Smart Antenna Systems and Wireless LANs

224 Pages·1999·6.88 MB·English

by  Garret Okamoto

SMART ANTENNA SYSTEMS
AND WIRELESS LANS
THE KLUWER INTERNATIONAL SERIES IN ENGINEERING
AND COMPUTER SCIENCE
SMART ANTENNA SYSTEMS
AND WIRELESS LANS
GARRET T. OKAMOTO
Assistant Professor and W. J. Nicholson Fellow
Department of Electrical Engineering
Santa Clara University
Santa Clara, CA 95053
USA
KLUWER ACADEMIC PUBLISHERS
NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW
eBookISBN: 0-306-47323-2
Print ISBN: 0-792-38335-4
©2002 Kluwer Academic Publishers
New York, Boston, Dordrecht, London, Moscow
All rights reserved
No part of this eBook may be reproduced or transmitted in any form or by any means, electronic,
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Created in the United States of America
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This book is dedicated to my parents, Matsuo and Betty Okamoto
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Table of Contents
Preface xi
Chapter 1. Introduction 1
1.1 Smart Antenna Systems . . . . . . . . . . . . . . . . . . . . . 1
1.2 Rapid Growth of Wireless LAN Systems . . . . . . . . . . . . 2
1.3 IEEE 802.11 and the Smart Wireless LAN System . . . . . . 4
Chapter 2. Background for Smart Antenna Systems 7
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Spatial Signature Definition . . . . . . . . . . . . . . . . . . . 7
2.3 Direction-of-Arrival Estimation . . . . . . . . . . . . . . . . . 11
2.4 Beamforming Techniques for Downlink . . . . . . . . . . . . . 11
Chapter 3. IEEE 802.11 Wireless LAN Standard 17
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2 Background on the IEEE 802.11 Wireless LAN Standard . . . 17
3.3 MAC Layer ofthe 802.11 System . . . . . . . . . . . . . . . . 19
3.3.1 The Challenges of Wireless Networking . . . . . . . . . 19
3.3.2 Protocol Design Objectives for IEEE 802.11 . . . . . . 28
3.3.3 The 802.11 Distributed Coordination Function (DCF)
and Point Coordination Function (PCF) . . . . . . . . 31
3.3.4 The 802.11 Power Saving Mechanism . . . . . . . . . . 34
3.3.5 The 802.11 Network Synchronization . . . . . . . . . . 37
3.3.6 The 802.11 Network Operation . . . . . . . . . . . . . . 39
3.3.7 Operation of the 802.11 DCF. . . . . . . . . . . . . . . 42
3.3.8 Operation of the 802.11 PCF . . . . . . . . . . . . . . . 43
3.3.9 Smart Antenna Systems and the 802.11 MAC Protocol 44
3.4 PHY Layer of the 802.11 System . . . . . . . . . . . . . . . . 46
3.5 Examples of Current Wireless LAN Products . . . . . . . . . 50
3.5.1 The Lucent WaveLAN DSSS System . . . . . . . . . . 50
3.5.2 The Proxim RangeLAN FHSS System . . . . . . . . . . 52
3.5.3 The RadioLAN BackboneLINK Narrow Band System . 54
3.5.4 The JVC Office LAN IR System . . . . . . . . . . . . . 56
Chapter 4. Smart Wireless LAN System Design 59
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.2 SWL Media Access Control Design . . . . . . . . . . . . . . . 60
4.3 SWL Physical Layer Design . . . . . . . . . . . . . . . . . . . 63
4.4 SWL Dynamic Slot Assignment Algorithms . . . . . . . . . . 68
4.5 SWL Timing Synchronization Algorithms . . . . . . . . . . . 70
Chapter 5. Experimental Setup for Smart Antenna Sys-
tems 79
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2 900 MHz Testbed . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2.1 Antenna Array . . . . . . . . . . . . . . . . . . . . . . . 82
5.2.2 RF/IF Unit . . . . . . . . . . . . . . . . . . . . . . . . 83
5.2.3 Distribution Boxes . . . . . . . . . . . . . . . . . . . . 83
5.2.4 MUX/DEMUX Boxes . . . . . . . . . . . . . . . . . . . 85
5.2.5 High Speed I/O boards and Sparc 10 Workstation . . . 85
5.2.6 Stability of the Smart Antenna Testbed . . . . . . . . 87
5.3 1.8 GHz Base Station . . . . . . . . . . . . . . . . . . . . . . . 87
5.3.1 Transmit/Receive Board . . . . . . . . . . . . . . . . . 89
5.3.2 SHARC Board . . . . . . . . . . . . . . . . . . . . . . 92
5.3.3 Vocoders and Telephone Handsets . . . . . . . . . . . . 93
5.3.4 Backplane . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.3.5 Antenna Array . . . . . . . . . . . . . . . . . . . . . . . 96
5.4 1.8 GHz Handset . . . . . . . . . . . . . . . . . . . . . . . .. 96
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5.4.1 Transmit/Receive Channel . . . . . . . . . . . . . . . . 96
5.4.2 DSP Chip . . . . . . . . . . . . . . . . . . . . . . . . . 98
5.4.3 Handset Antenna . . . . . . . . . . . . . . . . . . . . . 98
5.5 Experimental Environment . . . . . . . . . . . . . . . . . . . . 98
5.6 Low Earth Orbit Satellite Emulation . . . . . . . . . . . . . . 99
Chapter 6. Experimental Results for Smart Antenna Sys-
tems 105
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
6.2 Calculation ofSpatial Signature Variations . . . . . . . . . . . 106
6.3 Spatial Signature Stability for Stationary Users . . . . . . . . 107
6.4 Spatial Signature Variation with Frequency Shift . . . . . . . 113
6.5 Spatial Signature Variation with Displacement . . . . . . . . . 113
6.6 Spatial Signature Correlation for Closely Spaced Transmitters 119
6.7 Spatial Signature Variation Due to Small Displacement in Dif-
ferent Multipath Environments . . . . . . . . . . . . . . . . . 120
6.8 Multipath Angle Spread . . . . . . . . . . . . . . . . . . . . . 125
6.9 Feasibility ofDownlink Beamforming . . . . . . . . . . . . . . 130
6.10 Fading Reduction and Diversity Gain . . . . . . . . . . . . . . 133
6.11 Beamforming Algorithms for SIR Improvement . . . . . . . . 141
6.12 Low Earth Orbit Satellite Emulation Results . . . . . . . . . 147
6.13 Summary ofExperimental Results . . . . . . . . . . . . . . . 153
Chapter 7. Computer Simulation Results 157
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
7.2 SIR Performance for Beamforming Algorithms . . . . . . . . . 157
7.3 Dynamic Slot Allocation for Worst-Case SINR . . . . . . . . . 161
7.4 Dynamic Slot Allocation for Capacity Increase . . . . . . . . . 166
7.5 Timing Synchronization Results . . . . . . . . . . . . . . . . . 171
7.6 Physical Layer Simulation Results . . . . . . . . . . . . . . . . 179
7.7 Media Access Control Layer Simulation Results . . . . . . . . 185
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