Page 12 - Satellite Communications, Fourth Edition
P. 12
Dennis Roddy vii
11.7 Link Parameters Affected by Coding 331
11.8 Coding Gain 333
11.9 Hard Decision and Soft Decision Decoding 334
11.10 Shannon Capacity 336
11.11 Turbo Codes and LDPC Codes 338
11.11.1 Low density parity check (LDPC) codes 341
11.12 Automatic Repeat Request (ARQ) 344
11.13 Problems and Exercises 346
References 348
Chapter The Space Link 351
12.
12.1 Introduction 351
12.2 Equivalent Isotropic Radiated Power 351
12.3 Transmission Losses 352
12.3.1 Free-space transmission 353
12.3.2 Feeder losses 354
12.3.3 Antenna misalignment losses 355
12.3.4 Fixed atmospheric and ionospheric losses 356
12.4 The Link-Power Budget Equation 356
12.5 System Noise 357
12.5.1 Antenna noise 358
12.5.2 Amplifier noise temperature 360
12.5.3 Amplifiers in cascade 361
12.5.4 Noise factor 362
12.5.5 Noise temperature of absorptive networks 363
12.5.6 Overall system noise temperature 365
12.6 Carrier-to-Noise Ratio 366
12.7 The Uplink 367
12.7.1 Saturation flux density 368
12.7.2 Input backoff 370
12.7.3 The earth station HPA 371
12.8 Downlink 371
12.8.1 Output back-off 373
12.8.2 Satellite TWTA output 374
