Analogue and Digital Communication Techniques

The rapid expansion of digital communications, particularly in the fields of TV and mobile telephones does not overide the need for a clear understanding of analogue frequencies. Moreover, analogue technology will play an important role in communications well into the 21st century. Covering the principles behind analogue and digital communication systems, this book takes a less mathematical approach than is often found at this level. It begins with basic principles such as information systems, data compression and error detection before moving on to more advanced topics such as Pulse Code Modulation systems and digital microwave systems. Data protocols are also given so that the reader can gain a good understanding of more complex communication systems. 'Analogue and Digital Communication Techniques' has been designed for students studying HND electronic communication courses but will also be useful to junior undergraduates on similar courses. Some knowledge of basic elctronics is assumed. Audience: Undergraduate and HND students of electronic communications. Further education students of telecommunications, data communications and mechatronics. Front Cover......Page 1 Analogue and Digital Communication Techniques......Page 4 Copyright Page......Page 5 Contents......Page 6 About the author......Page 14 Acknowledgements......Page 16 1.2 Frequencies......Page 18 1.4 Analogue signal......Page 19 1.5 Digital signal......Page 20 1.6 Waveforms......Page 21 1.7 Measurement of signal level......Page 25 1.8 Review questions......Page 30 2.2 Frequency band classifications......Page 32 2.4 Amplitude modulation......Page 34 2.5 Frequency division multiplexing......Page 41 2.6 Modulation depth......Page 45 2.7 Practical circuits......Page 52 2.8 Angle modulation......Page 56 2.10 Review questions......Page 62 3.2. Spread spectrum systems......Page 63 3.5 Pseudorandom code generators, scramblers and descramblers......Page 64 3.6 Types of spread spectrum techniques......Page 67 3.7 Advantages and disadvantages of spread spectrum techniques......Page 74 3.8 Review questions......Page 75 4.1 Introduction......Page 76 4.2 Amplitude shift key modulation......Page 77 4.3 Frequency shift key modulation......Page 78 4.4 Phase shift key modulation......Page 83 4.5 Sixteen-quadrature amplitude modulation......Page 93 4.6 Bandwidths......Page 98 4.7 Differential phase modulation......Page 100 4.8 Review questions......Page 112 5.2 Time division multiplexing......Page 114 5.3 Principle of operation......Page 115 5.4 Recommended standards......Page 117 5.5 The 30/32-channel CEPT PCM system......Page 118 5.6 Aliasing distortion......Page 121 5.7 Quantising and encoding......Page 123 5.8 The 30/32-channel CEPT PCM system operation......Page 133 5.9 Importance of frame and multiframe alignment......Page 138 5.10 Alarms......Page 139 5.11 Dependent regenerative repeaters......Page 141 5.12 Power feeding......Page 142 5.13 Review questions......Page 143 6.2 Internal noise......Page 144 6.3 External noise......Page 149 6.4 System performance......Page 150 6.5 Noise figure/noise factor......Page 151 6.6 Effective noise temperature......Page 158 6.8 Review questions......Page 161 7.2 Amplitude distortion......Page 163 7.3 Frequency distortion......Page 164 7.4 Amplitude and frequency distortion......Page 165 7.6 Effects of noise......Page 166 7.6 Review questions......Page 171 8.1 Introduction......Page 172 8.2 Entropy......Page 173 8.3 Causes of errors on digital signals......Page 175 8.4 Probability of bit error rate......Page 176 8.5 Shannon and Hartley capacity theorem......Page 181 8.6 Comparison of unipolar and bipolar bit streams......Page 185 8.7 Review questions......Page 186 9.2 Asynchronous and synchronous transmission......Page 187 9.3 Codes used on computers......Page 188 9.4 Huffmann coding......Page 190 9.5 Hamming coding......Page 196 9.6 Review questions......Page 201 10.2 Error detection using parity bits......Page 202 10.3 Block check codes......Page 207 10.4 Frame check sequence or cyclic redundancy check......Page 210 10.5 The CRC process......Page 213 10.6 Convolutional encoding......Page 220 10.7 Review questions......Page 247 11.2 Requirements of line and interface codes......Page 248 11.3 Non-return to zero codes......Page 249 11.4 Return to zero (RZ)......Page 252 11.5 The phase-encoded group......Page 257 11.6 Pulse modulation......Page 260 11.7 Frequency distribution......Page 262 11.8 Review questions......Page 263 12.2 Message transfer and message switching......Page 264 12.3 Protocol Categories and Operation......Page 265 12.4 Types of protocols......Page 266 12.5 The International Standards Organisation seven-layer model......Page 268 12.6 Functions of the different layers......Page 269 12.8 Recommended interfaces......Page 272 12.10 Review questions......Page 295 Answers to review questions......Page 296 Bibliography......Page 305 Index......Page 306