Abbreviations
AC alternating current
ADC analog-to-digital conversion
ADM adaptive delta modulation
AM amplitude modulation
ANSI American National Standards Institute
APLL analog phase-locked loop
ATSC Advanced Television System Committee (U.S.)
AT&T American Telephone and Telegraph Company
AWGN additive white Gaussian noise
BER bit error rate
BPSK binary phase shift keying
CATV cable antenna television system
CCIR International Radio Consultative Committee
CCITT International Telegraph and Telephone Consultative Committee
CDMA code-division multiple access
CFT continuous Fourier transform
CMOS complementary metal oxide conductor
C/N or CNR
carrier-to-noise (power)ratio
CO central office
CRT cathode-ray tube
dB decibel
DC direct current
DFT discrete Fourier transform
DM delta modulation
DPCM differential pulse code modulation
DRM digital radio Mondiale
DSB-SC double-sideband suppressed carrier
DSL digital subscriber line

DSS digital satellite system
DTV digital television
EIRP effective isotropic radiated power
ERP effective radiated power
FCC Federal Communication Commission (U.S.)
FDM frequency-division multiplexing
FEC forward error-correction coding
FET field-effect transistor
FFT fast Fourier transform
FM frequency modulation
FSK frequency shift keying
GEO geostationary orbit
GSM group special mobile (cellular phone)
HDTV high-definition (digital) television
HF high frequency
HRC harmonic related carrier
IBOC inband on channel
IEEE Institute of Electrical and Electronics Engineers
IF intermediate frequency
IMD intermodulation distortion
IRC incrementally related carrier
ISDN integrated service digital network
ISI intersymbol interference
ISO International Organization for Standardization
ITU International Telecommunications Union
LAN local area network
LED light-emitting diode
LNA low-noise amplifier
LO local oscillator
LOS line of sight

LPF low-pass filter
LSSB lower single sideband
LTE long-term evolution (cell system)
MIMO multiple input multiple output
MPEG motion pictures expert group
MPSK M-ary phase shift keying
MQAM M-ary quadrature amplitude modulation
MSK minimum-shift keying
NBFM narrowband frequency modulation
NLOS non line of sight
NRZ nonreturn-to-zero
NTSC National Television System Committee (U.S.)
OFDM orthogonal frequency division multiplexing
OOK on-off keying
OQPSK offset quadrature phase-shift keying
PAM pulse amplitude modulation
PBX privite branch exchange
PCM pulse code modulation
PCS personal communication system
PD phase detection
PDF probability density function
PEP peak envelope power
PLL phase-locked loop
PM phase modulation
POTS plain old telephone service
PPM pulse position modulation
PSD power spectral density
PSK phase shift keying
PSTN public switched telephone networks
PTM pulse time modulation

PWM pulse width modulation
QAM quadrature amplitude modulation
QPSK quadrature phase-shift keying
RMS root-mean-square
RF radio frequency
RT remote terminal
RZ return-to-zero
SAW surface acoustics wave
SDARS satellite digital audio radio service
SDTV standard definition digital television
S/N or SNR signal-to-noise (power) ratio
SS spread spectrum (system)
SSB single sideband
TCP/IP transmission control protocal/internet protocal
TDM time-division multiplexing
TDMA time-division multiplex access
TELCO telephone company
THD total harmonic distortion
TTL transistor-transistor logic
TV television
TVRO TV receive only terminal
TWT traveling-wave tube
UHF ultra high frequency
USSB upper single sideband
VCO voltage-controlled oscillator
VF voice frequency
VHF very high frequency
VSAT very small aperture terminal
VSB vestigial sideband
WBFM wideband frequency modulation

WLAN wireless local area network
DIGITAL AND ANALOG
COMMUNICATION SYSTEMS
Eighth Edition
LEON W. COUCH, II
Professor Emeritus
Electrical and Computer Engineering
University of Florida, Gainesville
Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam
Cape Town Dubai London Madrid Milan Munich Paris Montréal Toronto Delhi
Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo
To my wife, Margaret Wheland Couch,
and to our children,
Leon III, Jonathan, and Rebecca
Library of Congress Cataloging-in-Publication Data
Couch, Leon W.
Digital & analog communication systems / Leon W. Couch, II.—8th ed.
p. cm.
ISBN-13: 978-0-13-291538-0 (alk. paper)
ISBN-10: 0-13-291538-3 (alk. paper)
1. Telecommunication systems. 2. Digital communications. I. Title.
II. Title: Digital and analog communication systems.
TK5101.C69 2013
384—dc23
2011038659
VP/Editorial Director, Engineering/Computer Science:
Marcia J. Horton
Executive Editor: Andrew Gilfillan
Senior Marketing Manager: Tim Galligan
Marketing Assistant: Jon Bryant

Project Manager: Pat Brown
Creative Director: Jayne Conte
Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on
appropriate page within text.
Copyright © 2013, 2007, 2002 Pearson Education, Inc., publishing as Prentice Hall, One Lake Street, Upper Saddle River,
New Jersey 07458. All rights reserved. Manufactured in the United States of America. This publication is protected
by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval
system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain
permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions
Department, One Lake Street, Upper Saddle River, New Jersey 07458.
Many of the designations by manufacturers and seller to distinguish their products are claimed as trademarks. Where those
designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in
initial caps or all caps.
ISBN-10: 0-13-291538-3
ISBN-13: 978-0-13-291538-0
Art Director: Kenny Beck
Cover Designer: Bruce Kenselaar
Media Editor: Daniel Sandin
Full-Service Project Management: Kiruthiga Anand
Composition: Integra
Printer/Binder: Courier Westford
Cover Printer: Lehigh-Phoenix
CONTENTS
PREFACE xiii
LIST OF SYMBOLS xvii
1 INTRODUCTION 1
1–1 Historical Perspective 3
1–2 Digital and Analog Sources and Systems 5
1–3 Deterministic and Random Waveforms 6
1–4 Organization of the Book 7

1–5 Use of a Personal Computer and MATLAB 8
1–6 Block Diagram of a Communication System 8
1–7 Frequency Allocations 10
1–8 Propagation of Electromagnetic Waves 12
1–9 Information Measure 17
1–10 Channel Capacity and Ideal Communication Systems 19
1–11 Coding 20
Block Codes, 21
Convolutional Codes, 23
Code Interleaving, 26
Code Performance, 26
Trellis-Coded Modulation, 28
iii
Contentsiv
1–12 Preview 30
1–13 Study-Aid Examples 30
Problems 31
2 SIGNALS AND SPECTRA 34
2–1 Properties of Signals and Noise 34
Physically Realizable Waveforms, 35
Time Average Operator, 36
DC Value, 37
Power, 38
RMS Value and Normalized Power, 40
Energy and Power Waveforms, 41
Decibel, 41
Phasors, 43
2–2 Fourier Transform and Spectra 44
Definition, 44
Properties of Fourier Transforms, 48

Parseval’s Theorem and Energy Spectral Density, 49
Dirac Delta Function and Unit Step Function, 52
Rectangular and Triangular Pulses, 55
Convolution, 60
2–3 Power Spectral Density and Autocorrelation Function 63
Power Spectral Density, 63
Autocorrelation Function, 65
2–4 Orthogonal Series Representation of Signals and Noise 67
Orthogonal Functions, 68
Orthogonal Series, 69
2–5 Fourier Series 71
Complex Fourier Series, 71
Quadrature Fourier Series, 72
Polar Fourier Series, 74
Line Spectra for Periodic Waveforms, 75
Power Spectral Density for Periodic Waveforms, 80
2–6 Review of Linear Systems 82
Linear Time-Invariant Systems, 82
Impulse Response, 82
Transfer Function, 83
Distortionless Transmission, 86
Distortion of Audio, Video, and Data Signals, 89
2–7 Bandlimited Signals and Noise 89
Bandlimited Waveforms, 90
Sampling Theorem, 90
Impulse Sampling and Digital Signal Processing, 93
Dimensionality Theorem, 95
2–8 Discrete Fourier Transform 97
Using the DFT to Compute the Continuous Fourier Transform, 98
Using the DFT to Compute the Fourier Series, 103

2–9 Bandwidth of Signals 105
2–10 Summary 112
2–11 Study-Aid Examples 113
Problems 117
3BASEBAND PULSE AND DIGITAL SIGNALING 132
3–1 Introduction 132
3–2 Pulse Amplitude Modulation 133
Natural Sampling (Gating), 133
Instantaneous Sampling (Flat-Top PAM), 137
3–3 Pulse Code Modulation 141
Sampling, Quantizing, and Encoding, 142
Practical PCM Circuits, 145
Bandwidth of PCM Signals, 146
Effects of Noise, 148
Nonuniform Quantizing: µ-Law and A-Law Companding, 152
3–4 Digital Signaling 155
Vector Representation, 157
Bandwidth Estimation, 160
Binary Signaling, 160
Multilevel Signaling, 162
3–5 Line Codes and Spectra 164
Binary Line Coding, 164
Power Spectra for Binary Line Codes, 167
Differential Coding, 174
Eye Patterns, 175
Regenerative Repeaters, 176
Bit Synchronization, 178
Power Spectra for Multilevel Polar NRZ Signals, 181
Spectral Efficiency, 184
3–6 Intersymbol Interference 185

Nyquist’s First Method (Zero ISI), 188
Raised Cosine-Rolloff Nyquist Filtering, 189
Nyquist’s Second and Third Methods for Control of ISI, 194
3–7 Differential Pulse Code Modulation 194
3–8 Delta Modulation 198
Granular Noise and Slope Overload Noise, 201
Adaptive Delta Modulation and Continuously Variable Slope Delta Modulation, 203
Speech Coding, 204
Contents v
3–9 Time-Division Multiplexing 206
Frame Synchronization, 206
Synchronous and Asynchronous Lines, 210
TDM Hierarchy, 213
The T1 PCM System, 215
3–10 Packet Transmission System 219
3–11 Pulse Time Modulation: Pulse Width Modulation and Pulse Position Modulation 220
3–12 Summary 224
3–13 Study-Aid Examples 224
Problems 228
4BANDPASS SIGNALING PRINCIPLES AND CIRCUITS 237
4–1 Complex Envelope Representation of Bandpass Waveforms 237
Definitions: Baseband, Bandpass, and Modulation, 238
Complex Envelope Representation, 238
4–2 Representation of Modulated Signals 241
4–3 Spectrum of Bandpass Signals 241
4–4 Evaluation of Power 245
4–5 Bandpass Filtering and Linear Distortion 248
Equivalent Low-Pass Filter, 248
Linear Distortion, 250
4–6 Bandpass Sampling Theorem 252

4–7 Received Signal Plus Noise 254
4–8 Classification of Filters and Amplifiers 254
Filters, 254
Amplifiers, 258
4–9 Nonlinear Distortion 259
4–10 Limiters 264
4–11 Mixers, Up Converters, and Down Converters 266
4–12 Frequency Multipliers 272
4–13 Detector Circuits 274
Envelope Detector, 274
Product Detector, 275
Frequency Modulation Detector, 277
4–14 Phase-Locked Loops and Frequency Synthesizers 282
4–15 Direct Digital Synthesis 290
Contentsvi
4–16 Transmitters and Receivers 290
Generalized Transmitters, 290
Generalized Receiver: The Superheterodyne Receiver, 292
Zero-IF Receivers, 296
Interference, 297
4–17 Software Radios 297
4–18 Summary 299
4–19 Study-Aid Examples 299
Problems 305
5 AM, FM, AND DIGITAL MODULATED SYSTEMS 313
5–1 Amplitude Modulation 314
5–2 AM Broadcast Technical Standards and Digital AM Broadcasting 319
Digital AM Broadcasting, 320
5–3 Double-Sideband Suppressed Carrier 321
5–4 Costas Loop and Squaring Loop 322

5–5 Asymmetric Sideband Signals 324
Single Sideband, 324
Vestigial Sideband, 328
5–6 Phase Modulation and Frequency Modulation 331
Representation of PM and FM Signals, 331
Spectra of Angle-Modulated Signals, 336
Narrowband Angle Modulation, 341
Wideband Frequency Modulation, 342
Preemphasis and Deemphasis in Angle-Modulated Systems, 346
5–7 Frequency-Division Multiplexing and FM Stereo 348
5–8 FM Broadcast Technical Standards and Digital FM Broadcasting 351
Digital FM Broadcasting, 351
5–9 Binary Modulated Bandpass Signaling 353
On-Off Keying (OOK), 353
Binary Phase-Shift Keying (BPSK), 357
Differential Phase-Shift Keying (DPSK), 359
Frequency-Shift Keying (FSK), 359
5–10 Multilevel Modulated Bandpass Signaling 366
Quadrature Phase-Shift Keying and M-ary Phase-Shift Keying, 367
Quadrature Amplitude Modulation (QAM), 370
OQPSK and /4 QPSK, 371
PSD for MPSK, QAM, QPSK, OQPSK, and /4 QPSK, 374
Spectral Efficiency for MPSK, QAM, QPSK, OQPSK, and /4 QPSK
with Raised Cosine Filtering, 376
p
p
p
Contents vii
5–11 Minimum-Shift Keying and GMSK 378
5–12 Orthogonal Frequency Division Multiplexing (OFDM) 385

5–13 Spread Spectrum Systems 388
Direct Sequence, 389
Frequency Hopping, 396
SS Frequency Bands, 397
5–14 Summary 397
5–15 Study-Aid Examples 397
Problems 401
6RANDOM PROCESSES AND SPECTRAL ANALYSIS 414
6–1 Some Basic Definitions 415
Random Processes, 415
Stationarity and Ergodicity, 416
Correlation Functions and Wide-Sense Stationarity, 420
Complex Random Processes, 423
6–2 Power Spectral Density 424
Definition, 424
Wiener-Khintchine Theorem, 426
Properties of the PSD, 428
General Formula for the PSD of Digital Signals, 433
White-Noise Processes, 435
Measurement of PSD, 436
6–3 DC and RMS Values for Ergodic Random Processes 437
6–4 Linear Systems 439
Input-Output Relationships, 439
6–5 Bandwidth Measures 444
Equivalent Bandwidth, 444
RMS Bandwidth, 444
6–6 The Gaussian Random Process 446
Properties of Gaussian Processes, 448
6–7 Bandpass Processes 450
Bandpass Representations, 450

Properties of WSS Bandpass Processes, 454
Proofs of Some Properties, 459
6–8 Matched Filters 464
General Results, 464
Results for White Noise, 466
Correlation Processing, 469
Transversal Matched Filter, 471
6–9 Summary 475
Contentsviii
6–10 Appendix: Proof of Schwarz’s Inequality 477
6–11 Study-Aid Examples 479
Problems 481
7 PERFORMANCE OF COMMUNICATION SYSTEMS
CORRUPTED BY NOISE 492
7–1 Error Probabilities for Binary Signaling 493
General Results, 493
Results for Gaussian Noise, 495
Results for White Gaussian Noise and Matched-Filter Reception, 497
Results for Colored Gaussian Noise and Matched-Filter Reception, 498
7–2 Performance of Baseband Binary Systems 499
Unipolar Signaling, 499
Polar Signaling, 502
Bipolar Signaling, 502
7–3 Coherent Detection of Bandpass Binary Signals 504
On-Off Keying, 504
Binary-Phase-Shift Keying, 506
Frequency-Shift Keying, 507
7–4 Noncoherent Detection of Bandpass Binary Signals 511
On-Off Keying, 511
Frequency-Shift Keying, 515

Differential Phase-Shift Keying, 517
7–5 Quadrature Phase-Shift Keying and Minimum-Shift Keying 519
7–6 Comparison of Digital Signaling Systems 521
Bit-Error Rate and Bandwidth, 521
Symbol Error and Bit Error for Multilevel Signaling, 523
Synchronization, 524
7–7 Output Signal-to-Noise Ratio for PCM Systems 525
7–8 Output Signal-to-Noise Ratios for Analog Systems 530
Comparison with Baseband Systems, 531
AM Systems with Product Detection, 532
AM Systems with Envelope Detection, 533
DSB-SC Systems, 535
SSB Systems, 535
PM Systems, 536
FM Systems, 540
FM Systems with Threshold Extension, 543
FM Systems with Deemphasis, 545
7–9 Comparison of Analog Signaling Systems 548
Ideal System Performance, 548
Contents ix
7–10 Summary 551
7–11 Study-Aid Examples 551
Problems 560
8 WIRE AND WIRELESS COMMUNICATION APPLICATIONS 569
8–1 The Explosive Growth of Telecommunications 569
8–2 Telephone Systems 570
Historical Basis, 570
Modern Telephone Systems and Remote Terminals, 571
8–3 Digital Subscriber Lines (DSL) 577
G.DMT and G.Lite Digital Subscriber Lines, 578

Video On Demand (VOD), 580
Integrated Service Digital Network (ISDN), 580
8–4 Capacities of Public Switched Telephone Networks 583
8–5 Satellite Communication Systems 583
Digital and Analog Television Transmission, 587
Data and Telephone Signal Multiple Access, 589
Satellite Radio Broadcasting, 595
8–6 Link Budget Analysis 597
Signal Power Received, 597
Thermal Noise Sources, 600
Characterization of Noise Sources, 601
Noise Characterization of Linear Devices, 602
Noise Characterization of Cascaded Linear Devices, 607
Link Budget Evaluation, 609
E
b
͞N
0
Link Budget for Digital Systems, 612
Path Loss for Urban Wireless Environments, 613
8–7 Fiber-Optic Systems 618
8–8 Cellular Telephone Systems 620
First Generation (1G)—The AMPS Analog Circuit-switched System, 624
Second Generation (2G)—The Digital Circuit-switched Systems, 626
Third Generation (3G)—Digital with Circuit and Packet Switching 629
Fourth Generation (4G)—Digital with Packet Switching 629
8–9 Television 630
Analog Black-and-White Television, 630
MTS Stereo Sound, 637
Analog Color Television, 637

Standards for TV and CATV Systems, 641
Digital TV (DTV), 649
8–10 Cable Data Modems 653
Contentsx
8–11 Wireless Data Networks 655
WiFi, 655
WiMAX, 656
8–12 Summary 657
8–13 Study-Aid Examples 657
Problems 662
APPENDIX A MATHEMATICAL TECHNIQUES, IDENTITIES, AND TABLES 669
A–1 Trigonometry and Complex Numbers 669
Definitions, 669
Trigonometric Identities and Complex Numbers, 669
A–2 Differential Calculus 670
Definition, 670
Differentiation Rules, 670
Derivative Table, 670
A–3 Indeterminate Forms 671
A–4 Integral Calculus 671
Definition, 671
Integration Techniques, 672
A–5 Integral Tables 672
Indefinite Integrals, 672
Definite Integrals, 673
A–6 Series Expansions 674
Finite Series, 674
Infinite Series, 674
A–7 Hilbert Transform Pairs 675
A–8 The Dirac Delta Function 675

Properties of Dirac Delta Functions, 676
A–9 Tabulation of Sa (x) = (sin x)͞x 677
A–10 Tabulation of Q (z) 678
APPENDIX B PROBABILITY AND RANDOM VARIABLES 680
B–1 Introduction 680
B–2 Sets 681
B–3 Probability and Relative Frequency 682
Simple Probability, 682
Joint Probability, 683
Conditional Probabilities, 684
B–4 Random Variables 685
Contents xi
B–5 Cumulative Distribution Functions and Probability Density Functions 685
Properties of CDFs and PDFs, 688
Discrete and Continuous Distributions, 688
B–6 Ensemble Average and Moments 692
Ensemble Average, 692
Moments, 693
B–7 Examples of Important Distributions 695
Binomial Distribution, 695
Poisson Distribution, 698
Uniform Distribution, 698
Gaussian Distribution, 698
Sinusoidal Distribution, 703
B–8 Functional Transformations of Random Variables 704
B–9 Multivariate Statistics 709
Multivariate CDFs and PDFs, 709
Bivariate Statistics, 711
Gaussian Bivariate Distribution, 712
Multivariate Functional Transformation, 712

Central Limit Theorem, 715
Problems 716
APPENDIX C USING MATLAB 723
C–1 About the MATLAB M-Files 724
C–2 Quick Start for Running M-Files 724
C–3 Programming in MATLAB 725
REFERENCES 727
ANSWERS TO SELECTED PROBLEMS 739
INDEX 747
Contentsxii
PREFACE
Continuing the tradition of the first through the seventh editions of Digital and Analog
Communication Systems, this eighth edition provides the latest up-to-date treatment of digital
communication systems. It is written as a textbook for junior or senior engineering students
and is also appropriate for an introductory graduate course. It also provides a modern
technical reference for the practicing electrical engineer. A Student Solutions Manual con-
tains detailed solutions for over 100 selected end-of-the-chapter homework problems. For the
selected problems that have computer solutions, MATLAB solution files are available for
downloading from the Web. To download the Student Solutions Manual and the MATLAB
files, go to www.pearsonhighered.com/couch.
One major change for this eighth edition is the addition of more than 100 examples dis-
tributed throughout the chapters of the text. Students are always asking for more examples. Most
of these new examples have a problem description that consists of only a few lines of text. The
solutions for these examples are contained within MATLAB files (downloaded from the Web
site given earlier). These files include the procedure for the solution (as described by comment
lines in the MATLAB program) and produce computed and plotted solutions. This presentation
procedure has several advantages. First, the description for each example takes only a few lines
xiii
in this textbook, so the book will not be extended in length. Second, the student will have the
experience of learning to work with MATLAB (as demonstrated with the example solutions).

Clearly plotted results, which are better than hand calculations, are given. The student can also
vary the parameters in the MATLAB example to discover how the results will be affected. The
author believes that this approach to examples is a great innovative teaching tool.
To learn about communication systems, it is essential to first understand how communica-
tion systems work. Based on the principles of communications that are covered in the first five
chapters of this book (power, frequency spectra, and Fourier analysis), this understanding is
motivated by the use of extensive examples, study-aid problems, and the inclusion of adopted
standards. Especially interesting is the material on wire and wireless communication systems.
Also of importance is the effect of noise on these systems, since, without noise (described by prob-
ability and random processes), one could communicate to the limits of the universe with negligible
transmitted power. In summary, this book covers the essentials needed for the understanding of
wire and wireless communication systems and includes adopted standards. These essentials are
• How communication systems work: Chapters 1 through 5.
• The effect of noise: Chapters 6 and 7.
• Wire and Wireless Communication Applications: Chapter 8.
This book is ideal for either a one-semester or a two-semester course. This book
emphasizes basic material and applications that can be covered in a one-semester course, as
well as the essential material that should be covered for a two-semester course. This emphasis
means that the page count needs to be limited to around 750 pages. For a book with a larger
page count, it is impossible to cover all that additional material, even in a two-semester
course. (Many schools are moving toward one basic course offering in communications.)
Topics such as, coding, wireless signal propagation, WiMAX, and Long Term Evolution
(LTE) of cellular systems are covered in this book. In-depth coverage of important topics such
as these should be done by additional courses with their own textbooks.
For a one-semester course, the basics of how communication systems work may be
taught by using the first five chapters (with selected readings from Chapter 8). For a two-
semester course, the whole book is used.
This book covers practical aspects of communication systems developed from a sound
theoretical basis.
THE THEORETICAL BASIS

• Digital and analog signals
• Magnitude and phase spectra
• Fourier analysis
• Orthogonal function theory
• Power spectral density
• Linear systems
• Nonlinear systems
• Intersymbol interference
• Complex envelopes
• Modulation theory
• Probability and random processes
• Matched filters
• Calculation of SNR
• Calculation of BER
• Optimum systems
• Block and convolutional codes
Prefacexiv
THE PRACTICAL APPLICATIONS
Preface xv
• PAM, PCM, DPCM, DM, PWM,
and PPM baseband signaling
• OOK, BPSK, QPSK, MPSK, MSK,
OFDM, and QAM bandpass digital
signaling
• AM, DSB-SC, SSB, VSB, PM, and
FM bandpass analog signaling
• Time-division multiplexing and the
standards used
• Digital line codes and spectra
• Circuits used in communication

systems
• Bit, frame, and carrier synchronizers
• Software radios
• Frequency-division multiplexing
and the standards used
• Telecommunication systems
• Telephone systems
• DSL modems
• Digital subscriber lines
• Satellite communication systems
• Satellite radio broadcasting systems
• Effective input-noise temperature
and noise figure
• Link budget analysis
• SNR at the output of analog commu-
nication systems
• BER for digital communication
systems
• Fiber-optic systems
• Spread-spectrum systems
• AMPS, GSM, iDEN, TDMA,
CDMA, WiMAX, and LTE cellular
telephone systems
• Digital and analog television systems
• Technical standards for AM, FM,
TV, DTV, and CATV
• Cable data modems
• Wi-Fi and WiMAX wireless networks
• MATLAB M files on the Web
• Mathematical tables

• Study-aid examples
• Over 100 examples with solutions.
About 80 of these examples include
MATLAB solutions
• Over 550 homework problems with
selected answers
• Over 60 computer-solution home-
work problems
• Extensive references
• Emphasis on the design of commu-
nication systems
• Student Solutions Manual (download)
WHAT’S NEW IN THIS EDITION
• Addition of over 100 examples with solutions that are distributed throughout the
chapters of the book. Most of them have MATLAB computer solutions obtained via
electronic M files which are downloaded free-of-charge from author’s Web site.
• Includes up-to-date descriptions of popular wireless systems, LTE (long-term evolution)
and WiMax 4G cellular systems, and personal communication applications.
• Includes latest updates on digital TV (DTV) technology.
• Brings terminology and standards up-to-date.
• Brings references up-to-date.
• Updates all chapters.
Prefacexvi
• Includes additional and revised homework problems.
• Includes suggestions for obtaining the latest information on applications and standards
by using the appropriate keyword queries on internet search engines, such as Google.
• Continues the emphasis on MATLAB computer solutions to problems. This approach
of using computer solutions is very important in training new communication
engineers. This is one of the very few books that includes the actual electronic files for
MATLAB solutions (available for free downloading from the internet). This is done so

that the reader does not have to spend days in error-prone typing of lines of computer
code that are listed in a textbook.
• Updates all MATLAB files to run on Version R2010b.
• Extends list of Answers to Selected Problems at the end of the book, with MATLAB
solutions if appropriate.
Many of the homework problems are marked with a personal computer symbol, . This
indicates that MATLAB computer solutions are available for this problem.
Homework problems are found at the end of each chapter. Complete solutions for those
marked with a ★, approximately 1/3, are found in the Student Solutions Manual, available
for free download at www.pearsonhighered.com/couch. Student M-files are also available
for download. Complete solutions for all problems, including the computer solution
problems, are given in the Instructor Solutions Manual (available only to instructors from
Pearson/Prentice Hall). These manuals include Acrobat pdf files for the written solutions.
Also, for the problems with computer solutions, MATLAB M files are given. Instructor’s
should contact their local Pearson rep for access.
This book is an outgrowth of my teaching at the University of Florida and is tempered
by my experiences as an amateur radio operator (K4GWQ). I believe that the reader will not
understand the technical material unless he or she works some homework problems.
Consequently, over 550 problems have been included. Some of them are easy, so that the
beginning student will not become frustrated, and some are difficult enough to challenge the
more advanced students. All of the problems are designed to provoke thought about, and
understanding of, communication systems.
I appreciate the help of the many people who have contributed to this book and the
very helpful comments that have been provided by the many reviewers over the years. In
particular, I thank K. R. Rao, University of Texas, Arlington; Jitendra J. Tugnait, Auburn
University; John F. McDonald, Rensselaer Polytechnic Institute; Bruce A. Ferguson, Rose-
Hulman Institute of Technology; Ladimer S. Nagurney, University of Hartford; Jeffrey
Carruthers, Boston University; and Hen-Geul Yeh, California State University, Long
Beach. I also appreciate the help of my colleagues at the University of Florida. I thank
my wife, Dr. Margaret Couch, who typed the original and revised manuscripts and has

proofread all page proofs.
L
EON W. COUCH,II
Gainesville, Florida

LIST OF SYMBOLS
There are not enough symbols in the English and Greek alphabets to allow the use of each letter
only once. Consequently, some symbols may be employed to denote more than one entity, but
their use should be clear from the context. Furthermore, the symbols are chosen to be generally
the same as those used in the associated mathematical discipline. For example, in the context of
complex variables, x denotes the real part of a complex number (i.e., c = x + jy), whereas in the
context of statistics, x might denote a random variable.
Symbols
a
n
a constant
a
n
quadrature Fourier series coefficient
A
c
level of modulated signal of carrier frequency, f
c
A
e
effective area of an antenna
b
n
quadrature Fourier series coefficient
B baseband bandwidth

B
p
bandpass filter bandwidth
xvii
B
T
transmission (bandpass) bandwidth
c a complex number (cxjy)+=
c a constant
c
n
complex Fourier series coefficient
C channel capacity
C capacitance
°C degrees Celsius
dB decibel
D
dimensions s, symbols s (DNT
0
), or baud rate>=>>
D
f
frequency modulation gain constant
D
n
polar Fourier series coefficient
D
p
phase modulation gain constant
e error

e the natural number 2.7183
E modulation efficiency
E energy
(f)Ᏹ energy spectral density (ESD)
E
b
N
0
>
ratio of energy per bit to noise power spectral density
f frequency (Hz)
f(x) probability density function (PDF)
f
c
carrier frequency
f
i
instantaneous frequency
f
0
a (frequency) constant; the fundamental frequency of a periodic waveform
f
s
sampling frequency
F noise figure
F(a) cumulative distribution function (CDF)
g(t) complex envelope
(t)g
'
corrupted complex envelope

G power gain
G(f) power transfer function
h
Planck’s constant, 6.63 * 10
-34
joule
-s
h(t) impulse response of a linear network
h(x) mapping function of x into h(x)
H entropy
H(f) transfer function of a linear network
i an integer
I
j
information in the jth message
j
the imaginary number 1-1
j an integer
k
Boltzmann’s constant, 1.38 * 10
-23
joule/K
k an integer
k(t) complex impulse response of a bandpass network
K number of bits in a binary word that represents a digital message
K degrees Kelvin (°C + 273)
List of Symbolsxviii
List of Symbols xix
l an integer
ഞ

number of bits per dimension or bits per symbol
L inductance
L number of levels permitted
m an integer
m mean value
m(t) message (modulation) waveform
(t)m
'
corrupted (noisy received) message
M an integer
M number of messages permitted
n an integer
n number of bits in message
n(t) noise waveform
N an integer
N number of dimensions used to represent a digital message
N noise power
N
0
level of the power spectral density of white noise
p(t) an absolutely time-limited pulse waveform
p(t) instantaneous power
p(m) probability density function of frequency modulation
P average power
P
e
probability of bit error
P(C) probability of correct decision
P(E) probability of message error
(f)ᏼ power spectral density (PSD)

Q(z) integral of Gaussian function
Q(x
k
) quantized value of the kth sample value, x
k
r(t) received signal plus noise
R data rate (bits/s)
R resistance
R(t) real envelope
R()t autocorrelation function
s(t) signal
(t)s
'
corrupted signal
SN>
ratio of signal power to noise power
t time
T a time interval
T absolute temperature (Kelvin)
T
b
bit period
T
e
effective input-noise temperature
T
0
duration of a transmitted symbol or message
T
0

period of a periodic waveform
T
0
standard room temperature (290 K)
T
s
sampling period
u
11
covariance
(t)v a voltage waveform
(t)v a bandpass waveform or a bandpass random process
w(t) a waveform
W( f) spectrum (Fourier transform) of w(t)
x an input
x a random variable
x real part of a complex function or a complex constant
x(t) a random process
y an output
y an output random variable
y imaginary part of a complex function or a complex constant
y(t) a random process
a a constant
b a constant
b
f
frequency modulation index
b
p
phase modulation index

d
step size of delta modulation
d
ij
Kronecker delta function
d(t) impulse (Dirac delta function)
F¢
peak frequency deviation (Hz)
u¢
peak phase deviation
P a constant
P error
h spectral efficiency [(bits/sec)/Hz]
(t)u phase waveform
l dummy variable of integration
l wavelength
(r)⌳
likelihood ratio
p 3.14159
r correlation coefficient
s standard deviation
t independent variable of autocorrelation function
t pulse width
(t)w
j
orthogonal function
f
n
polar Fourier series coefficient
v

c
radian carrier frequency, 2 f
c
p
K mathematical equivalence
!
mathematical definition of a symbol
List of Symbolsxx
List of Symbols xxi
DEFINED FUNCTIONS
J
n
(·) Bessel function of the first kind, nth order
ln(·) natural logarithm
log(·) base 10 logarithm
log
2
(·) base 2 logarithm
Q(z) integral of a Gaussian probability density function
Sa(z)
(sin z) z>
u(·) unit step function
(·)⌳
triangle function
Π(·) rectangle function
OPERATOR NOTATION
Im{·} imaginary part of
Re{·} real part of
[
#

]
ensemble average
[·]98
time average
[·]
*
[·] convolution
[·]
*
conjugate
l
[
#
] angle operator or angle itself, see Eq. (2–108)
|[·]| absolute value
[
#
N ] Hilbert transform
Ᏺ[·]
Fourier transform
ᏸ[·]
Laplace transform
[·] · [·] dot product
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