Smart Antenna Engineering For a complete listing of recent titles in theArtech House Mobile Communications Series,turn to the back of this book. Smart Antenna Engineering Ahmed El Zooghby artechhouse.com Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the U.S. Library of Congress. British Library Cataloguing in Publication Data El Zooghby, Ahmed Smart antenna engineering.—(Artech House mobile communications series) 1. Antennas (Electronics) 2. Software radio I. Title 621.3’824 ISBN-10: 1-58053-515-1 Cover design by Yekaterina Ratner The material covered in this book represents the views of the author, and does not necessarily reflect those of QUALCOMM Incorporated unless it is so indicated. © 2005 ARTECH HOUSE, INC. 685 Canton Street Norwood, MA 02062 Allrightsreserved.PrintedandboundintheUnitedStatesofAmerica.Nopartofthisbookmay bereproducedorutilizedinanyformorbyanymeans,electronicormechanical,includingpho- tocopying,recording,orbyanyinformationstorageandretrievalsystem,withoutpermissionin writing from the publisher. Alltermsmentionedinthisbookthatareknowntobetrademarksorservicemarkshavebeen appropriatelycapitalized.ArtechHousecannotattesttotheaccuracyofthisinformation.Useof aterminthisbookshouldnotberegardedasaffectingthevalidityofanytrademarkorservice mark. International Standard Book Number: 1-58053-515-1 10 9 8 7 6 5 4 3 2 1 Contents Preface xiii Acknowledgments xvii 1 Introduction 1 1.1 Wireless Mobile Communications Systems 1 1.2 Global Mobile Market Growth 3 1.3 Alternatives for Meeting Data Demand 4 1.4 Technology Peak Rates and Throughput 6 1.5 Why Smart Antennas? 7 1.6 Benefits of Smart Antennas 7 1.7 Types of Smart Antennas 8 1.8 Switched and Fixed Beam Antennas 9 1.9 Adaptive Arrays 10 References 11 2 Multiple Access Techniques for 2G and 3G Systems 13 2.1 Introduction 13 2.2 Multiple Access Wireless Communications 14 2.2.1 FDMASystems 14 2.2.2 TDMASystems 15 v vi Smart Antenna Engineering 2.2.3 FrequencyReuse 16 2.2.4 CochannelInterference 18 2.2.5 CDMASystems 20 2.3 Fundamentals of CDMA 21 2.3.1 IsolatedCellCapacity 24 2.3.2 CDMACodes 25 2.3.3 IS-95CDMASystems 29 2.4 Third Generation Systems 36 2.4.1 CDMA2000 37 2.4.2 WCDMA 43 2.4.3 HSDPA 45 2.5 Basic CDMA Procedures 49 2.5.1 AcquisitionState 49 2.5.2 IdleState 52 2.5.3 AccessStateandCallSetup 52 2.5.4 TrafficorDedicatedState 53 2.6 CDMA Embedded Cell Capacity 53 2.6.1 MultipathFading 55 2.7 Coverage Versus Capacity Trade-Off 55 2.7.1 Coverage-CapacityTrade-OffintheUplink 56 2.8 Conclusion 57 References 57 SelectedBibliography 59 3 Spatial Channel Modeling 61 3.1 Introduction 61 3.2 Radio Environments and Cell Types 63 3.3 The Multipath Channel 64 3.4 Channel Characterization 65 3.5 Path Loss Models 66 3.5.1 Okumura-HataPropagationModels 66 3.6 Spatial Channel Modeling 67 3.6.1 SpatialChannelModelParameters 68 Contents vii 3.6.2 NumberofClusters 69 3.6.3 SpatialDistributionofClustersandScatterers 69 3.6.4 BaseStationAzimuthPowerSpectrumandAngleSpread 69 3.6.5 MobileStationAzimuthPowerSpectrumandAngle Spread 74 3.7 Spatial Channel Model Application in System Simulations 74 3.8 Angle Spread Impact 77 References 80 SelectedBibliography 81 4 Fixed Beam Smart Antenna Systems 83 4.1 Introduction 83 4.2 Conventional Sectorization 83 4.3 Limitations of Conventional Sectorization 88 4.4 Antenna Arrays Fundamentals 89 4.4.1 BroadsideandEnd-FireArrays 91 4.4.2 ImpactofNumberofElements 92 4.4.3 ImpactofElementSpacing 93 4.4.4 FirstNullBeamwidth 96 4.4.5 Half-PowerBeamwidth 97 4.4.6 ArrayDirectivity 99 4.4.7 ArrayGain 100 4.4.8 Trade-OffAnalysis 100 4.4.9 ImpactofElementPattern 101 4.4.10 PlanarArrays 101 4.5 Beamforming 105 4.6 The Butler Matrix 107 4.7 Spatial Filtering with Beamformers 110 4.8 Switched Beam Systems 111 4.9 Multiple Fixed Beam Systems 113 4.10 Adaptive Cell Sectorization in CDMA Systems 114 References 116 viii Smart Antenna Engineering 5 Adaptive Array Systems 117 5.1 Uplink Processing 117 5.1.1 DiversityTechniques 117 5.1.2 AngleDiversity 118 5.1.3 MaximumRatioCombining 121 5.1.4 AdaptiveBeamforming 122 5.1.5 FixedMultipleBeamsVersusAdaptiveBeamforming 130 5.2 Downlink Processing 132 5.2.1 TransmitDiversityConcepts 134 5.2.2 TransmitDiversityin3GCDMAStandards 134 5.3 Downlink Beamforming 142 5.3.1 SpatialSignature-BasedBeamforming 145 5.3.2 DOA-BasedBeamforming 146 5.3.3 MaximumSNR 147 5.4 Conclusion 149 References 151 SelectedBibliography 152 6 Smart Antenna Receivers and Algorithms for Radio Base Stations 159 6.1 Reference Signal Methods 159 6.1.1 TheLeastMeanSquareAlgorithm 159 6.1.2 TheRecursiveLeastSquaresAlgorithm 161 6.1.3 BlindAdaptiveBeamforming 161 6.1.4 LeastSquares 161 6.1.5 ConstantModulusAlgorithm 162 6.1.6 Decision-DirectedAlgorithm 162 6.1.7 CyclostationaryAlgorithms 163 6.1.8 ConjugateGradientAlgorithm 164 6.1.9 LagrangeMultiplierMethod 167 6.1.10 ComparisonofAdaptiveAlgorithms 169 6.2 Neural NetworkDOA-Based Beamforming 170 6.2.1 GenerationofTrainingData 174 6.2.2 PerformancePhaseoftheRBFNN 174 Contents ix 6.3 Angle Spread Impact on Optimum Beamforming 175 6.4 Downlink Beamforming 181 6.5 Vector Rake Receivers 182 6.6 Channel Estimation 183 6.7 Beamforming 184 6.8 Conclusion 185 References 186 7 Coverage and Capacity Improvements in 3G Networks 191 7.1 Introduction 191 7.2 Link Budgets and Coverage 192 7.2.1 MobileStationParameters 192 7.2.2 BaseStationParameters 193 7.2.3 SystemParameters 193 7.2.4 Margins 193 7.2.5 OtherParameters 193 7.2.6 FadeMargin 194 7.2.7 Confidence(CellArea) 195 7.2.8 CDMATrafficLoading 196 7.3 Voice Services 197 7.3.1 UplinkBudgets 198 7.3.2 DownlinkBudgets 198 7.4 Data Applications 203 7.5 Limiting Links for Coverage and Capacity 209 7.5.1 CoverageLimitedScenarios 210 7.5.2 CapacityLimitedScenarios 211 7.6 Smart Antennas Impact on Uplink Coverage and Capacity 211 7.6.1 SmartAntennaImpactonDownlinkCapacity 216 7.7 Conclusions 226 References 227