View File - University of Engineering and Technology, Taxila

More documents

Recommendations

Info

If we consider a message X ¼ð1010Þ, the corresponding codeword Y,generated from (6.4), is231 0 0 0 1 1 10 1 0 0 1 1 0Y ¼ GX ¼ 674 0 0 1 0 1 0 15½1010Š ¼1010010 ð6:18aÞ0 0 0 1 0 1 1The syndrome231 1 1 0 1 0 0S ¼ YH D ¼½1010010Š41 1 0 1 0 1 05 ¼ 000 ð6:18bÞ1 0 1 1 0 0 1If instead of the valid received codeword Y, an error is inserted into the secondbit by changing the 0-bit to a 1-bit, and the corrupted codeword is written asZ ¼ 1110010ð6:19aÞwhere the underlined bit is the error bit, then the syndrome of the newlyreceived codeword is2 31 1 11 1 01 0 1S ¼½1110010Š0 1 1¼ 1106 1 0 074 0 1 050 0 1ð6:19bÞSince S is nonzero, two errors have been detected, indicating that the codewordis incorrect.Example 6.3: If the message word is the same as in Example 6.2 for the (7, 4)Hamming code but received corrupted codewords (i) 1011011 and (ii)1110100, determine whether these errors can be detected.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 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 202:
aud. The word ‘‘baud’’ hono
Page 206:
Noise power density N 0bandwidth:N
Page 210:
We observe in (3.11) that E b =N 0
Page 214:
to (3.23) shows that a margin of 11
Page 218:
FIGURE 3.12 Principle of scrambling
Page 222:
Equalization FilterAn equalization
Page 226:
that is, N zeros at the top and bot
Page 230:
Example 3.2: Consider a transmissio
Page 234:
which can be written as89>=R xy ðt
Page 238:
ecause a voice signal is usually hi
Page 242:
systems is discussed in Sec. 4.2. O
Page 246:
where T e is the equivalent tempera
Page 250:
operating principle of all directio
Page 254:
performance of the satellite commun
Page 258:
3. For two independent sources, wit
Page 262:
FIGURE 3.21 A representation of mut
Page 266:
In practice, Eqs. (3.78) and (3.76)
Page 270:
This condition is always satisfied
Page 274:
Copyright © 2002 by Marcel Dekker,
Page 278:
epeaters overshooting into subseque
Page 282:
6. Conventional BPSK modulation all
Page 286:
4Satellite LinksA satellite link co
Page 290:
FIGURE 4.2 Basic antenna parameters
Page 294:
For unity efficiency, and substitut
Page 298:
This expression neglects losses oth
Page 302:
This expression is equally valid fo
Page 306:
and Lin [5]:whereL ¼L o1 þ L oðr
Page 310:
3. Calculate attenuation A r in dB
Page 314:
4.2.1 Intersatellite LinksAs indica
Page 318:
We know from (4.4b) that f c is dep
Page 322:
FIGURE 4.9 Cross-link transmission
Page 326:
Follow the uplink procedure for the
Page 330:
Satellite:Frequencies:14.75 GHz up
Page 334: 6. For link to be maintained betwee
Page 338: 5.1 PRINCIPLES OF MULTIPLE ACCESSAs
Page 342: neously, their transmissions collid
Page 346: technique and would remain the most
Page 350: FIGURE 5.4 Typical TDMA frame struc
Page 354: FIGURE 5.6TDMA throughput for an IN
Page 358: and transmits through the satellite
Page 362: FIGURE 5.8FDMA total capacity respo
Page 366: tion; that is, log e ð1 þ xÞ x t
Page 370: REFERENCES1. Spilker, J.J. (1977).
Page 374: 6.1 CHANNEL CODINGNoise within a tr
Page 378: where G is a generator matrix that
Page 382: The syndrome is a single word of le
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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?