ITU handbook on satellite communications

1106 Pages·2002·9.119 MB·English

by  International Telecommunications Union

HANDBOOK ON SATELLITE
COMMUNICATIONS (HSC)
(Edition 3)

TABLE OF CONTENTS
Page
INTRODUCTION.............................................................................................................................. xxiii
CHAPTER 1 (cid:150) General...................................................................................................................... 1
1.1 Introduction....................................................................................................................... 1
1.2 Historical background....................................................................................................... 2
1.3 Definition of satellite services............................................................................................ 2
1.3.1 Fixed-satellite services FSS........................................................................................ 2
1.3.2 Other satellite services................................................................................................ 5
1.4 Characteristics and services.............................................................................................. 8
1.4.1 Main components of a communication satellite system............................................... 8
1.4.1.1 The space segment....................................................................................... 8
1.4.1.2 The earth segment........................................................................................ 11
1.4.2 Frequency bands......................................................................................................... 11
1.4.3 Different types of system............................................................................................ 13
1.4.3.1 Global coverage systems.............................................................................. 13
1.4.3.2 Regional and national systems...................................................................... 13
1.4.4 Basic characteristics of satellite telecommunications................................................... 15
1.4.4.1 Coverage...................................................................................................... 15
1.4.4.2 Multiple access............................................................................................. 16
1.4.4.3 Distribution.................................................................................................. 18
1.4.4.4 Frequency reuse and bandwidth utilization................................................... 18
1.4.4.5 Propagation delay......................................................................................... 20
1.4.4.6 Flexibility and availability............................................................................ 21
1.4.5 Range of services provided......................................................................................... 22
1.4.5.1 Telephony, fax, etc., services........................................................................ 23
1.4.5.2 Television/video and audio services.............................................................. 24
1.4.5.3 Data transmissions and business services...................................................... 26
1.4.5.4 Integrated services digital network (ISDN) services...................................... 28
1.4.5.5 Emergency communication services............................................................. 29
1.4.5.6 Cable restoration services............................................................................. 30
1.5 Regulatory considerations and system planning............................................................... 30
1.5.1 Introduction................................................................................................................ 30
1.5.2 Global regulations considerations............................................................................... 31
1.5.2.1 Existing satellite systems.............................................................................. 32
1.5.2.2 New satellite systems................................................................................... 34
1.5.3 Implementation of new systems.................................................................................. 35
1.5.3.1 Preliminary techno-economic studies............................................................ 36
1.5.3.2 Initial planning............................................................................................. 36
1.5.3.3 Detailed planning......................................................................................... 37
1.5.3.4 Installation................................................................................................... 38
1.5.3.5 Operation and maintenance.......................................................................... 39
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CHAPTER 2 (cid:150) Some basic technical issues....................................................................................... 41
2.1 Characteristics of a satellite link....................................................................................... 41
2.1.1 The basic satellite link................................................................................................ 41
2.1.2 Basic characteristics of an antenna.............................................................................. 43
2.1.2.1 Antenna gain definition................................................................................ 43
2.1.2.2 Antenna effective aperture and gain.............................................................. 44
2.1.3 Power radiated and received by an antenna................................................................. 46
2.1.3.1 Power flux-density, equivalent isotropically radiated power and free-
space attenuation.......................................................................................... 46
2.1.3.2 Additional losses.......................................................................................... 49
2.1.4 Noise power received on the link................................................................................ 49
2.1.4.1 Noise temperature........................................................................................ 49
2.1.4.2 Noise temperature of a receiver.................................................................... 50
2.1.4.3 Noise temperature of an antenna................................................................... 50
2.1.4.4 Noise temperature of a receiving system....................................................... 52
2.1.4.5 Figure of merit of a receiving station............................................................ 53
2.1.5 Non-linear effects in power amplifiers........................................................................ 54
2.1.5.1 General........................................................................................................ 54
2.1.5.2 Intermodulation............................................................................................ 55
2.1.5.3 Non-linear effects in digital transmission...................................................... 57
2.2 Quality and availability..................................................................................................... 58
2.2.1 Introduction................................................................................................................ 58
2.2.2 Quality of Service (QoS)............................................................................................ 60
2.2.3 ITU-R and ITU-T recommendations........................................................................... 61
2.2.3.1 Availability objectives.................................................................................. 61
2.2.3.2 Quality objectives, analogue transmission..................................................... 62
2.2.3.3 Quality objectives, digital transmission......................................................... 64
iii) SDH satellite transmission.......................................................................................... 67
iv) ATM satellite transmission......................................................................................... 68
2.2.4 Satellite operator standards......................................................................................... 68
2.2.5 Private corporate network operator performance requirements.................................... 69
2.3 Link calculations................................................................................................................ 71
2.3.1 Introduction................................................................................................................ 71
2.3.2 Uplink (C/N ) ............................................................................................................ 72
0 u
2.3.3 Downlink (C/N ) ....................................................................................................... 73
0 d
2.3.4 Link budget for a transparent transponder................................................................... 74
2.3.4.1 Combined uplink and downlink (C/N ) ...................................................... 74
0 ud
2.3.4.2 Other noise contributions to the link budget.................................................. 75
2.3.4.3 Total link budget (C/N ) ........................................................................ 76
0 total
2.3.4.4 Atmospheric losses....................................................................................... 78
2.3.4.5 Remarks....................................................................................................... 78
2.3.4.6 Conclusions................................................................................................. 79
2.3.5 Link budget for a regenerative transponder................................................................. 80
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2.4 Earth coverage and frequency reuse................................................................................. 81
2.4.1 Earth coverage by a geostationary satellite.................................................................. 81
2.4.1.1 Elevation angle from the Earth..................................................................... 81
2.4.1.2 Types of earth coverages and of satellite antenna beams............................... 85
2.4.2 Earth coverage by a non-geostationary satellite........................................................... 93
2.4.3 Frequency reuse......................................................................................................... 94
2.4.3.1 Spatial isolation frequency reuse................................................................... 95
2.4.3.2 Polarization discrimination frequency reuse.................................................. 96
2.4.3.3 Common application of both methods of frequency reuse............................. 97
2.4.3.4 Application of frequency reuse in non-geostationary satellite systems........... 98
2.5 Other topics in orbit/spectrum utilization......................................................................... 99
2.5.1 Introduction................................................................................................................ 99
2.5.2 Modulation and coding techniques.............................................................................. 99
2.5.3 Intersystem interference and orbit utilization.............................................................. 100
2.5.4 On-board signal processing......................................................................................... 102
2.5.5 Homogeneity between networks................................................................................. 102
APPENDIX 2.1 (cid:150) Antenna radiation diagrams and polarization..................................................... 103
AP2.1-1 Radiation diagrams and beamwidths...................................................................... 103
AP2.1-2 Nomogram for antennas with circular aperture...................................................... 106
AP2.1-2.1 General.................................................................................................... 106
AP2.1-2.2 Typical applications................................................................................. 106
AP2.1-3 Antenna side lobes................................................................................................ 109
AP2.1-4 Polarization........................................................................................................... 109
CHAPTER 3 (cid:150) Baseband signal processing and multiplexing.......................................................... 115
3.1 General............................................................................................................................... 115
3.2 Baseband signal processing (cid:150) analogue............................................................................. 116
3.2.1 Voice and audio.......................................................................................................... 116
3.2.1.1 Channel-by-channel syllabic companding..................................................... 116
3.2.1.2 Voice carrier activation................................................................................ 118
3.2.2 Video and TV............................................................................................................. 119
3.2.2.1 Composite analogue TV signal..................................................................... 119
3.2.2.2 MAC TV signal............................................................................................ 119
3.2.3 Energy dispersal......................................................................................................... 121
3.2.3.1 Introduction.................................................................................................. 121
3.2.3.2 Energy dispersal for analogue systems.......................................................... 121
3.3 Baseband signal processing (cid:150) digital................................................................................. 122
3.3.1 PCM, ADPCM........................................................................................................... 122
3.3.1.1 Pulse code modulation (PCM)...................................................................... 122
3.3.1.2 Delta modulation (DM)................................................................................ 126
3.3.1.3 Differential pulse code modulation (DPCM)................................................. 126
3.3.1.4 Pulse code modulation and adaptive differential coding at 32 kbit/s
(ADPCM).................................................................................................... 126
3.3.2 Voice low rate encoding (LRE) [Ref. 3-4].................................................................. 132
3.3.3 Data transmission [Ref. 3-1 and 3-2]........................................................................... 133
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3.3.4 Video and TV signal................................................................................................... 135
3.3.5 Error control coding................................................................................................... 137
3.3.5.1 Introduction to channel coding..................................................................... 137
3.3.5.2 The two basic error control coding techniques.............................................. 139
3.3.5.3 FEC (forward error correction)..................................................................... 140
3.3.5.4 Performance of error correcting coding techniques....................................... 141
3.3.5.5 Typical parameters of error correcting techniques......................................... 143
3.3.5.6 Error correcting coding in existing satellite transmission systems................. 144
3.3.5.7 System design with error correcting coding.................................................. 145
3.3.6 Encryption................................................................................................................. 146
3.3.7 Other signal processing techniques............................................................................. 147
3.3.7.1 Speech interpolation..................................................................................... 147
3.3.7.2 Digital circuit multiplication equipment (DCME)......................................... 147
3.3.7.3 Energy dispersal for digital systems (scrambling)......................................... 148
3.4 Multiplexing (cid:150) analogue.................................................................................................... 151
3.5 Multiplexing (cid:150) digital........................................................................................................ 153
3.5.1 General...................................................................................................................... 153
3.5.2 Plesiochronous digital hierarchy (PDH) [Ref. 3-1]...................................................... 153
3.5.3 The synchronous digital hierarchy (SDH) [Ref. 3-1 and 3-7]...................................... 156
3.5.3.1 General considerations................................................................................. 156
3.5.3.2 Transmission rate levels............................................................................... 157
3.5.3.3 Definitions of the frame structure and related elements................................. 158
3.5.3.4 Summary of SDH features............................................................................ 159
3.5.4 Asynchronous transfer mode [Ref. 3-1, 3-6]............................................................... 161
3.5.4.1 Introduction and overview............................................................................ 161
3.5.4.2 ATM entities and their relationships............................................................. 162
3.5.4.3 Transmission systems for ATM cells............................................................ 163
3.5.4.4 ATM on satellite links.................................................................................. 164
3.5.5 Generalities on ISDN concepts (cid:150) narrow and broadband [Ref. 3-1]............................. 164
3.5.5.1 The ISDN concept and requirements............................................................ 164
3.5.5.2 Broadband aspects of ISDN.......................................................................... 171
APPENDIX 3.1 (cid:150) Voice low bit-rate encoding [Ref. 3-3, 3-4]........................................................... 173
AP3.1-1 Speech coders standardization aspects................................................................... 173
AP3.1-2 The code excited linear prediction (CELP) concept............................................... 174
AP3.1-2.1 Linear prediction coding (LPC) technique................................................ 174
AP3.1-2.2 The CELP concept................................................................................... 176
AP3.1-3 Coding of speech at 16 kbit/s using low-delay code excited linear prediction
(LD-CELP) (ITU-T Recommendation G.728)............................................................ 176
AP3.1.3.1 LD-CELP encoder.................................................................................... 176
AP3.1-3.2 LD-CELP decoder.................................................................................... 177
AP3.1-3.3 Speech performance................................................................................. 178
AP3.1-3.4 Performance with voiceband data............................................................. 178
AP3.1-4 Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-
excited linear-prediction (CS-CELP) (ITU-T Recommendation G.729)...................... 179
AP3.1-4.1 General description of the coder............................................................... 179
AP3.1-4.2 Encoder.................................................................................................... 180
AP3.1-4.3 Decoder................................................................................................... 180
AP3.1-4.4 Delay....................................................................................................... 181
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APPENDIX 3.2 (cid:150) Error-correcting coding........................................................................................ 183
AP3.2-1 Introduction.......................................................................................................... 183
AP3.2-2 Convolutional codes with soft decision Viterbi decoding....................................... 184
AP3.2-2.1 Convolutional encoders............................................................................ 185
AP3.2-2.2 Distance properties of convolutional codes............................................... 188
AP3.2-2.3 Soft decision decoding Viterbi algorithm.................................................. 189
AP3.2-2.4 Punctured convolutional code and their decoding..................................... 191
AP3.2-2.5 Association of a binary convolutional code with QPSK modulation.......... 193
AP3.2-2.6 Performance of convolutionally coded QPSK system............................... 196
AP3.2-3 Concatenated coding system with Reed-Solomon outer code................................. 197
AP3.2-3.1 Basic configurations of the concatenated coding system........................... 197
AP3.2-3.2 Reed-Solomon codes and algebraic decoding........................................... 200
AP3.2-3.3 Interleaving.............................................................................................. 202
AP3.2-3.4 Word (interleaver) synchronization........................................................... 203
AP3.2-3.5 Block scrambling..................................................................................... 203
AP3.2-4 Conclusion............................................................................................................ 204
APPENDIX 3.3 (cid:150) Video signal compression techniques [Ref. 3-2, 3-5]............................................ 205
AP3.3-1 Principal bit-rate reduction methods...................................................................... 205
AP3.3-1.1 The first generation approach................................................................... 205
AP3.3-1.2 The second generation approach............................................................... 208
AP3.3-2 Selected standards for digital video and TV applications (cid:150) bit-rate reduction
techniques.................................................................................................................. 209
AP3.3-2.1 Videoconferencing (cid:150) ITU-T Recommendation H.261............................... 209
AP3.3-2.2 The Joint Photographic Experts Group (JPEG) standard........................... 209
AP3.3-2.3 The Moving Picture Experts Group (MPEG) standards............................. 210
AP3.3-2.4 The Digital Video Broadcasting (DVB) standard...................................... 211
APPENDIX 3.4 (cid:150) Asynchronous transfer mode (ATM) [Ref. 3-1]................................................... 212
AP3.4.1 The ATM/B-ISDN protocol reference model......................................................... 212
AP3.4-2 Main features of the ATM/B-ISDN protocol reference model layers...................... 213
AP3.4-3 ATM entities and their relationships (Figure AP3.4-2)........................................... 215
AP3.4-4 ATM resource control aspects............................................................................... 220
APPENDIX 3.5 (cid:150) The synchronous digital hierarchy (SDH) [Ref. 3-1]........................................... 221
AP3.5-1 SDH multiplexing structure................................................................................... 221
AP3.5-2 Bandwidth provisioning........................................................................................ 225
AP3.5-3 Network equipment............................................................................................... 225
AP3.5-4 Network management, availability and protection................................................. 227
CHAPTER 4 (cid:150) Carrier modulation techniques................................................................................ 231
4.1 Analogue modulation......................................................................................................... 231
4.1.1 Frequency modulation (FM)....................................................................................... 231
4.1.1.1 FDM-FM..................................................................................................... 231
4.1.1.2 SCPC-FM.................................................................................................... 233
4.1.1.3 System design (telephony)............................................................................ 234
4.1.1.4 TV-FM......................................................................................................... 235
4.1.2 Modulation................................................................................................................. 237
4.1.3 Demodulation............................................................................................................. 238
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4.2 Digital modulation............................................................................................................. 242
4.2.1 Modulation schemes for satellite communications...................................................... 242
4.2.2 BPSK and QPSK........................................................................................................ 246
4.2.3 Other digital modulation techniques........................................................................... 249
4.2.3.1 Quadrature schemes..................................................................................... 249
4.2.3.2 Trellis coded modulation.............................................................................. 257
4.2.4 Modems for digital communications........................................................................... 266
4.2.4.1 Digital transmissions.................................................................................... 266
4.2.4.2 Going through the key modules of the demodulator...................................... 268
4.2.5 Conventional modem architectures............................................................................. 269
4.2.5.1 Description of conventional modems............................................................ 269
4.2.5.2 Specific requirements of burst modems........................................................ 274
4.2.5.3 Sampling considerations............................................................................... 278
4.2.5.4 New techniques for TDMA mode transmission............................................. 279
4.2.6 Filtering techniques.................................................................................................... 280
4.2.6.1 Simplified theory.......................................................................................... 280
4.2.6.2 Basic presentation of FIR filters................................................................... 282
CHAPTER 5 (cid:150) Multiple access, assignment and network architectures......................................... 287
5.1 Introduction....................................................................................................................... 287
5.2 Frequency Division Multiple Access................................................................................. 288
5.2.1 Multiplexed FDMA.................................................................................................... 289
5.2.2 Single Channel Per Carrier (SCPC)............................................................................ 290
5.3 Time Division Multiple Access.......................................................................................... 292
5.3.1 System configuration.................................................................................................. 294
5.3.2 Synchronization in TDMA systems............................................................................ 295
5.3.3 A typical example (cid:150) The INTELSAT/EUTELSAT TDMA system............................. 296
5.3.4 Frequency and Time Division Multiple Access (FDMA-TDMA)................................ 299
5.3.5 Packet transmissions................................................................................................... 300
5.3.6 Random Access TDMA (RA-TDMA)........................................................................ 300
5.4 Code Division Multiple Access (CDMA)........................................................................... 301
5.4.1 CDMA and Spread Spectrum basic concepts.............................................................. 301
5.4.2 Direct sequence systems............................................................................................. 303
5.4.3 Frequency Hopping systems....................................................................................... 303
5.4.4 CDMA parameters and performance........................................................................... 303
5.4.5 Asynchronous and Synchronous CDMA..................................................................... 306
5.4.5.1 General........................................................................................................ 306
5.4.5.2 A-CDMA..................................................................................................... 306
5.4.5.3 S-CDMA...................................................................................................... 307
5.4.6 Power control techniques in CDMA systems.............................................................. 308
5.4.7 Other considerations on CDMA systems..................................................................... 309
5.4.7.1 Satellite transponder operation...................................................................... 309
5.4.7.2 Diversity implementation............................................................................. 309
5.4.7.3 Capacity of CDMA systems......................................................................... 309
5.4.7.4 Technological issues.................................................................................... 310
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5.5 Demand Assignment (DAMA)........................................................................................... 310
5.5.1 General definitions..................................................................................................... 310
5.5.2 Functional description of a DAMA system................................................................. 311
5.5.3 Services available in DAMA mode............................................................................. 312
5.5.4 SCPC/DAMA systems............................................................................................... 312
5.5.4.1 Operating principle for a telephone SCPC/DAMA system............................ 312
5.5.4.2 The SPADE system...................................................................................... 313
5.5.4.3 SCPC/DAMA systems for small-scale networks........................................... 313
5.5.5 TDMA/DAMA systems.............................................................................................. 315
5.5.6 MCPC/DAMA systems ("Bandwidth on Demand").................................................... 316
5.5.7 Dimensioning DAMA systems................................................................................... 316
5.6 Network architectures....................................................................................................... 321
5.6.1 One-way networks...................................................................................................... 321
5.6.2 Two-way networks..................................................................................................... 322
5.6.3 LEO satellites network architectures........................................................................... 327
APPENDIX 5.1 (cid:150) Additional considerations on coding, modulation and multiple access............... 328
AP5.1-1 Bandwidth limited versus power limited operation................................................ 328
AP5.1-2 Selection of multiple access, multiplexing and modulation.................................... 330
APPENDIX 5.2 (cid:150) Intermodulation interference in travelling wave tubes for multiple access
communication satellites.......................................................................................................... 335
AP5.2-1 Introduction.......................................................................................................... 335
AP5.2-2 Model representing non-linear satellite transponder............................................... 336
AP5.2-3 Intermodulation products level.............................................................................. 337
AP5.2-4 Frequency plan selection....................................................................................... 342
AP5.2-5 Formulas for SCPC............................................................................................... 342
APPENDIX 5.3 (cid:150) Erlang Tables........................................................................................................ 344
CHAPTER 6 (cid:150) Space segment........................................................................................................... 349
6.1 Satellite orbits.................................................................................................................... 349
6.1.1 Introduction................................................................................................................ 349
6.1.2 Background................................................................................................................ 349
6.1.3 Orbital dynamics........................................................................................................ 350
6.1.3.1 Keplerian orbits............................................................................................ 350
6.1.3.2 Orbit perturbations....................................................................................... 353
6.1.3.3 Orbit determination...................................................................................... 354
6.1.3.4 The geostationary orbit (GSO)...................................................................... 354
6.1.4 Orbit design................................................................................................................ 355
6.1.4.1 Environment constraints............................................................................... 355
6.1.4.2 Communication constraints.......................................................................... 356
6.1.4.3 Satellite ground track and coverage.............................................................. 357
6.1.4.4 Orbit comparison for communication applications........................................ 359
6.1.5 Constellation design................................................................................................... 360
6.1.5.1 Orbit and constellation trade-off................................................................... 360
6.1.5.2 Continuous single and multiple satellite coverage......................................... 360
6.1.5.3 Non-permanent coverage.............................................................................. 362
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6.2 General description of communication satellites.............................................................. 362
6.2.1 Introduction................................................................................................................ 362
6.2.2 Satellite structural designs.......................................................................................... 363
6.2.3 Thermal control system.............................................................................................. 367
6.2.4 Satellite attitude and orbit (station-keeping) control systems....................................... 369
6.2.4.1 Background.................................................................................................. 369
6.2.4.2 Attitude control............................................................................................ 369
6.2.4.3 Orbit (station-keeping) control...................................................................... 372
6.2.5 Power supply.............................................................................................................. 374
6.2.6 Telemetry, command and ranging (TCR).................................................................... 377
6.2.7 The apogee motor....................................................................................................... 378
6.2.8 Characteristics of the payload of some communication satellite.................................. 380
6.3 The communication payload............................................................................................. 381
6.3.1 Introduction................................................................................................................ 381
6.3.2 Antenna subsystem..................................................................................................... 382
6.3.2.1 General........................................................................................................ 382
6.3.2.2 Structures..................................................................................................... 383
6.3.2.3 Performance characteristics.......................................................................... 383
6.3.2.4 Antenna research and development trends.................................................... 390
6.3.3 Transparent (repeater) transponders............................................................................ 392
6.3.3.1 General........................................................................................................ 392
6.3.3.2 The wideband-receiver subsystem................................................................ 395
6.3.3.3 The channelized subsystem.......................................................................... 396
6.3.3.4 Transponders without on-board processing................................................... 400
6.3.3.5 Transponder research and development trends.............................................. 404
6.3.4 Transponders with on-board processing...................................................................... 406
6.3.4.1 RF switching................................................................................................ 406
6.3.4.2 Regenerative transponders............................................................................ 407
6.3.4.3 Bit stream processing................................................................................... 407
6.3.4.4 SS-TDMA with on-board TST switching stage............................................. 408
6.3.4.5 ISDN applications........................................................................................ 408
6.3.4.6 Digital transponders: an example.................................................................. 410
6.3.4.7 Recent developments in OBP technology..................................................... 412
6.4 Intersatellite links (ISL).................................................................................................... 414
6.4.1 Introduction................................................................................................................ 414
6.4.2 ISL benefits................................................................................................................ 415
6.4.3 Basic technologies...................................................................................................... 416
6.5 Special features of non-GSO (NGSO) satellite systems.................................................... 419
6.5.1 Introduction................................................................................................................ 419
6.5.2 Types of LEO networks.............................................................................................. 420
6.5.3 Benefits of broadband LEO networks......................................................................... 420
6.6 Launching, positioning and station-keeping..................................................................... 423
6.6.1 Launching.................................................................................................................. 423
6.6.2 Positioning on geostationary orbit............................................................................... 423
6.6.3 Station-keeping and payload operation monitoring..................................................... 427
6.7 Reliability and availability considerations........................................................................ 429
6.7.1 Satellite reliability...................................................................................................... 429
6.7.2 Satellite availability.................................................................................................... 431