View File - University of Engineering and Technology, Taxila

More documents

Recommendations

Info

FIGURE 3.8An M-ary PSK demodulator and decoder.The decoding operation involves reconstructing the data bit sequenceencoded onto the carrier. The lowest possibility of decoding a carrier in erroroccurs if phase-coherent decoding is used. Phase-coherent decoding requiresthe decoder to use a referenced carrier at the same frequency and phase as thereceived modulated carrier during each bit time. In addition, the exact timingof the beginning and ending of each bit must be known. Often the phase andtiming coherency is achieved using a separate synchronization device operatingtogether with the decoder. The function of the synchronization device is toextract the required reference and timing from the received modulated carrieritself.As seen in the previous subsections on PSK techniques, the mappingfrom binary to M-ary symbols is performed in a manner ensuring that any pairof adjacent symbols differs in only one binary digit. Such a mapping scheme isknown as Gray coding or, sometimes, the maximum distance coding. Thismapping scheme minimizes the number of bit errors that result from ademodulation error because when a digital receiver receives noise-inducederror signals, it incorrectly selects a symbol adjacent to the correct one [2].Using the Gray code results in only a single bit received in error.3.2.5 Transmission Bandwidth RequirementsCommunication speed depends on how fast data are generated from the‘‘source’’ and transferred through a channel. A channel is the path by whichpropagation signals take. It could be a telephone line, microwave link, satellitelink, or optical fiber. A one-way communication path is called a channel, and atwo-way path formed by two channels is a circuit. The data rate is stated inCopyright © 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 30:
and voice (telephone) communication
Page 34:
FIGURE 1.2Communication between two
Page 38:
interpreting or uncovering the deci
Page 42:
cryptographic keys K ti (where i ¼
Page 46:
FIGURE 1.6Block ciphering technique
Page 50:
FIGURE 1.7Part of block ciphering w
Page 54:
Based on the ordering sequence of (
Page 58:
TABLE 1.1 (continued )S612 1 10 15
Page 62:
For an uncoded message x and the fe
Page 66:
2. Your task is to develop a commun
Page 70:
FIGURE 2.1Geometry of a satellite.
Page 74:
Future trends in satellite antennas
Page 78:
In the United States, the three sat
Page 82:
TABLE 2.3Typical Links Frequency Ba
Page 86:
FIGURE 2.4Satellite period and orbi
Page 90:
FIGURE 2.6An illustration of covera
Page 94:
FIGURE 2.7constellation.A sketch of
Page 98:
width of 1:73 with reduced coverag
Page 102:
y ¼ elevation angle of satellite f
Page 106:
We can conclude that the antenna mu
Page 110:
FIGURE 2.9Design flowchart of a sat
Page 114:
Risk control and monitoring measure
Page 118:
TABLE 2.4Antenna Selection Criteria
Page 122:
Then the system availability can be
Page 126:
In fact, MTBF is the reciprocal of
Page 130:
2.7 ANTENNASBased on function, sate
Page 134:
Two kinds of horns in common use ar
Page 138:
FIGURE 2.13Geometry of a parabolic
Page 142:
FIGURE 2.14 Axisymmetric reflector
Page 146:
A transceiver antenna is a single a
Page 150: The gain, in the axial mode, of a h
Page 154: angles, spacecraft may shadow the s
Page 158: 3. The probability of both parallel
Page 162: the baseband signal (more details a
Page 166: matrix in the communications subsys
Page 170: FIGURE 2.24Typical transfer charact
Page 174: 4. Iridium LCC (1997). Iridium Syst
Page 178: 3Earth StationsIn Chap. 2 we discus
Page 182: The most popular forms of modulatio
Page 186: Small earth stations are antennas w
Page 190: FIGURE 3.2BPSK space diagram.Instea
Page 194: OQPSKOffset QPSK (OQPSK) is a modif
Page 198: FIGURE 3.7An 8-PSK space diagram.an
Page 204: where B is the allocated channel ba
Page 208: A frequently used function is the Q
Page 212: In view of (3.11), Eq. (3.18) can b
Page 216: Encoder and DecoderAn encoder is an
Page 220: Modulator and DemodulatorA modulato
Page 224: Zero Forcing Technique. Suppose the
Page 228: The adjoint of matrix A is obtained
Page 232: FIGURE 3.14The three-tap equalizer
Page 236: First, in the case of digital signa
Page 240: than 1=A. Whichever law is used, th
Page 244: FIGURE 3.16Block diagram for estima
Page 248: 3.4.2 Antenna TrackingAn earth stat
Page 252:
controlling antenna pointing. The m
Page 256:
FIGURE 3.19A generalized model of a
Page 260:
FIGURE 3.20Entropy of a binary sour
Page 264:
whereHðYÞ¼output entropy, the av
Page 268:
To have a feel for this expression,
Page 272:
2. The system’s overall condition
Page 276:
transmitted down the fiber as digit
Page 280:
10. Kantor, L. Y. (ed). (1987). Han
Page 284:
142. Simulate the probability of bi
Page 288:
FIGURE 4.1A simplex link.baseband c
Page 292:
Chapter 2, Sec. 2.7, discusses that
Page 296:
From (4.6), the received power P r
Page 300:
FIGURE 4.3A model of the combined-l
Page 304:
4.1.2 Rain AttenuationRain attenuat
Page 308:
FIGURE 4.5rates.Average rainstorm p
Page 312:
FIGURE 4.6Adjacent satellite interf
Page 316:
FIGURE 4.8Satellite separation dist
Page 320:
inability of satellite A to accurat
Page 324:
FIGURE 4.10 Cross-link E b =N 0 vs.
Page 328:
Then using (4.41), the overall C=N
Page 332:
(iv)(v)(vi)(vii)Calculate the recei
Page 336:
5Communication Networks andSystemsC
Page 340:
discriminate among carriers by temp
Page 344:
FIGURE 5.2 Principle of FDMA system
Page 348:
FIGURE 5.3 Operational concept of T
Page 352:
FIGURE 5.5TDMA: bit rate r b for 1
Page 356:
Copyright © 2002 by Marcel Dekker,
Page 360:
5.2 CAPACITY COMPARISON OFMULTIPLE-
Page 364:
Rearranging (5.11) in terms of ener
Page 368:
The transmission bit rate isR r ¼
Page 372:
6Error Detection and CorrectionCodi
Page 376:
the channel and reconstruct the sou
Page 380:
message sequence X . Thus, a system
Page 384:
If we consider a message X ¼ð1010
Page 388:
can be seen in Table 6.1 that the m
Page 392:
FIGURE 6.1A (7, 4) cyclic code gene
Page 396:
FIGURE 6.2Convolutional codes encod
Page 400:
Alternative methods of describing a
Page 404:
FIGURE 6.5 Code tree diagram of Fig
Page 408:
FIGURE 6.8 Code tree diagram of rat
Page 412:
consistent with the constraint leng
Page 416:
trellis depth is approximated to 5L
Page 420:
FIGURE P.1A convolutional coder.the
Page 424:
7Regulatory Agencies andProceduresT
Page 428:
of the radiofrequency spectrum, and
Page 432:
The CCIR works through the medium o
Page 436:
7.1.3 IFRBThe International Frequen
Page 440:
The national or regional spectrum m
Page 444:
3. The need to expand or enhance th
Page 448:
The DSP will be responsible for res
Page 452:
2. Provide a convenient framework w
Page 456:
FIGURE 8.3Types of user-to-network
Page 460:
H1-channels are designed to carry v
Page 464:
information. The transfer cell prov
Page 468:
The OSI layers are divided into two
Page 472:
plane is denoted by U, the control
Page 476:
interfacing, maintenance, and conne
Page 480:
adjoining base station to scan the
Page 484:
FIGURE 8.9Geometry of a polygon.The
Page 488:
FIGURE 8.11Splitting cells into sma
Page 492:
causes signal fading. Of course, th
Page 496:
FIGURE 8.14TCP=IP suite and its rel
Page 500:
access to an Internet point of pres
Page 504:
message security via satellite is d
Page 508:
REFERENCES1. Wu, W.W. (1989). Eleme
Page 512:
Appendix ANotationsThe symbols have
Page 516:
N sPP rP sP TRRðtÞR cR eR rR vSS
Page 520:
g Central anglez Channel gainZ Ante
Page 524:
AttenuationBandwidthBearer serviceB
Page 528:
Frequency divisionmultiple accessFr
Page 532:
MultiplexingNetworkOmnidirectionala
Page 536:
UplinkUser-to-networkinterfaceThe e
show all

View File - University of Engineering and Technology, Taxila

Create successful ePaper yourself

Delete template?

Save as template?