Description
Book SynopsisA GUIDE TO THE FUNDAMENTAL THEORY AND PRACTICE OF OPTICAL COMMUNICATION Fiber Optic and Atmospheric Optical Communication offers a much needed guide to characterizing and overcoming the drawbacks associated with optical communication links that suffer from various types of fading when optical signals with information traverse these wireless (atmospheric) or wired (fiber optic) channels. The authorsnoted experts on the topicpresent material that aids in predicting the capacity, data rate, spectral efficiency, and bit-error-rate associated with a channel that experiences fading. They review modulation techniques and methods of coding and decoding that are useful when implementing communications systems. The book also discusses how to model the channels, including treating distortion due to the various fading phenomena. Light waves and their similarity to radio waves are explored, and the way light propagates through the atmosphere, through materials, and through the boundary between two materials is explained. This important book: Characterizes principal optical sources and detectors, including descriptions of their advantages and disadvantages, to show how to design systems from start to finishProvides a new method of predicting and dealing with the dispersive properties of fiber optic cables and other optical guiding structures in order to increase data stream capacityHighlights effects of material and multimode (multi-ray) dispersion during propagation of optical signals with data through fiber optic channelsPresents modulation techniques and methods of coding and decoding that are useful when implementing communications systems Written for professionals dealing with optical and electro-optical communications, Fiber Optic and Atmospheric Optical Communication explores the theory and practice of optical communication both when the optical signal is propagating through the atmosphere and when it is propagating through an optical fiber.
Table of ContentsPreface xi
Acknowledgments xv
Abbreviations xvii
Nomenclature xix
Part I Optical Communication Link Fundamentals 1
1 Basic Elements of Optical Communication 3
1.1 Spectrum of Optical Waves 3
1.2 Optical Communication in Historical Perspective 4
1.3 Optical Communication Link Presentation 5
References 8
2 Optical Wave Propagation 11
2.1 Similarity of Optical and Radio Waves 11
2.2 Electromagnetic Aspects of Optical Wave Propagation 13
2.3 Propagation of Optical Waves in Free Space 16
2.4 Propagation of Optical Waves Through the Boundary of Two Media 16
2.4.1 Boundary Conditions 16
2.4.2 Main Formulations of Reflection and Refraction Coefficients 17
2.5 Total Intrinsic Reflection in Optics 20
2.6 Propagation of Optical Waves in Material Media 23
2.6.1 Imperfect Dielectric Medium 25
2.6.2 Good Conductor Medium 25
Problems 25
References 28
Part II Fundamentals of Optical Communication 29
3 Types of Signals in Optical Communication Channels 31
3.1 Types of Optical Signals 31
3.1.1 Narrowband Optical Signals 31
3.1.2 Wideband Optical Signals 34
3.2 Mathematical Description of Narrowband Signals 35
3.3 Mathematical Description of Wideband Signals 39
References 41
4 An Introduction to the Principles of Coding and Decoding of Discrete Signals 43
4.1 Basic Concepts of Coding and Decoding 43
4.1.1 General Communication Scheme 43
4.1.2 The Binary Symmetric Channel (BSC) 45
4.1.3 Channel Model with AWGN 46
4.2 Basic Aspects of Coding and Decoding 47
4.2.1 Criteria of Coding 47
4.2.2 Code Parameters for Error Correction 50
4.2.3 Linear Codes 51
4.2.4 Estimation of Error Probability of Decoding 54
4.3 Codes with Algebraic Decoding 56
4.3.1 Cyclic Codes 56
4.3.2 BCH Codes 57
4.3.3 Reed–Solomon Codes 59
4.4 Decoding of Cyclic Codes 60
References 63
5 Coding in Optical Communication Channels 67
5.1 Peculiarities of Cyclic Codes in Communication Systems 67
5.2 Codes with Low Density of Parity Checks 68
5.2.1 Basic Definitions 68
5.2.2 Decoding of LDPC Codes 72
5.2.3 Construction of Irregular LDPC Codes 73
5.2.4 Construction of Regular LDPC Codes 74
5.3 Methods of Combining Codes 76
5.4 Coding in Optical Channels 79
References 83
6 Fading in Optical Communication Channels 87
6.1 Parameters of Fading in Optical Communication Channel 87
6.1.1 Time Dispersion Parameters 88
6.1.2 Coherence Bandwidth 89
6.1.3 Doppler Spread and Coherence Time 89
6.2 Types of Small-Scale Fading 91
6.3 Mathematical Description of Fast Fading 93
6.3.1 Rayleigh PDF and CDF 94
6.3.2 Ricean PDF and CDF 96
6.3.2.1 Gamma-Gamma Distribution 99
6.4 Mathematical Description of Large-Scale Fading 100
6.4.1 Gaussian PDF and CDF 101
References 102
7 Modulation of Signals in Optical Communication Links 103
7.1 Analog Modulation 104
7.1.1 Analog Amplitude Modulation 104
7.1.2 Analog Angle Modulation – Frequency and Phase 106
7.1.2.1 Phase Modulation 107
7.1.3 Spectra and Bandwidth of FM or PM Signals 107
7.1.4 Relations Between SNR and Bandwidth in AM and FM Signals 108
7.2 Digital Signal Modulation 109
7.2.1 Main Characteristics of Digital Modulation 110
7.2.1.1 Power Efficiency and Bandwidth Efficiency 110
7.2.1.2 Bandwidth and Power Spectral Density of Digital Signals 111
7.2.2 Linear Digital Modulation 112
7.2.2.1 Amplitude Shift Keying (ASK) Modulation 112
7.2.2.2 Binary Phase Shift Keying (BPSK) Modulation 113
7.2.2.3 Quadrature Phase Shift Keying (QPSK) Modulation 114
7.2.3 Nonlinear Digital Modulation 114
7.2.3.1 Frequency Shift Keying (FSK) Modulation 114
Problems 115
References 115
8 Optical Sources and Detectors 117
8.1 Emission and Absorption of Optical Waves 117
8.2 Operational Characteristics of Laser 119
8.3 Light-Emitting Sources and Detectors 122
8.3.1 Light-Emitting p–n Type Diode 122
8.3.2 Laser p–n Type Diode 124
8.3.3 Photodiode 125
8.3.4 PiN and p–n Photodiodes – Principle of Operation 126
8.4 Operational Characteristics of Light Diodes 129
References 130
Part III Wired Optical Communication Links 133
9 Light Waves in Fiber Optic Guiding Structures 135
9.1 Propagation of Light in Fiber Optic Structures 135
9.1.1 Types of Optical Fibers 135
9.1.2 Propagation of Optical Wave Inside the Fiber Optic Structure 137
References 139
10 Dispersion Properties of Fiber Optic Structures 141
10.1 Characteristic Parameters of Fiber Optic Structures 141
10.2 Dispersion of Optical Signal in Fiber Optic Structures 142
10.2.1 Material Dispersion 142
10.2.2 Modal Dispersion 143
Problems 145
References 146
Part IV Wireless Optical Channels 147
11 Atmospheric Communication Channels 149
11.1 Basic Characteristics of Atmospheric Channel 149
11.2 Effects of Aerosols on Atmospheric Communication Links 150
11.2.1 Aerosol Dimensions 150
11.2.2 Aerosol Altitudes Localization 151
11.2.3 Aerosol Concentration 152
11.2.4 Aerosol Size Distribution and Spectral Extinction 152
11.3 Effects of Hydrometeors 154
11.3.1 Effects of Fog 154
11.3.2 Effects of Rain 155
11.3.3 Effects of Clouds 157
11.3.3.1 Snow 158
11.4 Effects of Turbulent Gaseous Structures on Optical Waves Propagation 158
11.4.1 Turbulence Phenomenon 158
11.4.2 Scintillation Phenomenon of Optical Wave Passing the Turbulent Atmosphere 161
11.4.3 Scintillation Index 162
11.4.4 Signal Intensity Scintillations in the Turbulent Atmosphere 162
11.4.5 Effects of Atmosphere Turbulences on Signal Fading 165
11.5 Optical Waves Propagation Caused by Atmospheric Scattering 166
References 168
Part V Data Stream Parameters in Atmospheric and Fiber Optic Communication Links with Fading 173
12 Transmission of Information Data in Optical Channels: Atmospheric and Fiber Optics 175
12.1 Characteristics of Information Signal Data in Optical Communication Links 176
12.2 Bit Error Rate in Optical Communication Channel 181
12.3 Relations Between Signal Data Parameters and Fading Parameters in Atmospheric Links 183
12.4 Effects of Fading in Fiber Optic Communication Link 188
References 191
Index 195
