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Satellite Communication Engineering Michael O. Kolawole Jolade Pty. Ltd. Melbourne,Australia Marcel Dekker, Inc. New York Basel • TM Copyright ©2002 by Marcel Dekker,Inc. All Rights Reserved. ISBN: 0-8247-0777-X Thisbookis printed onacid-free paper. Headquarters Marcel Dekker,Inc. 270Madison Avenue,NewYork, NY10016 tel: 212-696-9000;fax: 212-685-4540 EasternHemisphereDistribution Marcel DekkerAG Hutgasse 4,Postfach 812,CH-4001Basel, Switzerland tel: 41-61-261-8482;fax: 41-61-261-8896 World WideWeb http://www.dekker.com Thepublisheroffersdiscountsonthisbookwhenorderedinbulkquantities.Formore information,writetoSpecialSales=ProfessionalMarketingattheheadquartersaddress above. Copyright #2002by Marcel Dekker, Inc.All RightsReserved. Neitherthisbooknoranypartmaybereproducedortransmittedinanyformorbyany means,electronicormechanical,includingphotocopying,microfilming,andrecording, orbyanyinformationstorageandretrievalsystem,withoutpermissioninwritingfrom the publisher. Current printing (lastdigit): 109 8 7 65 4 3 21 PRINTED IN THEUNITED STATES OFAMERICA Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. This book is dedicated to my families in Australia and Nigeria for their belief in and support for me. The joy of family is divine. For this I am eternally blessed and grateful. Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. Series Introduction Over the past 50 years, digital signal processing has evolved as a major engineering discipline. The fields of signal processing have grown from the origin of fast Fourier transform and digital filter design to statistical spectral analysis and array processing, image, audio, and multimedia processing, and shaped developments in high-performance VLSI signal processor design. Indeed,therearefewfieldsthatenjoysomanyapplications—signalprocessing is everywhere in our lives. When one uses a cellular phone, the voice is compressed, coded, and modulatedusingsignalprocessingtechniques.Asacruisemissilewindsalong hillsides searching for the target, the signal processor is busy processing the imagestakenalongtheway.WhenwearewatchingamovieinHDTV,millions of audio and video data ar being sent to our homes and received with unbelievable fidelity. When scientists compare DNA samples, fast pattern recognition techniques are being used. On and on, one can see the impact of signal processing in almost every engineering and scientific discipline. Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. Because of the immense importance of signal processing and the fast- growing demands of business and industry, this series on signal processing servestoreportup-to-datedevelopmentsandadvancesinthefield.Thetopics of interest include but are not limited to the following. (cid:1) Signal theory and analysis (cid:1) Statistical signal processing (cid:1) Speech and audio processing (cid:1) Image and video processing (cid:1) Multimedia signal processing and technology (cid:1) Signal processing for communications (cid:1) Signal processing architectures and VLSI design Ihopethisserieswill provide theinterestedaudiencewithhigh-quality,state- of-the-art signal processing literature through research monographs, edited books, and rigorously written textbooks by experts in their fields. K. J. Ray Liu Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. Preface Satellite communication is one of the most impressive spin-offs from space programs, and has made a major contribution to the pattern of international communications. The engineering aspect of satellite communications combines such diverse topics as antennas, radio wave propagation, signal processing, data communication, modulation, detection, coding, filtering, orbital mechanics, and electronics. Each is a major field of study and each hasitsownextensiveliterature.SatelliteCommunicationEngineeringempha- sizes the relevant material from these areas that is important to the book’s subjectmatterandderivesequationsthatthereadercanfollowandunderstand. The aim of this book is to present in a simple and concise manner the fundamental principles common to the majority of information communications systems. Mastering the basic principles permits moving on to concrete realizations without great difficulty. Throughout, concepts are developed mostly on an intuitive, physical basis, with further insight provided by Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. meansofacombinationofapplicationsandperformancecurves.Problemsets areprovidedfor thoseseekingadditional training. Starredsections containing basicmathematicaldevelopmentmaybeskippedwithnolossofcontinuityby those seeking only a qualitative understanding. The book is intended for electrical, electronics, and communication engineering students, as well as practicing engineerswishing to familiarize themselveswith the broad field of information transmission, particularly satellite communications. The first of the book’s eight chapters covers the basic principles of satellite communications, including message security (cryptology). Chapter2discussesthetechnicalfundamentalsforsatellitecommunica- tionsservices,whichdonotchangeasrapidlyastechnologyandprovidesthe reader with the tools necessary for calculation of basic orbit characteristics such as period, dwell time, and coverage area; antenna system specifications such as type, size, beam width, and aperture-frequency product; and power system design. The system building blocks comprising satellite transponder and system design procedure are also described. While acknowledging that systems engineering is a discipline on its own, it is my belief that the reader will gain a broad understanding of system engineering design procedure, accumulated from my experience in large, complex turnkey projects. Earthstation,whichformsthevitalpartoftheoverallsatellitesystem,is the central theme of Chapter 3. The basic intent of data transmission is to provide quality transfer of information from the source to the receiver with minimum error due to noise in the transmission channel. To ensure quality information requires smart signal processing technique (modulation) and efficient use of system bandwidth (coding, discussed extensively in Chapter 6). The most popular forms of modulation employed in digital communications,suchasBPSK,QPSK,OQPSK,and8-PSK,arediscussedtogetherwith their performance criteria (BER). Anoverviewof information theoryisgiven to enhance the reader’s understanding of how maximum data can be trans- mitted reliably over the communication medium. Chapter 3 concludes by describing a method for calculating system noise temperature and the items that facilitate primary terrestrial links to and from the Earth stations. Chapter4discussestheprocessofdesigningandcalculatingthecarrier- to-noiseratioasameasureofthesystemperformancestandard.Thequalityof signals received by the satellite transponder and that retransmitted and received by the receiving earth station is important if successful information transfer via the satellite is to be achieved. Within constraints of transmitter power and information channel bandwidth, a communication system must be designed to meet certain minimum performance standards. The most important performance standard is ratio of the energy bit per noise density in the Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved. information channel, which carries the signals in a format in which they are delivered to the end users. Tobroadcastvideo,data,and=oraudiosignalsoverawideareatomany users,asingletransmissiontothesatelliteisrepeatedandreceivedbymultiple receivers. While this might be a common application of satellites, there are otherswhichmayattempttoexploittheuniquecapacityofasatellitemedium to create an instant network and connectivity between any points within its view.Toexploitthisgeometricadvantage,itisnecessarytocreateasystemof multiple accesses in which many transmitters can use the same satellite transponder simultaneously. Chapter 5 discusses the sharing techniques called multiple access. Sharing can be in many formats, such as sharing the transponder bandwidth in separate frequency slots (FDMA), sharing the transponder availability in time slots (TDMA), or allowing coded signals to overlap in time and frequency (CDMA). The relative performance of these sharing techniques is discussed. Chapter6explorestheuseoferror-correcting codes inanoisycommu- nication environment, and how transmission error can be detected and correction effected using the forward error correction (FEC) methods, namely, the linear block and convolutional coding techniques. Examples are sparingly used as illustrative tools to explain the FEC techniques. The regulation that covers satellite networks occurs on three levels: international, regional, and national. Chapter 7 discusses the interaction among these three regulatory levels. Customer’s demands for personalized services and mobility, as well as provision of standardized system solutions, have caused the proliferation of telecommunications systems. Chapter 8 examines basic mobile-satellite- system services and their interaction with land-based backbone networks—in particular the integrated service digital network (ISDN). Since the services covered by ISDN should also, in principle, be provided by digital satellite network, it is necessary to discuss in some detail the basic architecture of ISDN as well as its principal functional groups in terms of reference configurations, applications, and protocols. Chapter 8 concludes by briefly lookingatcellularmobilesystem,includingcellassignmentandinternetwork- ingprinciples,aswellastechnologicalobstaclestoprovidingefficientInternet access over satellite links. TheinspirationforwritingSatelliteCommunicationEngineeringcomes partly from my students who have wanted me to share the wealth of my experience acquired over the years and to ease their burden in understanding the fundamental principles of satellite communications.Avery specialthanks gotomydarlingwife,Dr.MarjorieHelenKolawole,whoactivelyremindsme Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved.