Satellite Communication Systems Design

Transcription

1 Satellite Communication Systems Design Edited by Sebastiano Tirro Plenum Press New York and London

2 Contents Introduction 1 S. Tirrö The History 1 The Perspectives 6 The Regulatory Bodies 7 1. Signals 11 E. Saggese and S. Tirrö I. Introduction 11 II. Speech Signals 11 A. Bandwidth 12 B. Voice Activity Factor and Speech Interpolation 12 C. The Constant-Volume Talker and the Measured Speech Volumes 13 D. Laplacian Representation of a Speech Signal 14 E. Multichannel Speech 16 F. Peak Factor 16 G. Test Tone Level 16 H. Multichannel Telephony Load 18 III. Sound-Program Signals 19 A. Bandwidth 19 B. Source Activity 19 C. Power Level Statistics 20 D. Test Tone Level 21 E. Compatibility with the FDM Telephony Primary Group IV. Video Signals 21 A. Colorimetry Fundamentals 21 B. Monochrome Television 25 C. Color Television 28 D. MAC Systems 33 XV

3 xvi Contents E. High-Definition Television 36 References Causes of Signal Impairment 41 S. Tirrö I. Introduction 41 II. Internal Noise 42 A. Shot Noise 42 B. Thermal Noise and Noise Temperature 42 C. Noise of an Attenuator 43 D. Noise Figure 44 III. External Noise 44 IV. Modeling of Internal and External Noise 46 V. Quantizing Noise and Digital Companding 48 VI. Equipment Linear Distortions 54 VII. Nonlinear Distortions 57 A. General 57 B. Unmodulated Carriers and Intermodulation Lines 59 C. Modulated Carriers and Intermodulation Noise 62 VIII. Spectrum Truncation 67 IX. Intelligible Crosstalk 68 X. Echo due to Equipment Mismatching 68 XI. Interferences 70 XII. Propagation Delay and Echo 70 A. General 70 B. The Effects of Propagation Delay 71 C. The Echo Phenomenon 71 References Baseband Signal Processing 75 E. Saggese I. Introduction 75 II. Speech Source Coding 76 A. General 76 B. Waveform Coding 78 С Vocoders 83 D. Hybrid Solutions 85 E. Some Major Commercial Standards 85 F. Conclusions 87

4 Contents xvii III. Video Source Coding 87 A. General 87 B. Redundancy Reduction 88 C. Controlled Image Degradation 91 D. Coding Color Signals 95 E. Effects of Channel Errors 96 F. Achievements and Trends in Image Coders 96 IV. Cryptography 97 A. Private-Key Cryptography 97 B. Public-Key Cryptography 99 C. Block Ciphering and Stream Ciphering 99 D. Cryptography in Communication Networks 101 E. Cryptography in Satellite Communication Systems 102 F. Pay-per-view Television 104 V. Multiplexing 105 A. Deterministic Multiplexing 105 B. Statistical Multiplexing 109 References Services 121 A. Puccio I. Introduction 121 II. Definition of Service 122 III. Technical Attributes of Bearer Services 123 A. Information Transfer Attributes 123 B. Access Attributes 126 С General Attributes 126 IV. Categories of Service 127 V. The Services Horizon 128 A. General 128 B. Telephony Evolution 128 C. Telex Evolution 130 D. Data Evolution 130 E. Television Evolution 131 References Quality of Service 133 A. Puccio, V. Speziale, and S. Tirro I. Introduction 133 II. Reference Circuits 134

5 XVUl III. SNR, ВЕР and Conventional Link Quality 135 IV. Availability Objectives of Satellite Systems 136 V. Propagation Performance of Satellite Systems 137 A. Performance Criterion for Analog Telephony 137 B. Performance Objectives for Digital Telephony 139 C. Performance Objectives for International ISDN Links D. Performance Evaluation for a Digital Satellite System 145 E. Performance Objectives for Sound-Program Circuits 146 F. Performance Objectives for Television Signals Transmission 151 G. Subjective Assessment of Sound and/or Video Signal Quality 154 VI. Transmission Performance of Satellite Systems 156 A. Propagation Delay and Echo 156 B. Linear and Nonlinear Distortions in FDM-FM Telephony C. Linear and Nonlinear Distortions in FM Television 157 D. Linear Distortions in Digital Systems 163 VII. Trafficability Performance 164 References System Outline 171 A. Bonetto, S. Tirro, and V. Violi I. Introduction 171 II. Basic Configuration of a Satellite Communication System 172 III. Evolution of Satellite Communication Systems 174 IV. Architectures of Satellite Systems for Network Services 175 V. Summary of Impairment Sources 176 VI. Antenna Characterization 179 A. General 179 B. Gain 180 C. Effective Area and Aperture Efficiency 181 D. Noise Temperature 182 E. Polarization 183 VII. Earth Station Characterization 188 A. General 188 B. The Frequency Coordination Problem 189 C. General Layout of a Satellite Earth Station 189 D. Earth Station Block Diagram 189 E. Low-Noise Amplifiers 191 F. High-Power Amplifiers G. Front-End Specifications 194 VIII. Satellite Characterization 195 A. General 195 B. Satellite Configurations 195 C. The Environment 199 D. Satellite Implementation Program 201

6 Contents xix E. Payload Efficiency 204 F. Reliability Considerations 205 G. Front-End Specifications 209 IX. Link Budgets 210 X. GEO Satellites versus Terrestrial Radio Links 215 XI. GEO Satellites versus non-geo Satellites 217 XII. Power versus Bandwidth Trade-offs 219 XIII. The Various Margins 222 A. General 222 B. Rain Margin 223 C. Breaking Margin 224 D. Demodulator Margin 224 E. Transmission Margin 225 F. Available Margin 225 XIV. The Balanced System. Power and Bandwidth Limitation 225 XV. Service Requirements and Propagation Statistics 227 XVI. Propagation- and Transmission-limited Systems 229 XVII. Clear-Weather and Bad-Weather Definitions 233 XVIII. Apportionment of Impairments 233 References Orbits and Controlled Trajectories 243 V. Violi and G. Vulpetti I. Introduction 243 II. Orbital Elements 244 III. Fundamental Orbital Laws 247 IV. Orbit Perturbations for a Telecommunication Satellite 252 V. Target Orbits 256 A. Sun-Synchronous Orbits 257 B. Low-Perigee High-Eccentricity Orbits 258 C. Geostationary and Quasi-Geostationary Orbits 258 VI. Achievement of the Geostationary Orbit 258 A. Rocket Propulsion 258 B. Thrust and Specific Impulse 259 C. Propellant Characteristics 260 D. Powered Flight Equation 261 E. The Hohmann Profile 265 F. Staging 267 G. Multiple-Burn Mission Profiles 270 VII. The Geostationary Orbit 273 A. Introduction 273 B. Satellite Ephemerides and Distance 274 C. Central Projection of the Earth 275 D. Eclipse 277 E. Sun Interference 279

7 xx Contents F. Apparent Motion of a Quasi-Geostationary Satellite 280 G. Velocity Increments Needed for Station-Keeping in the Geostationary Orbit 281 H. Doppler Effect 282 I. Polarization Rotation 282 VIII. Advanced Concepts 285 IX. Launch Vehicles 287 References Radio-Frequency Design Issues 299 A. Bonetto and E. Saggese I. Introduction 299 II. Basic Antenna Configurations 300 A. General 300 B. Factors Limiting Antenna Efficiency 300 С Radiation Patterns 302 D. The Parabolic Antenna 305 E. The Cassegrain Antenna 307 F. Offset Antennas 308 III. Propagation Phenomena 310 A. Faraday Rotation 310 B. Attenuation 311 С Depolarization 323 D. Refraction Effects 326 E. Adaptive Fade Countermeasures 327 References Analog Transmission 333 S. Tino I. Introduction 333 II. Syllabic Compandors 334 A. General 334 B. Compandor Transfer Characteristics 334 C. Effects of Companding 335 HI. Amplitude Modulation 338 A. Power Spectrum 338 B. Carrier-to-Noise and Signal-to-Noise Ratios 339 C. Transmission Quality for Multichannel Telephone Signals in SSB Systems 341 D. Amplitude-Companded Single Sideband with Multichannel Loading 341 IV. Frequency Modulation 342 A. Power Spectrum of a Carrier Modulated by a Sinusoid B. Bandwidth Occupied by a Multichannel Telephone Signal

8 Contents xxi C. Power Spectrum due to Multichannel Telephone Signal Modulation 343 D. Postdetection Noise Spectrum and Emphasis Laws 344 E. Measurement of Multichannel Telephone Signal Quality F. Frequency Modulation Advantage with Sinusoidal Modulation. 346 G. Frequency Modulation Advantage with Multichannel Telephone Signals 347 H. Single-Channel-Per-Carrier Systems in FM 347 I. Signal Suppression and Demodulation Threshold in FM J. Explanation of the Threshold Phenomenon due to Rice V. Design of FM Multichannel Telephone Systems 353 A. General 353 B. Parametric Calculation of Link Parameters 355 C. Calculation of Link Parameters for a Given Demodulator Margin 357 D. Threshold Extension and Related Advantages on Link Parameters 357 E. The FM Balanced System 358 F. Companded FM with Multichannel Loading 362 G. Experimental Results for Multichannel Telephony PL Demodulators 367 H. Success, Decline, and Possible Future of the PL Demodulator 376 I. Intermodulation Noise 378 J. Effect of Interferences 389 K. Truncation Effects due to Filtering 393 L. Carrier Energy Dispersal 395 M. Time-Assigned Speech Interpolation and its Effects 396 VI. The Design of FM-SCPC Telephone Systems. 398 A. General 398 B. Uncompanded FM-SCPC Systems 398 С Companded FM-SCPC Systems 399 D. Voice Activation 401 VII. Design of FM Television Systems 401 A. Experimental Results for Television PL Demodulators B. Truncation Effects due to Filtering 402 C. Nonlinear Distortions of FM TV Signals 404 D. Effect of Interference on FM TV Signals 406 E. Carrier Energy Dispersal 406 F. Point-to-Point Links: Video Only 407 G. Point-to-Point Links: Video + Audio 409 H. Broadcasting Systems 412 References Digital Transmission 417 F. Ananasso, R. Crescimbeni, G. Gallinaro and S. Tirro I. Introduction 417 II. Evaluation of Transmission Error Probability 419

9 xxü Contents A. General 419 B. Structure of the Optimal Receiver 422 C. Error Probability in Binary Communication Systems 425 D. L-ary Communication Systems 426 E. Transmission Bounds. The Shannon Limit 428 III. ISI and Modeling of Digital Communication Systems 429 A. General 429 B. Intersymbol Interference and Nyquist Pulses 430 C. Design of Linear Channels 433 D. Apportionment of Filtering with Practical Pulses 433 IV. Digital Amplitude Modulation Systems 436 A. General 436 B. On-Off Keying 436 С Amplitude-Shift Keying 442 D. Pulse Position Modulation 443 V. Frequency-Shift Keying 445 VI. Phase-Shift Keying 448 A. General 448 B. PSK as a Linear Modulation Scheme 449 C. Error Probability 451 D. Carrier Recovery 454 E. Clock Recovery 457 F. Unbalanced QPSK Modulation 460 G. Carrier Energy Dispersal 460 VII. Simulation of a QPSK Channel 461 A. General 461 B. Regenerative Channel Simulation 466 C. Transparent Channel Simulation 474 VIII. Offset Binary Modulations 478 A. Spectrum-Spreading Effect 478 B. Offset-QPSK and Minimum-Shift Keying 480 C. The Quadrature Overlapped Raised-Cosing Modulation IX. Channel-Ceding Background 485 A. General 485 B. Code Rate 486 С Coding Gain 487 D. Hard-Soft Decisors 488 E. Weight, Hamming Distance, and Correctable Errors 490 F. Types of Codes 491 G. Systematic Codes 491 H. Encoding-Decoding Operations 492 I. Decoding Threshold 497 J. Decoder Synchronization 498 K. Variable-Rate Coding 498 X. Automatic Repeat Request 499 A. Stop-and-Wait ARQ 500 B. Continuous ARQ 500

10 Contents xxui XI. Block Codes 500 A. General 500 B. Cyclic Codes 501 C. Word Error and Bit Error Probabilities 504 D. Golay Codes 505 E. BCH Codes 506 F. Reed-Solomon Codes 507 XII. Convolutional Codes 511 A. Coded Signal Generation 511 B. Distance Properties 513 C. Performance 516 D. The Viterbi Algorithm 519 XIII. Additional Topics on Forward Error Correction 521 A. Interleaving 521 B. Concatenated Codes 521 C. Concatenated Block Codes 522 D. Concatenated Block Plus Convolutional Codes 523 E. Performance Comparison for Various Coding Schemes XIV. Combined Coding and Modulation 528 A. General 528 B. Distance Properties of Signal Sets 530 C. Continuous-Phase Modulations 533 D. Trellis-Coded Modulations 540 E. Block-Coded Modulations 546 XI. Conclusions 548 References Bidirectional Circuit Design 553 S. Tirro I. Introduction 553 II. Power Control Policies and Optimum System Design 555 III. CNR Variations due to Atmospheric Propagation 563 IV. Intrasystem Interferences and Atmospheric Propagation 565 V. Transparent Single-Carrier-Per-Transponder Systems 568 A. General 568 B. SCPT Systems with Full UPPC 569 С SCPT Systems Not Using UPPC 570 D. SCPT Systems with Partial UPPC 570 VI. Transparent FDMA Systems 573 A. General 573 B. FDMA Systems with Full UPPC 574 С FDMA Systems Not Using UPPC 578 D. FDMA Systems Using Partial UPPC 579 VII. Regenerative Systems 579

11 xxiv Contents VIII. Determination of Transmission Parameters 582 A. General 582 B. FDM-FM Carriers 582 С PSK Carriers 584 IX. Determination of Front-End Characteristics 584 X. Discussion of Typical Examples 584 References Channel-Access Schemes 589 A. Vernucci I. Introduction 589 II. Frequency-Division Multiple Access 590 A. General 590 B. FDMA Solutions 591 С Enhanced FDMA Architectures 596 D. Frequency Plan 598 III. Time-Division Multiple Access 601 A. General 601 B. Traffic Bursts 603 C. Packetizing-Depacketizing 605 D. The TDMA Frame 607 E. The Reference Burst 608 F. The Unique Word 610 G. TDMA System Architectures 613 H. The Burst Time Plan 617 I. Acquisition and Synchronization 619 IV. Code-Division Multiple Access 622 A. General 622 B. Spread-Spectrum Concept 623 C. Spread-Spectrum Techniques 626 D. Synchronization Aspects 627 V. Access Techniques Comparison 629 A. General 629 B. Fundamental Behavior 629 C. Practical Comparison 631 D. Conclusions 634 References Networking 637 S. Tirro I. Introduction 637 II. Definitions and Basic Assumptions 638

12 Contents xxv A. Nodes and Edges 638 B. Circuits, Channels, Half-Circuits, and Terminations (Trunks) 639 C. Bundles of Circuits and Bundles of Half-Circuits 640 D. One-Way and Two-Way Circuit Operation 640 E. Traffic Rearrangement, Commutation, and Dynamic Management of Resources 640 F. Demand Assignment and Switching: Why Two Different Names? 641 G. Call Blocking and Network Efficiency 642 H. Delay and Throughput 643 III. Terrestrial Network Structure 643 A. Typical Structure of a Telephone Network 643 B. ISDN and N x 64 Services 646 C. Packet Services 646 D. High-Speed Services 647 IV. Typical Structures of Satellite Systems 649 A. Global Coverage with Single Transparent Repeater 650 B. Global Coverage with Multiple Transparent Repeaters C. Multiple-Beam Systems with Transparent Repeaters 652 D. Scanning-Beam Systems with Single Transparent Repeater E. Mixed Systems 656 F. Regenerative Systems with T-Stages Onboard 657 V. Connection Techniques and Network Structures for Telephony A. Hierarchy of Traffic Sources 657 B. Hierarchy of Bundles 658 C. Symmetric and Asymmetric Bundles 658 D. Number of Bundles and Network Efficiency 659 E. Commutation Functions 662 F. Systems with T-Stages Onboard 667 G. Optimization of System Efficiency 668 H. Evolution from Long to Short Frames 670 I. Compatibility Problems between T-Stages Onboard and DSI 671 J. Double-Rate Systems 672 K. Algorithms for Dynamic Management of Resources 672 VI. Connection Techniques and Network Structures for Other Services 673 A. N x 64 Services 673 B. Packet Services 675 C. High-Speed Services 678 D. Point-to-Multipoint Connection Techniques for Videoconferencing 679 VII. Summary of Advantages and Disadvantages of T-Stages Location Onboard the Satellite 683 VIII. Signaling Problems 684 A. Telephone Signaling (Fixed Assignment of the Satellite Channel) 684 B. Telephone Signaling (Demand Assignment of the Satellite Channel) 686

13 xxvi Contents C. N x 64 Services 688 D. Packet Transmissions 688 E. Packet-Switching Services 688 F. High-Speed Services 689 G. Possible Gathering Protocol for Videoconferencing 689 H. Asynchronous Protocols for Dynamic Management of Resources 691 IX. Integration of Satellite Systems with Terrestrial Networks 692 A. Developing Countries 692 B. Developed Countries 692 C. International Systems 694 X. Conclusions 695 References System Economics 697 S. Tino I. Introduction 697 II. Definitions 698 A. System Types 698 B. System Components 700 C. Economic Definitions and Basic Cost Data 700 D. Trunking, Network-Oriented, and User-Oriented Systems III. A Methodology for System Optimization 709 A. Introduction 709 B. Ground Segment Trade-Off 710 С Space System Trade-Off 711 IV. Unidirectional Systems Examples 712 A. Platform Data Collection 713 B. Data Dissemination 713 C. Sound Broadcasting 714 D. Television Broadcasting 714 V. Trunking Systems 716 A. Introduction 716 B. The INTELSAT System Case 717 С The EUTELSAT System Case 721 D. North-American Systems 724 VI. Satellite Systems for Public Telephone Networks 774 VII. Interactive Data User-Oriented Systems 726 VIII. Voice-Video-File Transfer User-Oriented System 728 A. Configuration B. Configuration С Configuration D. Configuration IX. Satellite Systems for Mobile Communications 732 X. Conclusions 734 References 734

14 Contents xxvü 15. Future Developments 737 G. Chiassarini, R. Crescimbeni, G. Gallinaro, R. Lo Fora, A. Puccio and S. Tirrö I. Introduction 737 II. Intersatellite Links 737 A. General 737 B. ISL Viability for Separated GEO Satellites 739 C. Optical Intersatellite Links 740 D. Microwave Intersatellite Links 743 III. Satellite Antennas 744 A. General 744 B. Some Antenna Configurations 745 C. Focused Multibeam Antennas 748 D. The Multiport Amplifier 750 E. Direct Radiating Arrays 751 F. Imaging Antenna Systems 753 G. Active Antennas Assessment 754 IV. Onboard Processing 756 A. General 756 B. Space Radiations and Radiation Hardening 756 C. Multicarrier Demodulators 761 D. FEC Decoding Onboard 766 E. Onboard Switching 767 F. FROBE Processing for SS-FDMA Systems 771 References 772 Appendix 1. Radio Regulations Provisions 775 E. D'Andria I. Introduction 775 II. Frequency Allocations 776 III. Interference Coordination 777 A. Modes of Interference between Space and Terrestrial Services 778 B. Modes of Interference between Stations of Different Space Systems in Frequency Bands with Separated Earth-to-Space and Space-to-Earth Allocations 779 C. Modes of Interference between ESs of Different Space Systems in Frequency Bands for Bidirectional Use 779 IV. Radiation Limitations 779 References 781 Appendix 2. Frequency Sharing among Fixed-Satellite Service Networks E. D'Andria I. Interference Evaluation to Determine if Coordination is Required 783 II. Detailed Coordination Calculations and Interference Criteria

15 xxviii Contents III. Possible Methods to Solve Incompatibilities 787 A. Increase in Angular Separation 787 B. Adjustment of Network Parameters 788 C. Frequency Separation (Staggering) 788 D. Departure from CCIR Recommendations 788 References 789 Appendix 3. Frequency Sharing between the Fixed-Satellite Service and E. D'Andria the Fixed Service 791 I. Determination of the Coordination Area 791 II. Detailed Coordination Calculations and Interference Criteria III. Possible Methods to Solve Incompatibilities 795 A. Frequency Separation 796 B. Adjustment of Network Parameters 797 С Other Methods 797 References 797 Appendix 4. Efficient Use of the Geostationary Orbit-Spectrum Resource 799 G. Quaglione I. Overcrowding in the Geostationary Orbit 799 II. Communication Capacity of the Geostationary Orbit 800 A. Method A (Pessimistic) 800 B. Method В (Optimistic) 801 С CCIR Methods 801 III. Major Factors Affecting the Efficiency of Geostationary Orbit-Spectrum Utilization 801 A. Frequency Reuse Potential 802 B. Spacecraft Antenna Radiation Characteristics 803 C. Earth Station Antenna Radiation Characteristics 804 D. Stationkeeping 805 E. Interference Allowance 805 F. Optimization of Frequency Assignments and Modulation Characteristics 806 IV. Outline of the Main Results of WARC-ORB '85-' References 809 Appendix 5. Authors of Individual Sections 811 Appendix 6. List of Acronyms 813 Index 821