Optical wireless communications system and channel modelling with matlab®

CRC Press Optical Wireless Communications System and Channel Modelling with MATLAB® Ay Z... Optical Wireless Communications... Optical Wireless Communications System and Channel

CRC Press Optical Wireless

Communications

System and Channel Modelling

with MATLAB®

Ay

Z Ghassemlooy

W Popoola

S Rajbhandari

Optical Wireless

Communications

Optical Wireless

Communications

System and Channel Modelling

with MATLAB®

Z Ghassemlooy

W Popoola

S Rajbhandari

MATLAB® and Simulink’ are trademarks of The MathWorks, Inc and are used with permission The MathWorks does not warrant the accuracy of the text or exercises in this book This book's use or discussion of MATLAB" and Simulink’ software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of the MATLAB" and Simulink" software

Cover credit: Z Ghassemlooy and D Wu of Northumbria University

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Version Date: 20120615

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Library of Congress Cataloging-in-Publication Data

Ghassemlooy, Zabih

Optical wireless communications : system and channel modelling with MATLAB / Z

Ghassemlooy, W Popoola, S Rajbhandari p.em

Includes bibliographical references and index

ISBN 978-1-4398-5188-3 (hardback)

1 Optical communications 2 Signal processit

3 Free space optical interconnects 4

Signals and signaling Mathematical models.5 MATLAB 1 Popoola, W II Rajbhandari, S

ML Title

'TK5103.592.F73G46 2012

.621.382'7028553 dc23 2012006800 Visit the Taylor & Francis Web site at

http://www.taylorandfrancis.com

Dedicated to Azar, Odunayo and Kanchan

Contents

Chpter 1 Introduction: Optical Wireless Communication Systems

Wireless Access Scheme:

A Brief History of OWC

1.3 OWC/Radio Comparison

1.4 Link Configuration

1.5 OWC Application Areas

1.6 Safety and Regulations

1.6.1 | Maximum Permissible Exposures 25

17 OWC Challenges 25

Chpter 2 Optical Sources and Detectors

Light Sources

Light-Emitting Diode

23

32.1 222) 2.2.3 2.2.4

LED Structure

Planar and Dome LED

Edge-Emitting LED

LED Efficiencies

Internal Quantum Efficiency External Quantum Efliciemcy

Power Efficiency

Luminous Efficiency

LED Modulation Bandwidith

Operating Principle of a Laser

Stimulated Emission

2.3.2.1 Population Inversion

Optical Feedback and Laser Oscillation

Basic Semiconductor Laser Structuree

The Structure of Common Laser Type:

2.3.5.1 Fabry-Perot Laser

2.3.5.2 Distributed Feedback Lasetr

viii

Chapter 3

Contents 2.3.5.3 Vertical-Cavity Surface-Emitting Laser

2.3.5.4 Superluminescent Diodes

2.3.6 Comparison of LED and Laser Diodes

2.4 Photodetectors

2.4.1 PIN Photodetectoi

2.4.2 APD Photodetector

2.5 _ Photodetection Technique:

2.5.1 Direct Detection

2.5.2 Coherent Detection

2.5.2.1 Heterodyne Detection 2.5.2.2 Homodyne Detection 2.6 Photodetection Noise

2.6.1 Photon Fluctuation Noise

2.6.2 Dark Current and Excess Noise

2.6.3 Background Radiation

2.6.4 Thermal Noise

2.6.5 Intensity Noise

2.6.6 Signal-to-Noise Ratio

2.7 Optical Detection Statistics

References

Channel Modelling

3.1

3.2

33

Indoor Optical Wireless Communication Channel

3.1.1 LOS Propagation Model

3.1.2 Non-LOS Propagation Model

3.1.3 Ceiling Bounce Model

3.1.4 Hayasaka-Ito Model

3.1.5 Spherical Model

Artificial Light Interference 3.2.1 Incandescent Lamp

3.2.2 Fluorescent Lamp Driven by Conventional Ballast

3.2.3 Fluorescent Lamp Model

Outdoor Channel

3.3.1 Atmospheric Channel Los:

3.3.2 Fog and Visibility 3.3.3 Beam Divergence

3.3.4 Optical and Window Loss

3.3.5 Pointing Loss 3.3.6 The Atmospheric 3.3.6.1 Log-Normal Turbulence Model 3.3.6.2 Spatial Coherence in Weak Turbulence 3.3.6.3 Limit of Log-Normal Turbulence Model 13 3.3.6.4 The Gamma-Gamma Turbulence Model

3.3.6.5 The Negative Exponential Turbulence

Model