数字与模拟通信系统

     CONTENTS
   PREFACE
   LIST OF SYMBOLS
   1 INTRODUCTION
    1-1 Historical Perspective
    1-2 Digital and Analog Sources and Systems
    1-3 Deterministic and Random Waveforms
    1-4 Organization of This Book
    1-5 Use of a Personal Computer and MATLAB
    1 -6 Block Diagram of a Communication System
    1-7 Frequency Allocations
    1-8 Propagation of Electromagnetic Waves
    1-9 Information Measure
    Example 1-1 Evatuation of Informalion and Entropy,
    1-10 Channel Capacity and Ideal Communication Systems
    1-11 Coding
    Block Codes,
    Convotutional Codes,
    Code Interleaving,
    Code Perfonfuance,
    Trellis-Coded Modulation,
    1-12 Preview
    1-13 Study-aid Examples
    Problems
   2 SIGNALS AND SPECTRA
    2-1 Properties of Signals and Noise
    Physically Realizable Waveforms,
    Time Average Operator,
    Dc Value,
    Power,
    ExaMple 2-1 Evaluation of Power,
    Rms Value and Normalized Power,
    Energy and Pcwer Waveforms,
    Decibel.
    Phasors,
    1-1 Fourier Transfonn and Spectra
    Definition,
    Example 2-2 Spectrum ofan Exponenlial Pulse,
    Propenies ofFourier Transfonns,
    Parseval 's Theorem and Energy Spectral Density,
    Example 2-3 Spectrum ofa Damped Sinusoid.
    Dirac Delta Function and Unit Step Function,
    Example 2-4 Spectrum ofa Sinusotd,
    Rectangular and Triangular-Pulses,
    Example 2-5 Spectrum ofa Rectmgular Pulse,
    Example 2-6 Spectrum ofa Triangular Pulse,
    Convolulion, 58
    Example 2-7 Convolution of a Rectangle wilh an Exponentiai,
    Example 2-8 Speclrum of a Triangular Pulse by Convolution.
    Example 2-9 Spectrum ofa Swilched Sinusoid,
    2-3 Power Spectral Density and Autocorrelation Function
    Power Spectral Density,
    Autocorrelation Function,
    Example 2-10 PSD ofa Sinusoid,
    2-4 Orthogonal Series Representation of Signals and Noise
    Orthogonal Functions,
    Example 2-11 Orthogonal Complex Exponential Functions,
    Orthogonat Series,
    2-5 Fourier Series
    Complex Fourier Series,
    Quadrature Fourier Series,
    Polar Fourier Series.
    Une Spectra for Periodic Waveforms,
    Example 2-12 Fourier Coefficients for a Rectangular Wave,
    Power Spectral Density for Periodic Waveforms,
    Example 2-13 PSDfor a Square Wave.
    2-6 Review of Linear Systems
    Linear Time-Invariant Systems,
    fmputse Response.
    Transfer Function,
    Example 2-14 RC Low-Pass FUter,
    Distortionless Transmission,
    Example 2-15 Distortion Caused by a Filler.
    2-7 Bandlimited Signals and Noise
    Bandlimited Waveforms,
    Sampling Theorem,
    Impulse Sampling,
    Dimensionality Theorem.
    2-8 Discfete Fourier Transform
    Using the DFT to Compute the Continuous Fourier Transform,
    Example 2-16 DFTfor a Reclangular Pulse,
    Using the DFT to Compute the Fourier Series,
    Example 2-17 Use the DFT toCompute the Spectrum ofa Sinusoid,
    2-9 Bandwidth of Signals
    Example 2-18 Bandwidths for a BPSK Signal.
    2-10 Summary
    2-11 Study-Aid Examples
    Problems
   3 BASEBAND PULSE AND DIGITAL SIGNALING
    3-1 Introduction
    3-2 Pulse Amplitude Modulation
    Natural Samplmg IGating),
    Instantaneous Sampling (Flat-Top PAM). ,
    3-3 Pulse Code Modulation
    Sampling, Quanting, and Encoding,
    Practical PCM Circuits,
    Bandwidth ofPCM,
    Effecls of Nmse,
    Example 3-1 Design of a PCM System,
    Nonunifonn Quantizing: -Law and A-Law Companding,
    3-4 Digital Signaling
    Vector Represenlation.
    Example 3-2 Vector Representalion ofa Binary Signal,
    Bandwidth Estimation,
    Binary Signaling,
    Example 3-3 Binary Signaling,
    Muttikvel Signaling,
    Example 3-4 L = 4 Mullilevel Signal,
    3-5 Line Codes and Spectra
    Binary Line Coding,
    Power Spectra for Binary Une Codes.
    Differential Coding,
    Eye Pattems,
    Regenerative Repeaters,
    Bit Synchronization,
    Power Spectrafor Multilevel Signals.
    Spectral Efficiency,
    3-6 Intersymbol Interference
    Nyquisl's First Method (Zero ISI),
    Raised Cosine-Rolloff Filtering,
    Example 3-1 (continued),
    Nyquisl's Second and Third Methodsfor Control oflSI,
    3-7 Differential Pulse Code Modulation
    3-8 Delta Modulation
    Granular Noise and Slope Overload Noise,
    Example 3-5 Design of a DM System,
    Adaptive Delta Modulation and Continuously Variable Slope
    Delta Modulation,
    Speech Coding.
    3-9 Time-Division Multiplexing
    Frame Synchronization.
    Synchronous and Asynchronous Lines,
    Example 3-6 Design ofa Time-Division Muhiplexer,
    TDM Hierarchy.
    The Tl PCM System,
    3-10 Pulse Time Modulation: Pulse Width Modulation
    and Pulse Position Modulation
    3-11 Summary
    3-12 Study-Aid Examples
    Problems
   4 BANDPASS SIGNALING PRINCIPLES AND CIRCUITS
    4-1 Complex Envelope Representation of Bandpass Waveforms
    Definitions: Baseband, Bandpass, and Modulation.
    Complex Envelope Representation,
    4-2 Representation of Modulated Signals
    4-3 Spectrum of Bandpass Signals
    4-4 Evaluation of Power
    Example 4-1 Amplitude-Modulated Signal.
    4-5 Bandpass Filtering and Linear Distortion
    Equivalent Low-Pass Filter,
    Unear Dislortion,
    4-6 Bandpass Sampling Theorem
    4-7 Received Signal Plus Noise
    4-8 Classification of Filters and Amplifiers
    Filters,
    Amplifiers,
    4-9 Nonlinear Distortion
    4-10 Limiters
    4-11 Mixers, Up Converters, and Down Converters
    4-12 Frequency Multipliers
    4-13 Detector Circuits
    Envelope Detector.
    Product Detector.
    Frequency Modulation Detector,
    4-14 Phase-Locked Loops and Frequency Synthesizers .
    4-15 Direct Digital Synthesis
    4-16 Transmitters and Receivers
    Generalized Transmitters,
    Generalized Receiver: The Superheterodyne Receiver,
    Example 4-2 AM Broadcast Superheterodyne Receiver,
    4-17 Summary
    4-18 Study-Aid Examples
    Problems
   5 AM, FM, AND DIGITAL MODULATED SYSTEMS
    5-1 Amplitude Modulation
    Example 5-l Power of an AM Signal,
    5-2 AM Broadcast Technical Standards
    5-3 Double-Sideband Suppressed Carrier
    5-4 Costas Loop and Squaring Loop
    5-5 Asymmetric Sideband Signals
    Single Sideband. 304
    Vestigiat Sideband, 308
    5-6 Phase Modulation and Frequency Modulation
    Representation of PM and FM signals,
    Spectra of Angle-Modulated Signals,
    Example 5-2 Spectrum of a PM or FM Signal
    with Sinusotdal Modulation,
    Narrowband Angle Modulation,
    Wideband Frequency Moduiation,
    Exwnple 5-3 Spectrwn for WBFM with Triangular Modulation,
    Preemphasis and Deemphasis in Angle-Modulated Systems,
    5-7 Frequency-Division Multiplexing and FM Stereo
    5-8 FM and Noise Reduction Standards
    FM Broadcast Technical Standards.
    Dolby and DBX Noise Reduction Systems,
    5-9 Binary Modulated Bandpass Signaling
    On-OffKeying (OOK),
    Binary-Phase Shift Keying (BPSK),
    Dtffi-rential Phase-Shifi Keying (DPSK).
    Frequency-Shift Keying (FSK),
    Example 5-4 Spectrum of the Bell-Type 103 FSK Modem.
    5-10 Multilevel Modulated Bandpass Signaling
    Quadramre Phase-Shift (QPSK) Keying and M-ary Phase-Shift Keying (MPSK),
    Quadrature Amplitude Modulation (QAM),
    Power Spectral Densityfor MPSK and QAM.
    5-11 Minimum-Shift Keying (MSK)
    5-12 Spread Spectrum Systems
    Direct Sequence,
    Frequency Hopping,
    5-13 Summary
    5-14 Study-Aid Examples
    Problems
   6 RANDOM PROCESSES AND SPECTRAL ANALYSIS
    6-1 Some Basic Definitions
    Random Processes.
    Stationarity and Ergodicity,
    Example 6-1 First-Order Stalionarity,
    Example 6-2 Ergodic Random Process,
    Correlation Functions and Wide-Sense Stationarity,
    Complex Random Processes,
    6-2 Power Spectral Density
    Definition.
    Wiener-Khintchine Theorem,
    Propenies ofthe PSD,
    Example 6-3 Evaluation of the PSDfor a Polar Baseband Signal,
    General Fornwla for the PSD of Digital Stgnals,
    White Notse Processes,
    Measurement ofPSD,
    6-3 Dc and Rms Values for Ergodic Random Processes
    6-4 Linear Systems
    Input-Output Relationships,
    Example 6-4 Output Autocorrelation and PSD
    for an RC Low-Pass Filler,
    Example 6-5 Signal-to-Noise Ratio
    at the Oulput of an RC Low-Pass Filler,
    6-5 Bandwidth Measures
    Equivalent Bandwidth,
    Rms Bmduiidth,
    Example 6-6 Equivalenl Bandwidth and Rms Bandwidth
    foranRCLPF,
    6-6 The Gaussian Random Process
    Properties ofGaussian Processes,
    Example 6-7 White Gaussian Noise Process,
    6-7 Bandpass Processes
    Bandpass Representations,
    Prvperties of WSS Bandpass Processes,
    Exampk 6-8 Spectrafor the Quadrature Components
    of White Bandpass Hoise,
    Example 6-9 PSD for a BPSK Signal.
    Proofs of Some Properties,
    Example 6-10 PDFfor the Envelope and Phase Functions
    ofa Gaussian Bandpass Process,
    6-8 Matched pilters
    General Results.
    Resultsfor White Noise,
    Example 6-11 Integrate-and-Dump (Matched) Filter,
    Correlation Processing,
    Example 6-12 Matched Filterfor Detection ofa BPSK Signal,
    Transversal Matched Filter,
    6-9 Summary
    6-10 Appendix:ProofofSchwars'sInequality
    6-11 Study-Aid Examples
    Problems
   7 PERFORMANCE OF COMMUNICATION SYSTEMS
    CORRUPTED BY NOISE
    7-1 Error Probabilities for Binary Signaling
    General Results,
    Resuttsfor Gaussian Noise,
    Resultsfor White Gaussian Noise and Matched-Filler Reception,
    Results for Colored Gaussian Noise and Matched-Filter Reception,
    7-2 Perfonnance of Baseband Binary Systems
    Unipolar Signaling,
    Polar Signaling,
    Bipolar Signaling,
    7-3 Coherent Detection of Bandpass Binary Signals
    On-Qff Keying,
    Binary-Phase-Shift Keying,
    Frequency-Shift Keying,
    7-4 Noncoherent Detection of Bandpass Binary Signals
    On-QffKeying,
    Frequency-Shift Keying,
    Differential Phase-Shift Keying,
    7-5 Quadrature Phase-Shift Keying and Minimum-Shift Keying
    7-6 Comparison of Digital Signaling Systems
    Bit Error Rate and Bandwidth,
    Synchronization,
    7-7 Output Signal-to-Noise Ratio for PCM Systeins
    7-8 Output Signal-to-Noise Ratios for Analog Systems
    Comparison with Baseband Systems,
    AM Systems with Product Detection,
    AM Systems with Envelope Delection,
    DSB-SC Systems.
    SSB Systems,
    PM Syslems,
    FM Syslems.
    FM Systems with Threshotd Extension,
    FM Systems with Deemphasis,
    7-9 Comparison of Analog Signaling Systems
    Ideal System Performance,
    7-10 Summary
    7-11 Study-Aid Examples
    Problems
   8 CASE STUDIES OF COMMUNICATION SYSTEMS
    8-1 Telecommunication Systems
    Time-Dtvision Multiplexmg,
    Frequency-Division Multiplexing,
    8-2 Telephone Systems
    Historical Basis,
    Modem Telephone Systems and Remote Terminals
    8-3 Integrated Service Digital Network
    8-4 Capacities of Public Switched Telephone Networks
    8-5 Satellite Communication Systems
    Dtgital and Analog Television Transmission,
    Data and Telephone Signal Multiple Access,
    Examplt 8-l Fixed Assigned Multiple-Access Mode Using
    an FDMA Format,
    Example 8-2 SPADE System,
    Personal Communications via Satellite,
    8-6 Link Budget Analysis
    Signal Power Received,
    Thermai Noise Sources,
    Characterization ofNoise Sources,
    Noise Cluaracterzaation ofLinear Devices,
    Example 8-3 T, and Ffor a Transmission Line,
    Noist Characterization ofCascaded Linear Devices,
    Lmk Budgel Evaluation,
    E/No Unk Budgelfor Digital Systems,
    Example 8-4 Link Budget Evaluation for a Television Receive-
    Only Terminalfor Satellile Sigmils,
    8-7 Fiber Optic Systems
    Example 8-5 Link Budgetfor a Fiber Oplic Syslem,
    8-8 Cellular Telephone Systems
    8-9 Telcvision
    Btack-and-White Television,
    MTS Stereo Sound,
    Color Television,
    Standardsfor TV and CATV Systems,
    HDTV,
    8-10 Summary
    8-11 Study-Aid Examples
    Problems
   A APPENDIX A MATHEMATICAL TECHNIQUES, IDENTITIES,
    AND TABLES
    A-1 Trigonometry
    Dffinitions,
    Trigonometric Identities,
    A-2 Differential Calculus
    Definition.
    Differentialion Rules,
    Derivative Table,
    A-3 Indeterminate Fonns
    A-4 Integral Calculus
    Defintion,
    Inlegration Techniques,
    A-5 Integral Tables
    Indefinite Inlegrals.
    Definite Integrals,
    A-6 Sehes Expansions
    Finite Series,
    Infinile Series,
    A-7 Hilbert Transform Pairs
    A-8 The Dirac Delta Function
    Properties of Dirac Della Function,
    A-9 Tabulation of Sa(x) = (sin x)/x
    A-IO Tabulation of Q(z)
   B APPENDIX B PROBABILITY AND RANDOM VARIABLES
    B-1 Introduction
    B-2 Sets
    B-3 Probability and Relative Frequency
    Simple Probability,
    Joint Probability.
    Example B-I Evaiuation of Probabilities.
    Example B-l (Cont'mued),
    Conditional Probabilities,
    Example B-l (Contmued).
    B-4 Random Variables
    Example B-l Random Variable,
    8-5 Cumulative Distribution Functions and Probability
    Density Functions
    Example 8-2 (Continued),
    Properties of CDFs and PDFs.
    Discrele and Continuous Distributions,
    Example B-3 A Continuous Distribution,
    Example B-3 (Conlinued).
    8-6 Ensemble Average and Moments
    Ensemble Average,
    Example 8-4 Evaluation ofan Average,
    Moments. 647
    8-7 Examples of Important Distributions
    Binomiai Distributton.
    Poisson Distribution,
    Uniform Distribution,
    Gaussian Distribution,
    Sinusoidal Distribution,
    8-8 Functional Transformations of Random Variables
    Example B-6 Sinusoidal Distribulion,
    Example B-6 PDFfor the Output of a Diode Characleristic,
    8-9 Multivariate Statistics
    Multivariale CDFs and PDFs,
    Bivariate Slatistics.
    Gaussian Bivariate Distribution.
    Multivariate Functional Transformation,
    Exampk B-7 PDFfor the Sum of Two Ramlom Variahles,
    Ceniral Limit Theorem.
    Example B-8 PDFfor the Sum of Three Independenl Uniformly
    Distributed Random Variables,
    Problems
    APPENDIX C STANDARDS AND TERMINOLOGY
   C FOR COMPUTER COMMUNICATIONS
    C-l Codes
    Baudot,
    ASCII,
    C-2 DTE/DCE and Ethernet Interface Standards
    Current Loop,
    RS-232C, RS-422A, RS-449, and RS-530 Interfaces,
    Centronics Parallel Interface,
    IEEE-488 Interface,
    Elhemet IIEEE 802.3) Inlerface,
    C-3 The ISO OSI Network Model
    C-4 Data Link Control Protocols
    BISYNC,
    SDLC,
    HDLC.
    CCITTX.25 Protocol,
    Asynchronous Transfer Mode (ATM),
    C-5 Modem Standards
    C-6 Brief Computer Communications Glossary
    REFERENCES
    ANSWERS TO SELECTED PROBLEMS
    INDEX
    FRONT ENDPAPERS
    Abbreviations
    BACK ENDPAPERS
    Fourier Transfonn Theorems
    Fourier Transform Pairs
    Q(z) Function