1. Introduction.- 1.1 Comparison of Infrared and Radio Communications.- 1.2 The Wireless Infrared Channel.- 1.3 History of Wireless Infrared Communications.- 1.4 A High-Speed Wireless LAN.- 1.5 Optoelectronic Components.- 1.6 Outline.- 2. Link Analysis and Optics Design.- 2.1 Introduction.- 2.2 Thin-Film Optical Filters.- 2.3 Truncated Spherical Concentrators.- 2.4 Joint Optimization of Transmitter and Filter.- 2.5 Summary and Conclusions.- 3. Receiver Design.- 3.1 Introduction.- 3.2 Limitations on Photodetector Bandwidth.- 3.3 Analysis of Current-Feedback Pair.- 3.4 Optimal Filtering for Quadratic Noise Spectrum.- 3.5 Choosing the Right Transistor.- 3.6 Design Procedures.- 3.7 Optional Design Embellishments.- 3.8 Summary and Conclusions.- 4. Modeling Multipath Dispersion.- 4.1 Introduction.- 4.2 Models for Diffuse Reflectors and Transmitters.- 4.3 Multiple-Bounce Impulse Response.- 4.4 Simulation and Experimental Results.- 4.5 Multipath-Induced Power Penalty.- 4.6 Summary.- 5. Modulation and Equalization.- 5.1 Intensity Modulation and Direct Detection.- 5.2 Binary Modulation.- 5.3 Multi-Level Modulation.- 5.4 Discussion.- 5.5 ML Sequence Detection and Equalization for PPM.- 5.6 Coherent Optical Communication.- 5.7 Summary.- 6. System-Level Issues.- 6.1 Introduction.- 6.2 Single-Cell Architectures.- 6.3 Overlapping Cells.- 6.4 Summary.- 7. Conclusions and Future Work.- 7.1 Conclusions.- 7.2 Future Work.- References.- A. Power Efficiency on the Linear Gaussian-Noise Channel.