Analogue and Digital Communication Techniques (eBook)

Cover 1
Contents 4
About the author 12
Preface 14
Acknowledgements 14
Chapter 1. Definition of terms 16
1.1 Introduction 16
1.2 Frequencies 16
1.3 Types of signal 17
1.4 Analogue signal 17
1.5 Digital signal 18
1.6 Waveforms 19
1.7 Measurement of signal level 23
1.8 Review questions 28
Chapter 2. Analogue modulation principles 30
2.1 Introduction 30
2.2 Frequency band classifications 30
2.3 Modulation techniques 32
2.4 Amplitude modulation 32
2.5 Frequency division multiplexing 39
2.6 Modulation depth 43
2.7 Practical circuits 50
2.8 Angle modulation 54
2.9 Comparison of amplitude, phase and frequency modulation 60
2.10 Review questions 60
Chapter 3. Spread spectrum systems 61
3.1 Introduction 61
3.2. Spread spectrum systems 61
3.3 Spread spectrum system criteria 62
3.4 Reasons for use of spread spectrum systems 62
3.5 Pseudorandom code generators, scramblers and descramblers 62
3.6 Types of spread spectrum techniques 65
3.7 Advantages and disadvantages of spread spectrum techniques 72
3.8 Review questions 73
Chapter 4. Digital modulation techniques 74
4.1 Introduction 74
4.2 Amplitude shift key modulation 75
4.3 Frequency shift key modulation 76
4.4 Phase shift key modulation 81
4.5 Sixteen-quadrature amplitude modulation 91
4.6 Bandwidths 96
4.7 Differential phase modulation 98
4.8 Review questions 110
Chapter 5. Pulse code modulation 112
5.1 Introduction 112
5.2 Time division multiplexing 112
5.3 Principle of operation 113
5.4 Recommended standards 115
5.5 The 30/32-channel CEPT PCM system 116
5.6 Aliasing distortion 119
5.7 Quantising and encoding 121
5.8 The 30/32-channel CEPT PCM system operation 131
5.9 Importance of frame and multiframe alignment 136
5.10 Alarms 137
5.11 Dependent regenerative repeaters 139
5.12 Power feeding 140
5.13 Review questions 141
Chapter 6. Noise figure and noise temperature 142
6.1 Introduction 142
6.2 Internal noise 142
6.3 External noise 147
6.4 System performance 148
6.5 Noise figure/noise factor 149
6.6 Effective noise temperature 156
6.7 Variation of noise figure with frequency 159
6.8 Review questions 159
Chapter 7. Effects of noise and distortion on analogue and digital signals 161
7.1 Introduction 161
7.2 Amplitude distortion 161
7.3 Frequency distortion 162
7.4 Amplitude and frequency distortion 163
7.5 Limited bandwidth 164
7.6 Effects of noise 164
7.6 Review questions 169
Chapter 8. Determination of bit error rates 170
8.1 Introduction 170
8.2 Entropy 171
8.3 Causes of errors on digital signals 173
8.4 Probability of bit error rate 174
8.5 Shannon and Hartley capacity theorem 179
8.6 Comparison of unipolar and bipolar bit streams 183
8.7 Review questions 184
Chapter 9. Source coding techniques 185
9.1 Introduction 185
9.2 Asynchronous and synchronous transmission 185
9.3 Codes used on computers 186
9.4 Huffmann coding 188
9.5 Hamming coding 194
9.6 Review questions 199
Chapter 10. Bit error detection and correction 200
10.1 Introduction 200
10.2 Error detection using parity bits 200
10.3 Block check codes 205
10.4 Frame check sequence or cyclic redundancy check 208
10.5 The CRC process 211
10.6 Convolutional encoding 218
10.7 Review questions 245
Chapter 11. Line and interface coding 246
11.1 Introduction 246
11.2 Requirements of line and interface codes 246
11.3 Non-return to zero codes 247
11.4 Return to zero (RZ) 250
11.5 The phase-encoded group 255
11.6 Pulse modulation 258
11.7 Frequency distribution 260
11.8 Review questions 261
Chapter 12. ISO open systems interconnect seven-layer model 262
12.1 Introduction 262
12.2 Message transfer and message switching 262
12.3 Protocol Categories and Operation 263
12.4 Types of protocols 264
12.5 The International Standards Organisation seven-layer model 266
12.6 Functions of the different layers 267
12.7 The ITU, ISO and CCITT 270
12.8 Recommended interfaces 270
12.9 ISO and CCITT recommended protocols 293
12.10 Review questions 293
Answers to review questions 294
Bibliography 303
Index 304