PREFACE
1
INTRODUCTION
1.1
Historical Review 1
1.2
Elements of an Electrical Communication System 4
1.2.1 Digital Communication System, 7
1.2.2 Early Work in Digital Communications, 10
1.3
Communication Channels and Their Characteristics 12
1.4
Mathematical Models for Communication Channels 19
1.5
Organization of the Book 22
1.6
Further Reading 23
2
FREQUENCY DOMAIN ANALYSIS OF SIGNALS AND SYSTEMS
24
2.1
Fourier Series 24
2.1.1 Fourier Series for Real Signals: the Trigonometric Fourier Series, 29
2.2
Fourier Transforms 31
2.2.1 Fourier Transform of Real, Even, and Odd Signals, 35
2.2.2 Basic Properties of the Fourier Transform, 36
2.2.3 Fourier Transform for Periodic Signals, 39
2.3
Power and Energy 40
2.3.1 Energy-Type Signals, 41
2.3.2 Power-Type Signals, 42
2.4
Sampling of Bandlimited Signals 45
2.5
Bandpass Signals 49
2.6
Further Reading 57
Problems 57
3
ANALOG SIGNAL TRANSMISSION AND RECEPTION
70
3.1
Introduction to Modulation 70
3.2
Amplitude Modulation AM
71
3.2.1 Double-Sideband Suppressed Carrier AM, 71
3.2.2 Conventional Amplitude Modulation, 78
3.2.3 Single-Sideband AM, 81
3.2.4 Vestigial-Sideband AM, 85
3.2.5 Implementation of AM Modulators and Demodulators, 88
3.2.6 Signal Multiplexing, 94
3.3
Angle Modulation 96
3.3.1 Representation of FM and PM Signals, 97
3.3.2 Spectral Characteristics of Angle-Modulated Signals, 101
3.3.3 Implementation of Angle Modulators and Demodulators, 107
3.4
Radio and Television Broadcasting 115
3.4.1 AM Radio Broadcasting, 115
3.4.2 FM Radio Broadcasting, 116
3.4.3 Television Broadcasting, 120
3.5
Mobile Radio Systems 128
3.6
Further Reading 131
Problems 131
4
RANDOM PROCESSES
144
4.1
Probability and Random Variables 144
4.2
Random Processes: Basic Concepts 159
4.2.1 Description of Random Processes, 162
4.2.2 StatisticaI Averages, 164
4.2.3 Stationary Processes, 166
4.2.4 Random Processes and Linear Systems, 174
4.3
Random Processes in the Frequency Domain 177
4.3.1 Power Spectrum of Stochastic Processes, 177
4.3.2 Transmission over LTI Systems, 183
4.4
Gaussian and White Processes 186
4.4.1 Gaussian Processes, 186
4.4.2 White Processes, 188
4.5
Bandlimited Processes and Sampling 192
4.6
Bandpass Processes 194
4.7
Further Reading 201
Problems 202
5
EFFECT OF NOISE ON ANALOG COMMUNICATION SYSTEMS 217
5.1
Effect of Noise on Linear-Modulation Systems 217
5.1.1 Effect of Noise on a Baseband System, 218
5.1.2 Effect of Noise on DSB-SC AM, 218
5.1.3 Effect of Noise on SSB AM, 220
5.1.4 Effect of Noise on Conventional AM, 221
5.2
Carrier-Phase Estimation with a Phase-Locked Loop PLL
225
5.2.1 The Phase-Locked Loop PLL , 226
5.2.2 Effect of Additive Noise on Phase Estimation, 229
5.3
Effect of Noise on Angle Modulation 234
5.3.1 Threshold Effect in Angle Modulation, 244
5.3.2 Pre-emphasis and De-emphasis Filtering, 248
5.4
Comparison of Analog-Modulation Systems 251
5.5
Effects of Transmission Losses and Noise in Analog
Communication Systems 252
5.5.1 Characterization of Thermal Noise Sources, 253
5.5.2 Effective Noise Temperature and Noise Figure, 254
5.5.3 Transmission Losses, 257
5.5.4 Repeaters for Signal Transmission, 258
5.6
Further Reading 261
Problems 261
6
INFORMATION SOURCES AND SOURCE CODING
267
6.1
Modeling of Information Sources 268
6.1.1 Measure of Information, 269
6.1.2 Joint and Conditional Entropy, 271
6.2
Source-Coding Theorem 273
6.3
Source-Coding Algorithms 276
6.3.1 The Huffman Source-Coding Algorithm, 276
6.3.2 The Lempel-Ziv Source-Coding Algorithm, 280
6.4
Rate-Distortion Theory 282
6.4.1 Mutual Information, 283
6.4.2 Differential Entropy, 284
6.4.3 Rate-Distortion Function, 285
6.5
Quantization 290
6.5.1 Scalar Quantization, 291
6.5.2 Vector Quantization, 300
6.6
Waveform Coding 302
6.6.1 Pulse-Code Modulation PCM , 302
6.6.2 Differential Pulse-Code Modulation DPCM , 307
6.6.3 Delta Modulation AM , 310
6.7
Analysis-Synthesis Techniques 312
6.8
Digital Audio Transmission and Digital Audio Recording 316
6.8.1 Digital Audio in Telephone Transmission Systems, 317
6.8.2 Digital Audio Recording, 319
6.9
The JPEG Image-Coding Standard 323
6.10
Further Reading 327
Problems 327
DIGITAL TRANSMISSION THROUGH THE ADDITIVE WHITE
GAUSSIAN NOISE CHANNEL
340
7.1
Geometric Representation of Signal Waveforms 341
7.2
Pulse Amplitude Modulation 345
7.3
Two-dimensional Signal Waveforms 350
7.3.1 Baseband Signals, 350
7.3.2 Two-dimensional Bandpass Signals--Carrier-Phase Modulation, 354
7.3.3 Two-dimensional Bandpass Signals---Quadrature Amplitude
Modulation, 357
7.4
Multidimensional Signal Waveforms 360
7.4.1 Orthogonal Signal Waveforms, 360
7.4.2 Biorthogonal Signal Waveforms, 365
7.4.3 Simplex Signal Waveforms, 366
7.4.4 Binary-Coded Signal Waveforms, 367
7.5
Optimum Receiver for Digitally Modulated Signals in Additive White
Gaussian Noise 370
7.5.1 Correlation-Type Demodulator, 370
7.5.2 Matched-Filter-Type Demodulator, 375
7.5.3 The Optimum Detector, 381
7.5.4 Demodulation and Detection of Carrier-Amplitude Modulated
Signals, 386
7.5.5 Dernodulation and Detection of Carrier-Phase Modulated Signals, 388
7.5.6 Demodulation and Detection of Quadrature Amplitude Modulated
Signals, 396
7.5.7 Demodulation and Detection of Frequency-Modulated Signals, 398
7.6
Probability of Error for Signal Detection in Additive White
Gaussian Noise 405
7.6.1
Probability of Error for Binary Modulation, 405
7.6.2
Probability of Error for M-ary PAM, 408
7.6.3
Probability of Error for Phase-Coherent PSI Modulation, 413
7.6.4
Probability of Error for DPSK, 417
7.6.5
Probability of Error for QAM, 418
7.6.6
Probability of Error for M-ary Orthogonal Signals, 423
7.6.7
Probability of Error for M-ary Biorthogonal Signals, 428
7.6.8
Probability of Error for M-ary Simplex Signals, 429
7.6.9
Probability of Error for Noncoherent Detection of FSK, 430
7.6.10 Comparison of Modulation Methods, 432
7.7
Performance Analysis for Wireline and Radio Communication Channels 436
7.7.1 Regenerative Repeaters, 437
7. 7.2 Link Budget Analysis for Radio Channels, 438
7.8
Symbol Synchronization 442
7.8.1 Early-Late Gate Synchronizers, 443
7.8.2 Minimum Mean-Square-Error Method, 445
7.8.3 Maximum-Likelihood Methods, 448
7.8.4 Spectral Line Methods, 449
7.8.5 Symbol Synchronization for Carrier-Modulated Signals, 451
7.9
Further Reading 452
Problems 453
8
DIGITAL TRANSMISSION THROUGH BANDLIMITED
AWGN CHANNELS
474
8.1
Digital Transmission through Bandlimited Channels 474
&1.1 Digital PAM Transmission through Bandlimited Baseband Channels, 478
&1.2 Digital Transmission through Bandlimited Bandpass Channels, 480
8.2
The Power Spectrum of Digitally Modulated Signals 482
8.2.1 The Power Spectrum of the Baseband Signal, 483
8.2.2 The Power Spectrum of a Carrier-Modulated Signal, 488
8.3
Signal Design for Bandlimited Channels 490
8.3.1 Design of Bandlimited Signals for Zero lSl The Nyquist Criterion, 492
8.3.2 Design of Bandlimited Signals with Controlled ISI--Partial Response Signals, 497
8.4
Probability of Error in Detection of Digital PAM 499
8.4.1 Probability of Error for Detection of Digital PAM with Zero ISI, 500
8.4.2 Symbol-by-Symbol Detection of Data with Controlled ISI, 501
&4.3 Probability of Error for Detection of Partial Response Signals, 504
8.5 ´
Digitally Modulated Signals with Memory 507
8.5.1 Modulation Codes and Modulation Signals with Memory, 508
8.5.2 The Maximum-Likelihood Sequence Detector, 521
8.5.3 Maximum-Likelihood Sequence Detection of Partial Response Signals, 525
8.5.4 The Power Spectrum of Digital Signals with Memory, 530
8.6
System Design in the Presence of Channel Distortion 534
8.6.1 Design of Transmitting and Receiving Filters for a Known ChanneL 535
8.6.2 Channel Equalization, 538
8.7
Multicarrier Modulation and OFDM 556
8.7.1 An OFDM System Implemented via the FFT Algorithm, 557
8.8
Further Reading 560
Problems 561
9
CHANNEL CAPACITY AND CODING
576
9.1
Modeling of Communication Channels 576
9.2
Channel Capacity 579
9.2.1 Gaussian Channel Capacity, 583
9.3
Bounds on Communication 586
9.3.1 Transmission of Analog Sources by PCM, 590
9.4
Coding for Reliable Communication 591
9.4.1 A Tight Bound on Error Probability of Orthogonal Signals, 592
9.4.2 The Promise of Coding, 595
9.5
Linear Block Codes 601
9.5.1 Decoding and Performance of Linear Block Codes, 606
9.5.2 Burst-Error-Correcting-Codes, 614
9.6
Cyclic Codes 615
9.6.1 The Structure of Cyclic Codes, 615
9.7
Convolutional Codes 623
9. 7.1 Basic Properties of Convolutional Codes, 624
9. 7.2 Optimum Decoding of Convolutional Codes--The Viterbi Algorithm, 629
9. 7.3 Other Decoding Algorithms for Convolutional Codes, 634
9. 7.4 Bounds on Error Probability of Convolutional Codes, 634
9.8
Complex Codes Based on Combination of Simple Codes 638
9.8.1 Product Codes, 639
9.8.2 Concatenated Codes, 640
9.8.3 Turbo Codes, 640
9.8.4 The BCJR Algorithm, 642
9.8.5 Performance of Turbo Codes, 644
9.9
Coding for Bandwidth-Constrained Channels 646
9.9.1 Combined Coding and Modulation, 647
9.9.2 Trellis-Coded Modulation, 649
9.10
Practical Applications of Coding 655
9.10.1 Coding for Deep-Space Communications, 656
9.10.2 Coding for Telephone-Line Modems, 657
9.10.3 Coding for Compact Discs, 658
9.11
Further Reading 661
Problems 661
10 WIRELESS COMMUNICATIONS
674
10.1
Digital Transmission on Fading Multipath Channels 674
10.1.1 Channel Models for T~me-Varlant Multipath Channels, 676
10.1.2 Signal Design for Fading Multipath Channels, 684
10.1.3 Performance of Binary Modulation in Frequency Nonselective Rayleigh
Fading Channels, 686
10.1.4 Performance Improvement Through Signal Diversity, 689
10.1.5 Modulation and Demodulation on Frequency Selective Channels--
The RAKE Demodulator, 694
10.1.6 Multiple Antenna Systems and Space-Time Codes, 697
10.2
Continuous Carrier-Phase Modulation 702
10.2.1 Continuous-Phase FSK CPFSK , 702
10.2.2 Continuous-Phase Modulation CPM , 711
10.2.3 Spectral Characteristics of CPFSK and CPM Signals, 715
10.2.4 Demodulation and Detection of CPM Signals, 720
10.2.5 Performance of CPM in AWGN and Rayleigh Fading Channels, 726
10.3
Spread-Spectrum Communication Systems 729
10.3.1 Model of a Spread-Spectrum Digital Communication System, 730
10.3.2 Direct-Sequence Spread-Spectrum Systems, 731
10.3.3 Some Applications of DS Spread-Spectrum Signals, 742
10.3.4 Effect of Pulsed Interference and Fading, 746
10.3.5 Generation of PN Sequences, 748
10.3.6 Frequency-Hopped Spread Spectrum, 752
10.3.7 Synchronization of Spread-Spectrum Systems, 758
10.4
Digital Cellular Communication Systems 766
10.4.1 The GSM System, 766
10.4.2 CDMA System Based on lS-95, 768
10.5
Further Reading 774
Problems 775
APPENDIX A: THE PROBABILITY OF ERROR FOR
MULTICHANNEL RECEPTION OF BINARY SIGNALS
782
REFERENCES
785
INDEX
794
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