现代通信系统 应用MATLABPDF电子书下载

1 Signals and Linear Systems 1

1.1 Preview 1

1.2 Fourier Series 1

1.2.1 Periodic Signals and LTI Systems 12

1.3 Fourier Transforms 17

1.3.1 Sampling Theorem 22

1.3.2 Frequency-Domain Analysis of LTI Systems 28

1.4 Power and Energy 32

1.5 Lowpass Equivalent of Bandpass Signals 35

2 Random Processes 47

2.1 Preview 47

2.2 Generation of Random Variables 47

2.3 Gaussian and Gauss-Markov Processes 52

2.4 Power Spectrum of Random Processes and White Processes 59

2.5 Linear Filtering of Random Processes 64

2.6 Lowpass and Bandpass Processes 71

3 Analog Modulation 81

3.1 Preview 81

3.2 Amplitude Modulation(AM) 81

3.2.1 DSB-AM 82

3.2.2 Conventional AM 92

3.2.3 SSB-AM 99

3.3 Demodulation of AM Signals 104

3.3.1 DSB-AM Demodulation 105

3.3.2 SSB-AM Demodulation 112

3.3.3 Conventional AM Demodulation 117

3.4 Angle Modulation 125

4 Analog-to-Digital Conversion 142

4.1 Preview 142

4.2 Measure of Information 143

4.2.1 Noiseless Coding 144

4.3 Quantization 149

4.3.1 Scalar Quantization 149

4.4 Pulse-Code Modulation 158

4.4.1 Uniform PCM 158

4.4.2 Nonuniform PCM 164

5 Baseband Digital Transmission 175

5.1 Preview 175

5.2 Binary Signal Transmission 175

5.2.1 Optimum Receiver for the AWGN Channel 176

5.2.2 Monte Carlo Simulation of a Binary Communication System 183

5.2.3 Other Binary Signal Transmission Methods 186

5.2.4 Signal Constellation Diagrams for Binary Signals 195

5.3 Multiamplitude Signal Transmission 197

5.3.1 Signal Waveforms with Four Amplitude Levels 198

5.3.2 Optimum Receiver for the AWGN Channel 199

5.3.3 Signal Waveforms with Multiple Amplitude Levels 205

5.4 Multidimensional Signals 209

5.4.1 Multidimensional Orthogonal Signals 209

5.4.2 Biorthogonal Signals 218

6 Digital Transmission Through Bandlimited Channels 228

6.1 Preview 228

6.2 The Power Spectrum of a Digital PAM Signal 228

6.3 Characterization of Bandlimited Channels and Channel Distortion 233

6.4 Characterization of Intersymbol Interference 244

6.5 Communication System Design for Bandlimited Channels 249

6.5.1 Signal Design for Zero ISI 250

6.5.2 Signal Design for Controlled ISI 255

6.5.3 Precoding for Detection of Partial Response Signals 259

6.6 Linear Equalizers 264

6.6.1 Adaptive Linear Equalizers 273

6.7 Nonlinear Equalizers 278

7 Digital Transmission via Carrier Modulation 286

7.1 Preview 286

7.2 Carrier-Amplitude Modulation 286

7.2.1 Demodulation of PAM Signals 289

7.3 Carrier-Phase Modulation 292

7.3.1 Phase Demodulation and Detection 296

7.3.2 Differential Phase Modulation and Demodulation 302

7.4 Quadrature Amplitude Modulation 309

7.4.1 Demodulation and Detection of Q AM 310

7.4.2 Probability of Error for QAM in an AWGN Channel 312

7.5 Carrier-Frequency Modulation 317

7.5.1 Frequency-Shift Keying 317

7.5.2 Demodulation and Detection of FSK Signals 319

7.5.3 Probability of Error for Noncoherent Detection of FSK 324

7.6 Synchronization in Communication Systems 328

7.6.1 Carrier Synchronization 329

7.6.2 Clock Synchronization 335

8 Channel Capacity and Coding 344

8.1 Preview 344

8.2 Channel Model and Channel Capacity 344

8.2.1 Channel Model 345

8.2.2 Channel Capacity 345

8.3 Channel Coding 356

8.3.1 Linear Block Codes 359

8.3.2 Convolutional Codes 373

9 Spread Spectrum Communication Systems 392

9.1 Preview 392

9.2 Direct-Sequence Spread Spectrum Systems 393

9.2.1 Signal Demodulation 395

9.2.2 Probability of Error 397

9.2.3 Two Applications of DS Spread Spectrum Signals 398

9.3 Generation of PN Sequences 404

9.4 Frequency-Hopped Spread Spectrum 410

9.4.1 Probability of Error for FH Signals 411

9.4.2 Use of Signal Diversity to Overcome Partial-Band Interference 416

References 423

Index 425