Signal Processing for Digital Communications

533 Pages·2006·1.72 MB·english

by  George J. Miao

Signal Processing in
Digital Communications
i
ii SignalProcessinginDigitalCommunications
Signal Processing in
Digital Communications
First Edition
George J. Miao
ARTECHHOUSE
iii
iv SignalProcessinginDigitalCommunications
ToLisa,Kathleen,and Julia
Contents
Preface xv
1 Introduction 1
1.1 AHistory of Communications UsingElectricity 1
1.2 Digital Communication Systems 3
1.3 Digital RFSystems 6
1.3.1 Digital Transceivers 7
1.3.2 A/D Converter Challenge 9
1.3.3 Digital Downconversion and Channelization 12
1.4 LinkBudget 17
1.4.1 NoiseFigure 19
1.4.2 ReceiverSensitivity 19
1.4.3 Maximum PathLoss 20
1.5 Summary 21
References 22
2 Probability, Random Variables, and Stochastic Signal
Processing 25
2.1 Introduction 25
2.2 Probability 26
2.2.1 Intuitive Probability 27
2.2.2 Axiomatic Probability 27
2.2.3 Conditional Probability 29
2.2.4 Independence 31
2.3 Random Variables 31
2.4 Probability Distributions andDensities 32
2.4.1 Probability Distributions 32
2.4.2 Probability Densities 33
2.4.3 Joint Probability Distributions andDensities 34
vii
viii SignalProcessinginDigitalCommunications
2.4.4 StatisticalAveragesandJoint Moments 35
2.4.5 Moment Generation Function 37
2.5 Functionsof Random Variables 39
2.5.1 Sumsof Random Variables 39
2.5.2 Transformations of RandomVariables 43
2.6 DiscreteDistributions and Densities 45
2.6.1 DiscreteUniform Distribution 45
2.6.2 Binomial Distribution 46
2.6.3 PoissonDistribution 48
2.7 Continuous Distributions andDensities 51
2.7.1 GaussianDensityFunction 51
2.7.2 Error Function 54
2.7.3 Q-Function 56
2.7.4 Multivariate GaussianDistribution 58
2.7.5 Uniform Density Function 58
2.7.6 Chi-Square Distribution 60
2.7.7 F Distribution 61
2.7.8 Rayleigh Distribution 63
2.7.9 RiceDistribution 64
2.8 Upper Boundson theProbability 66
2.8.1 ChebyshevInequality 67
2.8.2 LawofLargeNumbers 68
2.8.3 Central Limit Theorem 69
2.9 StochasticSignalProcesses 70
2.9.1 Definition of Discrete-TimeRandomProcess 71
2.9.2 Stationary Processes 73
2.9.3 EstimatedFunctions 73
2.9.4 PowerSpectrum 74
2.9.5 StochasticProcessesfor LinearSystems 76
2.9.6 MeanSquareEstimation 81
2.10 Detection TheoryandOptimum Receivers 83
2.10.1 Optimality Criterion 83
2.10.2 Maximum Likelihood Detector 85
2.10.3 Probability ofError 87
2.11 Summary 87
References 89
3 SamplingTheory 91
3.1 Introduction 91
Contents ix
3.2 Discrete-TimeSampledSignals 92
3.2.1 Instantaneous Sampling 92
3.2.2 Ideal SampledSignal 94
3.3 Nyquist Sampling Theorem 94
3.3.1 Time-Domain Interpolation Formula 96
3.3.2 Frequency-Domain Interpolation Formula 98
3.3.3 Aliasing 99
3.4 Undersampling 100
3.4.1 Minimum Sampling Rate 102
3.4.2 Antialiasing BandpassFilter 103
3.5 StochasticSampling Theorem 105
3.6 Summary 106
References 108
4 ChannelCapacity 109
4.1 Introduction 109
4.2 GaussianChannelCapacity 110
4.3 Bandlimited ChannelCapacity 112
4.4 MIMOChannel Capacity 117
4.5 SIMOChannelCapacity 121
4.6 MISOChannelCapacity 121
4.7 Summary 122
References 123
5 SmartAntennaSystems 125
5.1 Introduction 125
5.2 SmartAntennas andBeamforming Structures 126
5.2.1 SwitchedBeamforming 126
5.2.2 Delay-and-Sum Beamforming 128
5.2.3 Space-TimeBeamforming 129
5.2.4 Interpolation Beamforming 130
5.3 Beamforming Algorithms 133
5.3.1 MMSEBeamformer 133
5.3.2 Maximum SNRof theBeamformer 135
5.3.3 Minimum VarianceBeamformer 137
5.4 Summary 139
References 140
x SignalProcessinginDigitalCommunications
6 ChannelCharacterizationandDistortion 141
6.1 Introduction 141
6.2 WirelessChannels 143
6.2.1 FreeSpacePropagation 143
6.2.2 FlatSurfacePropagation 146
6.2.3 Multipath Propagation 148
6.2.4 Parametersof Multipath Channels 150
6.2.5 FadingCharacteristics 156
6.2.6 Large-ScaleFading 157
6.2.7 Small-ScaleFading 159
6.3 WiredChannels 163
6.3.1 TransmissionLoop 163
6.3.2 Crosstalk 168
6.3.3 Simulation LoopModel 169
6.4 ChannelDistortion 171
6.4.1 Intersymbol Interference 172
6.4.2 EyeDiagrams 174
6.4.3 Nyquist Criterion 178
6.5 PulseShaping 180
6.5.1 Raised-CosinePulse 181
6.5.2 GaussianShapingPulse 182
6.6 MatchedFiltering 183
6.7 Summary 184
References 187
7 ChannelEstimationandBlindIdentification 189
7.1 Introduction 189
7.2 Discrete-TimeChannelModels 191
7.3 ChannelEstimators 194
7.3.1 Maximum Likelihood Estimator 194
7.3.2 LeastSquaresEstimator 198
7.3.3 GeneralizedLeastSquaresEstimator 201
7.3.4 MMSEEstimator 202
7.4 Adaptive ChannelEstimation andAlgorithms 208
7.4.1 TheLMSAlgorithms 210
7.4.2 TheLMSAlgorithm Convergence 214
7.4.3 TheLMSEMSEAnalysisandMisadjustment 217
7.4.4 TheRLSAlgorithms 219
7.4.5 TheRLSAlgorithm Convergence 223
Contents xi
7.4.6 TheRLSEMSEAnalysisandMisadjustment 224
7.4.7 Comparison of theAdaptive Algorithms 225
7.5 ChannelModels andHOSEstimations 226
7.5.1 SISOChannelModel andEstimation 226
7.5.2 SIMOChannelModel andEstimation 229
7.5.3 MIMOChannel ModelandEstimation 233
7.6 Blind ChannelIdentification 238
7.6.1 Blind Identification for SISOChannel 239
7.6.2 SubspaceBlind Identification for SIMO
Channel 242
7.6.3 Blind Identification for MIMOChannel 246
7.7 Summary 252
References 253
8 AdaptiveEqualizersinCommunicationReceivers 257
8.1 Introduction 257
8.2 LinearEqualizer 260
8.2.1 Channel Equalizer 262
8.2.2 Mean-Square-Error Criterion 266
8.3 Adaptive LinearEqualizer 272
8.3.1 Adaptive Algorithms for anEqualizer 274
8.3.2 TrainingMethodology 277
8.3.3 TapLength ofEqualizer Coefficients 278
8.4 Fractionally SpacedEqualizer 279
8.4.1 Multirate Communication SystemModel 280
8.4.2 Multichannel Model-BasedEqualizer 283
8.4.3 FSE-MMSEFunction 287
8.4.4 FSEConstant ModulusAlgorithm 293
8.4.5 FSE-CMNoisy CostFunction 297
8.4.6 FSE-CMPerformances 298
8.5 DecisionFeedbackEqualizer 299
8.5.1 MMSEfor DFE 301
8.5.2 PredictiveDFE 307
8.5.3 FSE-DFE 310
8.5.4 Error Propagation 312
8.6 Space-TimeEqualizer 315
8.6.1 Time-Only Equalizer 316
8.6.2 Space-OnlyEqualizer 318
8.6.3 Space-TimeMMSEEqualizer 320