A complete and comprehensive reference on modulation and signal processing for visible light communication
This informative new book on state-of-the-art visible light communication (VLC) provides, for the first time, a systematical and advanced treatment of modulation and signal processing for VLC. Visible Light Communications: Modulation and Signal Processing offers a practical guide to designing VLC, linking academic research with commercial applications.
In recent years, VLC has attracted attention from academia and industry since it has many advantages over the traditional radio frequency, including wide unregulated bandwidth, high security, and low cost. It is a promising complementary technique in 5G and beyond wireless communications, especially in indoor applications. However, lighting constraints have not been fully considered in the open literature when considering VLC system design, and its importance has been underestimated. That’s why this book - written by a team of experts with both academic research experience and industrial development experience in the field - is so welcome. To help readers understand the theory and design of VLC systems, the book:
- Details many modern techniques on both modulation and signal processing aspects
- Links academic research with commercial applications in visible light communications as well as other wireless communication systems
- Combines theoretical rigor with practical examples in presenting optical camera communication systems
Visible Light Communications: Modulation and Signal Processing serves as a useful tool and reference book for visible light communication professionals, as well as wireless communication system professionals and project managers. It is also an important guide for undergraduates and graduates who want to conduct research in areas of wireless communications.
Table of Contents
Preface ix
1 Introduction to Visible Light Communications 1
1.1 History 1
1.2 Advantages and applications 4
1.3 Overview of modulation and signal processing 6
1.4 Standards 10
2 Visible Light Communications: Channel and Capacity 17
2.1 LED characteristics 17
2.1.1 Operation principles 19
2.1.2 LED nonlinearity 21
2.2 LED lighting constraints 23
2.2.1 Dimming control 23
2.2.2 Chromaticity control 25
2.2.3 Flicker-free communication 26
2.3 Photodiode characteristics 27
2.4 Propagation links 29
2.4.1 LOS link 31
2.4.2 NLOS link 32
2.5 Noise in VLC systems 33
2.6 Channel capacity 35
2.6.1 Channel models 36
2.6.2 Capacity bounds for free-space optical intensity channel 38
2.6.3 Capacity bounds for discrete-time Poisson channel 47
2.6.4 Capacity bounds for improved free-space intensity channel 50
2.7 Conclusion 53
3 Single Carrier/Carrierless Modulation and Coding 57
3.1 Pulse amplitude modulation 57
3.2 Pulse position modulation 62
3.3 Carrierless amplitude phase modulation 68
3.3.1 Principles of CAP 69
3.3.2 Multidimensional CAP 73
3.4 Modulation and coding schemes for dimmable VLC 77
3.4.1 Modulation schemes for dimmable VLC 78
3.4.2 Coding schemes for dimmable VLC 80
3.5 Conclusion 82
4 Multicarrier Modulation 89
4.1 Optical OFDM for visible light communications 90
4.1.1 DC-biased optical OFDM 90
4.1.2 ACO-OFDM and PAM-DMT 93
4.1.3 Unipolar OFDM 97
4.1.4 Performance comparison 98
4.2 Performance enhancement for optical OFDM 99
4.2.1 DC bias and scaling optimization 100
4.2.2 LED nonlinearity mitigation 103
4.2.3 PAPR reduction 107
4.3 Spectrum- and power-efficient optical OFDM 111
4.3.1 Hybrid optical OFDM 111
4.3.2 Enhanced U-OFDM 118
4.3.3 Layered ACO-OFDM 121
4.4 Optical OFDM under lighting constraints 131
4.4.1 Pulse width modulation 133
4.4.2 Reverse polarity optical OFDM 136
4.4.3 Asymmetrical hybrid optical OFDM 137
4.5 Conclusion 142
5 Multicolor Modulation 147
5.1 Color shift keying 147
5.1.1 Constellation 148
5.1.2 Color calibration 151
5.1.3 Constellation optimization 152
5.1.4 CSK with Quad-LED 155
5.2 CSK with coded modulation 156
5.3 Wavelength division multiplexing with predistorion 159
5.3.1 System model 160
5.3.2 Receiver-side predistortion 161
5.3.3 Performance evaluation 164
5.4 Conclusion 166
6 Optical MIMO 169
6.1 Non-imaging optical MIMO techniques 170
6.1.1 Channel response 170
6.1.2 Optical MIMO techniques 171
6.1.3 Performance comparison 175
6.2 Imaging optical MIMO techniques 178
6.3 Multiuser precoding techniques 180
6.4 Optical MIMO-OFDM 190
6.4.1 DCO-OFDM-based MU-MIMO VLC 193
6.4.2 ACO-OFDM-based MU-MIMO VLC 194
6.4.3 Performance evaluation 195
6.5 Conclusion 197
7 Signal Processing and Optimization 201
7.1 Sum-rate maximization for the multi-chip-based VLC system 201
7.1.1 System model 202
7.1.2 Constraints on illumination and communication 203
7.1.3 Sum-rate maximization 205
7.1.4 Performance evaluation 208
7.2 Heterogeneous VLC-WiFi optimization 212
7.2.1 System model 213
7.2.2 Efficient VHO scheme 214
7.2.3 Performance evaluation 219
7.3 Signal estimation and modulation design for VLC with SDGN 223
7.3.1 Signal estimation for VLC with SDGN 223
7.3.2 Suboptimal estimation for VLC with SDGN 228
7.3.3 Efficient signal design for VLC with SDGN 230
7.4 Conclusion 236
8 Optical Camera Communication: Fundamentals 239
8.1 Why OCC 239
8.1.1 Wide spectrum 240
8.1.2 Image-sensor-based receiver 240
8.1.3 Advantages of image sensor receiver 241
8.1.4 Challenges for OCC implementation 244
8.2 OCC applications: beyond imaging 246
8.2.1 Indoor localization 246
8.2.2 Intelligent transportation 249
8.2.3 Screen–camera communication 250
8.2.4 Privacy protection 251
8.3 Fundamentals of OCC 252
8.3.1 Optical imaging system 252
8.3.2 Image sensor architecture 253
8.3.3 Noise characteristics in the image-sensor-based receiver 261
8.3.4 Channel model for OCC 270
8.4 Capacity bounds for OCC 275
8.4.1 SISO-OCC channel capacity with M-SDGN 275
8.4.2 Capacity-achieving probability measurement with M-SDGN 276
8.4.3 Capacity of imaging optical MIMO systems with bounded inputs 280
8.5 Outage capacity for OCC with misalignment 284
8.6 Conclusion 285
9 Optical Camera Communication: Modulation and System Design 291
9.1 Coding and decoding 292
9.1.1 Multilevel coding and multi-stage decoding 293
9.1.2 Single-level coding and joint decoding 295
9.2 Modulation schemes 297
9.2.1 Undersampling-based modulation 298
9.2.2 Rolling shutter effect-based modulation 301
9.2.3 Spatial OFDM 304
9.2.4 Spatial WPDM 307
9.3 System impairment factors 309
9.3.1 Impairment factors in spatial OFDM 309
9.3.2 Impairment mitigation techniques 322
9.4 Synchronization in OCC 329
9.4.1 Synchronization challenges 329
9.4.2 Per-line tracking and inter-frame coding 331
9.4.3 Rateless coding 333
9.5 OCC system experimental platform 336
9.5.1 Design and implementation of a real-time OCC system 336
9.6 Conclusion 347
10 Index 353
