文件名称：Digital Transmission Engineering (Second Edition)
文件大小：6.82MB
文件格式：PDF
更新时间：2017-11-05 03:21:37
Digital
Preface to the First Edition xi Preface to the Second Edition xv List of Programs xvii List of Major Examples xix 1 Introduction to Digital Transmission 1 1.1 Some History and Some Themes 2 1.2 Why Digital? 6 1.3 Contents of the Book 7 1.4 The Computer Programs 11 References 12 2 Baseband Pulse Transmission 13 2.1 Introduction 13 2.2 Properties of Pulse Trains 14 2.2.1 Pulse Formatting 14 2.2.2 Overlapping Pulses: The Nyquist Criterion 17 2.2.3 Orthogonal Pulses 25 2.3 Pulse Train Spectra 29 2.3.1 General Spectrum Problem 30 2.3.2 Linear Modulation Spectra 31 2.3.3 Spectral and Power Out-of-Band Plots 32 2.4 Transmission Impairments 35 2.4.1 Intersymbol Interference 35 2.4.2 Eye Patterns 36 2.4.3 Channel Filter Effects 39 2.5 Signal Space Analysis 43 2.5.1 Maximum-Likelihood and MAP Receivers 43 2.5.2 Definition of Signal Space 45 2.5.3 Signal Space for White Gaussian Noise 50 2.5.4 Decision Regions and Signal Constellations 53 2.6 Maximum Likelihood Receivers 56 2.6.1 ML Receiver Error Calculations 56 2.6.2 ML Receiver Implementations 63 Problems 74 References 77 3 Carrier Transmission 79 3.1 Modulation with a Carrier 79 3.2 Phase-Shift Keying 81 3.2.1 Binary PSK 82 3.2.2 BPSK Spectra 85 3.2.3 Quaternary PSK 87 3.2.4 Envelopes and I/Q Plots 93 3.3 Quadrature Transmitter and Receiver 93 3.4 Generalizations of Phase-Shift Keying 97 3.4.1 General PSK 97 3.4.2 Offset QPSK 100 3.4.3 Differential PSK 102 3.5 Quadrature Amplitude Modulation 105 3.5.1 QAM Spectra and Error Performance 107 3.5.2 Partial-Response Signaling 115 3.6 Frequency-Shift Keying 119 3.6.1 Basic FSK 120 3.6.2 FSK Spectra 123 3.6.3 FSK Examples 126 3.6.4 CPM Coded Modulation 129 3.7 FSK Detectors 131 3.7.1 FSK Maximum-Likelihood Detection 131 3.7.2 Coherency in FSK Detection 132 3.7.3 Digital FM View 133 3.8 Transmission Impairments 135 3.8.1 Filtering 137 3.8.2 Other Signal Impairments 142 Problems 144 References 148 Appendix 3A Baseband Representation of Bandpass Filters 149 Appendix 3B Bandpass Noise 153 Appendix 3C Discrete-Time Implementation and Simulation 157 4 Synchronization 161 4.1 Some Synchronizer Principles 161 4.2 Phase Synchronizer Circuits 164 4.2.1 Raised-Power Loops 165 4.2.2 Remodulation and Costas Loops 168 4.2.3 S-Curves and Lock Points 169 4.2.4 Effects of Error in the Phase Reference 171 4.3 The Analog Phase-Lock Loop 174 4.3.1 PLL as a Control System 174 4.3.2 Phase Transient Responses 177 4.3.3 Responses During Acquisition 186 4.4 PLL Responses to Noise 188 4.4.1 Gaussian Channel Noise 188 4.4.2 Phase Noise 192 4.4.3 Data Noise 194 4.5 Design Examples 195 4.6 Digital Phase-Lock Loops 203 4.6.1 Review of z-Transforms 204 4.6.2 Simple Conversion of Analog PLLs 205 4.6.3 Second-Order Discrete PLLs Based on an Accumulator 210 4.7 Symbol Timing Recovery 214 4.7.1 Early–Late Gate Synchronizer 214 4.7.2 Timing Based on Zero Crossings 216 4.8 Frame Synchronization and Networking 219 4.8.1 Sequences and Their Boundaries 220 4.8.2 Finding a Frame Marker 227 4.8.3 Hierarchical Networks and Their Synchronization 231 Problems 236 References 241 Appendix 4A: Data Noise in QPSK 242 5 Channels 247 5.1 Guided Channels 248 5.1.1 Characteristics of Wires and Cables 249 5.1.2 The Telephone Channel 253 5.1.3 Glass Fibers 256 5.2 The Simple Radio Link 258 5.2.1 Antennas and Propagation 258 5.2.2 Receiver Noise 261 5.2.3 Detailed Link Budgets 270 5.3 Terrestrial Radio Channels 276 5.3.1 Reflection, Refraction, Diffraction, and Absorption 276 5.3.2 Medium-Wave and Shortwave Propagation 282 5.3.3 Statistical View of Terrestrial Channels 283 5.4 Fading Channels 285 5.4.1 Basic Ideas of Fading 285 5.4.2 The Rayleigh Fading Model 288 ...