Description   About the Authors   How to Order	Simulation Techniques: Models of Communication Signals and Processes TABLE OF CONTENTS Preface Nomenclature 1 Introduction 2 Representation of Analog Signals and Noise 3 Representation of Analog Filters 4 Representation of Analog Signal Processes 5 Digital Simulation of Analog Signals and Processes 6 Computer Modeling of Analog Filters 7 Generation of Data Signals 8 Overview of Reception Processes 9 Generation of Noise 10 Shifters and Interpolators 11 Synchronization 12 Symbol Detection and Demapping 13 Evaluation of Performance 14 Feedback Loops and Control Signals 15 Simulation of Digital Processes 16 Sample Rate Conversion 17 Entry and Builder Routines 18 Graphical Displays 19 Programming Issues 1 Introduction 1.1 Role of Simulation 1.1.1 Simulator Capabilities 1.1.2 User Background 1.1.3 Limits of Simulation 1.2 Transmission Links 1.2.1 Hierarchy 1.2.2 Link Elements 1.3 Pertinent Literature 1.4 Study Plan 2 Representation of Analog Signals and Noise 2.1 Baseband Signal Representations 2.1.1 Time-Limited Versus Bandlimited Pulses 2.1.2 Pulse Amplitude Modulation (PAM) 2.1.3 Nyquist Shaping 2.1.4 Other Pulse Formats 2.2 Passband Signal Representations 2.2.1 Basic Modulation Formats 2.2.2 Quadrature Amplitude Modulation (QAM) 2.2.3 Examples of Passband Signal Formats 2.3 Power, Energy, and Spectrum Relations 2.3.1 Baseband Signals 2.3.2 Passband Signals and Complex Envelopes 2.4 Noise 2.4.1 Additive Gaussian Noise 2.4.2 Counterexamples: Non-AWGN 2.5 Key Points 2.5.1 Baseband Signals 2.5.2 Passband Signals 2.5.3 Power, Energy, and Spectrum 2.5.4 Noise 3 Representation of Analog Filters 3.1 Categories of Filter Representation 3.1.1 Differential Equation Representation 3.1.2 Rational Transfer Functions 3.1.3 Nonrational Transfer Functions 3.1.4 Impulse Response 3.1.5 Summary of Categories 3.2 Filters for Complex Signals 3.2.1 Bandpass Filters 3.2.2 Signal Transmission Through a Bandpass Filter 3.2.3 Filter Structure 3.3 Conversion to Complex Filters 3.3.1 Frequency-Domain Conversion 3.3.2 Time-Domain Conversion 3.4 Key Points 3.4.1 Filter Categories 3.4.2 Complex Filters 3.4.3 Conversion to Complex Filters 3.4.4 STÆDT Processes Appendix 3A: Complex Conversion of Time-Domain Filters 4 Representation of Analog Signal Processes 4.1 Modulators 4.1.1 Complex Envelope 4.1.2 Angle Modulations 4.1.3 Analytic Signal 4.2 Demodulators 4.2.1 I-Q Demodulation 4.2.2 Demodulator Coherence 4.3 PAM Link Model; Matched Filters 4.3.1 PAM-QAM Link Model 4.3.2 Matched Filters 4.4 Symbol Detection 4.4.1 Symbol-by-Symbol Detection 4.4.2 Decision Rules 4.5 Nonlinear Processes 4.6 Key Points 4.6.1 Modulators 4.6.2 Demodulators 4.6.3 PAM Link Model; Matched Filters 4.6.4 Symbol Detection for PAM-QAM Coherent Reception 4.6.5 Nonlinear Processes 4.6.6 STÆDT Processes 5 Digital Simulation of Analog Signals and Processes 5.1 Digitization 5.1.1 Quantization 5.1.2 Sampling 5.1.3 Aliasing 5.1.4 Other Features 5.1.5 Digital Representation 5.2 Digitized Signals in the Frequency Domain 5.2.1 z-Transform 5.2.2 Discrete Fourier Transform (DFT) 5.2.3 Time/Frequency Relations 5.3 Structures and Nomenclature 5.3.1 Simulation Modules 5.3.2 Data Formats 5.3.3 Properties of the Data Formats 5.4 Energy and Power Relations 5.4.1 Energy Formulas 5.4.2 Energy of Analog Pulse Trains 5.4.3 Power 5.4.4 Rationale 5.5 Key Points 5.5.1 Digitization 5.5.2 Discrete Fourier Transform 5.5.3 Structures and Formats 5.5.4 Energy and Power 5.5.5 STÆDT Processes Appendix 5A: Aliasing Energy Appendix 5B: Upper Bound on Magnitude of Aliasing Error Appendix 5C: Analog/Digital Energy Relations 6 Computer Modeling of Analog Filters 6.1 Filter Algorithms 6.1.1 Frequency-Domain Filters 6.1.2 Time-Domain Convolution with Unit-Sample Response 6.1.3 Time-Domain Recursive Difference Equations 6.1.4 Complex Coefficients 6.1.5 Linear Blocks from Frequency-Domain Filters 6.2 Analog-to-Digital Filter Transformation 6.2.1 Frequency-Domain Transformations 6.2.2 Time-Domain Transformations of IIR Filters 6.2.3 Time-Domain Transformations of FIR Filters 6.3 Key Points 6.3.1 On-Line Filter Processes 6.3.2 Filter Preparation 6.3.3 STÆDT Processes 7 Generation of Data Signals 7.1 Message Source 7.1.1 Binary Shift-Register Sequences 7.1.2 Representative Sequences 7.2 Symbol Mapping 7.2.1 Mapping for Linear Modulations 7.2.2 Differential Encoding 7.2.3 Mapping for Nonlinear Modulations 7.3 Pulse Shaping 7.3.1 Generating Impulse Trains 7.3.2 Pulse-Shaping Filters 7.4 Modulators 7.4.1 Linear Modulation 7.4.2 Nonlinear Modulation 7.5 Amplifiers 7.5.1 Linear Amplifiers and Attenuators 7.5.2 Nonlinear Amplifiers 7.6 Key Points 7.6.1 Message Source 7.6.2 Symbol Mapping 7.6.3 Pulse Shaping 7.6.4 Modulators 7.6.5 Amplifiers 7.6.6 STÆDT Processes Appendix 7A: Differential Encoding Examples 8 Overview of Reception Processes 8.1 Simple Channels 8.1.1 Model of the Medium 8.1.2 Processes Required in Receiver 8.1.3 Performance Evaluation 8.2 More-Complicated Channels 8.2.1 Nonwhite, Non-Gaussian, and Nonadditive Disturbances 8.2.2 Frequency-Selective Channels 8.2.3 Time-Varying Channels 8.3 Spread-Spectrum Processes 8.4 Afterword 9 Generation of Noise 9.1 Uniformly Distributed Samples 9.2 Gaussian Noise Generation 9.2.1 Transformation Algorithm 9.2.2 Scaling 9.2.3 Colored Noise 9.2.4 Phase Noise 9.3 Non-Gaussian Variates 9.4 Key Points 9.4.1 Noise Generation 9.4.2 STÆDT Processes Appendix 9A: Complex Envelope of Bandpass Gaussian Noise 10 Shifters and Interpolators 10.1 Phase Shifters 10.1.1 Phase Shifting of Complex Signals 10.1.2 Phase Shifting of Real Signals 10.2 Frequency Shifters 10.2.1 Frequency Shifting of Time-Domain Complex Signals 10.2.2 Frequency Shifting of Frequency-Domain Signals 10.2.3 Frequency Shifting of Real Signals 10.3 Time Shifters 10.3.1 Discrete Time Shifts: Delays 10.3.2 Continuous Time Shifts via Transforms 10.4 Interpolation 10.4.1 Interpolator Model 10.4.2 Characteristics of Interpolating Filters 10.4.3 Simulation of Interpolation 10.4.4 Variable Delay by Interpolation 10.5 Key Points 10.5.1 Phase Shifters 10.5.2 Frequency Shifters 10.5.3 Time Shifters 10.5.4 Interpolation 10.5.5 STÆDT Processes 11 Synchronization 11.1 Synchronization by Calibration 11.1.1 Hardwire Synchronization 11.1.2 Calibration by Recovery Synchronizers 11.2 Recovery Synchronizers 11.2.1 Synchronizer Categories 11.2.2 Synchronizer Operations 11.3 Synchronizer Elements 11.3.1 Correctors 11.3.2 Timing Controllers (Feedback) 11.3.3 Carrier Regenerators 11.3.4 Clock Regenerators 11.3.5 Parameter Extractors 11.3.6 Error Detectors 11.4 Synchronizer Processes 11.5 Key Points 11.5.1 Recovery Configurations 11.5.2 Synchronizer Elements 11.5.3 STÆDT Processes Appendix 11A: Synchronization by Correlation Appendix 11B: Carrier Regenerators Appendix 11C: Locating Zero Crossings by Inverse Linear Interpolation 12 Symbol Detection and Demapping 12.1 PAM-QAM Decisions 12.1.1 Minimum-Distance Decisions 12.1.2 Quantizer Decisions 12.1.3 Differential Detection of MPSK 12.2 Multiple-Strobe Decisions 12.3 Key Points 12.3.1 Minimum-Distance Detection 12.3.2 Quantizer Detection 12.3.3 Differential Detection 12.3.4 Largest-of Detection 12.3.5 Demapping 12.3.6 STÆDT Processes 13 Evaluation of Performance 13.1 Monte Carlo Counting 13.1.1 Monte Carlo Configuration 13.1.2 Monte Carlo Statistics 13.1.3 Importance Sampling 13.2 Quasianalytic Method 13.2.1 Overview of QA Methods 13.2.2 QA Computation of Error Probability 13.2.3 Phantom Noise Calibration 13.2.4 Implications of Time Invariance 13.3 Key Points 13.3.1 Monte Carlo Method 13.3.2 QA Method 13.3.3 Alignment 13.3.4 Signal and Noise Calibration 13.3.5 STÆDT Processes Appendix 13A: Error Probabilities for Quasianalytical Evaluations Appendix 13B: Theoretical Error Performance Appendix 13C: Evaluation of Q(X) Appendix 13D: Delay and Phase Alignment for Performance Evaluations Appendix 13E: Phantom Noise Calibration Appendix 13F: Truncation of Infinite Impulse Responses 14 Feedback Loops and Control Signals 14.1 Simulation of Feedback 14.1.1 Single-Point Format 14.1.2 Opened-Loop Simulation 14.1.3 Multiple Loops 14.2 Control Signals 14.2.1 Configuration and Properties 14.2.2 Loop Filters for Control Signals 14.3 Key Points 14.3.1 Feedback Loops 14.3.2 Control Signals 14.3.3 STÆDT Processes 15 Simulation of Digital Processes 15.1 Quantization 15.1.1 Quantizer Laws 15.1.2 Simulation of Quantizers 15.1.3 Quantizer Applications 15.2 Other Digital Issues 15.2.1 Number Representation 15.2.2 Overflow and Underflow 15.2.3 Processing Delays 15.3 Key Points 15.3.1 Quantization 15.3.2 Other Digital Issues 15.3.3 STÆDT Processes 16 Sample Rate Conversion 16.1 Block-Mode Conversions 16.1.1 Resampling Definitions 16.1.2 Block-Mode Issues 16.1.3 Reblocking 16.1.4 Block-Mode Interpolation 16.2 Single-Point Conversions 16.2.1 Flag-Mediated Control 16.2.2 Internal Scheduling 16.2.3 Mixed Scheduling 16.3 Rate-Changing Processes 16.3.1 Downsampling Processes 16.3.2 Upsampling Processes 16.3.3 Block Alterations 16.4 Key Points 16.4.1 Sample Rate Conversion 16.4.2 Interpolation 16.4.3 Block Mode 16.4.4 Single-Point Mode 16.4.5 STÆDT Processes 17 Entry and Builder Routines 17.1 Overview 17.2 Entry Routines 17.2.1 File Formats 17.2.2 Entry Tools 17.3 Conditioning 17.3.1 Conditioning of Nonlinear Amplifiers 17.3.2 Frequency Response of Filters 17.3.3 Other Conditioning Tasks 17.4 Nonlinearity Builder Routines 17.4.1 Nonlinearity Overview 17.4.2 Function Fitting 17.4.3 Interpolation 17.5 Filter Builder Routines 17.5.1 Filter Builder Constituents 17.5.2 Standard Filters 17.5.3 Frequency-Domain Builder Routines 17.5.4 Time-Domain Builder Routines 17.5.5 Specimens of Frequency Rescaling 17.6 Key Points 17.6.1 Nonlinearity Builders 17.6.2 Filter Builders 17.6.3 STÆDT Processes 18 Graphical Displays 18.1 Types of Plots 18.1.1 Time-Domain Plots 18.1.2 Frequency-Domain Plots 18.1.3 Other Plots 18.2 Units and Scales 18.2.1 Abscissas 18.2.2 Ordinates 18.2.3 Plot Windows 18.3 Data Conditioning 18.3.1 Computation of Delay 18.3.2 Spectrum Conditioning 18.4 Key Points 18.4.1 Types of Plots 18.4.2 Units and Scales 18.4.3 Data Conditioning 18.4.4 STÆDT Processes 19 Programming Issues 19.1 Simulation Language 19.1.1 Evolution of Simulation Language 19.1.2 Relation to Programming Language 19.1.3 High Level Versus Low Level 19.2 Architecture and Rules 19.2.1 User's Interface 19.2.2 Parameter Entry 19.2.3 Order of Execution 19.2.4 Data Connectivity 19.2.5 Types 19.2.6 Composite Commands 19.3 Interpreters Versus Compilers 19.3.1 Interpreters 19.3.2 Compilers 19.4 Auxiliary Features 19.5 Key Points REFERENCES INDEX
Models of Communication Signals and Processes | The STÆDT Program
Description   About the Authors   How to Order   Software Updates   System Requirements: IBM-compatible PC, 640K RAM minimum, 3.5" high-density floppy drive, and hard drive. STÆDT runs under DOS 3.3 or later or as a DOS application under Windows 3.1 or 95. Graphics support: CGA, EGA, VGA, Olivetti, AT&T, or Hercules Monochrome Graphics (Hercules requires driver not included with STÆDT).   Command Names used with STÆDT	Simulation Techniques: The STÆDT Program TABLE OF CONTENTS OF THE REFERENCE MANUAL 1. Overview and Installation 1.1 System Requirements 1.2 Installation 1.2.1 Installation Procedures 1.2.2 Windows® Operation 1.2.3 Memory Configuration 1.3 Disk Contents 1.4 Hard Copy 1.5 Organization 1.6 Study Plan 2. Preparing and Running Simulations with STÆDTTM 2.1 What Is a Command List? 2.2 What Is a Module? 2.3 The Command Library 2.3.1 Signal Generation Processes 2.3.2 Filters 2.3.3 Signal Processes 2.3.4 Noise Generation and Calibration Processes 2.3.5 Signal Reception Processes 2.3.6 Performance-Evaluation Processes 2.3.7 Control Signal Processes 2.3.8 Data Conversion Processes 2.3.9 Single-Point Processes 2.3.10 Display Commands 2.3.11 Flow Control Commands 2.3.12 Housekeeping 2.3.13 Declaration and Assignments 2.3.14 Builder Routines 2.3.15 Composite Modules 2.3.16 LET and LETS 2.4 How a Simulation Is Conducted 2.4.1 System Block Diagram 2.4.2 System Capture to a Command List 2.4.3 Running a Simulation 2.4.4 Postsimulation User Activities 2.5 Key Points 3 Rules for Command Lists 3.1 Order of Execution of Commands 3.2 Data Connectivity 3.2.1 Naming Rules 3.2.2 Exceptions to Naming Rules 3.3 Mode Rules: Block or Single Point 3.3.1 Mode Switching 3.3.2 Block Storage 3.3.3 Single-Point Storage 3.3.4 Storage of Variables and Control Signals 3.3.5 Intermodal Connectivity 3.4 Feedback Loops 3.5 Initialization of State Information 3.5.1 Initialization Flags 3.5.2 Initial Values 3.6 Composite Modules 3.7 Sample-Rate Changing 3.7.1 Visible Tools 3.7.2 Hidden Tools 3.8 Builder Routines 3.9 Arrays 3.9.1 Array Allocations 3.9.2 Reallocation with DIM 3.10 Directories and Files 3.11 Documentation 3.11.1 Run-Time Documentation 3.11.2 Archival Documentation 3.12 Key Points 3.12.1 Fundamental Rules 3.12.2 Other Rules 4 Using the Menus Program 4.1 Starting the Menus Program 4.2 Exiting from the Menus Program 4.3 Making Menu Selections 4.3.1 Moving Between Menu Boxes 4.3.2 List Boxes 4.3.3 Input Boxes 4.3.4 Message Boxes 4.4 Leaving a Menu 4.5 Creating a New Command List 4.5.1 The EDIT Menu 4.5.2 The APPEND Submenu 4.5.3 Command Input Box 4.5.4 Name List Box 4.5.5 Deleting a Selected Command 4.5.6 Intermediate Save of Command List 4.5.7 Command List Length Limit 4.5.8 Leaving the APPEND Submenu 4.6 Specifying Process Parameters 4.6.1 Parameter Selection Menu 4.6.2 Navigating in the Parameter Tables 4.6.3 Allowable Entries for Parameter Values 4.7 The File Menu 4.7.1 The File Selection Menu 4.7.2 SAVE a Command List 4.7.3 LOAD a Command List 4.7.4 VIEW a Command List 4.7.5 PRINT a Command List 4.7.6 TRANSLATE a Command List 4.7.7 EXECUTE a Command List 4.7.8 RETURN to Main Menu 4.8 Editing an Existing Command List 4.8.1 ERASE ALL Existing Command List 4.8.2 APPEND after 4.8.3 INSERT before 4.8.4 Entering New Commands 4.8.5 DELETE LINE 4.8.6 CHANGE Parameter Values 4.8.7 MERGE Command Lists 4.8.8 Composite Special Procedure 4.8.9 RETURN to Main Menu 4.9 The Colors Menu 4.9.1 Color Options 4.9.2 UPDATE Color Selections 4.9.3 Return to Main Menu 4.10 DOS SHELL 5 Command Library Reference 5.1 Command Names 5.2 Signals and Variables 5.2.1 Data Signals 5.2.2 Variables and Control Signals 5.3 Parameters 5.3.1 Output- and Input-Name Parameters 5.3.2 Parameter Values 5.3.3 Parameters That Name Files 5.3.4 Parameters That Require Variables 5.3.5 Selection Parameters 5.3.6 Bypass Parameters 5.3.7 Initialization Parameters 5.4 Plot and Print Commands 5.4.1 Operating Procedures 5.4.2 Display Formats 5.5 Command Documentation (Reference material for each command, arranged in alphabetical order by abbreviated command name) STÆDTTM Commands 6 Applications of STÆDTTM 6.1 Preliminaries 6.1.1 System Checkout: SMRTCHK 6.1.2 Command List Features 6.1.3 Interpretation of Displays 6.2 Guide to the Exercises 6.3 Circular-Block Examples 6.3.1 QPSK Example: CIRQPSK 6.3.2 VSB Example: CIRVSB 6.4 Linear-Block Examples 6.4.1 p/4-QPSK Example: PI-4QPSK 6.4.2 p/4-QPSK with Nonlinear Transmitter: NLPI-4 6.5 Single-Point, Feedback Example 6.5.1 Digital Phase-Locked Loop: DPLL 6.6 Cross Reference of Commands in Examples 7 Creating Your Own Signal Process 7.1 Overview 7.2 What You Will Need 7.3 Software Architecture 7.3.1 Command Tasks 7.3.2 Using the Template XXX.BAS 7.3.3 Summary of Housekeeping Activities 7.3.4 Data Structure in COMMON 7.3.5 Data Signal I/O 7.3.6 Command List Variables and Control Signals 7.3.7 Functions 7.3.8 State Variables 7.3.9 Error Handling 7.4 Step 1: Write Source Code by Template and Example 7.4.1 Naming the New Command 7.4.2 The Function Declaration 7.4.3 $INCLUDE and $DYNAMIC Statement 7.4.4 Comment Lines 7.4.5 Function Definition 7.4.6 Declare Local Variables 7.4.7 Set Return Value 7.4.8 Finding a Command's Parameters 7.4.9 Finding Data-Signal Input 7.4.10 Bypass/No Input 7.4.11 Initializations 7.4.12 Retrieve Previous State Variables 7.4.13 Error Handling 7.4.14 Code for the Core Algorithm 7.4.15 Write Outputs from Your Command 7.4.16 Terminate Your Command 7.4.17 Save the Source Code 7.5 Steps 2-7: Incorporate the New Command into STÆDT 7.5.1 Step 2: Modify the Library Manager 7.5.2 Step 3: Compile the New Command 7.5.3 Step 4: Link the New Command 7.5.4 Step 5: Modify the Menus Program 7.5.5 Step 6: Test and Debug New Command 7.5.6 Step 7: Prepare Documentation Appendix A: Menus Quick Reference Appendix B: String Constants Used in Parameters Appendix C: Command List Format Appendix D: Error Messages Appendix E: Procedures Available to New Commands INDEX