PREFACE xv
1 INTRODUCTION 1
1.1 COMMUNICATION SYSTEMS 2
1.2 DESIGN CHALLENGES: CHANNEL DISTORTIONS AND NOISES 3
1.3 MESSAGE SOURCES 4
1.4 CHANNEL EFFECT, SIGNAL-TO-NOISE RATIO, AND CAPACITY 8
1.5 MODULATION AND DETECTION 11
1.6 DIGITAL SOURCE CODING AND ERROR CORRECTION CODING 13
1.7 A BRIEF HISTORICAL REVIEW OF MODERN TELECOMMUNICATIONS 15
2 SIGNALS AND SIGNAL SPACE 21
2.1 SIZE OF A SIGNAL 21
2.2 CLASSIFICATION OF SIGNALS 26
2.3 SOME USEFUL SIGNAL OPERATIONS 29
2.4 UNIT IMPULSE SIGNAL 33
2.5 SIGNALS VERSUS VECTORS 36
2.6 CORRELATION OF SIGNALS 42
2.7 ORTHOGONAL SIGNAL SETS 47
2.8 TRIGONOMETRIC FOURIER SERIES 51
2.9 FREQUENCY DOMAIN AND EXPONENTIAL FOURIER SERIES 62
2.10 MATLAB EXERCISES 69
3 ANALYSIS AND TRANSMISSION OF SIGNALS 84
3.1 FOURIER TRANSFORM of SIGNALS 84
3.2 TRANSFORMS OF SOME USEFUL FUNCTIONS 90
3.3 SOME FOURIER TRANSFORM PROPERTIES 97
3.4 SIGNAL TRANSMISSION THROUGH A LINEAR TIME-INVARIANT SYSTEM 114
3.5 IDEAL VERSUS PRACTICAL FILTERS 119
3.6 SIGNAL DISTORTION OVER A COMMUNICATION CHANNEL 124
3.7 SIGNAL ENERGY AND ENERGY SPECTRAL DENSITY 128
3.8 SIGNAL POWER AND POWER SPECTRAL DENSITY 137
3.9 NUMERICAL COMPUTATION OF FOURIER TRANSFORM: THE DFT 145
3.10 MATLAB EXERCISES 150
4 ANALOGUE MODULATIONS AND DEMODULATIONS 167
4.1 BASEBAND VERSUS CARRIER COMMUNICATIONS 167
4.2 DOUBLE-SIDEBAND AMPLITUDE MODULATION 169
4.3 AMPLITUDE MODULATION (AM) 178
4.4 BANDWIDTH-EFFICIENT AMPLITUDE MODULATIONS 185
4.5 FM AND PM: NONLINEAR ANGLE MODULATIONS 199
4.6 BANDWIDTH ANALYSIS OF ANGLE MODULATIONS 205
4.7 DEMODULATION OF FM SIGNALS 213
4.8 FREQUENCY CONVERSION AND SUPERHETERODYNE RECEIVERS 215
4.9 GENERATING FM SIGNALS 218
4.10 FREQUENCY DIVISION MULTIPLEXING (FDM) 224
4.11 PHASE-LOCKED LOOP AND APPLICATIONS 225
4.12 MATLAB EXERCISES 233
5 DIGITISATION OF ANALOGUE SOURCE SIGNALS 255
5.1 SAMPLING THEOREM 255
5.2 PULSE CODE MODULATION (PCM) 270
5.3 DIGITAL TELEPHONY: PCM IN T1 SYSTEMS 282
5.4 DIGITAL MULTIPLEXING HIERARCHY 286
5.5 DIFFERENTIAL PULSE CODE MODULATION (DPCM) 291
5.6 DELTA MODULATION 296
5.7 MATLAB EXERCISES 301
6 PRINCIPLES OF DIGITAL DATA TRANSMISSION 317
6.1 DIGITAL COMMUNICATION SYSTEMS 317
6.2 BASEBAND LINE CODING 320
6.3 PULSE SHAPING 335
6.4 SCRAMBLING 347
6.5 DIGITAL RECEIVERS AND REGENERATIVE REPEATERS 350
6.6 EYE DIAGRAMS: AN IMPORTANT DIAGNOSTIC TOOL 360
6.7 PAM: M-ARY BASEBAND SIGNALLING 363
6.8 DIGITAL CARRIER SYSTEMS 366
6.9 M-ARY DIGITAL CARRIER MODULATION 368
6.10 MATLAB EXERCISE 374
7 FUNDAMENTALS OF PROBABILITY THEORY 388
7.1 CONCEPT OF PROBABILITY 388
7.2 RANDOM VARIABLES 404
7.3 STATISTICAL AVERAGES (MEANS) 423
7.4 CORRELATION 432
7.5 LINEAR MEAN SQUARE ESTIMATION 436
7.6 SUM OF RANDOM VARIABLES 439
7.7 CENTRAL LIMIT THEOREM 442
8 RANDOM PROCESSES AND SPECTRAL ANALYSIS 453
8.1 FROM RANDOM VARIABLE TO RANDOM PROCESS 453
8.2 CLASSIFICATION OF RANDOM PROCESSES 458
8.3 POWER SPECTRAL DENSITY 462
8.4 MULTIPLE RANDOM PROCESSES 477
8.5 TRANSMISSION OF RANDOM PROCESSES THROUGH LINEAR SYSTEMS 478
8.6 BANDPASS RANDOM PROCESSES 499
9 PERFORMANCE ANALYSIS OF DIGITAL COMMUNICATION SYSTEMS 523
9.1 OPTIMUM LINEAR DETECTOR FOR BINARY POLAR SIGNALLING 523
9.2 GENERAL BINARY SIGNALLING 529
9.3 COHERENT RECEIVERS FOR DIGITAL CARRIER MODULATIONS 537
9.4 SIGNAL SPACE ANALYSIS OF OPTIMUM DETECTION 542
9.5 VECTOR DECOMPOSITION OF WHITE NOISE RANDOM PROCESSES 547
9.6 OPTIMUM RECEIVER FOR WHITE GAUSSIAN NOISE CHANNELS 553
9.7 GENERAL ERROR PROBABILITY OF OPTIMUM RECEIVERS 578
9.8 NONWHITE (COLOURED) CHANNEL NOISE 587
9.9 OTHER USEFUL PERFORMANCE CRITERIA 587
9.10 NONCOHERENT DETECTION 591
9.11 MATLAB EXERCISES 599
10 SPREAD SPECTRUM COMMUNICATIONS 618
10.1 FREQUENCY HOPPING SPREAD SPECTRUM (FHSS) SYSTEMS 618
10.2 MULTIPLE FHSS USER SYSTEMS AND PERFORMANCE 622
10.3 APPLICATIONS OF FHSS 625
10.4 DIRECT SEQUENCE SPREAD SPECTRUM 629
10.5 RESILIENT FEATURES OF DSSS 632
10.6 CODE DIVISION MULTIPLE-ACCESS (CDMA) OF DSSS 634
10.7 MULTIUSER DETECTION (MUD) 642
10.8 MODERN PRACTICAL DSSS CDMA SYSTEMS 648
10.9 MATLAB EXERCISES 657
11 DIGITAL COMMUNICATIONS OVER LINEARLY DISTORTIVE CHANNELS 673
11.1 LINEAR DISTORTIONS OF WIRELESS MULTIPATH CHANNELS 673
11.2 RECEIVER CHANNEL EQUALISATION 677
11.3 LINEAR T-SPACED EQUALISATION (TSE) 683
11.4 LINEAR FRACTIONALLY SPACED EQUALISERS (FSE) 693
11.5 CHANNEL ESTIMATION 698
11.6 DECISION FEEDBACK EQUALISER 699
11.7 OFDM (MULTICARRIER) COMMUNICATIONS 702
11.8 REAL-LIFE APPLICATIONS OF OFDM AND DMT 714
11.9 BLIND EQUALISATION AND IDENTIFICATION 719
11.10 TIME-VARYING CHANNEL DISTORTIONS DUE TO MOBILITY 720
11.11 MATLAB EXERCISES 723
12 INTRODUCTION TO INFORMATION THEORY 744
12.1 MEASURE OF INFORMATION 744
12.2 SOURCE ENCODING 748
12.3 ERROR-FREE COMMUNICATION OVER A NOISY CHANNEL 754
12.4 CHANNEL CAPACITY OF A DISCRETE MEMORYLESS CHANNEL 757
12.5 CHANNEL CAPACITY OF A CONTINUOUS MEMORYLESS CHANNEL 764
12.6 MULTIPLE-INPUT–MULTIPLE-OUTPUT COMMUNICATION SYSTEMS 781
12.7 MATLAB EXERCISES 790
13 ERROR CORRECTING CODES 802
13.1 OVERVIEW 802
13.2 REDUNDANCY FOR ERROR CORRECTION 803
13.3 LINEAR BLOCK CODES 806
13.4 CYCLIC CODES 813
13.5 THE BENEFIT OF ERROR CORRECTION 823
13.6 CONVOLUTIONAL CODES 827
13.7 TRELLIS DIAGRAM OF BLOCK CODES 837
13.8 CODE COMBINING AND INTERLEAVING 838
13.9 SOFT DECODING 841
13.10 SOFT-OUTPUT VITERBI ALGORITHM (SOVA) 843
13.11 TURBO CODES 845
13.12 LOW-DENSITY PARITY CHECK (LDPC) CODES 854
13.13 MATLAB EXERCISES 860
APPENDICES
A ORTHOGONALITY OF SOME SIGNAL SETS 875
A.1 TRIGONOMETRIC SINUSOID SIGNAL SET 875
A.2 ORTHOGONALITY OF THE EXPONENTIAL SINUSOID SIGNAL SET 876
B CAUCHY-SCHWARZ INEQUALITY 877
C GRAM-SCHMIDT ORTHOGONALISATION OF A VECTOR SET 878
INDEX 881