-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 3 [112/12] 18.2.2005 5:15PM
Spread Spectrum andCDMAPrinciples and Applications
Valery P. Ipatov
University of Turku, Finland
and
St. Petersburg Electrotechnical University LETI, Russia
Innodata0470091797.jpg
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 2 [112/12] 18.2.2005 5:15PM
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 1 [112/12] 18.2.2005 5:15PM
Spread Spectrum and CDMA
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 2 [112/12] 18.2.2005 5:15PM
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 3 [112/12] 18.2.2005 5:15PM
Spread Spectrum andCDMAPrinciples and Applications
Valery P. Ipatov
University of Turku, Finland
and
St. Petersburg Electrotechnical University LETI, Russia
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 4 [112/12] 18.2.2005 5:15PM
Copyright 2005 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester,West Sussex PO19 8SQ, England
Telephone (44) 1243 779777
Email (for orders and customer service enquiries): [email protected]
Visit our Home Page on www.wiley.com
All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise,
except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued
by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the
permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions
Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ,
England, or emailed to [email protected], or faxed to (44) 1243 770620.
Designations used by companies to distinguish their products are often claimed as trademarks. All brand
names and product names used in this book are trade names, service marks, trademarks or registered
trademarks of their respective owners. The Publisher is not associated with any product or vendor
mentioned in this book.
This publication is designed to provide accurate and authoritative information in regard to the subject matter
covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services.
If professional advice or other expert assistance is required, the services of a competent professional
should be sought.
Other Wiley Editorial Offices
John Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USA
Jossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USA
Wiley-VCH Verlag GmbH, Boschstr. 12, D-69469 Weinheim, Germany
John Wiley & Sons Australia Ltd, 33 Park Road, Milton, Queensland 4064, Australia
John Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809
John Wiley & Sons Canada Ltd, 22 Worcester Road, Etobicoke, Ontario, Canada M9W 1L1
Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be
available in electronic books.
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
ISBN 0-470-09178-9 (HB)
Typeset in 10/12pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India.
Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire.
This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least
two trees are planted for each one used for paper production.
http://www.wiley.com
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 5 [112/12] 19.2.2005 12:52PM
Contents
Preface xi
1 Spread spectrum signals and systems 1
1.1 Basic definition 1
1.2 Historical sketch 5
2 Classical reception problems and signal design 7
2.1 Gaussian channel, general reception problem and optimal decision rules 7
2.2 Binary data transmission (deterministic signals) 11
2.3 M-ary data transmission: deterministic signals 17
2.4 Complex envelope of a bandpass signal 23
2.5 M-ary data transmission: noncoherent signals 26
2.6 Trade-off between orthogonal-coding gain and bandwidth 28
2.7 Examples of orthogonal signal sets 31
2.7.1 Time-shift coding 31
2.7.2 Frequency-shift coding 33
2.7.3 Spread spectrum orthogonal coding 33
2.8 Signal parameter estimation 37
2.8.1 Problem statement and estimation rule 37
2.8.2 Estimation accuracy 39
2.9 Amplitude estimation 41
2.10 Phase estimation 43
2.11 Autocorrelation function and matched filter response 43
2.12 Estimation of the bandpass signal time delay 46
2.12.1 Estimation algorithm 46
2.12.2 Estimation accuracy 48
2.13 Estimation of carrier frequency 53
2.14 Simultaneous estimation of time delay and frequency 55
2.15 Signal resolution 58
2.16 Summary 61
Problems 62
Matlab-based problems 68
3 Merits of spread spectrum 77
3.1 Jamming immunity 77
3.1.1 Narrowband jammer 78
3.1.2 Barrage jammer 80
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 6 [112/12] 19.2.2005 12:52PM
3.2 Low probability of detection 82
3.3 Signal structure secrecy 87
3.4 Electromagnetic compatibility 88
3.5 Propagation effects in wireless systems 89
3.5.1 Free-space propagation 90
3.5.2 Shadowing 90
3.5.3 Multipath fading 91
3.5.4 Performance analysis 95
3.6 Diversity 98
3.6.1 Combining modes 98
3.6.2 Arranging diversity branches 100
3.7 Multipath diversity and RAKE receiver 102
Problems 106
Matlab-based problems 109
4 Multiuser environment: code division multiple access 115
4.1 Multiuser systems and the multiple access problem 115
4.2 Frequency division multiple access 117
4.3 Time division multiple access 118
4.4 Synchronous code division multiple access 119
4.5 Asynchronous CDMA 121
4.6 Asynchronous CDMA in the cellular networks 124
4.6.1 The resource reuse problem and cellular systems 124
4.6.2 Number of users per cell in asynchronous CDMA 125
Problems 129
Matlab-based problems 130
5 Discrete spread spectrum signals 135
5.1 Spread spectrum modulation 135
5.2 General model and categorization of discrete signals 136
5.3 Correlation functions of APSK signals 137
5.4 Calculating correlation functions of code sequences 139
5.5 Correlation functions of FSK signals 142
5.6 Processing gain of discrete signals 145
Problems 145
Matlab-based problems 146
6 Spread spectrum signals for time measurement, synchronization
and time-resolution 149
6.1 Demands on ACF: revisited 149
6.2 Signals with continuous frequency modulation 151
6.3 Criterion of good aperiodic ACF of APSK signals 154
6.4 Optimization of aperiodic PSK signals 155
6.5 Perfect periodic ACF: minimax binary sequences 159
6.6 Initial knowledge on finite fields and linear sequences 161
6.6.1 Definition of a finite field 161
6.6.2 Linear sequences over finite fields 163
6.6.3 m-sequences 165
6.7 Periodic ACF of m-sequences 167
6.8 More about finite fields 170
vi Contents
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 7 [112/12] 19.2.2005 12:52PM
6.9 Legendre sequences 172
6.10 Binary codes with good aperiodic ACF: revisited 174
6.11 Sequences with perfect periodic ACF 176
6.11.1 Binary non-antipodal sequences 177
6.11.2 Polyphase codes 179
6.11.3 Ternary sequences 181
6.12 Suppression of sidelobes along the delay axis 185
6.12.1 Sidelobe suppression filter 186
6.12.2 SNR loss calculation 187
6.13 FSK signals with optimal aperiodic ACF 192
Problems 194
Matlab-based problems 196
7 Spread spectrum signature ensembles for CDMA applications 203
7.1 Data transmission via spread spectrum 203
7.1.1 Direct sequence spreading: BPSK data modulation and
binary signatures 203
7.1.2 DS spreading: general case 207
7.1.3 Frequency hopping spreading 212
7.2 Designing signature ensembles for synchronous DS CDMA 214
7.2.1 Problem formulation 214
7.2.2 Optimizing signature sets in minimum distance 215
7.2.3 Welch-bound sequences 223
7.3 Approaches to designing signature ensembles for asynchronous
DS CDMA 227
7.4 Time-offset signatures for asynchronous CDMA 232
7.5 Examples of minimax signature ensembles 235
7.5.1 Frequency-offset binary m-sequences 235
7.5.2 Gold sets 236
7.5.3 Kasami sets and their extensions 239
7.5.4 Kamaletdinov ensembles 241
Problems 243
Matlab-based problems 246
8 DS spread spectrum signal acquisition and tracking 251
8.1 Acquisition and tracking procedures 251
8.2 Serial search 253
8.2.1 Algorithm model 253
8.2.2 Probability of correct acquisition and average number of steps 254
8.2.3 Minimizing average acquisition time 258
8.3 Acquisition acceleration techniques 261
8.3.1 Problem statement 261
8.3.2 Sequential cell examining 262
8.3.3 Serial-parallel search 263
8.3.4 Rapid acquisition sequences 264
8.4 Code tracking 265
8.4.1 Delay estimation by tracking 265
8.4.2 Earlylate DLL discriminators 267
8.4.3 DLL noise performance 270
Problems 273
Matlab-based problems 274
Contents vii
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 8 [112/12] 19.2.2005 12:52PM
9 Channel coding in spread spectrum systems 277
9.1 Preliminary notes and terminology 277
9.2 Error-detecting block codes 279
9.2.1 Binary block codes and detection capability 279
9.2.2 Linear codes and their polynomial representation 281
9.2.3 Syndrome calculation and error detection 284
9.2.4 Choice of generator polynomials for CRC 285
9.3 Convolutional codes 286
9.3.1 Convolutional encoder 286
9.3.2 Trellis diagram, free distance and asymptotic
coding gain 289
9.3.3 The Viterbi decoding algorithm 292
9.3.4 Applications 296
9.4 Turbo codes 296
9.4.1 Turbo encoders 296
9.4.2 Iterative decoding 299
9.4.3 Performance 300
9.4.4 Applications 301
9.5 Channel interleaving 302
Problems 302
Matlab-based problems 304
10 Some advancements in spread spectrum systems development 307
10.1 Multiuser reception and suppressing MAI 307
10.1.1 Optimal (ML) multiuser rule for synchronous CDMA 307
10.1.2 Decorrelating algorithm 309
10.1.3 Minimum mean-square error detection 311
10.1.4 Blind MMSE detector 314
10.1.5 Interference cancellation 315
10.1.6 Asynchronous multiuser detectors 316
10.2 Multicarrier modulation and OFDM 316
10.2.1 Multicarrier DS CDMA 317
10.2.2 Conventional MC transmission and OFDM 318
10.2.3 Multicarrier CDMA 322
10.2.4 Applications 325
10.3 Transmit diversity and spacetime coding in CDMA systems 326
10.3.1 Transmit diversity and the spacetime coding problem 326
10.3.2 Efficiency of transmit diversity 327
10.3.3 Time-switched spacetime code 329
10.3.4 Alamouti spacetime code 331
10.3.5 Transmit diversity in spread spectrum applications 333
Problems 334
Matlab-based problems 336
11 Examples of operational wireless spread spectrum systems 339
11.1 Preliminary remarks 339
11.2 Global positioning system 339
11.2.1 General system principles and architecture 340
11.2.2 GPS ranging signals 341
11.2.3 Signal processing 343
viii Contents
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 9 [112/12] 19.2.2005 12:52PM
11.2.4 Accuracy 344
11.2.5 GLONASS and GNSS 344
11.2.6 Applications 345
11.3 Air interfaces cdmaOne (IS-95) and cdma2000 345
11.3.1 Introductory remarks 345
11.3.2 Spreading codes of IS-95 346
11.3.3 Forward link channels of IS-95 347
11.3.3.1 Pilot channel 347
11.3.3.2 Synchronization channel 347
11.3.3.3 Paging channels 348
11.3.3.4 Traffic channels 349
11.3.3.5 Forward link modulation 351
11.3.3.6 MS processing of forward link signal 352
11.3.4 Reverse link of IS-95 353
11.3.4.1 Reverse link traffic channel 353
11.3.4.2 Access channel 355
11.3.4.3 Reverse link modulation 355
11.3.5 Evolution of air interface cdmaOne to cdma2000 356
11.4 Air interface UMTS 357
11.4.1 Preliminaries 357
11.4.2 Types of UMTS channels 358
11.4.3 Dedicated physical uplink channels 359
11.4.4 Common physical uplink channels 360
11.4.5 Uplink channelization codes 361
11.4.6 Uplink scrambling 362
11.4.7 Mapping downlink transport channels to physical channels 363
11.4.8 Downlink physical channels format 364
11.4.9 Downlink channelization codes 365
11.4.10 Downlink scrambling codes 365
11.4.11 Synchronization channel 366
11.4.11.1 General structure 366
11.4.11.2 Primary synchronization code 366
11.4.11.3 Secondary synchronization code 367
References 369
Index 375
Contents ix
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 10 [112/12] 19.2.2005 12:52PM
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 11 [112/12] 18.2.2005 5:15PM
Preface
Spread spectrum and CDMA (code division multiple access) are up-to-date technologieswidely used in operational radar, navigation and telecommunication systems and play-ing a dominant role in the philosophy of the forthcoming generations of systems andnetworks. The amount of interest and effort invested in this encouraging area byresearch institutions and industry is gigantic and constantly growing, especially afterthe prominent commercial success of CDMA mobile telephone IS-95 and the use ofCDMA as the basic platform of 3G (and beyond) mobile radio. No wonder that thefundamentals of spread spectrum theory have assumed a solid place in the basicuniversity disciplines, while the detailed issues form the contents of numerous advancedcourses.
This book was conceived as a textbook for postgraduate and undergraduate students,and is also expected to be useful in training industry personnel and in the daily work ofresearchers. It is based on the experience and knowledge gained by the author duringmore than three decades of research activity in the area, as well as on his lecture courses.The original version of such a course started in the late 1970s at the Saint PetersburgElectrotechnical University LETI and has since been continually developed and mod-ernized, absorbing many state-of-the-art achievements and being presented to audiencesfrom Russia, the UK, Australia, China, Finland and other countries.
The intention of the author in preparing this book was to present the key ideas ofspread spectrum in the most general form equally applicable to both systems of collect-ing and recovering information (such as radar and navigation) and telecommunicationsystems or networks. The authors second concern was to link the material as tightly aspossible to classical signal and communication theory, which gives Chapter 2 a specialrole. The goal pursued everywhere was harmony between mathematical rigour andphysical transparency of some or other issue under discussion and the readers deepunderstanding of the reasons underlying the preference for spread spectrum andCDMA. The main question the author tried to answer in considering this or thatproblem was Why?i.e. why a designer may or should prefer one solution over others.
A particular emphasis of the book is designing spread spectrum signals. Manypopular books, although deservedly reputable, do not go into this problem beyondpresenting a brief survey of m-sequences and Gold codes. A reader may thereby geta false idea that nothing valuable exists outside this narrow range of attractive signalfamilies. In Chapters 6 and 7 we try to show that the designers freedom and the
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/PRELIMS.3D 12 [112/12] 18.2.2005 5:15PM
multitude of alternatives are much broader and comprise many solutions potentiallycompetitive or clearly superior to those mentioned above.
In no way is this book intended to be looked upon as a manual introducing concreteoperational or projected systems and standards. However, some such systems give a richsoil to illustrate the theory and for this reason are frequently mentioned in the text asexamples of practical realization of spread spectrum principles. Another aid for betteradoption of the contents is offered by the problems at the end of every theoreticalchapter. Especially recommended are the Matlab-based problems, since their runninginvolves and develops investigatory skills and allows execution of an extensive experi-mental study.
The book is supported by the companion website on which instructors and lecturerscan find a solutions manual for the problems and matlab programming within the book,electronic versions of some of the figures and other useful resources such as a listof abbreviations etc. Please go to ftp://ftp.wiley.co.uk/pub/books/ipatov. If you haveany comments regarding the book please feel free to contact the author directly [email protected].
The author is sceptical enough to realize that no bookincluding this onecan betotally free of shortcomings. In our case the difficulties were greatly intensified by thenecessity of writing in a non-mother tongue. Nevertheless, the author is entirely respon-sible for all of the statements as well as the drawbacks of the book and is ready to acceptany constructive remarks or criticism.
I would like to express my sincere gratitude to the Department of InformationTechnology of the University of Turku for the friendly and creative atmosphere duringmy work in Finland. I address my special appreciation to Professor Jouni Isoaho andDr Esa Tjukanoff for their daily support and cooperation.
Many thanks to my colleagues Dr Nastooh Avessta and Dr Igor Samoilov, whokindly and carefully read the manuscript and, by way of innumerable discussions,helped in my endeavour to streamline it. The assistance of Jarkko Paavola and AlexeyDudkov in rectifying and debugging the manuscript can hardly be overestimated, too.
This is a good opportunity to emphasize my deepest gratitude to my dear teachersProfessor Yu. A. Kolomensky, Professor Yu. M. Kazarinov and ProfessorYu. D. Ulianitsky, who introduced me to the fascinating world of signals and noise,and were for decades my advisors in many professional as well as personal matters.
Warmest thanks to all my colleagues at the Department of Radio Systems of SaintPetersburg State Electrotechnical University LETI for a long-standing collaboration.
I bring my gratitude also to Sarah Hinton and her colleagues at John Wiley &Sons, Ltd for initiating this project and inspiring me in the course of writing, and myspecial thanks to the Nokia Foundation for the grant awarded to me at the final stage ofpreparing the manuscript.
And finally I cannot help mentioning my wifes patience and care during the year ofmy working on this book.
Valery P. Ipatov
xii Preface
-
//INTEGRAS/KCG/PAGINATION/WILEY/SSPA/FINALS_17-02-05/C01.3D 1 [16/6] 18.2.2005 5:15PM
1
Spread spectrum signals andsystems
1.1 Basic definition
The term spread spectrum is today one of the most popular in the radio engineeringand communication community. At the same time, it may appear difficult to formulatean unequivocal and precise definition distinctively separating the spread spectrumphilosophy from a non-spread spectrum one. Certainly, every expert in system designand every experienced researcher has an intuitive understanding of the core of the issue,butunlike a newcomersuch a person does not need to think about definitions inorder to respond successfully to his or her professional challenges. From the point ofview of the target audience of the book it seems worthwhile to dedicate some space toelaborating an appropriate explanation of what is implied in the following text under thespread spectrum concept.
Let us start with a reminder of the basics of spectral analysis. Every signal s(t) of finiteenergy can be synthesized as a sum of an uncountable number of harmonics whoseamplitudes and phases within the infinitesimal frequency range [f , f df ] aredetermined by a spectral density or spectrum ~ss(f ). It is the pair of inverse and directFourier transforms that expresses this fact mathematically:
st Z11
~ssf expj2ft df ~ssf Z11
st expj2ft dt 1:1
Due to the one-to-one correspondence between the signal representation in the timedomain s(t) and in the frequency domain ~ss(f ), we are able to switch arbitrarily betweenthese two tools, selecting the more convenient one for any specific task. To characterizethe size of the zones occupied by signal energy in the time and frequency domains we usethe notions of signal duration T and bandwidth W, respectively. A signal whose energy
Spread Spectrum and CDMA: Principles and Applications Valery P. Ipatov
2005 John Wiley & Sons, Ltd