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and voice (telephone) communications for their audiences. Intelsat was thefirst commercial global satellite system owned and operated by a consortiumof more than 100 nations; hence its name, which stands for InternationalTelecommunications Satellite Organization. The first organization to provideglobal satellite coverage and connectivity, it continues to be the majorcommunications provider with the broadest reach and the most comprehensiverange of services.Other providers for industrial and domestic markets include Westar in1974, Satcom in 1975, Comstar in 1976, SBS in 1980, Galaxy and Telstar in1983, Spacenet and Anik in 1984, Gstar in 1985, Aussat in 1985–86, Optus A2in 1985, Hughes-Ku in 1987, NASA ACTS in 1993, Optus A3 in 1997, andIridium and Intelsat VIIIA in 1998. Even more are planned. Some of thesesatellites host dedicated military communication channels. The need to havemarket domination and a competitive edge in military surveillance and tacticalfields results in more sophisticated developments in the satellite field.1.2 COMMUNICATIONS VIA SATELLITERadiowaves, suitable as carriers of information with a large bandwidth, arefound in frequency ranges where the electromagnetic waves are propagatedthrough space almost in conformity with the law of optics, so that only line-ofsightradio communication is possible [1]. As a result, topographical conditionsand the curvature of the earth limit the length of the radio path. Relaystations, or repeaters, must be inserted to allow the bridging of greaterdistances (see Fig. 1.1). Skyway radar uses the ionosphere, at height of 70to 300 km, to transmit information beyond the horizon and may not requirerepeaters. However, transmission suffers from ionospheric distortions andfading. To ensure that appropriate frequencies are optimally selected, additionalmonitoring equipment is required to sample the ionospheric conditionsinstantaneously.A communication satellite in orbit around the earth exceeds the latterrequirement. Depending on the orbit’s diameter, satellites can span largedistances almost half the earth’s circumference. However, a communicationlink between two subsystems—for instance, earth stations or terminals—viathe satellite may be considered a special case of radio relay, as shown in Fig.1.2, with a number of favorable characteristics:A desired link between two terminals in the illumination zone can beestablished.Copyright © 2002 by Marcel Dekker, Inc. All Rights Reserved.
Page 2: SatelliteCommunicationEngineeringMi
Page 6: This book is dedicated to my famili
Page 10: Because of the immense importance o
Page 14: means of a combination of applicati
Page 18: about my promise to my students, an
Page 22: 2.3 Coverage Area and Satellite Net
Page 26: 1Basic Principles of SatelliteCommu
Page 32: FIGURE 1.1Intercontinental communic
Page 36: 3. Satellite circuits in a common c
Page 40: decryption algorithm D y with the c
Page 44: earthstations, RS( j) (more issaid
Page 48: Technology developed an advanced en
Page 52: FIGURE 1.8Sequence of the transform
Page 56: TABLE 1.1The DES Selection Function
Page 60: and the 32-bit block input isY ¼ y
Page 64: communication package placed in orb
Page 68: 2Satellites2.1 OVERVIEWA satellite
Page 72: stable over their operating tempera
Page 76: FIGURE 2.3 Geometric properties of
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at the altitudes of satellites, the
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whereg ¼ acceleration due to gravi
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2.3 COVERAGE AREA AND SATELLITENETW
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The apex angle required at the sate
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the frontline satellites is then pa
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station antenna must be pointed to
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and the azimuth angle is a z ¼ 180
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2.5.3 Swath WidthThe width of the v
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2.6.3 System Speci¢cations: Analys
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Like all materials that require cou
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By the first definition, the system
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SolutionFrom (2.28), we can estimat
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FIGURE 2.11An example of redundancy
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adiators. An antenna array is a fam
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Example 2.3: The earth subtends an
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eam is assumed symmetrical (i.e., y
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FIGURE 2.15Feed array elements ðy
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If the steering is in the direction
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2.8 SATELLITE POWER SYSTEMSA key co
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Calculate (1) the probability that
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FIGURE 2.20Carrier processing.infor
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FIGURE 2.22(d) elliptic.Types of ba
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FIGURE 2.23A klystron. (Courtesy of
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FIGURE 2.25A simple block diagram o
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tional protection is required to en
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3.1 BASIC PRINCIPLE OF EARTH STATIO
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3.1.1 Technical and Operational Req
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excellent protection against noise
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FIGURE 3.3QPSK modulator.FIGURE 3.4
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TABLE 3.28-PSK Truth TableInput bit
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FIGURE 3.8An M-ary PSK demodulator
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where B is the allocated channel ba
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A frequently used function is the Q
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In view of (3.11), Eq. (3.18) can b
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Encoder and DecoderAn encoder is an
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Modulator and DemodulatorA modulato
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Zero Forcing Technique. Suppose the
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The adjoint of matrix A is obtained
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FIGURE 3.14The three-tap equalizer
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First, in the case of digital signa
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than 1=A. Whichever law is used, th
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FIGURE 3.16Block diagram for estima
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3.4.2 Antenna TrackingAn earth stat
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controlling antenna pointing. The m
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FIGURE 3.19A generalized model of a
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FIGURE 3.20Entropy of a binary sour
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whereHðYÞ¼output entropy, the av
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To have a feel for this expression,
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2. The system’s overall condition
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transmitted down the fiber as digit
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10. Kantor, L. Y. (ed). (1987). Han
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142. Simulate the probability of bi
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FIGURE 4.1A simplex link.baseband c
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Chapter 2, Sec. 2.7, discusses that
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From (4.6), the received power P r
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FIGURE 4.3A model of the combined-l
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4.1.2 Rain AttenuationRain attenuat
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FIGURE 4.5rates.Average rainstorm p
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FIGURE 4.6Adjacent satellite interf
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FIGURE 4.8Satellite separation dist
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inability of satellite A to accurat
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FIGURE 4.10 Cross-link E b =N 0 vs.
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Then using (4.41), the overall C=N
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(iv)(v)(vi)(vii)Calculate the recei
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5Communication Networks andSystemsC
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discriminate among carriers by temp
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FIGURE 5.2 Principle of FDMA system
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FIGURE 5.3 Operational concept of T
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FIGURE 5.5TDMA: bit rate r b for 1
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Copyright © 2002 by Marcel Dekker,
Page 360:
5.2 CAPACITY COMPARISON OFMULTIPLE-
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Rearranging (5.11) in terms of ener
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The transmission bit rate isR r ¼
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6Error Detection and CorrectionCodi
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the channel and reconstruct the sou
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message sequence X . Thus, a system
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If we consider a message X ¼ð1010
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can be seen in Table 6.1 that the m
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FIGURE 6.1A (7, 4) cyclic code gene
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FIGURE 6.2Convolutional codes encod
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Alternative methods of describing a
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FIGURE 6.5 Code tree diagram of Fig
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FIGURE 6.8 Code tree diagram of rat
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consistent with the constraint leng
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trellis depth is approximated to 5L
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FIGURE P.1A convolutional coder.the
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7Regulatory Agencies andProceduresT
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of the radiofrequency spectrum, and
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The CCIR works through the medium o
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7.1.3 IFRBThe International Frequen
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The national or regional spectrum m
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3. The need to expand or enhance th
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The DSP will be responsible for res
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2. Provide a convenient framework w
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FIGURE 8.3Types of user-to-network
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H1-channels are designed to carry v
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information. The transfer cell prov
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The OSI layers are divided into two
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plane is denoted by U, the control
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interfacing, maintenance, and conne
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adjoining base station to scan the
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FIGURE 8.9Geometry of a polygon.The
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FIGURE 8.11Splitting cells into sma
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causes signal fading. Of course, th
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FIGURE 8.14TCP=IP suite and its rel
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access to an Internet point of pres
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message security via satellite is d
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REFERENCES1. Wu, W.W. (1989). Eleme
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Appendix ANotationsThe symbols have
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N sPP rP sP TRRðtÞR cR eR rR vSS
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g Central anglez Channel gainZ Ante
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AttenuationBandwidthBearer serviceB
Page 528:
Frequency divisionmultiple accessFr
Page 532:
MultiplexingNetworkOmnidirectionala
Page 536:
UplinkUser-to-networkinterfaceThe e
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