Contemporary
Communication
Systems
M F Mesiya
, Contemporary Communication Systems
M F Mesiya
Rensselaer Polytechnic Institute
mes80369_fm_i-xviii.indd i 13/12/11 4:43 PM
, CONTEMPORARY COMMUNICATION SYSTEMS
Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the
Americas, New York, NY 10020. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved.
Printed in the United States of America. No part of this publication may be reproduced or distributed in any
form or by any means, or stored in a database or retrieval system, without the prior written consent of The
McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or
transmission, or broadcast for distance learning.
Some ancillaries, including electronic and print components, may not be available to customers outside the
United States.
This book is printed on recycled, acid-free paper containing 10% postconsumer waste.
1 2 3 4 5 6 7 8 9 0 QDB/QDB 1 0 9 8 7 6 5 4 3 2
ISBN 978-0-07-338036-0
MHID 0-07-338036-9
Vice President & Editor-in-Chief: Marty Lange
Vice President of Specialized Publishing: Janice M. Roerig-Blong
Editorial Director: Michael Lange
Publisher: Raghothaman Srinivasan
Senior Sponsoring Editor: Peter E. Massar
Senior Marketing Manager: Curt Reynolds
Development Editor: Darlene M. Schueller
Lead Project Manager: Jane Mohr
Design Coordinator: Margarite Reynolds
Cover Designer: Margarite Reynolds
Cover Image: Nick Rowe/Getty Images, © Don Bishop/Getty Images, McGraw-Hill Companies, © Lars A. Niki
Buyer: Susan K. Culbertson
Media Project Manager: Prashanthi Nadipalli
Compositor: Laserwords Private Limited
Typeface: 10/12 Times LT Std Roman
Printer: Quad Graphics
All credits appearing on page or at the end of the book are considered to be an extension of the copyright page.
Library of Congress Cataloging-in-Publication Data
Mesiya, Mohammed Farooque.
Contemporary communication systems / Mohammed Farooque Mesiya.
p. cm.
ISBN 978-0-07-338036-0 (alk. paper)
1. Telecommunication. I. Title.
TK5101.M4233 2012
384—dc23
2011028902
www.mhhe.com
mes80369_fm_i-xviii.indd ii 13/12/11 4:43 PM
, In loving memory of my parents
Aisha and Kassem Mesiya
To
Sieglinde for her tremendous patience and support
Yasmin and Misha for inspiring me to pursue
the opportunities the future offers
mes80369_fm_i-xviii.indd iii 13/12/11 4:43 PM
, Brief Contents
CHAPTER 1
Introduction 1
CHAPTER 2
Review of Signals and Linear Systems 24
CHAPTER 3
Simulation of Communication Systems Using MATLAB/Simulink 104
CHAPTER 4
Amplitude Modulation 141
CHAPTER 5
Angle Modulation 206
CHAPTER 6
Probability and Random Processes 278
CHAPTER 7
Noise Performance of Analog Communication Systems 371
CHAPTER 8
Conversion of Analog Signals to Digital Format 422
CHAPTER 9
Digital Baseband Modulation 489
CHAPTER 10
Detection of Baseband Signals in Noise 532
CHAPTER 11
Digital Information Transmission Using Carrier Modulation 592
CHAPTER 12
Digital Signal Transmission Through Time Dispersive Channels 679
CHAPTER 13
Digital Multiplexing and Synchronization 741
CHAPTER 14
Information Theory and Compression Techniques 787
CHAPTER 15
Channel Coding Techniques 854
iv
mes80369_fm_i-xviii.indd iv 13/12/11 4:43 PM
, Table of Contents
Preface xv
CHAPTER 1
Introduction 1
1.1 Elements of a Communication System 2
1.2 Communication Channels 2
1.2.1 Coaxial Cable 4
1.2.2 Optical Fibers 5
1.2.3 Radio Channels 8
1.3 Analog and Digital Communication Systems 10
1.3.1 Digital Communication Systems 10
1.3.2 Why Digital Transmission? 12
1.4 History of Communications 14
1.4.1 Wireless Communications 18
1.5 Key Themes and Drivers 19
Final Remarks 21
Further Readings 21
CHAPTER 2
Review of Signals and Linear Systems 24
2.1 Basic Signal Concepts 25
2.1.1 Some Useful Basic Signals 27
2.1.2 Energy and Power Signals 33
2.1.3 Logarithmic Power Calculations 35
2.1.4 Some Basic Operations on Signals 35
2.2 Basic System Concepts 38
2.2.1 Classification of Systems 39
2.2.2 Characterization of LTI Systems 42
2.3 Frequency Domain Representation 46
2.4 Fourier Series 47
2.4.1 Trigonometric Fourier Series 48
2.4.2 Parseval’s Theorem 52
2.4.3 Convergence of Fourier Series 54
2.5 Fourier Transform 55
2.5.1 Fourier Transforms of Some Common Signals 56
2.5.2 Properties of Fourier Transform 58
2.5.3 Fourier Transforms of Periodic Signals 65
2.6 Time-Bandwidth Product 68
2.7 Transmission of Signals Through LTI Systems 70
2.7.1 Distortionless Transmission 73
2.8 LTI Systems as Frequency Selective Filters 74
2.8.1 Ideal Filters 74
2.8.2 Realizable Approximations to Ideal Filters 78
2.8.3 Analog Filter Design Using MATLAB 80
v
mes80369_fm_i-xviii.indd v 13/12/11 4:43 PM
, vi Table of Contents
2.9 Power Spectral Density 84
2.9.1 Time-Average Autocorrelation Function 86
2.9.2 Relationship Between Input and Output Power Spectral Densities 87
2.10 Frequency Response Characteristics of Transmission Media 88
2.10.1 Twisted Wire Pairs 88
2.10.2 Coaxial Cable 92
2.11 Fourier Transforms for Discrete-Time Signals 92
Final Remarks 96
Further Readings 97
Problems 97
MATLAB Problems 100
CHAPTER 3
Simulation of Communication Systems Using MATLAB/Simulink 104
3.1 Getting Started in Simulink 105
3.1.1 Solvers 111
3.2 Modeling in Simulink 112
3.2.1 Subsystems 115
3.3 Simulation of Signal and Noise Sources 119
3.3.1 Deterministic Signals 119
3.3.2 Random Signals 121
3.3.3 Modeling of AWGN Channel 125
3.4 Modeling of Communication Systems 128
3.4.1 Time-Domain Modeling 128
3.4.2 Transform-Domain Description 131
3.5 Displaying Signals in Frequency Domain 134
3.6 Using Simulink with MATLAB 136
3.6.1 Running Simulations from MATLAB 137
Final Remarks 139
Further Readings 140
CHAPTER 4
Amplitude Modulation 141
4.1 Low-Pass and Bandpass Signals 143
4.2 Double-Sideband Suppressed-Carrier AM 144
4.2.1 Spectrum of the DSB-SC AM Signal 144
4.2.2 Demodulation of DSB-SC AM Signals 147
Experiment 4.1 DSB-SC AM Modulation and Demodulation 149
4.3 Conventional Amplitude Modulation 152
4.3.1 Spectrum of the Conventional AM Signal 154
4.3.2 Demodulation of Conventional AM Signal 160
Experiment 4.2 Conventional AM Modulation and Demodulation 164
4.4 Alternative Representations for BP Signals and Systems 166
4.4.1 Frequency Spectrum of Complex Envelope and Analytic Representations 168
4.4.2 Complex Envelope Representation of BP Systems 170
4.5 Single-Sideband AM 173
4.5.1 Demodulation of SSB-AM Signals 177
Experiment 4.3 SSB-AM Modulation and Demodulation 179
4.6 Vestigial-Sideband AM 181
4.7 Quadrature Multiplexing 185
4.8 Multiplexing 186
4.8.1 Frequency Division Multiplexing 186
mes80369_fm_i-xviii.indd vi 13/12/11 4:43 PM
, Table of Contents vii
4.9 Frequency Translation and Selection 190
4.9.1 Down-Conversion Mixer 190
4.9.2 Image-Reject Mixers 192
4.10 Communication Receivers 193
4.10.1 Superheterodyne Receivers 194
4.10.2 Direct-Conversion Receivers 196
4.10.3 Low-IF Receiver Architectures 197
Final Remarks 198
Further Readings 199
Problems 199
MATLAB Problems 201
APPENDIX 4A: Hilbert Transform 203
CHAPTER 5
Angle Modulation 206
5.1 FM and PM Signals 206
5.1.1 FM and PM Signals with Sinusoidal Modulating Signal 211
5.1.2 Power in Angle-Modulated Signal 214
5.2 Spectrum of Angle-Modulated Signals 215
5.2.1 Bandwidth of a Sinusoidally Modulated FM Signal 216
5.2.2 Bandwidth of an FM Signal Modulated by Arbitrary Message Signal 219
5.3 Narrowband FM 221
5.4 Demodulation of Angle-Modulated Signals 223
5.4.1 Bandpass Limiter 224
5.4.2 Frequency Discriminator 225
Experiment 5.1 Simulink Model of an FM System with Frequency Discriminator 226
Experiment 5.2 FM Demodulation with Balanced Slope Detector 230
5.4.3 Phase-shift Discriminator: Quadrature Detector 231
5.5 Phase-Locked Loop 233
5.5.1 Analog Phase-Locked Loop 234
5.5.2 APLL Linear Model 238
5.5.3 First-Order PLL 239
Experiment 5.3 First-Order PLL 242
5.5.4 Second-Order PLL 243
Experiment 5.4 Second-Order PLL 252
5.5.5 Acquisition Process: APLL in the Unlocked State 253
5.6 PLL as FM Demodulator 255
Experiment 5.5 PLL as FM Demodulator 256
5.7 FM Broadcasting 258
5.7.1 FM Stereo 258
5.8 Analog Television 260
5.8.1 Black-and-White Image 260
5.8.2 Black-and-White Television 262
5.8.3 Color Television 267
5.8.4 Multichannel Television Sound 272
Final Remarks 273
Further Readings 274
Problems 274
MATLAB Problems 276
CHAPTER 6
Probability and Random Processes 278
6.1 Probability Concepts 279
mes80369_fm_i-xviii.indd vii 14/12/11 6:59 PM
, viii Table of Contents
6.1.1 Relative Frequency 279
6.1.2 Probability Axioms 280
6.1.3 Union Bound 281
6.1.4 Conditional Probability 282
6.2 Random Variables 286
6.2.1 Discrete Random Variables 287
6.2.2 Some Common Discrete Random Variables 288
6.3 Continuous Random Variables 291
6.3.1 Some Common Continuous Random Variables 293
6.3.2 PDFs for Discrete and Mixed Random Variables 298
6.4 Functions of a Random Variable 299
6.4.1 Case I: g(x) Monotonically Increasing or Decreasing 299
6.4.2 Case II: Arbitrary g(x) 301
6.5 Statistics of Random Variables 302
6.5.1 Moments and Characteristic Functions 304
6.6 Pairs of Random Variables 307
6.6.1 Marginal Distributions 309
6.6.2 Function of Two Random Variables: Expected Values 310
6.7 Conditional Distributions 313
6.7.1 Conditional Expected Values 316
6.7.2 Independent Random Variables 316
6.8 Jointly Gaussian Random Variables 318
6.8.1 Two Functions of Two Random Variables 321
6.8.2 Central Limit Theorem 323
6.9 Random Processes: Introduction 324
6.9.1 Characterization of a Random Process 327
6.9.2 Stationary Random Processes 330
6.9.3 Wide-Sense Stationary Random Processes 331
6.9.4 Ergodic Random Processes 331
6.9.5 Properties of the Autocorrelation Function 332
6.9.6 Uncorrelated, Orthogonal, and Independent Random Processes 333
6.10 Power Spectrum of a Random Process 333
6.10.1 Wiener-Khinchin Theorem 334
6.10.2 Transmission of Random Signals Through Linear Time-Invariant Systems 336
6.11 Some Important Random Processes 338
6.11.1 Gaussian Random Process 338
6.11.2 White Gaussian Noise 339
6.11.3 Filtered White Gaussian Noise 340
6.12 Narrowband Noise 342
6.12.1 Narrowband White Gaussian Noise 344
6.12.2 Envelope of Sine Wave in Narrowband Noise 348
6.13 Noise Sources in Communication Systems 350
6.13.1 Thermal Noise 350
6.13.2 Available Power 352
6.13.3 Shot Noise 353
6.14 Characterization of System Noise 354
6.14.1 Noise Factor and Noise Figure 355
6.14.2 Effective Input Noise Temperature of a Subsystem 356
6.14.3 Noise Figure of a Cascade of Subsystems 357
6.14.4 Noise Factor of a Lossy Two-Port Network 359
6.15 MATLAB Simulation of Random Processes 360
6.15.1 Generating Arbitrary PDF Random Variables 361
6.15.2 Autocorrelation Function and Spectral Density 362
6.15.3 Samples of White Gaussian Noise 362
Final Remarks 364
Further Readings 364
mes80369_fm_i-xviii.indd viii 13/12/11 4:43 PM
, Table of Contents ix
Problems 364
MATLAB Problems 367
CHAPTER 7
Noise Performance of Analog Communication Systems 371
7.1 Noise Performance of Baseband Systems 372
7.2 Effect of Noise on the Performance of AM Systems 373
7.2.1 Noise Performance of DSB-SC 374
Experiment 7.1 Noise Performance of a DSB-SC AM System 376
7.2.2 Noise Performance of SSB-AM 378
Experiment 7.2 Noise Performance of an SSB-AM System 381
7.2.3 Noise Performance of Conventional AM 383
Experiment 7.3 Noise Performance of Conventional AM System 388
7.3 Noise Performance of Angle-Modulation Systems 390
7.3.1 High-CNR Operation 391
7.3.2 FM System Operation: Low-CNR Case 398
Experiment 7.4 Noise Performance of an FM System 403
7.4 Preemphasis and Deemphasis 405
7.5 Comparison of Analog Modulation Systems 407
7.6 Link Design 409
7.6.1 Analog Repeater 410
7.6.2 Performance of Analog Communication System Using Cascade of Repeaters 411
Final Remarks 415
Further Readings 416
Problems 416
MATLAB Problems 418
CHAPTER 8
Conversion of Analog Signals to Digital Format 422
8.1 Sampling of Low-Pass Signals 423
8.1.1 Nyquist-Shannon Sampling Theorem 425
8.1.2 DFT of the Sampled Sequence 426
8.1.3 Reconstruction of the Analog Signal 427
8.1.4 Practical Sampling Techniques 429
8.2 Aliasing 432
Experiment 8.1 Natural Sampling of a LP Random Signal 436
8.3 Digitization of Analog Signals 438
8.3.1 Quantization 439
8.3.2 Coding of Quantized Samples 440
8.3.3 Errors Introduced by Quantization Process 442
Experiment 8.2 Study of m-Bit Quantization Errors 442
8.3.4 Quantization Noise 444
8.4 Pulse Code Modulation 447
8.4.1 Nonuniform Quantization 448
8.5 Differential Pulse Code Modulation 454
8.6 Oversampling in Analog-to-Digital Conversion 457
8.7 Delta Modulation 460
8.7.1 Slope Overload and Granular Noise 462
8.7.2 Adaptive Delta Modulation 463
8.7.3 Continuously Variable Slope Delta Modulation 464
8.7.4 Quantization Noise 465
Experiment 8.3 Delta Modulation 468
mes80369_fm_i-xviii.indd ix 14/12/11 6:59 PM
Communication
Systems
M F Mesiya
, Contemporary Communication Systems
M F Mesiya
Rensselaer Polytechnic Institute
mes80369_fm_i-xviii.indd i 13/12/11 4:43 PM
, CONTEMPORARY COMMUNICATION SYSTEMS
Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the
Americas, New York, NY 10020. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved.
Printed in the United States of America. No part of this publication may be reproduced or distributed in any
form or by any means, or stored in a database or retrieval system, without the prior written consent of The
McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or
transmission, or broadcast for distance learning.
Some ancillaries, including electronic and print components, may not be available to customers outside the
United States.
This book is printed on recycled, acid-free paper containing 10% postconsumer waste.
1 2 3 4 5 6 7 8 9 0 QDB/QDB 1 0 9 8 7 6 5 4 3 2
ISBN 978-0-07-338036-0
MHID 0-07-338036-9
Vice President & Editor-in-Chief: Marty Lange
Vice President of Specialized Publishing: Janice M. Roerig-Blong
Editorial Director: Michael Lange
Publisher: Raghothaman Srinivasan
Senior Sponsoring Editor: Peter E. Massar
Senior Marketing Manager: Curt Reynolds
Development Editor: Darlene M. Schueller
Lead Project Manager: Jane Mohr
Design Coordinator: Margarite Reynolds
Cover Designer: Margarite Reynolds
Cover Image: Nick Rowe/Getty Images, © Don Bishop/Getty Images, McGraw-Hill Companies, © Lars A. Niki
Buyer: Susan K. Culbertson
Media Project Manager: Prashanthi Nadipalli
Compositor: Laserwords Private Limited
Typeface: 10/12 Times LT Std Roman
Printer: Quad Graphics
All credits appearing on page or at the end of the book are considered to be an extension of the copyright page.
Library of Congress Cataloging-in-Publication Data
Mesiya, Mohammed Farooque.
Contemporary communication systems / Mohammed Farooque Mesiya.
p. cm.
ISBN 978-0-07-338036-0 (alk. paper)
1. Telecommunication. I. Title.
TK5101.M4233 2012
384—dc23
2011028902
www.mhhe.com
mes80369_fm_i-xviii.indd ii 13/12/11 4:43 PM
, In loving memory of my parents
Aisha and Kassem Mesiya
To
Sieglinde for her tremendous patience and support
Yasmin and Misha for inspiring me to pursue
the opportunities the future offers
mes80369_fm_i-xviii.indd iii 13/12/11 4:43 PM
, Brief Contents
CHAPTER 1
Introduction 1
CHAPTER 2
Review of Signals and Linear Systems 24
CHAPTER 3
Simulation of Communication Systems Using MATLAB/Simulink 104
CHAPTER 4
Amplitude Modulation 141
CHAPTER 5
Angle Modulation 206
CHAPTER 6
Probability and Random Processes 278
CHAPTER 7
Noise Performance of Analog Communication Systems 371
CHAPTER 8
Conversion of Analog Signals to Digital Format 422
CHAPTER 9
Digital Baseband Modulation 489
CHAPTER 10
Detection of Baseband Signals in Noise 532
CHAPTER 11
Digital Information Transmission Using Carrier Modulation 592
CHAPTER 12
Digital Signal Transmission Through Time Dispersive Channels 679
CHAPTER 13
Digital Multiplexing and Synchronization 741
CHAPTER 14
Information Theory and Compression Techniques 787
CHAPTER 15
Channel Coding Techniques 854
iv
mes80369_fm_i-xviii.indd iv 13/12/11 4:43 PM
, Table of Contents
Preface xv
CHAPTER 1
Introduction 1
1.1 Elements of a Communication System 2
1.2 Communication Channels 2
1.2.1 Coaxial Cable 4
1.2.2 Optical Fibers 5
1.2.3 Radio Channels 8
1.3 Analog and Digital Communication Systems 10
1.3.1 Digital Communication Systems 10
1.3.2 Why Digital Transmission? 12
1.4 History of Communications 14
1.4.1 Wireless Communications 18
1.5 Key Themes and Drivers 19
Final Remarks 21
Further Readings 21
CHAPTER 2
Review of Signals and Linear Systems 24
2.1 Basic Signal Concepts 25
2.1.1 Some Useful Basic Signals 27
2.1.2 Energy and Power Signals 33
2.1.3 Logarithmic Power Calculations 35
2.1.4 Some Basic Operations on Signals 35
2.2 Basic System Concepts 38
2.2.1 Classification of Systems 39
2.2.2 Characterization of LTI Systems 42
2.3 Frequency Domain Representation 46
2.4 Fourier Series 47
2.4.1 Trigonometric Fourier Series 48
2.4.2 Parseval’s Theorem 52
2.4.3 Convergence of Fourier Series 54
2.5 Fourier Transform 55
2.5.1 Fourier Transforms of Some Common Signals 56
2.5.2 Properties of Fourier Transform 58
2.5.3 Fourier Transforms of Periodic Signals 65
2.6 Time-Bandwidth Product 68
2.7 Transmission of Signals Through LTI Systems 70
2.7.1 Distortionless Transmission 73
2.8 LTI Systems as Frequency Selective Filters 74
2.8.1 Ideal Filters 74
2.8.2 Realizable Approximations to Ideal Filters 78
2.8.3 Analog Filter Design Using MATLAB 80
v
mes80369_fm_i-xviii.indd v 13/12/11 4:43 PM
, vi Table of Contents
2.9 Power Spectral Density 84
2.9.1 Time-Average Autocorrelation Function 86
2.9.2 Relationship Between Input and Output Power Spectral Densities 87
2.10 Frequency Response Characteristics of Transmission Media 88
2.10.1 Twisted Wire Pairs 88
2.10.2 Coaxial Cable 92
2.11 Fourier Transforms for Discrete-Time Signals 92
Final Remarks 96
Further Readings 97
Problems 97
MATLAB Problems 100
CHAPTER 3
Simulation of Communication Systems Using MATLAB/Simulink 104
3.1 Getting Started in Simulink 105
3.1.1 Solvers 111
3.2 Modeling in Simulink 112
3.2.1 Subsystems 115
3.3 Simulation of Signal and Noise Sources 119
3.3.1 Deterministic Signals 119
3.3.2 Random Signals 121
3.3.3 Modeling of AWGN Channel 125
3.4 Modeling of Communication Systems 128
3.4.1 Time-Domain Modeling 128
3.4.2 Transform-Domain Description 131
3.5 Displaying Signals in Frequency Domain 134
3.6 Using Simulink with MATLAB 136
3.6.1 Running Simulations from MATLAB 137
Final Remarks 139
Further Readings 140
CHAPTER 4
Amplitude Modulation 141
4.1 Low-Pass and Bandpass Signals 143
4.2 Double-Sideband Suppressed-Carrier AM 144
4.2.1 Spectrum of the DSB-SC AM Signal 144
4.2.2 Demodulation of DSB-SC AM Signals 147
Experiment 4.1 DSB-SC AM Modulation and Demodulation 149
4.3 Conventional Amplitude Modulation 152
4.3.1 Spectrum of the Conventional AM Signal 154
4.3.2 Demodulation of Conventional AM Signal 160
Experiment 4.2 Conventional AM Modulation and Demodulation 164
4.4 Alternative Representations for BP Signals and Systems 166
4.4.1 Frequency Spectrum of Complex Envelope and Analytic Representations 168
4.4.2 Complex Envelope Representation of BP Systems 170
4.5 Single-Sideband AM 173
4.5.1 Demodulation of SSB-AM Signals 177
Experiment 4.3 SSB-AM Modulation and Demodulation 179
4.6 Vestigial-Sideband AM 181
4.7 Quadrature Multiplexing 185
4.8 Multiplexing 186
4.8.1 Frequency Division Multiplexing 186
mes80369_fm_i-xviii.indd vi 13/12/11 4:43 PM
, Table of Contents vii
4.9 Frequency Translation and Selection 190
4.9.1 Down-Conversion Mixer 190
4.9.2 Image-Reject Mixers 192
4.10 Communication Receivers 193
4.10.1 Superheterodyne Receivers 194
4.10.2 Direct-Conversion Receivers 196
4.10.3 Low-IF Receiver Architectures 197
Final Remarks 198
Further Readings 199
Problems 199
MATLAB Problems 201
APPENDIX 4A: Hilbert Transform 203
CHAPTER 5
Angle Modulation 206
5.1 FM and PM Signals 206
5.1.1 FM and PM Signals with Sinusoidal Modulating Signal 211
5.1.2 Power in Angle-Modulated Signal 214
5.2 Spectrum of Angle-Modulated Signals 215
5.2.1 Bandwidth of a Sinusoidally Modulated FM Signal 216
5.2.2 Bandwidth of an FM Signal Modulated by Arbitrary Message Signal 219
5.3 Narrowband FM 221
5.4 Demodulation of Angle-Modulated Signals 223
5.4.1 Bandpass Limiter 224
5.4.2 Frequency Discriminator 225
Experiment 5.1 Simulink Model of an FM System with Frequency Discriminator 226
Experiment 5.2 FM Demodulation with Balanced Slope Detector 230
5.4.3 Phase-shift Discriminator: Quadrature Detector 231
5.5 Phase-Locked Loop 233
5.5.1 Analog Phase-Locked Loop 234
5.5.2 APLL Linear Model 238
5.5.3 First-Order PLL 239
Experiment 5.3 First-Order PLL 242
5.5.4 Second-Order PLL 243
Experiment 5.4 Second-Order PLL 252
5.5.5 Acquisition Process: APLL in the Unlocked State 253
5.6 PLL as FM Demodulator 255
Experiment 5.5 PLL as FM Demodulator 256
5.7 FM Broadcasting 258
5.7.1 FM Stereo 258
5.8 Analog Television 260
5.8.1 Black-and-White Image 260
5.8.2 Black-and-White Television 262
5.8.3 Color Television 267
5.8.4 Multichannel Television Sound 272
Final Remarks 273
Further Readings 274
Problems 274
MATLAB Problems 276
CHAPTER 6
Probability and Random Processes 278
6.1 Probability Concepts 279
mes80369_fm_i-xviii.indd vii 14/12/11 6:59 PM
, viii Table of Contents
6.1.1 Relative Frequency 279
6.1.2 Probability Axioms 280
6.1.3 Union Bound 281
6.1.4 Conditional Probability 282
6.2 Random Variables 286
6.2.1 Discrete Random Variables 287
6.2.2 Some Common Discrete Random Variables 288
6.3 Continuous Random Variables 291
6.3.1 Some Common Continuous Random Variables 293
6.3.2 PDFs for Discrete and Mixed Random Variables 298
6.4 Functions of a Random Variable 299
6.4.1 Case I: g(x) Monotonically Increasing or Decreasing 299
6.4.2 Case II: Arbitrary g(x) 301
6.5 Statistics of Random Variables 302
6.5.1 Moments and Characteristic Functions 304
6.6 Pairs of Random Variables 307
6.6.1 Marginal Distributions 309
6.6.2 Function of Two Random Variables: Expected Values 310
6.7 Conditional Distributions 313
6.7.1 Conditional Expected Values 316
6.7.2 Independent Random Variables 316
6.8 Jointly Gaussian Random Variables 318
6.8.1 Two Functions of Two Random Variables 321
6.8.2 Central Limit Theorem 323
6.9 Random Processes: Introduction 324
6.9.1 Characterization of a Random Process 327
6.9.2 Stationary Random Processes 330
6.9.3 Wide-Sense Stationary Random Processes 331
6.9.4 Ergodic Random Processes 331
6.9.5 Properties of the Autocorrelation Function 332
6.9.6 Uncorrelated, Orthogonal, and Independent Random Processes 333
6.10 Power Spectrum of a Random Process 333
6.10.1 Wiener-Khinchin Theorem 334
6.10.2 Transmission of Random Signals Through Linear Time-Invariant Systems 336
6.11 Some Important Random Processes 338
6.11.1 Gaussian Random Process 338
6.11.2 White Gaussian Noise 339
6.11.3 Filtered White Gaussian Noise 340
6.12 Narrowband Noise 342
6.12.1 Narrowband White Gaussian Noise 344
6.12.2 Envelope of Sine Wave in Narrowband Noise 348
6.13 Noise Sources in Communication Systems 350
6.13.1 Thermal Noise 350
6.13.2 Available Power 352
6.13.3 Shot Noise 353
6.14 Characterization of System Noise 354
6.14.1 Noise Factor and Noise Figure 355
6.14.2 Effective Input Noise Temperature of a Subsystem 356
6.14.3 Noise Figure of a Cascade of Subsystems 357
6.14.4 Noise Factor of a Lossy Two-Port Network 359
6.15 MATLAB Simulation of Random Processes 360
6.15.1 Generating Arbitrary PDF Random Variables 361
6.15.2 Autocorrelation Function and Spectral Density 362
6.15.3 Samples of White Gaussian Noise 362
Final Remarks 364
Further Readings 364
mes80369_fm_i-xviii.indd viii 13/12/11 4:43 PM
, Table of Contents ix
Problems 364
MATLAB Problems 367
CHAPTER 7
Noise Performance of Analog Communication Systems 371
7.1 Noise Performance of Baseband Systems 372
7.2 Effect of Noise on the Performance of AM Systems 373
7.2.1 Noise Performance of DSB-SC 374
Experiment 7.1 Noise Performance of a DSB-SC AM System 376
7.2.2 Noise Performance of SSB-AM 378
Experiment 7.2 Noise Performance of an SSB-AM System 381
7.2.3 Noise Performance of Conventional AM 383
Experiment 7.3 Noise Performance of Conventional AM System 388
7.3 Noise Performance of Angle-Modulation Systems 390
7.3.1 High-CNR Operation 391
7.3.2 FM System Operation: Low-CNR Case 398
Experiment 7.4 Noise Performance of an FM System 403
7.4 Preemphasis and Deemphasis 405
7.5 Comparison of Analog Modulation Systems 407
7.6 Link Design 409
7.6.1 Analog Repeater 410
7.6.2 Performance of Analog Communication System Using Cascade of Repeaters 411
Final Remarks 415
Further Readings 416
Problems 416
MATLAB Problems 418
CHAPTER 8
Conversion of Analog Signals to Digital Format 422
8.1 Sampling of Low-Pass Signals 423
8.1.1 Nyquist-Shannon Sampling Theorem 425
8.1.2 DFT of the Sampled Sequence 426
8.1.3 Reconstruction of the Analog Signal 427
8.1.4 Practical Sampling Techniques 429
8.2 Aliasing 432
Experiment 8.1 Natural Sampling of a LP Random Signal 436
8.3 Digitization of Analog Signals 438
8.3.1 Quantization 439
8.3.2 Coding of Quantized Samples 440
8.3.3 Errors Introduced by Quantization Process 442
Experiment 8.2 Study of m-Bit Quantization Errors 442
8.3.4 Quantization Noise 444
8.4 Pulse Code Modulation 447
8.4.1 Nonuniform Quantization 448
8.5 Differential Pulse Code Modulation 454
8.6 Oversampling in Analog-to-Digital Conversion 457
8.7 Delta Modulation 460
8.7.1 Slope Overload and Granular Noise 462
8.7.2 Adaptive Delta Modulation 463
8.7.3 Continuously Variable Slope Delta Modulation 464
8.7.4 Quantization Noise 465
Experiment 8.3 Delta Modulation 468
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