Fundamentals-of-wimax-understanding-broadband-wireless-networking

Praise for Fundamentals of WiMAX
This book is one of the most comprehensive books I have reviewed … it is a must
read for engineers and students planning to remain current or who plan to pursue a
career in telecommunications. I have reviewed other publications on WiMAX and
have been disappointed. This book is refreshing in that it is clear that the authors
have the in-depth technical knowledge and communications skills to deliver a logically laid out publication that has substance to it.
—Ron Resnick, President, WiMAX Forum
This is the first book with a great introductory treatment of WiMAX technology. It
should be essential reading for all engineers involved in WiMAX. The high-level
overview is very useful for those with non-technical background. The introductory
sections for OFDM and MIMO technologies are very useful for those with implementation background and some knowledge of communication theory. The chapters
covering physical and MAC layers are at the appropriate level of detail. In short, I
recommend this book to systems engineers and designers at different layers of the
protocol, deployment engineers, and even students who are interested in practical
applications of communication theory.
—Siavash M. Alamouti, Chief Technology Officer, Mobility Group, Intel
This is a very well-written, easy-to-follow, and comprehensive treatment of WiMAX.
It should be of great interest.
—Dr. Reinaldo Valenzuela, Director of Wireless Research, Bell Labs
Fundamentals of WiMAX is a comprehensive guide to WiMAX from both industry
and academic viewpoints, which is an unusual accomplishment. I recommend it to
anyone who is curious about this exciting new standard.
—Dr. Teresa Meng, Professor, Stanford University,
Founder and Director, Atheros Communications
Andrews, Ghosh, and Muhamed have provided a clear, concise, and well-written text
on 802.16e/WiMAX. The book provides both the breadth and depth to make sense of
the highly complicated 802.16e standard. I would recommend this book to both development engineers and technical managers who want an understating of WiMAX and
insight into 4G modems in general.
—Paul Struhsaker, VP of Engineering, Chipset platforms, Motorola Mobile Device
Business Unit, former vice chair of IEEE 802.16 working group

Fundamentals of WiMAX is written in an easy-to-understand tutorial fashion. The
chapter on multiple antenna techniques is a very clear summary of this important
technology and nicely organizes the vast number of different proposed techniques into
a simple-to-understand framework.
—Dr. Ender Ayanoglu, Professor, University of California, Irvine,
Editor-in-Chief, IEEE Transactions on Communications
Fundamentals of WiMAX is a comprehensive examination of the 802.16/WiMAX
standard and discusses how to design, develop, and deploy equipment for this wireless communication standard. It provides both insightful overviews for those wanting to know what WiMAX is about and comprehensive, in-depth chapters on
technical details of the standard, including the coding and modulation, signal processing methods, Multiple-Input Multiple-Output (MIMO) channels, medium
access control, mobility issues, link-layer performance, and system-level performance.
—Dr. Mark C. Reed, Principle Researcher, National ICT Australia,
Adjunct Associate Professor, Australian National University
This book is an excellent resource for any engineer working on WiMAX systems.
The authors have provided very useful introductory material on broadband wireless
systems so that readers of all backgrounds can grasp the main challenges in
WiMAX design. At the same time, the authors have also provided very thorough
analysis and discussion of the multitudes of design options and engineering tradeoffs, including those involved with multiple antenna communication, present in
WiMax systems, making the book a must-read for even the most experienced wireless system designer.
—Dr. Nihar Jindal, Assistant Professor, University of Minnesota
This book is very well organized and comprehensive, covering all aspects of WiMAX
from the physical layer to the network and service aspects. The book also includes
insightful business perspectives. I would strongly recommend this book as a mustread theoretical and practical guide to any wireless engineer who intends to investigate the road to fourth generation wireless systems.
—Dr. Yoon Chae Cheong, Vice President, Communication Lab, Samsung
The authors strike a wonderful balance between theoretical concepts, simulation performance, and practical implementation, resulting in a complete and thorough exposition of the standard. The book is highly recommended for engineers and managers
seeking to understand the standard.
—Dr. Shilpa Talwar, Senior Research Scientist, Intel

Fundamentals of WiMAX is a comprehensive guide to WiMAX, the latest frontier
in the communications revolution. It begins with a tutorial on 802.16 and the key
technologies in the standard and finishes with a comprehensive look at the predicted performance of WiMAX networks. I believe readers will find this book
invaluable whether they are designing or testing WiMAX systems.
—Dr. James Truchard, President, CEO and Co-Founder, National Instruments
This book is a must-read for engineers who want to know WiMAX fundamentals
and its performance. The concepts of OFDMA, multiple antenna techniques, and
various diversity techniques—which are the backbone of WiMAX technology—are
explained in a simple, clear, and concise way. This book is the first of its kind.
—Amitava Ghosh, Director and Fellow of Technical Staff, Motorola
Andrews, Ghosh, and Muhamed have written the definitive textbook and reference
manual on WiMAX, and it is recommended reading for engineers and managers
alike.
—Madan Jagernauth, Director of WiMAX Access Product Management, Nortel


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Fundamentals of WiMAX


Prentice Hall Communications Engineering
and Emerging Technologies Series
Theodore S. Rappaport, Series Editor

DI BENEDETTO & GIANCOLA
DOSTERT

Understanding Ultra Wide Band Radio Fundamentals

Powerline Communications
Space–Time Wireless Channels Technologies, Standards, and QoS

DURGIN
GARG

Wireless Network Evolution: 2G to 3G

GARG

IS-95 CDMA and cdma2000: Cellular/PCS Systems Implementation

LIBERTI & RAPPAPORT
MURTHY & MANOJ
NEKOOGAR

Smart Antennas for Wireless Communications: IS-95 and Third Generation
CDMA Applications
Ad Hoc Wireless Networks: Architectures and Protocols

Ultra-Wideband Communications: Fundamentals and Applications

PAHLAVAN & KRISHNAMURTHY
PATTAN

Principles of Wireless Networks: A Unified Approach

Robust Modulation Methods and Smart Antennas in Wireless Communication

RADMANESH
RAPPAPORT

Radio Frequency and Microwave Electronics Illustrated
Wireless Communications: Principles and Practice, Second Edition

REED

Software Radio: A Modern Approach to Radio Engineering

REED

An Introduction to Ultra Wideband Communication Systems

SKLAR

Digital Communications: Fundamentals and Applications, Second Edition

STARR, SORBARA, CIOFFI, & SILVERMAN

DSL Advances

TRANTER, SHANMUGAN, RAPPAPORT, & KOSBAR Principles of Communication Systems Simulation
with Wireless Applications
VANGHI, DAMNJANOVIC, & VOJCIC The cdma2000 System for Mobile Communications:
3G Wireless Evolution
WANG & POOR

Wireless Communication Systems: Advanced Techniques for Signal Reception

Fundamentals of WiMAX
Understanding Broadband Wireless Networking

Jeffrey G. Andrews, Ph.D.
Department of Electrical and Computer Engineering
The University of Texas at Austin

Arunabha Ghosh, Ph.D.
AT&T Labs Inc.

Rias Muhamed
AT&T Labs Inc.

Upper Saddle River, NJ • Boston • Indianapolis • San Francisco
New York • Toronto • Montreal • London • Munich • Paris • Madrid
Capetown • Sydney • Tokyo • Singapore • Mexico City


Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where
those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed
with initial capital letters or in all capitals.
The authors and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any
kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in
connection with or arising out of the use of the information or programs contained herein.
The publisher offers excellent discounts on this book when ordered in quantity for bulk purchases or special sales, which
may include electronic versions and/or custom covers and content particular to your business, training goals, marketing
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For sales outside the United States, please contact:
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Library of Congress Cataloging-in-Publication Data
Andrews, Jeffrey G.
Fundamentals of WiMAX : understanding broadband wireless networking / Jeffrey G. Andrews, Arunabha Ghosh, Rias
Muhamed.
p. cm.
Includes bibliographical references and index.
ISBN 0-13-222552-2 (hbk : alk. paper)
1. Wireless communication systems. 2. Broadband communication systems. I. Ghosh, Arunabha. II. Muhamed, Rias. III.
Title.
TK5103.2.A56 2007
621.382—dc22
2006038505
Copyright © 2007 Pearson Education, Inc.
All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must
be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any
form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions,
write to:
Pearson Education, Inc.
Rights and Contracts Department
One Lake Street
Upper Saddle River, NJ 07458
Fax: (201) 236-3290
ISBN 0-13-222552-2
Text printed in the United States on recycled paper at Courier in Westford, Massachusetts.
First printing, February 2007

Dedicated to Catherine and my parents, Greg and Mary
—Jeff

Dedicated to Debolina and my parents, Amitabha and Meena
—Arunabha

Dedicated to Shalin, Tanaz, and my parents, Ahamed and Fathima
—Rias


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Contents
Foreword
Preface
Acknowledgments
About the Authors
Part I

Chapter 1

xix
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Overview of WiMAX

1

Introduction to Broadband Wireless

3

1.1 Evolution of Broadband Wireless
1.1.1 Narrowband Wireless Local-Loop Systems
1.1.2 First-Generation Broadband Systems
1.1.3 Second-Generation Broadband Systems
1.1.4 Emergence of Standards-Based Technology
1.2 Fixed Broadband Wireless: Market Drivers and Applications
1.3 Mobile Broadband Wireless: Market Drivers and Applications
1.4 WiMAX and Other Broadband Wireless Technologies
1.4.1 3G Cellular Systems
1.4.2 Wi-Fi Systems
1.4.3 WiMAX versus 3G and Wi-Fi
1.4.4 Other Comparable Systems
1.5 Spectrum Options for Broadband Wireless
1.6 Business Challenges for Broadband Wireless and WiMAX
1.7 Technical Challenges for Broadband Wireless
1.7.1 Wireless Radio Channel
1.7.2 Spectrum Scarcity
1.7.3 Quality of Service
1.7.4 Mobility
1.7.5 Portability
1.7.6 Security
1.7.7 Supporting IP in Wireless
1.7.8 Summary of Technical Challenges

1.8 Summary and Conclusions
1.9 Bibliography

xi

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5
6
8
8
10
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13
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Chapter 2

Part II

Chapter 3

Contents

Overview of WiMAX

33

2.1 Background on IEEE 802.16 and WiMAX
2.2 Salient Features of WiMAX
2.3 WiMAX Physical Layer
2.3.1 OFDM Basics
2.3.2 OFDM Pros and Cons
2.3.3 OFDM Parameters in WiMAX
2.3.4 Subchannelization: OFDMA
2.3.5 Slot and Frame Structure
2.3.6 Adaptive Modulation and Coding in WiMAX
2.3.7 PHY-Layer Data Rates
2.4 MAC-Layer Overview
2.4.1 Channel-Access Mechanisms
2.4.2 Quality of Service
2.4.3 Power-Saving Features

2.4.4 Mobility Support
2.4.5 Security Functions
2.4.6 Multicast and Broadcast Services
2.5 Advanced Features for Performance Enhancements
2.5.1 Advanced Antenna Systems
2.5.2 Hybrid-ARQ
2.5.3 Improved Frequency Reuse
2.6 Reference Network Architecture
2.7 Performance Characterization
2.7.1 Throughput and Spectral Efficiency
2.7.2 Sample Link Budgets and Coverage Range
2.8 Summary and Conclusions
2.9 Bibliography

33
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54
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59
60
60
61
63

Technical Foundations of WiMAX

65

The Challenge of Broadband Wireless Channels

67

3.1 Communication System Building Blocks
3.2 The Broadband Wireless Channel: Pathloss and Shadowing
3.2.1 Pathloss
3.2.2 Shadowing
3.3 Cellular Systems
3.3.1 The Cellular Concept

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Contents

Chapter 4

xiii

3.3.2 Analysis of Cellular Systems
3.3.3 Sectoring
3.4 The Broadband Wireless Channel: Fading
3.4.1 Delay Spread and Coherence Bandwidth
3.4.2 Doppler Spread and Coherence Time
3.4.3 Angular Spread and Coherence Distance
3.5 Modeling Broadband Fading Channels
3.5.1 Statistical Channel Models
3.5.2 Statistical Correlation of the Received Signal
3.5.3 Empirical Channel Models
3.6 Mitigation of Fading
3.6.1 Narrowband (Flat) Fading
3.6.2 Broadband Fading
3.6.3 Spread Spectrum and Rake Receivers
3.6.4 Equalization
3.6.5 The Multicarrier Concept
3.7 Summary and Conclusions
3.8 Bibliography

79
82
84
86
87
90
91
91
95
99
104
105
107
108
109
110
110
110

Orthogonal Frequency Division Multiplexing

113

4.1 Multicarrier Modulation
4.2 OFDM Basics
4.2.1 Block Transmission with Guard Intervals
4.2.2 Circular Convolution and the DFT
4.2.3 The Cyclic Prefix
4.2.4 Frequency Equalization
4.2.5 An OFDM Block Diagram

4.3 An Example: OFDM in WiMAX
4.4 Timing and Frequency Synchronization
4.4.1 Timing Synchronization
4.4.2 Frequency Synchronization
4.4.3 Obtaining Synchronization in WiMAX
4.5 The Peak-to-Average Ratio
4.5.1 The PAR Problem
4.5.2 Quantifying the PAR
4.5.3 Clipping: Living with a High PAR
4.5.4 PAR-Reduction Strategies
4.6 OFDM’s Computational Complexity Advantage
4.7 Simulating OFDM Systems

114
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140

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Chapter 5

Chapter 6

Contents

4.8 Summary and Conclusions
4.9 Bibliography

145
145

Multiple-Antenna Techniques

149

5.1 The Benefits of Spatial Diversity
5.1.1 Array Gain
5.1.2 Diversity Gain and Decreased Error Rate
5.1.3 Increased Data Rate
5.1.4 Increased Coverage or Reduced Transmit Power
5.2 Receive Diversity
5.2.1 Selection Combining
5.2.2 Maximal Ratio Combining

5.3 Transmit Diversity
5.3.1 Open-Loop Transmit Diversity
5.3.2 Nt × Nr Transmit Diversity
5.3.3 Closed Loop-Transmit Diversity
5.4 Beamforming
5.4.1 DOA-Based Beamforming
5.4.2 Eigenbeamforming
5.5 Spatial Multiplexing
5.5.1 Introduction to Spatial Multiplexing
5.5.2 Open-Loop MIMO: Spatial Multiplexing
without Channel Feedback
5.5.3 Closed-Loop MIMO: The Advantage of Channel
Knowledge
5.6 Shortcomings of Classical MIMO Theory
5.6.1 Multipath
5.6.2 Uncorrelated Antennas
5.6.3 Interference-Limited MIMO Systems
5.7 Channel Estimation for MIMO-OFDM
5.7.1 Preamble and Pilot
5.7.2 Time versus Frequency-Domain Channel Estimation
5.8 Channel Feedback
5.9 Advanced Techniques for MIMO
5.9.1 Switching Between Diversity and Multiplexing
5.9.2 Multiuser MIMO Systems

150
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154
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190

Orthogonal Frequency Division Multiple Access

199

6.1 Multiple-Access Strategies for OFDM

200

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Contents

xv

6.1.1 Random Access versus Multiple Access
6.1.2 Frequency Division Multiple Access
6.1.3 Time Division Multiple Access—“Round Robin”
6.1.4 Code Division Multiple Access
6.1.5 Advantages of OFDMA
6.2 Multiuser Diversity and Adaptive Modulation
6.2.1 Multiuser Diversity
6.2.2 Adaptive Modulation and Coding
6.3 Resource-Allocation Techniques for OFDMA
6.3.1 Maximum Sum Rate Algorithm
6.3.2 Maximum Fairness Algorithm
6.3.3 Proportional Rate Constraints Algorithm
6.3.4 Proportional Fairness Scheduling
6.3.5 Performance Comparison
6.4 OFDMA in WiMAX: Protocols and Challenges
6.4.1 OFDMA Protocols
6.4.2 Cellular OFDMA
6.4.3 Limited Diversity Gains
6.5 Summary and Conclusions

6.6 Bibliography

Chapter 7

201
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211
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216
216
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219
219
220

Networking and Services Aspects of Broadband Wireless 223
7.1 Quality of Service
7.1.1 QoS Mechanisms in Packet Networks
7.1.2 IP QoS Technologies
7.2 Multimedia Session Management

7.2.1 Session Initiation Protocol
7.2.2 Real-Time Transport Protocol
7.3 Security
7.3.1 Encryption and AES
7.3.2 Public Key Infrastructure
7.3.3 Authentication and Access Control
7.4 Mobility Management
7.4.1 Location Management
7.4.2 Handoff Management
7.4.3 Mobile IP
7.5 IP for Wireless: Issues and Potential Solutions
7.5.1 TCP in Wireless
7.5.2 Header Compression

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260

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xvi

Contents

7.6 Summary and Conclusions
7.7 Bibliography

265
266

Part III

Understanding WiMAX and Its Performance

269

Chapter 8

PHY Layer of WiMAX

271

8.1 Channel Coding
8.1.1 Convolutional Coding
8.1.2 Turbo Codes
8.1.3 Block Turbo Codes and LDPC Codes
8.2 Hybrid-ARQ

8.3 Interleaving
8.4 Symbol Mapping
8.5 OFDM Symbol Structure
8.6 Subchannel and Subcarrier Permutations
8.6.1 Downlink Full Usage of Subcarriers
8.6.2 Downlink Partial Usage of Subcarriers
8.6.3 Uplink Partial Usage of Subcarriers
8.6.4 Tile Usage of Subcarriers
8.6.5 Band Adaptive Modulation and Coding
8.7 Slot and Frame Structure
8.8 Transmit Diversity and MIMO
8.8.1 Transmit Diversity and Space/Time Coding
8.8.2 Frequency-Hopping Diversity Code
8.9 Closed-Loop MIMO
8.9.1 Antenna Selection
8.9.2 Antenna Grouping
8.9.3 Codebook Based Feedback
8.9.4 Quantized Channel Feedback
8.9.5 Channel Sounding
8.10 Ranging
8.11 Power Control
8.12 Channel-Quality Measurements
8.13 Summary and Conclusions
8.14 Bibliography

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304

MAC Layer of WiMAX

307

9.1 Convergence Sublayer

309

Chapter 9


Contents

Chapter 10

xvii

9.1.1 Packet Header Suppression
9.2 MAC PDU Construction and Transmission
9.3 Bandwidth Request and Allocation
9.4 Quality of Service
9.4.1 Scheduling Services
9.4.2 Service Flow and QoS Operations
9.5 Network Entry and Initialization
9.5.1 Scan and Synchronize Downlink Channel
9.5.2 Obtain Uplink Parameters
9.5.3 Perform Ranging
9.5.4 Negotiate Basic Capabilities
9.5.5 Register and Establish IP Connectivity
9.5.6 Establish Service Flow
9.6 Power-Saving Operations
9.6.1 Sleep Mode
9.6.2 Idle Mode
9.7 Mobility Management
9.7.1 Handoff Process and Cell Reselection

9.7.2 Macro Diversity Handover and Fast BS Switching
9.8 Summary and Conclusions
9.9 Bibliography

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333

WiMAX Network Architecture

335

10.1 General Design Principles of the Architecture
10.2 Network Reference Model
10.2.1 ASN Functions, Decompositions, and Profiles
10.2.2 CSN Functions
10.2.3 Reference Points
10.3 Protocol Layering Across a WiMAX Network
10.4 Network Discovery and Selection
10.5 IP Address Assignment
10.6 Authentication and Security Architecture
10.6.1 AAA Architecture Framework
10.6.2 Authentication Protocols and Procedure
10.6.3 ASN Security Architecture
10.7 Quality-of-Service Architecture
10.8 Mobility Management
10.8.1 ASN-Anchored Mobility

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Chapter 11

Chapter 12

Contents

10.8.2 CSN-Anchored Mobility for IPv4
10.8.3 CSN Anchored Mobility for IPv6
10.9 Radio Resource Management
10.10 Paging and Idle-Mode Operation
10.11 Summary and Conclusions
10.12 Bibliography

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360
362
362

Link-Level Performance of WiMAX

365

11.1 Methodology for Link-Level Simulation

11.2 AWGN Channel Performance of WiMAX
11.3 Fading Channel Performance of WiMAX
11.3.1 Channel Estimation and Channel Tracking
11.3.2 Type I and Type II Hybrid-ARQ
11.4 Benefits of Multiple-Antenna Techniques in WiMAX
11.4.1 Transmit and Receive Diversity
11.4.2 Open-Loop and Closed-Loop MIMO
11.5 Advanced Receiver Structures and Their Benefits
for WiMAX
11.6 Summary and Conclusions
11.7 Bibliography

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387
389

System-Level Performance of WiMAX

401

12.1 Wireless Channel Modeling
12.2 Methodology for System-Level Simulation
12.2.1 Simulator for WiMAX Networks
12.2.2 System Configurations
12.3 System-Level Simulation Results

12.3.1 System-Level Results of Basic Configuration
12.3.2 System-Level Results of Enhanced Configurations
12.4 Summary and Conclusions
12.5 Appendix: Propagation Models
12.5.1 Hata Model
12.5.2 COST-231 Hata Model
12.5.3 Erceg Model
12.5.4 Walfish-Ikegami Model
12.6 Bibliography

402
404
405
410
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412
416
421
422
422
424
424
426
427

Acronyms
Index

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439

396
398
399


Foreword
Within the last two decades, communication advances have reshaped the way we live our daily
lives. Wireless communications has grown from an obscure, unknown service to an ubiquitous
technology that serves almost half of the people on Earth. Whether we know it or not, computers
now play a dominant role in our daily activities, and the Internet has completely reoriented the
way people work, communicate, play, and learn.
However severe the changes in our lifestyle may seem to have been over the past few years,
the convergence of wireless with the Internet is about to unleash a change so dramatic that soon
wireless ubiquity will become as pervasive as paper and pen. WiMAX—which stands for
Worldwide Interoperability for Microwave Access—is about to bring the wireless and Internet
revolutions to portable devices across the globe. Just as broadcast television in the 1940’s and
1950’s changed the world of entertainment, advertising, and our social fabric, WiMAX is poised
to broadcast the Internet throughout the world, and the changes in our lives will be dramatic. In a
few years, WiMAX will provide the capabilities of the Internet, without any wires, to every living room, portable computer, phone, and handheld device.
In its simplest form, WiMAX promises to deliver the Internet throughout the globe, connecting the “last mile” of communications services for both developed and emerging nations. In
this book, Andrews, Ghosh, and Muhamed have done an excellent job covering the technical,
business, and political details of WiMAX. This unique trio of authors have done the reader a
great service by bringing their first-hand industrial expertise together with the latest results in
wireless research. The tutorials provided throughout the text are especially convenient for those
new to WiMAX or the wireless field. I believe Fundamentals of WiMAX will stand out as the
definitive WiMAX reference book for many years to come.
—Theodore S. Rappaport
Austin, Texas

xix