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本帖最后由 liyuanliu 于 2010-2-2 23:26 编辑
Digital Transmission[Springer.2009]
【原书作者】：Dayan Adionel Guimaraes
【ISBN 】：3642013589
【页数 】： 887
【出版社】 ： Springer
【出版日期】：15 Dec 2009
【文件格式】： PDF
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1 A Review of Probability and Stochastic Processes . . . . . . . . . . . . . . . . . . 1
1.1 Set Theory Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 The Venn Diagram and Basic Set Operations . . . . . . . . . . . . . 2
1.1.2 Other Set Operations and Properties . . . . . . . . . . . . . . . . . . . . . 3
1.2 Definitions and Axioms of Probability . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Counting Methods for Determining Probabilities . . . . . . . . . . . . . . . . 5
1.3.1 Distinct Ordered k-Tuples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.2 Sampling with Replacement and with Ordering . . . . . . . . . . . 6
1.3.3 Sampling Without Replacement and with Ordering . . . . . . . . 6
1.3.4 Permutation of Distinct Objects . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3.5 Sampling Without Replacement and Without Ordering . . . . . 6
1.3.6 Sampling with Replacement and Without Ordering . . . . . . . . 7
1.4 Conditional Probability and Bayes Rule . . . . . . . . . . . . . . . . . . . . . . . . 7
Simulation 1.1 – Conditional Probability . . . . . . . . . . . . . . . . . . . . . . . 9
1.5 Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.5.1 The Cumulative Distribution Function . . . . . . . . . . . . . . . . . . . 10
1.5.2 Types of Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.6 Conditional Probability Densities and Mass Functions . . . . . . . . . . . . 16
1.6.1 The Bayes Rule Revisited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.6.2 The Total Probability Theorem Revisited . . . . . . . . . . . . . . . . 17
1.7 Statistical Averages of Random Variables . . . . . . . . . . . . . . . . . . . . . . . 17
1.7.1 Mean of Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.7.2 Moments of Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.7.3 Joint Moments of Random Variables . . . . . . . . . . . . . . . . . . . . 20
1.7.4 The Characteristic and the Moment-Generating Functions . . 21
1.7.5 Conditional Expected Value . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.8 Some Discrete Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.8.1 Bernoulli Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.8.2 Binomial Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.8.3 Geometric Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.8.4 Poisson Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Simulation 1.2 – Discrete Random Variables . . . . . . . . . . . . . . . . . . . . 26
1.9 Some Continuous Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.9.1 Uniform Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.9.2 Exponential Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1.9.3 Gaussian Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.9.4 Rayleigh Random Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Simulation 1.3 – Continuous Random Variables . . . . . . . . . . . . . . . . . 32
1.9.5 Multivariate Gaussian Random Variables . . . . . . . . . . . . . . . . 34
1.10 Sum of Random Variables and the Central Limit Theorem . . . . . . . . . 35
1.10.1 Mean and Variance for the Sum of Random Variables . . . . . . 35
1.10.2 Moments of the Sum of Random Variables . . . . . . . . . . . . . . . 36
1.10.3 PDF of the Sum of Random Variables . . . . . . . . . . . . . . . . . . . 36
1.10.4 The Central Limit Theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1.11 Transformations of Random Variables . . . . . . . . . . . . . . . . . . . . . . . . . 38
Simulation 1.4 – A Communication System Analysis . . . . . . . . . . . . 46
1.12 Parameter Estimation via SampleMean . . . . . . . . . . . . . . . . . . . . . . . . 47
1.12.1 The SampleMean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
1.12.2 The Confidence Interval on the Sample Mean . . . . . . . . . . . . . 50
Simulation 1.5 – Confidence Interval on BER Estimations . . . . . . . . 53
1.12.3 The Law of Large Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
1.13 Generation of Random Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
1.13.1 Congruential Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
1.13.2 Inverse CDFMethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
1.13.3 Acceptance/Rejection Methods . . . . . . . . . . . . . . . . . . . . . . . . . 57
1.13.4 Box-MullerMethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Simulation 1.6 – Random Numbers Generation . . . . . . . . . . . . . . . . . . 58
1.14 Random Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Simulation 1.7 – The Concept of Random Process . . . . . . . . . . . . . . . 62
1.14.1 Stationarity Classes for Random Processes . . . . . . . . . . . . . . . 63
1.14.2 Averages of Stationary Random Processes . . . . . . . . . . . . . . . 64
Simulation 1.8 – Estimating Averages of Random Processes . . . . . . . 71
1.14.3 Random Processes Through Linear Systems . . . . . . . . . . . . . . 73
1.14.4 The Gaussian Random Process . . . . . . . . . . . . . . . . . . . . . . . . . 76
Simulation 1.9 – Filtered Complex Gaussian Process . . . . . . . . . . . . . 77
1.14.5 Thermal Noise Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
1.15 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
1.16 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
2 Signals and Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2.1 Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2.1.1 Classification of Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2.1.2 Typical Deterministic Signals . . . . . . . . . . . . . . . . . . . . . . . . . . 90
2.2 Fourier Analysis of Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
2.2.1 Fourier Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Simulation 2.1 – Gibbs Phenomenon . . . . . . . . . . . . . . . . . . . . . . . . . . 97
2.2.2 Continuous-Time Fourier Transform . . . . . . . . . . . . . . . . . . . . 100
2.2.3 Discrete-Time Fourier Transform . . . . . . . . . . . . . . . . . . . . . . . 106
2.2.4 Discrete Fourier Transform . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Simulation 2.2 – The FFT via VisSim/Comm . . . . . . . . . . . . . . . . . . . 111
2.2.5 Laplace and Z-Transforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
2.3 Sampling of Deterministic and Random Signals . . . . . . . . . . . . . . . . . 115
2.3.1 Ideal Sampling of Deterministic Signals . . . . . . . . . . . . . . . . . 115
2.3.2 Ideal Sampling of Stochastic Processes . . . . . . . . . . . . . . . . . . 117
2.3.3 Practical Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Simulation 2.3 – Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
2.3.4 Analog-to-Digital Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Simulation 2.4 – Uniform and Non-uniform Quantization . . . . . . . . . 127
2.4 Linear Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
2.4.1 Time-Domain Characterization of Linear Systems . . . . . . . . . 130
2.4.2 Frequency-Domain Characterization of Linear Systems . . . . 132
2.4.3 Classifications and Properties of Linear Systems . . . . . . . . . . 135
2.4.4 Mapping a Discrete-Time into a Continuous-Time Frequency139
Simulation 2.5 – Moving Average Filter . . . . . . . . . . . . . . . . . . . . . . . . 142
2.5 Complex Representation of Signals and Systems. . . . . . . . . . . . . . . . . 146
Simulation 2.6 – Real Versus Complex Simulation . . . . . . . . . . . . . . . 148
2.6 The Power Spectral Density Revisited . . . . . . . . . . . . . . . . . . . . . . . . . 150
2.6.1 The PSD of Passband Signals . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Simulation 2.7 – Estimating the PSD of Passband Signals . . . . . . . . . 153
2.6.2 Estimation of the PSD via the Periodogram . . . . . . . . . . . . . . 155
Simulation 2.8 – Periodogram Estimation of the PSD . . . . . . . . . . . . 156
2.6.3 The PSD of Baseband Digital Communication Signals . . . . . 159
2.7 The Bandwidth of Communication Signals . . . . . . . . . . . . . . . . . . . . . 162
2.7.1 Absolute Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
2.7.2 −3 dB (or Half Power) Bandwidth . . . . . . . . . . . . . . . . . . . . . . 163
2.7.3 Equivalent Noise Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
2.7.4 Root Mean Square (rms) Bandwidth . . . . . . . . . . . . . . . . . . . . 163
2.7.5 Null-to-Null or Main Lobe Bandwidth . . . . . . . . . . . . . . . . . . . 164
2.7.6 Spectral Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
2.8 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
2.9 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
3 Communication Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
3.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
3.1.1 Communication Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
3.1.2 Channel Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
3.1.3 Channel Sounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
3.1.4 Empirical, Deterministic and Stochastic Channel Models . . . 175
3.2 AWGN Channel Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
3.2.1 Vector AWGN Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Simulation 3.1 – Waveform and Vector Channel Simulation . . . . . . . 178
3.3 Discrete Memoryless Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
3.3.1 The Binary Symmetric Channel Revisited . . . . . . . . . . . . . . . . 181
Simulation 3.2 – Waveform and BSC Channel Simulation . . . . . . . . . 181
3.4 Discrete Channels with Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
3.5 Wireline Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
3.5.1 Twisted Pair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
3.5.2 Coaxial Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
3.5.3 Waveguide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
3.5.4 Optical Fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
3.5.5 Low-Voltage Power-Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
3.6 Wireless Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
3.6.1 Mobile Outdoor Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Simulation 3.3 – Large-Scale and Small-Scale Propagation . . . . . . . . 208
Simulation 3.4 – Mobile Channel Simulator . . . . . . . . . . . . . . . . . . . . 217
Simulation 3.5 – Exploring the Coherence Bandwidth . . . . . . . . . . . . 226
Simulation 3.6 – Exploring the Coherence Time . . . . . . . . . . . . . . . . . 227
Simulation 3.7 – Flat and Frequency Selective Channel . . . . . . . . . . . 229
Simulation 3.8 – A Modulated Signal Under Selective Fading . . . . . 231
3.6.2 Mobile Indoor Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Simulation 3.9 – Saleh-Valenzuela Indoor Channel Model . . . . . . . . 237
3.6.3 Terrestrial Microwave Channel . . . . . . . . . . . . . . . . . . . . . . . . . 239
Simulation 3.10 – Rummler Terrestrial Microwave Channel Model . 247
3.6.4 Spatial Wireless Channel Models . . . . . . . . . . . . . . . . . . . . . . . 250
3.6.5 Other Wireless Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
3.7 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
3.8 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
4 Baseband Digital Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
4.1 Definitions and Typical Baseband Signals . . . . . . . . . . . . . . . . . . . . . . 265
4.1.1 Line Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Simulation 4.1 – Line Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
4.1.2 M-ary PAMSignaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Simulation 4.2 –M-ary PAMSignaling . . . . . . . . . . . . . . . . . . . . . . . . 276
4.2 Detection of Baseband Pulses in Noise . . . . . . . . . . . . . . . . . . . . . . . . . 278
4.2.1 Modeling andMotivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Simulation 4.3 – Motivation for Baseband Detection Analysis . . . . . 279
4.2.2 The Matched Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Simulation 4.4 – Pulse Signal-to-Noise Ratio Measurement . . . . . . . 286
4.2.3 Equivalence Between the Matched Filter and the Correlator 289
Simulation 4.5 – Equivalence Matched Filter × Correlator . . . . . . . . 292
4.2.4 Error Probability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Simulation 4.6 – Equivalence Matched Filter × Correlator Revisited 302
4.2.5 MAP and ML Decision Rules for Binary Transmission . . . . . 304
4.3 Intersymbol Interference (ISI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
4.3.1 Distortion-Free Channel and ISI Channel . . . . . . . . . . . . . . . . 307
Simulation 4.7 – Distortion-Free Channel . . . . . . . . . . . . . . . . . . . . . . 310
4.3.2 Nyquist Criterion for ISI-Free Transmission . . . . . . . . . . . . . . 312
Simulation 4.8 – Vestigial Symmetry . . . . . . . . . . . . . . . . . . . . . . . . . . 315
4.3.3 The Raised Cosine Spectrum. . . . . . . . . . . . . . . . . . . . . . . . . . . 317
4.3.4 The Root-Raised Cosine Spectrum . . . . . . . . . . . . . . . . . . . . . . 319
Simulation 4.9 – Nyquist Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
4.3.5 The Eye Diagram and the Bathtub Diagram . . . . . . . . . . . . . . 323
Simulation 4.10 – Eye Diagram for M-PAMSignaling . . . . . . . . . . . 325
Simulation 4.11 – Bathtub Diagram for Binary Signaling . . . . . . . . . 331
4.4 Correlative Coding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Simulation 4.12 – Polybinary and Polybipolar Signal Generation . . . 334
4.4.1 Duobinary and Modified Duobinary Signaling . . . . . . . . . . . . 335
4.4.2 Generalized Partial Response Signaling . . . . . . . . . . . . . . . . . . 340
Simulation 4.13 – Duobinary Signaling Using a Matched Filter . . . . 341
4.5 Notions of Channel Equalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
4.5.1 Zero Forcing (ZF) Equalization . . . . . . . . . . . . . . . . . . . . . . . . 344
Simulation 4.14 – ZF Equalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
4.5.2 Least Mean Square (LMS) Equalization . . . . . . . . . . . . . . . . . 349
Simulation 4.15 – LMS Equalization . . . . . . . . . . . . . . . . . . . . . . . . . . 354
4.6 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
4.7 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
5 Signal-Space Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
5.2 Geometric Representation of Signals . . . . . . . . . . . . . . . . . . . . . . . . . . 363
5.3 Dimensionality of a Signal and of a Signal-Space . . . . . . . . . . . . . . . . 366
5.4 Gram-Schmidt Orthogonalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
5.5 Signal Constellation with Symbol Transitions . . . . . . . . . . . . . . . . . . . 370
5.6 Statistics of the Correlator’s Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Simulation 5.1 – Signal Space Analysis . . . . . . . . . . . . . . . . . . . . . . . . 376
5.7 The Vector AWGN Channel Revisited . . . . . . . . . . . . . . . . . . . . . . . . . 378
Simulation 5.2 – The Vector AWGN Channel Revisited . . . . . . . . . . . 379
5.8 Generalized Maximum Likelihood Receiver . . . . . . . . . . . . . . . . . . . . 381
Simulation 5.3 – Generalized ML Receiver . . . . . . . . . . . . . . . . . . . . . 385
5.9 Error Probability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
5.9.1 Rotation and Translation Invariance of the Error Probability 387
5.9.2 MinimumEnergy Constellation . . . . . . . . . . . . . . . . . . . . . . . . 388
Simulation 5.4 – Constellation Rotation and Translation . . . . . . . . . . 389
5.9.3 The Union Bound for Symbol Error Probability Estimation . 391
Simulation 5.5 – Verifying the Validity of the Union Bound . . . . . . . 394
5.9.4 Symbol Versus Bit Error Probability . . . . . . . . . . . . . . . . . . . . 396
Simulation 5.6 – Symbol Error Rate versus Bit Error Rate . . . . . . . . 401
5.10 Symbol-by-Symbol ML Receiver for Channels with ISI . . . . . . . . . . . 402
5.11 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
5.12 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
6 Passband Digital Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
6.1 Definitions and Basic Digital Modulation Schemes . . . . . . . . . . . . . . . 411
6.1.1 Basic Digital Modulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
6.1.2 Coherent and Non-coherent Detection . . . . . . . . . . . . . . . . . . . 413
6.1.3 Spectral Efficiency and Power Efficiency . . . . . . . . . . . . . . . . 413
6.1.4 A Note on a Frequently Used Notation . . . . . . . . . . . . . . . . . . 414
6.2 M-PSK Modulations with Coherent Detection . . . . . . . . . . . . . . . . . . 415
6.2.1 Binary PSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Simulation 6.1 – BPSK Generation and Coherent Detection . . . . . . . 420
6.2.2 M-ary PSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Simulation 6.2 – M-PSK Generation and Coherent Detection . . . . . . 432
6.3 M-QAM Modulations with Coherent Detection . . . . . . . . . . . . . . . . . 434
6.3.1 M-QAM Modulated Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
6.3.2 M-QAM Base-Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
6.3.3 Square M-QAM Modulations . . . . . . . . . . . . . . . . . . . . . . . . . . 435
6.3.4 Non-square M-QAM Modulations . . . . . . . . . . . . . . . . . . . . . . 437
6.3.5 M-QAM Generation and Coherent Detection . . . . . . . . . . . . . 439
Simulation 6.3 – I&Q Generation of a 32-QAM and a 64-QAM . . . . 441
6.3.6 M-QAM Symbol and Bit Error Probability over the
AWGN Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442
6.3.7 Power Spectral Density of an M-QAM Modulated Signal . . 446
6.3.8 Spectral Efficiency of an M-QAM Modulated Signal . . . . . . 447
Simulation 6.4 – M-QAM Generation and Coherent Detection . . . . . 447
6.3.9 Comparing M-PSK and M-QAM Modulations . . . . . . . . . . . 449
6.4 M-FSK Modulations with Coherent Detection . . . . . . . . . . . . . . . . . . 450
6.4.1 Tone Separation and Carrier Frequency for Orthogonality . . 450
6.4.2 Binary FSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
Simulation 6.5 – Analysis of Tones Used by an FSK Modulation . . . 456
Simulation 6.6 – BFSK Modulation Methods . . . . . . . . . . . . . . . . . . . 461
6.4.3 M-ary FSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464
Simulation 6.7 – M-FSK Generation and Coherent Detection . . . . . . 471
6.5 MSK Modulation with Coherent Detection . . . . . . . . . . . . . . . . . . . . . 475
6.5.1 MSK Signal Generation and Detection . . . . . . . . . . . . . . . . . . 476
Simulation 6.8 – BFSK and FFSK Generation via VCO . . . . . . . . . . 479
Simulation 6.9 – MSK Generation via Complex Representation . . . . 483
Simulation 6.10 – MSK Generation via OQPSK Approach . . . . . . . . 486
Simulation 6.11 – MSK Modem via OQPSK Approach . . . . . . . . . . . 488
Simulation 6.12 – MSK Modem via Signal-Space Approach . . . . . . 493
6.5.2 MSK Bit Error Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495
Simulation 6.13 – MSK Modem Performance . . . . . . . . . . . . . . . . . . . 496
6.5.3 MSK with Conventional FSK Detection . . . . . . . . . . . . . . . . . 497
Simulation 6.14 – MSK with Conventional FSK Detection . . . . . . . . 502
6.5.4 Power Spectral Density of the MSK Signal . . . . . . . . . . . . . . . 502
Simulation 6.15 – Power Spectral Density of the MSK Signal . . . . . 504
6.5.5 Further Attributes and Uses for the MSK Modulation . . . . . . 505
6.5.6 Answering Some Questions About the MSK Modulation . . . 506
6.6 OQPSK, π/4QPSK and GMSK Modulations . . . . . . . . . . . . . . . . . . . . 507
Simulation 6.16 – Distortion Caused by Nonlinear Amplification . . . 508
6.6.1 Offset QPSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512
Simulation 6.17 – OQPSK Signal Generation . . . . . . . . . . . . . . . . . . . 514
6.6.2 π/4DQPSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516
Simulation 6.18 – π/4DQPSK Generation and Detection . . . . . . . . . 520
6.6.3 GMSK Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
Simulation 6.19 – GMSK Generation and Detection . . . . . . . . . . . . . 527
6.6.4 Nonlinear Amplification Distortion Revisited . . . . . . . . . . . . . 529
Simulation 6.20 – Nonlinear Amplification of Modulated Signals . . 530
6.7 Non-coherent M-FSK and Differentially Coherent BPSK . . . . . . . . . 534
6.7.1 Non-coherent M-FSK Modulations . . . . . . . . . . . . . . . . . . . . . 534
Simulation 6.21 – Non-coherently Detected Binary FSK . . . . . . . . . . 538
6.7.2 Differentially-Coherent BPSK Modulation . . . . . . . . . . . . . . . 542
Simulation 6.22 – DBPSK Generation and Detection . . . . . . . . . . . . . 545
6.8 Carrier and Symbol-Timing Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . 546
6.8.1 Parameter Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548
6.8.2 Carrier Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551
Simulation 6.23 – PLL Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555
Simulation 6.24 – BPSK Phase Tracking with Costas Loop. . . . . . . . 557
Simulation 6.25 – M-th Power Loop for QPSK Phase Tracking . . . . 561
6.8.3 Symbol Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564
Simulation 6.26 – Operation of the Early-Late Synchronizer . . . . . . . 565
Simulation 6.27 – Carrier and Symbol Synchronization . . . . . . . . . . . 568
6.9 Performance of Digital Modulations over Fading Channels . . . . . . . . 570
6.9.1 Optimum Receiver Structures for Fading Channels . . . . . . . . 570
6.9.2 The Effect of Fading on the Error Probability . . . . . . . . . . . . . 571
6.9.3 Performance of Digital Modulations over Fading Channels . 573
6.10 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576
6.11 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 579
7 Wideband Transmission Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
7.1 Spread-Spectrum Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
7.1.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585
7.1.2 A Brief History About the Spread-Spectrum . . . . . . . . . . . . . . 586
7.1.3 Direct-Sequence Spread-Spectrum . . . . . . . . . . . . . . . . . . . . . . 587
7.1.4 Attributes of a Spread-Spectrum Signal . . . . . . . . . . . . . . . . . . 588
Simulation 7.1 – DS-SS Signal Under Jamming . . . . . . . . . . . . . . . . . 591
Simulation 7.2 – Channel Sounding . . . . . . . . . . . . . . . . . . . . . . . . . . . 596
Simulation 7.3 – RAKE Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608
7.1.5 Spreading Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611
Simulation 7.4 – Generation of m-Sequences . . . . . . . . . . . . . . . . . . . 617
Simulation 7.5 – White Noise Generation with m-Sequences . . . . . . 618
Simulation 7.6 – Exploring Correlation Properties for Synchronism 620
Simulation 7.7 – Exploring Correlation Properties for CDMA . . . . . 627
7.1.6 Frequency-Hopping Spread-Spectrum . . . . . . . . . . . . . . . . . . . 629
Simulation 7.8 – FH-SS Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631
7.1.7 Processing Gain and Jamming Margin for DS-SS and FH-SS 633
7.1.8 Acquisition and Tracking of Spread-Spectrum Signals . . . . . 634
Simulation 7.9 – Serial-Search Acquisition . . . . . . . . . . . . . . . . . . . . . 636
7.2 Multi-carrier Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640
7.2.1 Multi-carrier Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641
7.2.2 Multi-carrier CDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642
7.2.3 Multi-carrier DS-CDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643
7.2.4 Multi-tone CDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644
7.2.5 Multi-carrier DS-CDMA using frequency-spread coding . . . 644
7.2.6 Modified Multi-carrier DS-CDMA . . . . . . . . . . . . . . . . . . . . . . 645
7.2.7 Implementation Aspects of MC-CDMA Systems . . . . . . . . . . 646
Simulation 7.10 – OFDM Modem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653
7.2.8 Comments on the Performance of MC-CDMA Systems . . . . 656
7.2.9 MC-CDMA with Double Spreading Code . . . . . . . . . . . . . . . . 657
Simulation 7.11 – DC-DS-CDMA Modem . . . . . . . . . . . . . . . . . . . . . 663
7.3 Ultra Wideband Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665
7.3.1 UWB Signaling Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . 666
7.3.2 UWB Channel Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 671
7.3.3 Reception of UWB Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672
Simulation 7.12 – TH-PPM Ultra Wideband Modem . . . . . . . . . . . . . 673
Simulation 7.13 – Exploring the Time Reversal Technique . . . . . . . . 677
7.4 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679
7.5 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682
8 Notions of Information Theory and Error-Correcting Codes . . . . . . . . . 689
8.1 Notions of Information Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689
8.1.1 Uncertainty, Information and Entropy . . . . . . . . . . . . . . . . . . . 690
Simulation 8.1 – Estimating the Entropy of a Source . . . . . . . . . . . . . 693
8.1.2 Source Coding and the Source-Coding Theorem . . . . . . . . . . 694
8.1.3 Discrete Memoryless Channels Revisited . . . . . . . . . . . . . . . . 699
8.1.4 Mutual Information and Channel Capacity . . . . . . . . . . . . . . . 700
8.1.5 Channel Coding Theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 701
8.1.6 Channel Capacity of Some Channels . . . . . . . . . . . . . . . . . . . . 703
8.1.7 Channel Capacity of Other Important Channels . . . . . . . . . . . 710
8.2 Notions of Error-Correcting Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 729
8.2.1 Terminology and Background . . . . . . . . . . . . . . . . . . . . . . . . . . 729
8.2.2 Hamming and Reed-Muller Codes . . . . . . . . . . . . . . . . . . . . . . 739
8.2.3 Syndrome Decoding of Binary Linear Block Codes . . . . . . . . 744
Simulation 8.2 – Hard-Decision Versus Soft-Decision ML Decoding 746
Simulation 8.3 – Coded and Uncoded System Performance. . . . . . . . 749
8.2.4 Construction of Extension Fields and Polynomial Algebra . . 751
8.2.5 Cyclic Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 753
Simulation 8.4 – LFSR Encoding of a Hamming (7, 4) Code . . . . . . 762
Simulation 8.5 – Meggitt Decoding of a Hamming (7, 4) Code . . . . . 763
8.2.6 Bose-Chaudhuri-Hocquenghem and Reed-Solomon Codes . . 764
Simulation 8.6 – Reed-Solomon Code Performance . . . . . . . . . . . . . . 770
8.2.7 Performance of Binary Linear Block Codes . . . . . . . . . . . . . . 772
8.2.8 Convolutional Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 776
Simulation 8.7 – Finite Trace-Back Viterbi Decoding . . . . . . . . . . . . 786
Simulation 8.8 – Convolutional Code Performance . . . . . . . . . . . . . . . 794
8.2.9 Trellis-Coded Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795
Simulation 8.9 – Four-State 8PSK Trellis-Coded Modulation . . . . . . 804
8.2.10 Turbo and Low-Density Parity Check Codes. . . . . . . . . . . . . . 806
8.2.11 Remarks on Coding for Fading Channels . . . . . . . . . . . . . . . . 828
8.3 Summary and Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 830
8.4 Additional Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 832
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833 |
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发表于 2010-2-2 23:24:49
发表于 2014-4-23 21:01:34
