SATELLITE COMMUNICATIONS - Springer978-94-010-9760-4/1.pdf · SATELLITE COMMUNICATIONS SECOND...
Transcript of SATELLITE COMMUNICATIONS - Springer978-94-010-9760-4/1.pdf · SATELLITE COMMUNICATIONS SECOND...
SATELLITE COMMUNICATIONS
SATELLITE COMMUNICATIONS SECOND EDITION
Robert M. Gagliardi Department of Electrical Engineering University of Southern California
~ VAN NOSTRAND REINHOLD ~ _____ New York
Copyright © 1991 by Van Nostrand Reinhold
Softcover reprint of the hardcover 1st edition 1991
Library of Congress Catalog Number 90-40748
ISBN 978-94-010-9762-8 ISBN 978-94-010-9760-4 (eBook) DOI 10.1007/978-94-010-9760-4
All rights reserved. No part of this work covered by the copyright hereon may be reproduced or used in any form by any means--graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems--without written permission of the publisher.
VanNostrand Reinhold 115 Fifth Avenue New York, New York 10003
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Thomas Nelson Australia 102 Dodds Street South Melbourne 3205 Victoria, Australia
Nelson Canada 1120 Birchmount Road Scarborough, Ontario MIK 5G4, Canada
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Library of Congress Cataloging-in-Publication Data
Gagliardi, Robert M., 1934-Satellite communications / Robert M. Gagliardi.-2nd ed.
p. ca. Includes bibliographical references and index.
1. Artificial satellites in telecommunication. I. Title. TK5104.G33 1991 621.382' 54-dc20 90-40748
CIP
In dedication to the memory of my beloved mother and father, Louise Musco Gagliardi and Michael Gagliardi, Hamden, Connecticut
Contents
Preface xiii
1 Introduction 1
1.1 Historical Development of Satellites 2 1.2 Communication Satellite Systems 2 1 .3 Communication Satellites 9 1.4 Orbiting Satellites 13 1.5 Satellite Frequency Bands 23 1.6 Satellite Multiple-Access Formats 26
References 29 Problems 30
2 Modulation, Encoding, and Decoding 31
2.1 Analog Modulation 32 2.2 Analog FM Carriers 37 2.3 Digital Encoding 40 2.4 Spectral Shaping 50 2.5 Digital Decoding 58 2.6 Error-Correction Decoding 72 2.7 Block Waveform Encoding 77
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3
4
CONTENTS
2.8 Digital Throughput 88 References 92 Problems 93
The Satellite Channel 95
3.1 Electromagnetic Field Propagation 95 3.2 Antennas 99 3.3 Atmospheric Losses 108 3.4 Receiver Noise 114 3.5 Carrier-to-Noise Ratios 118 3.6 Satellite Link Analysis 121 3.7 Dual Polarization 137 3.8 Effect of Depolarization on Dual Polarized
Communications 142 3.9 Spot Beams in Satellite Downlinks
References 153 Problems 153
Satellite Electronics 157
4.1 The Transponder Model 157 4.2 The Satellite Front End 159 4.3 RF Filtering of Digital Carriers 170 4.4 Satellite Signal Processing 177 4.5 Frequency Generators 186 4.6 Transponder Limiting 194 4.7 Nonlinear Satellite Amplifiers 202
References 210 Problems 211
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5 Frequency-Division Multiple Access 215
5.1 The FDMA System 216 5.2 Nonlinear Amplification with Multiple FDMA Carriers 222 5.3 FDMA Nonlinear Analysis 234 5.4 FDMA Channelization 240 5.5 AM/PM Conversion with FDMA 244 5.6 Satellite-Switched FDMA 246
References 248 Problems 249
6 Time-Division Multiple Access 251
6.1 The TDMA System 252 6.2 Preamble Design 258 6.3 Satellite Effects on TDMA Performance 271 6.4 Network Synchronization 273 6.5 SS-TDMA 279
References 287 Problems 288
7 Code-Division Multiple Access 289
7.1 Direct-Sequence CDMA Systems 290
CONTENTS Ix
7.2 Code Generation for DS-CDMA Systems 297 7.3 Performance of DS-CDMA Systems 302 7.4 Combined Error Correction and Code Addressing in
DS-CDMA 309 7.5 Antijam Advantages of Direct Code Addressing 311 7.6 Satellite Jamming with DS-CDMA 316 7.7 DS-CDMA Code Acquisition and Tracking 318
References 332 Problems 333
8 Frequency-Hopped Communications 337
8.1 The Frequency-Hopped System 337 8.2 Frequency-Hopping Synthesizers 342 8.3 Performance of Frequency-Hopped Systems 351 8.4 Frequency-Hopped CDMA Systems 355 8.5 Jamming in Frequency-Hopped Systems 358 8.6 Code Acquisition and Tracking in FH Systems 362
References 364 Problems 365
9 On-Board Processing 367
9.1 On-Board Processing Subsystems 367 9.2 Baseband Digital Decoding 369 9.3 Data Reclocking, Routing, and Multiplexing 376 9.4 TDM-FDM Conversion 383 9.5 On-Board Remodulation 388 9.6 On-Board Baseband Processing with Beam Hopping 391
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9.7 Multiple Spot Beaming 393 9.8 Photonic On-Board Processing 398
References 402 Problems 403
10 Satellite Crosslinks 405
10.1 The Crosslink System 405 10.2 Crossline Power Budget 409 10.3 Coherent and Noncoherent Communications at EHF 414 10.4 Autotracking 422 10.5 Autotrack Loop Analysis 428 10.6 Effect of Autotract Pointing Errors on PE 432 10.7 Optical Crosslinks 435
References 455 Problems 456
11 VSAT and Mobile-Satellite Systems 461
11 .1 VSAT -Satellite-System Concept 462 11.2 Small-Terminal-Satellite Link Analysis 465 11.3 VSAT and Hub Networks 470 11.4 Direct Home TV Broadcasting 475 11.5 The Mobile-Satellite Channel 477 11 .6 Communicating over the Mobile-Satellite Channel 482 11.7 Interleaving to Combat Deep Fading 490 11 .8 Combined Coding and Modulation for the Mobile
Channel 493 References 498 Problems 499
Appendices A REVIEW OF DIGITAL COMMUNICATIONS 501
A.1 Baseband Digital Waveforms 501 A.2 BPSK Systems 503 A.3 QPSK Carrier Waveform 507 A.4 FSK 510 A.5 DPSK 51.2 A.6 MPSP 514
CONTENTS xi
A 7 Correlation Detection of Orthogonal BPSK 514 A8 MFSK 517 A9 Effect of Phase Noise on Noncoherent FSK and DPSK
Systems 518 A10 MASK 521
References 523
B CARRIER RECOVERY AND BIT TIMING 525
B.1 Carrier Recovery 525 B.2 BPSK Carrier Recovery 532 B.3 QPSK Carrier Referencing 539 B.4 MPSK Carrier Referencing Systems 545 B.5 Bit Timing 547
References 555
C SATELLITE RANGING AND POSITION LOCATION SYSTEMS 557
C.1 Ranging Systems 557 C.2 Component Range Codes 561 C.3 Tone-Ranging Systems 564 C.4 Position Locating and Navigation 570
D NONLINEAR AMPLIFICATION OF CARRIER WAVEFORMS 575
Index 581
Preface
This second edition of Satellite Communications is a revised, updated, and improved version of the first edition (Van Nostrand, 1984) and has been extended to include many newer topics that are rapidly becoming important in modem and next-generation satellite systems. The first half of the book again covers the basics of satellite links, but has been updated to include additional areas such as Global Positioning and deep space satellites, dual polarization, multiple beaming, advanced satellite electronics, frequency synthesizers, and digital frequency generators. The second half of the book is all new, covering frequency and beam hopping, on-board processing, EHF and optical crosslinks, and mobile satellites and VSAT systems. All of these latter topics figure to be important aspects of satellite systems and space platforms of the twenty-first century.
As in the first edition, the objective of the new edition is to present a unified approach to satellite communications, helping the reader to become familiar with the terminology, models, analysis procedures, and evolving design directions for modem and future satellites. The presentation stresses overall system analysis and block diagram design, as opposed to complicated mathematical or physics descriptions. (Backup mathematics is relegated to the appendices where a reader can digest the detail at his own pace.) The discussion begins with the simplest satellite systems and builds to the more complex payloads presently being used.
The book is intended for students, engineers, and scientists working in the area of satellite communications. It can be used in the classroom, for continuing
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education or in-house courses, and as· an at-home or on-the-job selfreading aid. A newcomer to the satellite field should benefit from this unified treatment, beginning with the simplest concepts and extending to the more complex. The practicing engineer will find the text useful for review, for aiding in analytical studies and performance evaluation, and for addressing issues posed by newer satellite technologies.
The material is presented at a senior or first-year graduate level and assumes the reader has some basic electrical engineering background. Previous knowledge of communication systems is advantageous, but not necessary. Key background needed would be Fourier transforms, some electromagnetic theory and electronics, and elementary probability and noise theory.
Chapter 1 introduces and summarizes the various types of satellite links and their key parameters and constraints. Chapter 2 serves as a basic review of modulation, decoding, and coding and emphasizes those most common in satellite links. (Appendices A and B act as a backup for this review.) Chapter 3 reviews and applies basic link power analysis to satellites, pointing out the key design equations, system tradeoffs, and inherent problem areas. Chapter 4 examines the satellite payload and electronics, discussing the modem technologies and signal processing limitations. Chapter 5 develops the FDMA format, Chapter 6 the TDMA format, and Chapter 7 the COMA and spread spectrum format. Advantages and disadvantages of each are derived and highlighted.
The remainder of the text introduces completely new chapters. Chapter 8 covers frequency-hopping systems. Chapter 9 discusses the advantages and technologies of on-board processing, a topic that is becoming increasingly important as satellite payloads get bigger and more sophisticated. Chapter 10 examines the latest technology in satellite crosslinks, including antenna pointing and autotracking. Chapter 11 considers the use of satellites for direct mobile and home broadcasting, and the use of small earth stations (VSATs). An appendix on ranging and position location is included to aid text discussion.
Each chapter contains a homework problem set, with problems ranging from straightforward to moderate difficulty, aiding the student in reviewing and understanding the text presentations. The book includes over 50 tables and 250 figures to simplify discussion and catalog reference material for on-the-job task solutions.
I wish to personally thank Ms. Georgia Lum of the Electrical Engineering Department at USC for typing the manuscript. I also acknowledge the help of the staff of the Communication Science Institute at USC, Ms. Milly Montenegro, Ms. Cathy Cassells, and Ms. Neela Sastry in putting together the
PREFACE xv
new edition. Lastly, I would like to thank the practicing engineers, classroom students, and university instructors who used the ftrst edition for their criticisms, comments, and suggestions that aided me in upgrading this edition.
SATELLITE COMMUNICATIONS