless communication over a relatively short distance (150 yards)

6


Historical Background

– 1901, Guglielmo Marconi• Demo : wireless communication over a long distance (1700 miles)

– 1906, Reginald Fessenden• Conducting the first radio broascast

– 1918, Edwin H. Armstrong• Invented the superheterodyne radio receiver

– 1933, Edwin H. Armstrong• Demonstrated another modulation scheme ( Frequency nodulation)

• Telephone– 1875, Alexander Graham Bell

• Invented the telephone– 1897, A. B. Strowger

• Devised the autiomatic step-by-step switch

7


Historical Background• Electronics

– 1904, John Abbrose Eleming• Invented the vacuum-tube diode

– 1906, Lee de Forest• Invented the vacuum-tube triode

– 1948, Walter H. Brattain, William Shockley (Bell Lab.)• Invented the transistor

– 1958, Robert Noyce• The first silicon integrated circuit (IC) produce

• Television– 1928, Philo T. Farnsworth

• First all-electronic television system– 1929, Vladimir K. Zworykin

• All-electronic television system– 1939, BBC

• Broadcasting television service on a commercial basis8


Historical Background• Digital Communications

– 1928, Harry Nyquist• The theory of signal transmission in telegraphy

– 1937, Alex Reeves• Invent pulse-code modulation

– 1958, (Bell Lab.)• First call through a stored-program system

– 1960, (Morris, Illinois)• The first commercial telephone service with digital switching begin.

– 1962, (Bell Lab.)• The first T-1 carrier system transmission was installed

– 1943, D. O. North• Matched filter for the optimum detection of a unknown signal in a additive

white noise– 1948, Claude Shannon

• The theoretical foundation of digital communications were laid

9


Historical Background• Computer Networks

– 1943~1946, Univ. of Pennsylvania• ENIAC : first electronic digital computer

– 1950s• Computers and terminals started communicating with each other

– 1965, Robert Lucky• Idea of adaptive equalization

– 1982, G. Ungerboeck• Efficient modulation techniques

– 1950~1970• Various studies were made on computer networks

– 1971• Advanced Research Project Agency Network(APRANET) service

– 1985, • APRANET was renamed the Internet

– 1990, Tim Berners-Lee• Proposed a hypermedia software interface to internet (World Wide Web)

10


Historical Background• Satellite Communications

– 1945, C. Clark• Studied the use of satellite for communications

– 1955, John R. Pierce• Proposed the use of satellite for communications

– 1957, (Soviet Union)• Launched Sputnik I

– 1958, (United States)• Launched Explorer I

– 1962, (Bell Lab.)• Launched Telstar I

• Optical Communications– 1966, K.C. Kao, G. A. Hockham

• Proposed the use of a clad glass fiber as a dielectric waveguide– 1959~1960

• The laser had been invented and developed11


Applications

• Elements of communication systems– Source of information

• video, audio, text message, file data– Transmitter– Channel

• radio frequency, cable, visible light, underwater– Receiver

12[Ref] Introduction to Analog and Digital Communications,

by Haykin and Moher, Wiley


Applications

• Broadcasting– Which involves the use of a single powerful transmitter and numerous

receivers that are relatively inexpensive to build– AM and FM radio

• The voices are transmitted from broadcasting stations– Television

• Transmits visual images and voice

• Point-to-point communications– In which the communication process takes place over a link between a

single transmitter and a single receiver.– Satellite communication

• Built around a satellite in geostationary orbit, relies on line-of-sight radio propagation for the operation of an uplink and a downlink

13


Applications

• Satellite communication




Applications

• Communication Networks– Consists of the interconnection of a number of routers that are made up

of intelligent processors– Circuit switching

• Is usually controlled by a centralized hierarchical control mechanism with knowledge of the network’s entire organization

– Packet switching• Store and forward

– Any message longer than a specified size is subdivided prior to transmission into segments

– The original message is reassembled at the destination on a packet-by-packet basis

• Advantage– When a link has traffic to sent, the link tends to be more fully utilized.

15


Applications

• Communication Networks




Applications

• Data Networks– Layer

• A process or device inside a computer system that is designed to perform a specific function

– Open systems interconnection (OSI) reference model• The communications and related-connection functions are organized as a

series of layers with well-defined interfaces.• Composed of seven layers

17


Applications• OSI 7 Layers




Applications

• Integration of Telephone and Internet– VOIP (Voice over IP)– Packet loss ratio :

• the number of packets lost in transport across the network to the total number of packets pumped into the network

– Connection delay :• The time taken for a packet of a particular host-to-host connection to

transmit across the network– In near future

• VOIP will replace private branch exchanges (PBXs)• If the loading is always low and response time is fast, VOIP telephony may

become mainstream and widespread

19


Primary Resources and Operations

• The systems are designed to provide for the efficient utilization of the two primary communication resources – Transmitted power

• The average power of the transmitted signal– Channel bandwidth

• The width of the passband of the channel

• Classify communication channel– Power-limited channel

• Wireless channels• Satellite channels• Deep-space links

– Band-limited channel• Telephone channels• Television channels

20


Primary Resources and Operations

• The design of a communication system boils down to a tradeoff between signal-to-noise ratio and channel bandwidth

• Improve system performance method– Signal-to-noise ratio is increased to accommodate a limitation imposed

on channel bandwidth– Channel bandwidth is increased to accommodate a limitation imposed

on signal-to-noise ratio.

21


Underlying Theories of Communications

• Modulation Theory– Sinusoidal carrier wave

• Whose amplitude, phase, or frequency is the parameter chosen for modification by the information-bearing signal

– Periodic sequence of pulses• Whose amplitude, width, or position is the parameter chosen for modification

by the information-bearing signal– The issues in modulation theory

• Time-domain description of the modulation signal.• Frequency-domain description of the modulated signal• Detection of the original information-bearing signal and evaluation of the

effect of noise on the receiver.

22



• Fourier Analysis– Fourier analysis provides the mathematical basis for evaluating the

following issues• Frequency-domain description of a modulated signal, including its

transmission bandwidth• Transmission of a signal through a linear system exemplified by a

communication channel or filter• Correlation between a pair of signals

• Probability Theory and Random Processes– Probability theory for describing the behavior of randomly occurring

events in mathematical terms– Statistical characterization of random signals and noise.

23



• Detection Theory– Signal-detection problem

• The presence of noise• Factors such as the unknown phase-shift introduced into the carrier wave

due to transmission of the sinusoidally modulated signal over the channel– In digital communications, we look at

• The average probability of symbol error at the receiver output• The issue of dealing with uncontrollable factors• Comparison of one digital modulation scheme against another.

24


Announcement and Assignment

• Reading assignment– Fourier Transform chapter of Signals and Systems– Details of convolution– Relationship between time and frequency

25

Date post:	20-Mar-2020
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

Communication System Icontents.kocw.net/KOCW/document/2014/hanyang/namhaeun/1.pdf · 2016-09-09 ·...

Documents