Wimax Rf Systems Engineering (Artech House Mobile Communications Library)

340 Pages·2009·4.19 MB·English

by  Abate. Zerihun

WiMAX RF Systems Engineering
For a list of titles in the
Artech House Mobile Communications Series,
turn to the back of this book.
WiMAX RF Systems Engineering
Zerihun Abate
artechhouse.com
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Cover design by Igor Valdman
ISBN 13: 978-1-59693-975-2
© 2009ARTECHHOUSE
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10 9 8 7 6 5 4 3 2 1
To my mother, Gete Ayele,
whose love and prayers sustained me through the years,
and to my late father, Abate Negatu,
who brought me up with love and instilled confidence in me.

Contents
Preface xvii
Part I: Introduction 1
1 Introduction 3
1.1 WiMAX System 4
1.2 WiMAX and Related Standards 6
1.2.1 WiMAX802.16d(802.16-2004) 6
1.2.2 WiMAX802.16e(802.16-2005) 8
1.2.3 WiMAX802.16/d/eandRelatedStandardsSummary 8
1.2.4 Upcoming802.16mStandard 8
1.3 Range and Spectrum Efficiency Summary 10
1.4 WiMAX Spectrum Worldwide 11
1.5 What Is OFDM? 11
1.6 The Key Features of WiMAX 11
1.6.1 IntersymbolInterference(ISI) 12
1.6.2 FrequencySelectiveFading 13
1.6.3 AdaptiveModulationandCoding(AMC) 14
1.6.4 VeryHighDataRate 14
vii
viii WiMAX RF Systems Engineering
1.6.5 DelayVersusDopplerSpreadsandFrequencyDiversity 15
1.7 WiMAX Transceiver 15
1.8 OFDM Signal Generation 15
1.9 OFDM Challenges and Mitigations 16
References 18
2 OFDM Flavors, ISI, Doppler, Rayleigh, and Fading 19
2.1 OFDM Flavors 19
2.2 Subchannelization 21
2.3 Scalable OFDMA, Doppler Shift, and ISI 22
2.3.1 DopplerSpread 23
2.4 Coherence Bandwidth 23
2.5 ISI, Delay, and Fading 24
2.5.1 SelectiveFrequencyFadingDerivation 25
2.5.2 Frequency-SelectiveFadingandFlatFading 26
2.5.3 RayleighFadingSimulator 29
2.5.4 FadeRateandDopplerEffect—SlowFadingandFast
FadingSpread 30
References 32
Part II: Technical Background 33
3 Modulation 35
3.1 Overview 35
3.2 Digital Modulation (Representing Digital Bits with
Analog Signals) 36
3.3 Encoding and Decoding Phase Information 40
3.4 Quadrature Amplitude Modulation 44
3.5 Multicarrier Modulation Transmissions and OFDM 46
3.6 Adaptive Modulation and Coding (AMC) 48
References 48
Contents ix
4 RF Propagations, Measurements, and Models 49
4.1 RF Propagation 49
4.1.1 CellSiteDefinitions 49
4.1.2 FreeSpacePathLoss 50
4.1.3 ConfidenceLevel 51
4.1.4 ConfidenceInterval 53
4.2 Measurements and Drive Test Considerations 54
4.3 Propagation Models 57
4.3.1 FreeSpacePathLossModel 59
4.3.2 TheOkumura-HataModel 60
4.3.3 PCSExtensiontotheHataModel 61
4.3.4 Longely-RiceModel 62
4.3.5 IndoorPropagationModel 62
References 64
5 Communication Channel Characterization 65
5.1 Gaussian Noise and Line-of-Sight and Nonline-of-Sight
Paths 65
5.2 Characterizing the Radio Environment 65
5.3 Multipaths and Doppler Shifts 68
5.4 Nyquist and Shannon-Hartley 72
5.4.1 Noise,NoiseFloor,andInterferenceDefinitions 72
5.4.2 NyquistMinimumBandwidth 73
5.4.3 Shannon-Hartley 73
5.5 Separation of Colocated Antennas 75
5.5.1 VerticalandHorizontalSeparation 75
5.6 Intermodulation 77
5.6.1 StrategiestoAvoid,Troubleshoot,andMitigateIM 78
5.7 WiMAX Versus Satellite Interference Consideration [5] 80
5.8 Interferences 81
5.8.1 AdjacentChannelInterference 81
5.8.2 DistancePathLossofGeographicSeparation 81
5.8.3 Near-End-Far-End 81