Wireless Optical Communication Systems - Hranilovic, Steve

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Résumé :
The use of optical free-space emissions to provide indoor wireless com- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary - volving such far flung areas such as optics design? indoor propagation studies? electronics design? communications systems design amongothers. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic n- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel. Additionally? the elegant design meth- ologies developed for electrical channels are not directly applicable due to the amplitude constraints of the optical intensity channel. This text is devoted to presenting optical intensity signalling techniques which are spectrally efficient? i. e. ? techniques which exploit careful pulse design or spatial degrees of freedom to improve data rates on wireless optical channels. The material presented here is complementary to both the comprehensive work of Barry [2] and to the later book by Otte et al. [3] which focused prim- ily on the design of the optical and electronic sub-systems for indoor wireless optical links. The signalling studies performed in these works focused p- marily on the analysis of popular signalling techniques for optical intensity channels and on the use of conventional electrical modulation techniques with some minor modifications (e. g. ? the addition of a bias).

Sommaire:
Part I Introduction. 1. INTRODUCTION. 1.1 A Brief History of Wireless Optical Communications. 1.2 Overview. 2. WIRELESS OPTICAL INTENSITY CHANNELS. 2.1 Wireless Optical Intensity Channels. 2.2 Optoelectronic Components. 2.3 Noise. 2.4 Channel Topologies. 2.5 Summary. 3. AN INTRODUCTION TO OPTICAL INTENSITY SIGNALLING. 3.1 Communication System Model. 3.2 Bandwidth. 3.3 Example Modulation. 3.4 The Communication System Design Problem. Part II Signalling Design. 4. OPTICAL INTENSITY SIGNAL SPACE MODEL. 4.1 Signal Space of Optical Intensity Signals. 4.2 Examples. 4.3 Conclusions. 5. LATTICE CODES. 5.1 Definition of Lattice Codes. 5.2 Constellation Figure of Merit, Gain. 5.3 Baseline Constellation. 5.4 Spectral Considerations. 5.5 Gain versus a Baseline Constellation. 5.6 Continuous Approximation to Optical Power Gain. 5.7 Coding Gain. 5.8 Shaping Gain. 5.9 Shaping Gain: Expression. 5.10 Shaping Gain: Peak-Symmetric Schemes. 5.11 Opportunistic Secondary Channels. 5.12 Example Lattice Codes. 5.13 Conclusions. 6. CHANNEL CAPACITY. 6.1 Background. 6.2 Problem Definition. 6.3 Bandwidth Constraint. 6.4 Upper bound on Channel Capacity. 6.5 Lower bound on Channel Capacity. 6.6 Examples and Discussion. 6.7 Conclusions. Part III Multi-Element Techniques. 7. THE MULTIPLE-INPUT / MULTIPLE-OUTPUT WIRELESS OPTICAL CHANNEL. 7.1 Previous Work. 7.2 The MIMO Wireless Optical Channel. 7.3 Design Challenges. 7.4 Pixel-Matched System. 7.5 The Pixelated Wireless Optical Channel. 7.6 Conclusions. 8. PROTOTYPE MIMO OPTICAL CHANNEL: MODELLING & SPATIO-TEMPORAL CODING. 8.1 Experimental Prototype. 8.2 Channel Model. 8.3 Pixel-Matched Systems. 8.4 Pixelated Wireless Optical Channel. 8.5 Conclusions. 9. CONCLUSIONS AND FUTURE DIRECTIONS. 9.1 Conclusions. 9.2 Future Work