Essentials of Modern Communications. Edition No. 1

Table of Contents

About the Authors xxi

Preface xxiii

Acknowledgments xxvii

1 Modern Communications: What It Is? 1

Objectives and Outcomes of Chapter 1 1

1.1 What and Why of Modern Communications 4

Objectives and Outcomes of Section 1.1 4

1.1.1 What is Modern Communications? 5

1.1.2 General Block Diagram of a Communication System 6

1.1.3 Operation of a Communication System 7

1.1.4 Why DoWe Need Modern Communications? 8

1.1.5 From Today to Tomorrow - Two Examples 9

1.1.5.1 The Internet of Things (IoT) 10

1.1.5.2 Data Centers 12

Questions and Problems for Section 1.1 13

1.2 Communication Technology on a Fast Track 16

Objectives and Outcomes of Section 1.2 16

Sidebar 1.2.S.1 Brief Notes on History of Telegraph, Telephone, Radio, and Television 22

1.2.1 The Internet 28

1.2.1.1 Basics of Networks 28

1.2.1.2 The Internet: From a Point-to-Point Link to a Network of Networks 37

1.2.2 Optical Communications 42

1.2.2.1 Introduction to Optical Communications 43

1.2.2.2 Developments in Optical Communications: From First Inventions to Modern Advances 46

1.2.3 Wireless Communications 49

1.2.3.1 Introduction to Wireless Communications 49

1.2.3.2 Contemporary Wireless Communications Technologies 54

1.2.3.3 Mobile Cellular Communications 57

1.2.4 Satellite Communications 59

1.2.4.1 Historical Notes 59

1.2.4.2 Principle of Operation of Satellite Communication Systems 60

1.2.4.3 Satellite Orbits 62

Questions and Problems for Section 1.2 67

1.3 Fundamental Laws and Principles of Modern Communications 75

1.3.1 Fundamental Laws of Modern Communications 75

1.3.1.1 Hartley’s Information Law 75

1.3.1.2 Signal Bandwidth and Transmission Bandwidth from the Transmission Standpoint 76

1.3.1.3 Bandwidth and Bit Rate, Nyquist’s Formula, and Hartley’s Capacity Law 77

1.3.1.4 Shannon’s Law (Limit) 79

1.3.1.5 More Clarifications of the Shannon Law 82

1.3.1.6 The Shannon Law for Digital Communications 83

1.3.2 Fundamental Principles of Modern Communications 86

1.3.2.1 Channel Capacity, Bandwidth, and Carrier Frequency 86

1.3.2.2 Bandwidth-Length Product 90

1.3.2.3 Power-Bandwidth Trade-Off 91

1.3.2.4 Spectral Efficiency and Transmission Technology 92

1.3.2.5 Bit Rate vs. Bandwidth in Digital Transmission 93

1.3.3 Laws, Principles, and Models - Importance, Limitations, and Applications 94

1.3.3.1 Limitations and Applications of the Laws and Principles 94

1.3.3.2 Models 96

1.3.3.3 Modeling and Simulation 98

Questions and Problems for Section 1.3 99

2 Analog Signals and Analog Transmission 103

Objectives and Outcomes of Chapter 2 103

2.1 Analog Signals - Basics 104

Objectives and Outcomes of Section 2.1 104

2.1.1 Definitions 104

2.1.1.1 Waveforms 104

2.1.1.2 Analog and Digital Signals 108

2.1.2 Sinusoidal Signal 110

2.1.2.1 The Waveform of a Sinusoidal Signal 110

2.1.2.2 Period and Frequency 111

2.1.2.3 Frequency, Radian (Angular) Frequency and Angle 115

2.1.2.4 Phase Shift (Initial Phase) 117

2.1.2.5 Amplitude 121

Questions and Problems for Section 2.1 125

2.2 Analog Signals - Introduction 129

Objectives and Outcomes of Section 2.2 129

2.2.1 More About a Sinusoidal Signal 130

2.2.1.1 Considering All Three Parameters - the Formula for a Sinusoidal Signal 130

2.2.1.2 The Phase of a Sinusoidal Signal: a Detailed Look 132

2.2.1.3 Cosine and Sine Signals 138

Sidebar 2.2.S.1 Phasor and Sinusoidal Signal 139

Sidebar 2.2.S.2 Signal and Function 146

2.2.2 Frequency Domain and Bandwidth 151

2.2.2.1 Frequency Domain 151

2.2.2.2 Cosine and Sine Signals in Frequency Domain 151

2.2.2.3 Bandwidth 156

2.2.2.4 Bandwidth: a Sophisticated Entity 159

Questions and Problems for Section 2.2 162

2.3 Analog Signals - Advanced Study 167

Objectives and Outcomes of Section 2.3 167

2.3.1 Revisiting the Waveforms 168

2.3.1.1 More about Waveforms 168

2.3.1.2 Waveform and Signal’s Power 174

2.3.2 Waveforms and Phasors 178

2.3.2.1 Practically Realizable Waveforms 178

2.3.2.2 Phasors and Phasor Diagrams 178

2.3.2.3 Waveforms and Phasors for a Resistor, an Inductor, and a Capacitor 181

2.3.2.4 Impedances and Phasors 185

Questions and Problems for Section 2.3 189

2.3.A Mathematical Foundation of Phasor Presentation 191

2.3.A.1 Phasors and Complex Numbers 191

2.3.A.2 Applications of Phasor Presentation to the Analysis of Electronic Communications Circuitry 195

2.3.A.2.1 Summation of Signals 195

Optional: Questions and Problems for Appendix 2.3.A 200

3 Digital Signals and Digital Transmission 203

Objectives and Outcomes of Chapter 3 203

3.1 Digital Communications - Basics 203

Objectives and Outcomes of Section 3.1 203

3.1.1 Why Go to Digital Communications 204

3.1.1.1 Main Advantage of Digital Transmission over the Analog 204

3.1.1.2 Case Study 1: The Advantages of Using Digital Signals in Transmission 207

3.1.1.3 Case Study 2 of Digital Communications: Transmission with Integrated-Circuit Digital Logic Families 210

3.1.1.4 Why Go to Digital Communications: A Summary 214

3.1.2 How to Go to Digital Communications 215

3.1.2.1 From Characters to Bits 215

3.1.2.2 From Bits to Electrical Pulses 222

3.1.2.3 How to Go Digital Communications: A Summary 224

Questions and Problems for Section 3.1 225

3.1.A Brief History of Character Codes 229

3.1.A.1 International Morse Code 229

3.1.A.2 Baudot Code 230

3.2 Digital Signals and Digital Transmission - Introduction 232

Objectives and Outcomes of Section 3.2 232

3.2.1 Ideal Digital Signal and Characteristics of Digital Transmission 233

3.2.1.1 The Waveform of an Ideal Digital Signal 233

3.2.1.2 Pulse Interval and Transmission Rate; Bit Time and Bit Rate 235

3.2.1.3 Important Note: The Definition of Bit Time 237

3.2.1.4 Bit Rate and Channel (Shannon’s) Capacity 237

3.2.2 Parameters of a Real Digital Signal and the Characteristics of Digital Transmission 239

3.2.2.1 Waveform of an Actual Digital Signal 239

3.2.2.2 Amplitude and Pulse Width 240

3.2.2.3 Rise Time and Fall Time 241

3.2.2.4 Rise/Fall Time and Bit Rate 244

3.2.2.5 More on Timing Parameters of a Digital Signal: Bit Time Revisited 247

3.2.2.6 Duty Cycle 250

Questions and Problems for Section 3.2 253

4 Analog-to-Digital Conversion (ADC) and Digital-to-Analog Conversion (DAC) 259

Objectives and Outcomes of Chapter 4 259

4.1 Analog-to-Digital Conversion, ADC 259

Objectives and Outcomes of Section 4.1 259

4.1.1 The Need for ADC and DAC 261

4.1.2 Three Major Steps of ADC 263

4.1.3 Sample-and-Hold (S&H) Operation 263

4.1.3.1 Sampling (S&H) Technique and the Nyquist Theorem 263

4.1.3.2 Aliasing 267

4.1.4 Quantization in ADC 272

4.1.4.1 Quantization Process 272

4.1.4.2 Quantization Errors and Quantization Noise 284

4.1.5 Encoding 285

Questions and Problems for Section 4.1 291

4.1.A Decimal and Binary Numbering Systems 299

4.1.A.1 Decimal Numbering System 299

4.1.A.2 Binary Numbering System 300

4.1.A.3 Conversion from the Decimal Number System to the Binary 301

4.2 Digital-to-Analog Conversion, DAC, Pulse-Amplitude Modulation, PAM, and Pulse-Code Modulation, PCM 303

Objectives and Outcomes of Section 4.2 303

4.2.1 Digital-to-Analog Conversion, DAC 304

4.2.2 Pulse Amplitude Modulation, PAM 304

4.2.3 Pulse Code Modulation, PCM 306

4.2.3.1 PCM: Principle of Operation 306

4.2.3.2 PCM: Advantages and Drawbacks 308

4.2.3.3 PCM Applications 309

Questions and Problems for Section 4.2 309

4.2.A Modes of Digital Transmission 311

4.2.A.1 Simplex, Half Duplex and Full Duplex Transmission 311

4.2.A.2 Serial and Parallel Transmissions 312

4.2.A.3 The General Formula for Bit Rate 314

4.2.A.4 The Need for Synchronization in Digital Transmission 315

4.2.A.4.1 Digital Signals and Timing 315

4.2.A.4.2 Timing in Digital Transmission 316

4.2.A.4.3 Time Discrepancy Between Transmitter and Receiver Clocks 317

4.2.A.4.4 How Time Discrepancy Between Transmitter and Receiver Clocks Deteriorates the Quality of Digital

Transmission 319

4.2.A.4.5 A Short Summary on Synchronization Issues 320

4.2.A.5 Asynchronous and Synchronous Transmission 320

4.2.A.5.1 Asynchronous Transmission 321

4.2.A.5.2 Synchronous Transmission 323

5 Filters 325

Objectives and Outcomes of Chapter 5 325

5.1 Filtering - Basics 326

Objectives and Outcomes of Section 5.1 326

5.1.1 Filtering: What and Why 327

5.1.2 RC Low-Pass Filter (LPF) 330

5.1.2.1 Frequency Responses of a Resistor, R, and a Capacitor, C 330

5.1.2.2 RC Low-Pass Filter: Principle of Operation 333

5.1.2.3 Output Waveforms of an RC LPF 334

5.1.2.4 An RC LPF: Formulas for Attenuation and Phase Shift 335

5.1.2.5 Frequency Response of an RC LPF 339

5.1.2.6 Cutoff (Critical) Frequency of an RC LPF 342

Sidebar 5.1.S Filter’s Characteristics in Absolute Values and in dB 345

5.1.3 Filter Operation in Time Domain and Frequency Domain 347

5.1.3.1 Waveform Change and Frequency Response 347

5.1.3.2 Bandwidth of an RC LPF 349

5.1.3.3 Characterization of an RC LPF 349

5.1.3.4 The Role of R and C Parameters in Characterization of an RC LPF 352

5.1.4 General Filter Specifications 354

5.1.4.1 Amplitude Specifications 354

5.1.4.2 Phase Specifications 359

Questions and Problems for Section 5.1 360

5.2 Filtering - Introduction 365

Objectives and Outcomes of Section 5.2 365

5.2.1 High-Pass Filter (HPF), Band-Pass Filter (BPF), and Band-Stop Filter (BSF) 366

5.2.1.1 High-Pass Filter (HPF) 367

5.2.1.2 Band-Pass Filter (BPF) 371

5.2.1.3 Band-Stop Filter (BSF) 378

5.2.1.4 Applications of RC Filters 380

5.2.1.5 Final Notes on RC Filters 380

5.2.2 Transfer Function of a Filter 381

5.2.2.1 Input and Output of a Filter 381

5.2.2.2 Transfer Function of an RC LPF 384

5.2.2.3 Graphical Presentation of a Transfer Function: Bode Plots 387

Questions and Problems for Section 5.2 394

5.2.A RL Filter and Resonance Circuits as Filters 400

5.2.A.1 RL Filter 400

5.2.A.2 Resonance Circuits as Filters 402

5.2.A.2.1 Resonance Circuits: A Review 402

5.2.A.2.2 Quality Factor 405

5.2.A.2.3 Resonance Circuit as a Band-Pass Filter 406

5.2.A.2.4 Resonance Circuit as a Band-Stop Filter 407

5.3 Active and Switched-Capacitor Filters 409

Objectives and Outcomes of Section 5.3 409

5.3.1 Active Filters 410

5.3.1.1 Drawbacks of Passive Filters 410

5.3.1.2 Operational Amplifier 413

5.3.1.3 Active Filters: Concept and Circuits 418

5.3.1.4 Transfer Functions of an Active Filter: General View 419

5.3.1.5 Specific Types of Active Filters 420

5.3.1.6 Concluding Remarks on Active Filters 424

5.3.2 Switched-Capacitor Filters 424

5.3.2.1 Switched-Capacitor Filters: Concept and Circuits 424

5.3.2.2 Applications of Switched-Capacitor Filters 428

Questions and Problems for Section 5.3 431

5.3.A Active BPF and BSF 436

5.3.A.1 Active BPF 436

5.3.A.2 Active BSF 439

5.4 Filter Prototypes and Filter Design 441

Objectives and Outcomes of Section 5.4 441

5.4.1 Filter Prototypes 444

5.4.1.1 The Problem in the Filter Design - The Need for the Filter Prototypes 444

5.4.1.2 Another Problem for Filter’s Designer: Relationship Between Amplitude and Phase Responses 445

5.4.1.3 Main Filter Prototypes - What and Why 446

5.4.1.4 Transfer Function of the Butterworth Filter 450

5.4.1.5 Amplitude Response of the Butterworth Filter 451

5.4.1.6 Amplitude Response of the Butterworth Filter in Logarithmic Scale 453

5.4.1.7 Phase Response (Shift) and Time Group Delay of the Butterworth Filter 456

5.4.1.8 Poles of the Butterworth Filter’s Transfer Function 457

5.4.2 Introduction to Filter Design 459

5.4.2.1 Two Main Steps in Filter Design 459

5.4.2.2 Automated Design Options 460

5.4.2.3 Design of a Second-order Butterworth Filter 462

5.4.2.4 Using the Poles of a Transfer Function 468

5.4.3 The Design Process: Key Questions, Answers, and Salient Points 469

5.4.3.1 Questions and Answers 469

5.4.3.2 Salient Points 470

5.4.3.3 Choosing Filter Technology 471

Questions and Problems for Section 5.4 472

5.4.A Tables of the Butterworth Polynomials 478

5.5 Digital Filters 479

Objectives and Outcomes of Section 5.5 479

5.5.1 What are Digital Filters? 479

5.5.1.1 Digital Filters - Principle of Operation 479

5.5.1.2 ADC and DAC Operations Revisited 481

5.5.1.3 Digital Filters - Difference Equation, Order, and Coefficients 484

5.5.1.4 Recursive (IIR) and Nonrecursive (FIR) Digital Filters and Their Difference Equations 486

5.5.1.5 Impulse Response of Digital Filters 487

5.5.1.6 Transfer Function of a Digital Filter 488

5.5.2 Conclusive Remarks on Digital and Analog Filters 491

5.5.2.1 Some Final Comments on Digital Filters 491

5.5.2.2 Adaptive Filters 491

5.5.2.3 Comparison of Analog and Digital Filters 492

5.5.2.4 Summary of Applications of Various Filter Technologies 492

Questions and Problems for Section 5.5 494

What are Digital Filters? 494

6 Spectral Analysis 1 - The Fourier Series in Modern Communications 497

Objectives and Outcomes of Chapter 6 497

6.1 Basics of Spectral Analysis 498

Objective and Outcomes of Section 6.1 498

6.1.1 Time Domain and Frequency Domain 498

6.1.1.1 Periodic and Nonperiodic Signals 498

6.1.1.2 Time Domain and Frequency Domain Revisited 500

6.1.1.3 Signal Spectrum 509

6.1.2 The Fourier Series 511

6.1.2.1 The Fourier Theorem 511

Sidebar 6.1.S.1 Calculating the Coefficients of a Fourier Series 515

6.1.2.2 Spectral Analysis - From the Whole to the Parts 519

6.1.3 Spectral Synthesis 520

6.1.3.1 Spectral Synthesis - From Parts to the Whole 520

Questions and Problems for Section 6.1 528

6.2 Introduction to Spectral Analysis 534

Objectives and Outcomes of Section 6.2 534

6.2.1 More About the Fourier Series 534

6.2.1.1 Coefficients of the Fourier Series 534

6.2.1.2 Amplitude and Phase Spectra 537

Sidebar 6.2.S.1 Using the Signal’s Symmetry for Finding the Fourier Series Coefficients 542

6.2.1.3 Finding the Fourier Series of Various Signals 544

6.2.2 Effect of Filtering on Signals 546

6.2.2.1 Statement of the Problem 546

6.2.2.2 Filtering a Single Harmonic 552

6.2.2.3 Filtering a Periodic Signal - Time and Frequency Domains 554

6.2.2.4 Filtering a Signal - The Entire Picture 560

6.2.2.5 A Final Note on Effect of Filtering on Signals 566

6.2.3 Harmonic Distortion 566

Questions and Problems for Section 6.2 572

6.3 Spectral Analysis of Periodic Signals: Advanced Study 578

Objectives and Outcomes of Section 6.3 578

6.3.1 Mathematical Foundation of the Fourier Series 579

6.3.1.1 The Fourier Series in Exponential and Phasor Forms 579

Sidebar 6.3.S.1 The Other Forms of an Exponential Fourier Series 587

6.3.1.2 Two-Sided and One-Sided Spectra and Three Equivalent Forms of the Fourier Series 588

6.3.2 Conditions for Application of the Fourier Series 591

Sidebar 6.3.S.2 Convergence of the Fourier Series 591

6.3.2.1 Gibbs Phenomenon 593

6.3.3 Power Spectrum of a Periodic Signal 594

6.3.3.1 Power and Energy Signals 594

6.3.3.2 Parseval’s Theorem 595

6.3.3.3 A Signal’s Bandwidth and Transmission Issues Associated with a Power Spectrum 598

Questions and Problems for Section 6.3 609

6.3.A Fourier Coefficients of a Two-sided and a One-sided Spectrum of the Periodic Pulse Train for Example 6.3.2. 613

7 Spectral Analysis 2 - The Fourier Transform in Modern Communications 615

Objectives and Outcomes of Chapter 7 615

7.1 Basics of the Fourier Transform 616

Objectives and Outcomes of Section 7.1 616

7.1.1 The Fourier Transform in Spectral Analysis 617

7.1.1.1 From a Periodic to a Nonperiodic Signal 617

7.1.1.2 From the Fourier Series to the Fourier Transform 628

7.1.1.3 The Fourier Transform Briefly Explained 629

7.1.2 First Examples of the Fourier Transform Applications 632

7.1.2.1 A Rectangular Pulse 632

7.1.2.2 Basics of the Spectral Analysis of a Nonperiodic Signal 635

7.1.2.3 Rayleigh Energy Theorem 639

Summary of Section 7.1 642

Questions and Problems for Section 7.1 643

7.2 Continuous-Time Fourier Transform: A Deeper Look 644

Objectives and Outcomes of Section 7.2 644

7.2.1 Definition and Existence of the Fourier Transform 645

7.2.2 The Concept of Function and the Transform 646

Sidebar 7.2.S.1 Dirac Delta Function 649

7.2.3 Table of the Fourier Transform 654

7.2.4 Properties of the Fourier Transform 656

7.2.4.1 Units 656

7.2.4.2 Linearity 657

7.2.4.3 Duality 657

7.2.4.4 Modulation 657

7.2.4.5 Convolution in Time and in Frequency and a Transfer Function 658

7.2.4.6 Time Differentiation 659

7.2.4.7 Other Properties of the Fourier Transform 659

7.2.5 Example of Using the Fourier Transform 659

Sidebar 7.2.S.2 The Impulse Response of an RC LPF 662

Sidebar 7.2.S.3 Alternative Methods of Finding a Transfer Function 667

7.3 The Fourier Transforms and Digital Signal Processing 670

Objectives and Outcomes of Section 7.3 670

7.3.1 Signals and the Fourier Transformations 671

Sidebar 7.3.S.1 A Word About DSP 677

7.3.2 Determining the Fourier Transform Required for DSP 681

7.3.3 Digital Signal Processing (DSP) and Discrete Fourier Transform (DFT) 681

7.3.3.1 The Problem: Choosing the Best Type of FT for DSP 681

7.3.3.2 How Discrete Fourier Transform (DFT)Works 682

7.3.3.3 Can DFT Work with Any Signal? 690

7.3.4 Relationship Among All Fourier Transforms 697

7.3.5 Fast Fourier Transform (FFT) 699

8 Analog Transmission with Analog Modulation 707

Objectives and Outcomes of Chapter 8 707

8.1 Basics of Analog Modulation 708

Objectives and Outcomes of Section 8.1 708

8.1.1 Why We Need Modulation: Baseband and Broadband Transmission 710

8.1.1.1 Baseband Transmission and Its Major Problems 710

8.1.1.2 Solution to the Problems of Baseband

Transmission - Broadband Transmission 712

8.1.2 Basics of Amplitude Modulation 715

8.1.2.1 What Type of Analog Modulation Can We Have? 715

8.1.2.2 What is Amplitude Modulation (AM) 715

8.1.2.3 Modulation Index 719

8.1.2.4 Relationship Between Frequencies of Information and Carrier Signals 722

8.1.2.5 The Formula for an AM Signal and It Instantaneous Value 723

8.1.2.6 The Spectrum of an AM Signal 725

8.1.2.7 Power Distribution in an AM Signal 728

8.1.2.8 AM Modulation and Demodulation 730

8.1.2.9 The Main Drawback of Amplitude Modulation 732

8.1.3 Basics of Frequency Modulation (FM) 733

8.1.3.1 Frequency Modulation: Why and What 733

8.1.3.2 The Frequency of an FM Signal 734

8.1.3.3 Modulation Index of an FM Signal 738

8.1.3.4 The Spectrum and Bandwidth of an FM Signal 740

8.1.3.5 Relationship Between Parameters of Message and Carrier Signals in FM Transmission 746

8.1.3.6 FM Modulation and Demodulation 746

8.1.4 Basics of Phase Modulation (PM) 750

8.1.4.1 How to Generate a Phase-Modulated Signal 750

8.1.4.2 Instantaneous Value of a Sinusoidal PM Signal 754

Questions and Problems for Section 8.1 754

8.1.A Drawbacks of Baseband Transmission 759

8.2 Analog Modulation for Analog Transmission - An Advanced Study 762

Objectives and Outcomes of Section 8.2 762

8.2.1 Classification of Modulation Revisited 763

8.2.2 Advanced Consideration of Amplitude Modulation, AM, and Its Application in Analog Transmission 766

8.2.2.1 Full (Double-Sideband Transmitted Carrier, DSB-TC) Amplitude Modulation 766

8.2.2.2 Problems of Full AM Transmission 774

8.2.2.3 Double-Sideband Suppressed Carrier (DSB-SC) AM 774

8.2.2.4 Single-Sideband Suppressed Carrier (SSB-SC) AM 779

8.2.2.5 Full AM, DSB, or SSB - Which Type to Choose? 782

8.2.2.6 Applications of AM Transmission 784

8.2.3 Advanced Consideration of Angular (Phase and Frequency) Modulation and Its Application in Analog Transmission 784

8.2.3.1 Angular Modulation 784

8.2.3.2 Sinusoidal (Single-Tone) Frequency Modulation (FM) 788

8.2.3.3 The Spectrum of a Single-Tone FM Signal, the Main Properties of the Bessel Functions, and Narrowband and Wideband FM 790

8.2.3.4 The Bandwidth of a Single-Tone FM Signal 793

8.2.3.5 General Case of an FM Signal (An Arbitrary Message Signal) 799

8.2.3.6 Effect of Noise on an FM Signal 807

Questions and Problems for Section 8.2 810

8.2.A Finding the Spectrum of an FM Signal with MATLAB 814

9 Digital Transmission with Binary Modulation 823

Objectives and Outcomes of Chapter 9 823

9.1 Digital Transmission - Basics 824

Objectives and Outcomes of Section 9.1 824

9.1.1 Essentials of Digital Transmission Revisited 827

9.1.1.1 Block Diagram of a Communication System 827

9.1.1.2 Characteristics of a Transmitter, Tx 828

9.1.1.3 Characteristics of a Receiver, Rx 829

9.1.1.4 Characteristics of a Transmission Channel (Link) 830

9.1.1.5 The Model of Noise in Shannon’s Law 835

9.1.1.6 An Amplifier in a Transmission Channel: Internal Noise, SNR, and Noise Figure 839

9.1.2 Assessing the Quality of Digital Transmission: The Gaussian (Bell) Curve and the Probability Value 843

9.1.2.1 Gaussian (Bell) Normal Probability Distribution 843

9.1.2.2 Finding the Probability Value with the Bell Curve 844

9.1.2.3 Standard Normal Probability Distribution 847

9.1.2.4 The Gaussian Curve and Q-Function 850

9.1.3 Assessing the Quality of Digital Transmission: Bit Error Rate and More 852

9.1.3.1 Decision-Making Procedure in the Presence of Noise 852

9.1.3.2 The Probability of Error in Detecting the Received Signal: Bit Error Rate (Ratio) 855

9.1.3.3 BER: A Discussion 858

9.1.4 Eye Diagram 860

9.1.4.1 Eye Diagram: The Concept 860

9.1.4.2 Estimating Transmission Quality with an Eye Diagram 865

Questions and Problems for Section 9.1 869

9.2 Introduction to Digital Transmission - Binary Shift-Keying Modulation 878

Objectives and Outcomes of Section 9.2 878

9.2.1 Digital Signal over a Sinusoidal Carrier - Binary Shift-Keying Modulation 881

9.2.2 Binary Amplitude-Shift Keying (ASK) 881

9.2.2.1 ASK Concept and Waveform 881

9.2.2.2 Mathematical Description of ASK 883

9.2.2.3 ASK Spectrum 884

9.2.2.4 ASK Bandwidth 888

9.2.2.5 Bandwidth and Bit Rate of ASK 893

9.2.2.6 Bit Error Ratio, BER, of ASK System 895

9.2.2.7 ASK Advantages, Drawbacks, and Applications 898

9.2.2.8 Detection (Demodulation) of an ASK Signal 900

9.2.3 Binary Frequency-Shift Keying (FSK) 901

9.2.3.1 FSK Concept and Waveform 901

9.2.3.2 Mathematical Description of FSK 903

9.2.3.3 FSK Spectrum and Bandwidth with Square Wave Message 904

9.2.3.4 FSK Spectrum and Bandwidth with a Rectangular Pulse-Train Message 906

9.2.3.5 Bit Error Ratio, BER, and Remarks on our BFSK Discussion 908

9.2.3.6 Discontinuous-Phase FSK (DPFSK) and Continuous-Phase FSK (CPFSK) 910

9.2.3.7 Mathematical Description of a CPFSK Signal 911

9.2.3.8 Detection (Demodulation) of an FSK Signal 916

9.2.3.9 BFSK: Advantages, Drawbacks, and Applications 921

9.2.4 Binary Phase-Shift Keying (PSK) 922

9.2.4.1 PSK Concept and Waveform 922

9.2.4.2 PSK Mathematical Description; PSK Spectrum and Bandwidth with a Square Wave Message 925

9.2.4.3 Demodulation of a Binary PSK Signal 926

9.2.4.4 Bit Error Ratio, BER, of a BPSK Transmission 929

9.2.4.5 BPSK Advantages and Applications 932

9.2.4.6 Comparison of Binary ASK, FSK, and PSK 932

Questions and Problems for Section 9.2 932

9.2.A Jitter 940

10 Digital Transmission with Multilevel Modulation 943

Objectives and Outcomes of Chapter 10 943

10.1 Quadrature Modulation Systems 943

Objectives and Outcomes of Section 10.1 943

10.1.1 Multilevel (M-ary) Modulation Formats - What and Why 945

10.1.1.1 The Concept of Multilevel Modulation 945

10.1.1.2 Symbols and Bits 948

10.1.2 Quadrature Phase-Shift Keying, QPSK 951

10.1.2.1 Introduction to Quadrature Phase-Shift Keying, QPSK 951

10.1.2.2 QPSK Signal:Waveform and Constellation Diagram 953

10.1.2.3 Generating (Modulating) a QPSK Signal 957

10.1.3 Working with QPSK Signaling 964

10.1.3.1 Properties of a QPSK Signal 964

10.1.3.2 QPSK Demodulation 965

10.1.3.3 Assessing the Quality of QPSK Transmission 967

10.1.3.4 Offset QPSK, Differential QPSK, and Minimum SK 968

Questions and Problems for Section 10.1 970

10.2 Multilevel PSK and QAM Modulation 974

Objectives and Outcomes of Section 10.2 974

10.2.1 Multilevel (M-ary) PSK 975

10.2.1.1 Introduction to M-ary PSK 975

10.2.1.2 BER of M-ary PSK 977

10.2.2 Multilevel Quadrature Amplitude Modulation, M-QAM 981

10.2.2.1 The Concept of Multilevel Quadrature Amplitude Modulation, M-QAM 981

10.2.2.2 BER of M-QAM 984

10.2.3 Final Thoughts 991

10.2.3.1 Spectral Efficiency, Signal-to-Noise Ratio, and Multilevel Modulation 991

10.2.3.2 Bandwidth-Power Trade-off 994

10.2.3.3 Applications of Multilevel Signaling 995

Questions and Problems for Section 10.2 995

10.A Multiplexing 999

10.A.1 Multiplexing: Definition and Advantages 999

10.A.2 Time-Based Multiplexing Principles 1000

10.A.2.1 Synchronous Time-Division Multiplexing, sync-TDM 1000

Sidebar 10.A.2.S Two sync-TDM Systems: T and Synchronous Optical Network (SONET) 1002

10.A.2.2 Statistical (Asynchronous) Time-Division Multiplexing, stat-TDM 1008

10.A.3 Frequency-Based Multiplexing Techniques 1010

10.A.3.1 Frequency-Division Multiplexing, FDM 1010

10.A.3.2 Orthogonal Frequency Division Multiplexing, OFDM 1011

10.A.3.3 Wavelength-Division Multiplexing, WDM 1016

10.A.3.3.1 Why We Need WDM and How WDM Works 1016

10.A.3.3.2 WDM Technology 1018

10.A.3.4 CWDM and Other Types of Multiplexing in Optical Communications 1020

10.A.4 Code-Division Multiplexing, CDM 1023

10.A.4.1 CDM: The Principle of Operation 1023

10.A.4.2 Spread-Spectrum Technique 1024

10.A.4.3 CDM: Benefits and Applications 1026

Bibliography 1029

Specialized Bibliographies 1037

Index 1043

Authors

Djafar K. Mynbaev Lowell L. Scheiner