Cognitive Wireless Networks Using the CSS Technology

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    Lecture Notes in Electrical Engineering 384

    Meiling LiAnhong WangJeng-Shyang Pan

    Cognitive

    WirelessNetworks

    Using the CSSTechnology

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    Lecture Notes in Electrical Engineering

    Volume 384

    Board of Series editors

    Leopoldo Angrisani, Napoli, Italy

    Marco Arteaga, Coyoacá n, México

    Samarjit Chakraborty, München, Germany

    Jiming Chen, Hangzhou, P.R. China

    Tan Kay Chen, Singapore, Singapore

    Rüdiger Dillmann, Karlsruhe, Germany

    Haibin Duan, Beijing, China

    Gianluigi Ferrari, Parma, Italy

    Manuel Ferre, Madrid, Spain

    Sandra Hirche, München, Germany

    Faryar Jabbari, Irvine, USA

    Janusz Kacprzyk, Warsaw, Poland

    Alaa Khamis, New Cairo City, Egypt 

    Torsten Kroeger, Stanford, USATan Cher Ming, Singapore, Singapore

    Wolfgang Minker, Ulm, Germany

    Pradeep Misra, Dayton, USA

    Sebastian Möller, Berlin, Germany

    Subhas Mukhopadyay, Palmerston, New Zealand

    Cun-Zheng Ning, Tempe, USA

    Toyoaki Nishida, Sakyo-ku, Japan

    Bijaya Ketan Panigrahi, New Delhi, India

    Federica Pascucci, Roma, ItalyTariq Samad, Minneapolis, USA

    Gan Woon Seng, Nanyang Avenue, Singapore

    Germano Veiga, Porto, Portugal

    Haitao Wu, Beijing, China

    Junjie James Zhang, Charlotte, USA

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     About this Series

    “Lecture Notes in Electrical Engineering (LNEE)”   is a book series which reports

    the latest research and developments in Electrical Engineering, namely:

    •   Communication, Networks, and Information Theory

    •   Computer Engineering

    •   Signal, Image, Speech and Information Processing

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    http://www.springer.com/series/7818http://www.springer.com/series/7818

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    Meiling Li   • Anhong Wang

    Jeng-Shyang Pan

    Cognitive Wireless Networks

    Using the CSS Technology

     1 3

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    Meiling LiTaiyuan University of Science

    and TechnologyTaiyuanPeople’s Republic of China

    Anhong WangTaiyuan University of Science

    and TechnologyTaiyuanPeople’s Republic of China

    Jeng-Shyang PanFujian University of TechnologyFuzhou, FujianPeople’s Republic of China

    ISSN 1876-1100 ISSN 1876-1119 (electronic)Lecture Notes in Electrical EngineeringISBN 978-3-319-31094-7 ISBN 978-3-319-31095-4 (eBook)DOI 10.1007/978-3-319-31095-4

    Library of Congress Control Number: 2016934678

    ©   Springer International Publishing Switzerland 2016This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specically the rights of translation, reprinting, reuse of illustrations,recitation, broadcasting, reproduction on microlms or in any other physical way, and transmissionor information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar 

    methodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specic statement, that such names are exempt fromthe relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in thisbook are believed to be true and accurate at the date of publication. Neither the publisher nor theauthors or the editors give a warranty, express or implied, with respect to the material contained herein or 

    for any errors or omissions that may have been made.

    Printed on acid-free paper 

    This Springer imprint is published by Springer NatureThe registered company is Springer International Publishing AG Switzerland

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    Preface

    With the rapid development of wireless networks, more and more radio spectrum

    resources will be needed. Cognitive radio (CR) is an exciting emerging technology

    to improve spectrum ef ciency, by which the licensed spectrum resources can be

    shared dynamically by cognitive users. The accurate and effective spectrum sensing

    technologies are key to realizing the cognitive radio, which are still research

    hot-spots in the wireless sphere.

    The aim of this book is to provide some useful methods to improve the spectrum

    sensing performance in a systematic way, and point out an effective method for the

    application of cognitive radio technology in wireless communications. After givinga state-of-the-art survey, we propose some new cooperative spectrum sensing

    (CSS) methods, with an attempt to achieve better performance. For each CSS, the

    main idea and their corresponding algorithm design are elaborated in detail.

    This book covers the fundamental concepts and the core technologies of CSS,

    especially its latest developments. Each chapter is presented in a self-suf cient and

    independent way so that the reader can select the chapters interesting to them. The

    methodologies are described in detail so that the readers can repeat the corre-

    sponding experiments easily.

    For researchers, it would be a good book to understand the classi

    cations of CSS, inspiring new ideas about the novel CSS technology for CR, and a quick way

    to learn new ideas from the current status of CSS. For engineers, it would be a good

    guidebook to develop practical applications for CSS.

    Chapter  1 provides a broad view of CR. Chapter  2 shows the CSS technologies

    and current researches. Chapter  3 focuses on the CSS based on hard combination,

    mainly devoted to the relationship of each performance parameter. Chapters 4–6 are

    devoted to algorithms to solve the actual existing problems, mainly focusing on the

    current research fruits of the authors. We provide the basic frameworks and the

    experimental results, which may help the readers   nd some new ideas. Chapter  7

    introduces the application of CR and provides a basic realization method for mobile

    communications.

    v

    http://dx.doi.org/10.1007/978-3-319-31095-4_1http://dx.doi.org/10.1007/978-3-319-31095-4_2http://dx.doi.org/10.1007/978-3-319-31095-4_3http://dx.doi.org/10.1007/978-3-319-31095-4_4http://dx.doi.org/10.1007/978-3-319-31095-4_6http://dx.doi.org/10.1007/978-3-319-31095-4_7http://dx.doi.org/10.1007/978-3-319-31095-4_7http://dx.doi.org/10.1007/978-3-319-31095-4_6http://dx.doi.org/10.1007/978-3-319-31095-4_4http://dx.doi.org/10.1007/978-3-319-31095-4_3http://dx.doi.org/10.1007/978-3-319-31095-4_2http://dx.doi.org/10.1007/978-3-319-31095-4_1

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    This work was supported in part by the National Natural Science Foundation of 

    China (No. 61272262), National Science Foundation for Young Scientists of 

    Shanxi Province, China (Grant No. 2014021021-2) and Doctor Startup Foundation

    of TYUST, China (No. 20122032).

    We are grateful to the Springer in-house editors for the editorial assistance andexcellent cooperative collaboration to produce this important scientic work. We

    hope that the reader will share our excitement to present this book and will  nd it 

    useful.

    Taiyuan, Shanxi

    November 2015

    vi Preface

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    Contents

    1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1

    1.1 Dissertation Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1

    1.2 Cognitive Radio Technology . . . . . . . . . . . . . . . . . . . . . . . . . . .   3

    1.2.1 Spectrum Sensing  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4

    1.2.2 Spectrum Management . . . . . . . . . . . . . . . . . . . . . . . . . .   5

    1.2.3 Spectrum Mobility. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6

    1.2.4 Spectrum Sharing   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7

    1.2.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8

    1.3 Spectrum Sensing Technology. . . . . . . . . . . . . . . . . . . . . . . . . .   101.3.1 Spectrum Sensing Classication   . . . . . . . . . . . . . . . . . . .   10

    1.3.2 Spectrum Sensing Method   . . . . . . . . . . . . . . . . . . . . . . .   12

    1.4 Motivation   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   15

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   16

    2 CSS Technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   23

    2.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   23

    2.2 Cooperative Communication Model . . . . . . . . . . . . . . . . . . . . . .   24

    2.2.1 Cooperative Diversity   . . . . . . . . . . . . . . . . . . . . . . . . . .   24

    2.2.2 Relay Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   252.3 CSS Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   30

    2.3.1 Cooperative Diversity for CSS   . . . . . . . . . . . . . . . . . . . .   30

    2.3.2 Relay Diversity for CSS. . . . . . . . . . . . . . . . . . . . . . . . .   32

    2.4 The Process of CSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   34

    2.5 Research Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   37

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   39

    3 The Relationship Among the Performance Parameters in CSS . . . . .   43

    3.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   43

    3.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   45

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    3.3 The CSS Detection Performance . . . . . . . . . . . . . . . . . . . . . . . .   46

    3.3.1 Local Detection Performance   . . . . . . . . . . . . . . . . . . . . .   46

    3.3.2 CSS Performance Based on Decision Fusion. . . . . . . . . . .   48

    3.3.3 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   50

    3.4 The CSS Secondary Throughput   . . . . . . . . . . . . . . . . . . . . . . . .   533.4.1 Spectrum Utilization   . . . . . . . . . . . . . . . . . . . . . . . . . . .   53

    3.4.2 Secondary Throughput . . . . . . . . . . . . . . . . . . . . . . . . . .   56

    3.4.3 The Optimal Algorithm  . . . . . . . . . . . . . . . . . . . . . . . . .   58

    3.4.4 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   60

    3.5 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   66

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   66

    4 The Censoring Based CSS   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   69

    4.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   69

    4.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   71

    4.3 The C-CSS Detection Performance   . . . . . . . . . . . . . . . . . . . . . .   72

    4.3.1 Performance Analysis   . . . . . . . . . . . . . . . . . . . . . . . . . .   72

    4.3.2 Optimal Algorithm   . . . . . . . . . . . . . . . . . . . . . . . . . . . .   76

    4.3.3 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   79

    4.4 The C-CSS Secondary Throughput   . . . . . . . . . . . . . . . . . . . . . .   83

    4.4.1 Performance Analysis   . . . . . . . . . . . . . . . . . . . . . . . . . .   83

    4.4.2 Optimal Algorithm   . . . . . . . . . . . . . . . . . . . . . . . . . . . .   84

    4.4.3 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   86

    4.5 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   92

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   92

    5 CSS Technology with Relay  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   95

    5.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   95

    5.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   97

    5.2.1 Problem Description   . . . . . . . . . . . . . . . . . . . . . . . . . . .   97

    5.2.2 Signal Model   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   99

    5.3 Proposed Best Relay CSS Scheme . . . . . . . . . . . . . . . . . . . . . . .   101

    5.3.1 Problem Description   . . . . . . . . . . . . . . . . . . . . . . . . . . .   1015.3.2 The SINR-BRCS Scheme . . . . . . . . . . . . . . . . . . . . . . . .   103

    5.3.3 Proposed   Pe_BRCS Scheme . . . . . . . . . . . . . . . . . . . . . .   103

    5.3.4 Complexity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . .   105

    5.3.5 Detection Performance . . . . . . . . . . . . . . . . . . . . . . . . . .   105

    5.3.6 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   106

    5.4 Proposed C-BR-CSS Scheme   . . . . . . . . . . . . . . . . . . . . . . . . . .   108

    5.4.1 Problem Description   . . . . . . . . . . . . . . . . . . . . . . . . . . .   108

    5.4.2 System Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   109

    5.4.3 Performance Analysis   . . . . . . . . . . . . . . . . . . . . . . . . . .   111

    5.4.4 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   116

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    5.5 Proposed Adaptive CSS Scheme with Best Relay   . . . . . . . . . . . .   118

    5.5.1 Problem Description   . . . . . . . . . . . . . . . . . . . . . . . . . . .   118

    5.5.2 Algorithm Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   119

    5.5.3 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   120

    5.6 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   122References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   122

    6 CSS Based on Soft Combination. . . . . . . . . . . . . . . . . . . . . . . . . . .   125

    6.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   125

    6.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   126

    6.3 SC-EF-CSS Performance   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   127

    6.3.1 Performance Analysis   . . . . . . . . . . . . . . . . . . . . . . . . . .   127

    6.3.2 The Optimal Algorithm Based on N-P Criterion  . . . . . . . .   131

    6.3.3 The Optimal Algorithm Based on MDC . . . . . . . . . . . . . .   133

    6.3.4 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   134

    6.4 SC-DF-CSS Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   136

    6.4.1 Performance Analysis   . . . . . . . . . . . . . . . . . . . . . . . . . .   136

    6.4.2 The Optimal Algorithm Based on N-P Criterion  . . . . . . . .   138

    6.4.3 The Optimal Algorithm Based on MDC . . . . . . . . . . . . . .   140

    6.4.4 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   141

    6.5 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   143

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   143

    7 The SS Application in ICIC  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1457.1 Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   145

    7.2 Problem Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   147

    7.2.1 The SFR Scheme   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   147

    7.2.2 Interference Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . .   148

    7.3 The ICI Coordination Based on SS   . . . . . . . . . . . . . . . . . . . . . .   150

    7.3.1 Scheme Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   150

    7.3.2 Interference Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . .   153

    7.3.3 Detection Algorithm   . . . . . . . . . . . . . . . . . . . . . . . . . . .   155

    7.3.4 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1557.4 Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   158

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   158

    Contents ix

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    SDC Selective Diversity Combining

    SFR Soft Frequency Reuse

    SINR Signal to Interference and Noise Ratio

    SNR Signal-to-Noise Ratio

    SON Self-organization NetworkSR Secondary Relay

    SU Secondary User  

    TDMA Time Division Multiple Access

    WiMAX Worldwide Interoperability for Microwave Access

    xG Next Generation

    xii Abbreviations

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    Chapter 1

    Introduction

    In this chapter, the background of the cognitive radio technology is stated. The key

    technologies are then introduced simply. Finally, the classication and methods of 

    the spectrum sensing technology are described.

    1.1 Dissertation Background

    With the rapid development of wireless networks, the demand of radio spectrumresources also grow with each passing day, which results that the scarcity of 

    wireless spectrum resource is also becoming increasingly prominent. In the current 

    spectrum allocation framework, there are a lot of frequency bands being long-term

    idle in time and space [1–7], which results the lower spectrum utilization. Visibly,

    the spectrum scarcity problem is not only the actual lack of physical resources, but 

    also being related to the current wireless spectrum allocation mode. In the existing

    xed spectrum allocation mode, each frequency band is   xedly assigned to the

    different authorized institutions. Other unlicensed users can not use those idle

    spectrum resources, even if the licensed spectrum resources are not being usedtemporarily. For this reason, this part of the idle spectrum resources can not be fully

    utilized which severely limited the utilization of spectrum resources and restricted

    the development of wireless communication. Therefore, how to enhance the uti-

    lization of the radio spectrum is one of the hot issues in the  elds of domestic and

    international communication at home and abroad. Dynamic spectrum access

    (DSA) technology can effectively alleviate the contradiction between the low

    spectrum utilization and the scarcity of spectrum resources, in which the unlicensed

    users can use the free spectrum resources in time or space when assuring not 

    bringing influences to the licensed users’   communications, so as to achieve the

    reuse of the spectrum resources [8–

    14]. Cognitive radio (CR) is a kind of frequency

    reuse technologies, which can achieve the dynamic spectrum sharing and improve

    the spectrum ef ciency by DSA [15–20]. The concept of CR originates from the

    ©   Springer International Publishing Switzerland 2016

    M. Li et al.,  Cognitive Wireless Networks Using the CSS Technology,

    Lecture Notes in Electrical Engineering 384,

    DOI 10.1007/978-3-319-31095-4_1

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    Pioneering research of Dr. Joseph Mitola III [21]. It has been quickly get wide

    attentions from all around the world after the concept of CR was proposed.

    Thereafter the spectrum management departments, the standardization organiza-

    tions and the research institutions all over the world have launched their researches

    on CR [22–

    27].The standards related to CR include IEEE 802.22, 802.16 h and IEEE P1900.

    The IEEE 802.22 working group is the rst standardization organization based on the

    CR technology in the world [28], which is mainly to plan the air interface standard for 

    the cognitive users when accessing the broadcasting bands and assure that the

    broadcasting services can not be interfered [27]. The IEEE 802.22 standard is of great 

    signicance to the development of CR technology. The IEEE 802.16 working group

    has committed to the research of wireless broadband access technology, i.e. WiMAX

    (Worldwide Interoperability for Microwave Access), which is limited to the spectrum

    resources. For this reason, the 802.16 h working group was established, the purposeof which is that the series of 802.16 standards can be applied in the license-free band

    by using CR technology [29]. In order to make a further study of CR, IEEE estab-

    lished IEEE P1900 standard group [30–32], which committed to the next generation

    wireless communication technology and advanced spectrum management technol-

    ogy. This working group has great signicance to the development of CR technology

    and the co-ordination and co-existence with other wireless communication systems.

    The future mobile communication network will be a ubiquitous and heterogeneous

    network mode, with the ability of self-conguration, self-optimization and

    self-learning in the future [33]. Recently, in order to accommodate the need of thefuture network’s development, the network should perform the self-organization

    functions, such as self-conguration or self optimization in IEEE 802.16m. The

    concept and requirement of the self-organizing network (SON) have also been

    proposed in LTE-Advanced. It requires that the network has the ability of 

    self-conguration, self-optimization or self-healing [33], which mainly rely on the

    CR technology [34, 35]. At present, the discussion of SON is still in the preliminary

    stage in the IEEE and LTE organization. There are still a lot of related technologies

    which need in-depth study so that the SON can be applied in actual system.

    Not only the standardization organizations have recognized the enormouspotential of CR, but also the academic communities have done widely researches to

    the CR technology. Professor Simon Haykin, an international famous scholar,

    dened the concept of CR from the perspective of signal processing [36,  37]. He

    pointed out that the CR is an intelligent wireless communication system, which can

    be aware of its surrounding environment (i.e., its outside world), and uses the

    methodology of understanding-by-building to learn from the environment and adapt 

    its internal states to statistical variations in the incoming radio frequency

    (RF) stimuli by making corresponding changes in certain operating parameters

    (e.g., transmit power, carrier frequency, and modulation strategy) in real time, with

    two primary objectives in mind: (1) Highly reliable communications whenever and

    wherever needed; and (2) Ef cient utilization of the radio spectrum. The denitions

    have been put forwarded by Simon Haykin promote a lot of extensive studies on

    CR technology in the  eld such as academic world, industries, research institutions

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    and industry. A lot of projects have also been started, such as the CORVUS system

     jointly developed by the University of California, Berkeley and the Technology

    University of Berlin, Germany [38], the OCRA systems developed by the

    Polytechnic University of Georgia, USA [19], the XG (next Generation) project and

    E3 (End to End Ef ciency) project [39] that developed by U.S. military DARPA[40, 41]. Under the support of these projects, the CR has obtained some achieve-

    ments in the  eld of basic theory, network architecture, and its protocol design in

    wireless communication systems.

    Compared with foreign, the research on CR technology has also received highly

    attention in our country. The national 973 program, the national 863 program and

    the National Natural Science Foundation of China all set up a special issue of CR.

    Tsinghua University, Beijing University of Post and Telecommunications,

    University of Electronic Science and Technology, Hong Kong University Science

    & Technology and other universities have also make in-depth studies on CRtechnology. ZTE, Huawei and other companies has also been involved in the

    related work in the standards development of IEEE 802.22. Judging from the

    momentum of the development at home and abroad, the study on CR technology is

    still in the ascendant. CR technology, as the   “next big thing”   in the wireless

    communication area, opens up an effective way to solve the low utilization of the

    spectrum resources and the shortage of spectrum resource. However, the study of 

    CR is still at a preliminary stage, there are still a lot of challenges to deal with

    before the   nal application such as the system architecture, protocol architecture,

    standards, the specic key techniques etc.

    1.2 Cognitive Radio Technology

    CR technologies provide the capability to use or share the spectrum in an oppor-

    tunistic manner. DSA technologies allow the CR to operate in the best available

    channel. The term, CR, can formally be dened as follows [2, 19]:

    A  ‘‘

    Cognitive Radio’’

     is a radio that can change its transmitter parameters basedon interaction with the environment in which it operates. From this denition, two

    main characteristics of the cognitive radio can be dened [19, 36, 42]:

    •   Cognitive capability: Cognitive capability refers to the ability of the radio

    technology to capture or sense the information from its radio environment. This

    capability cannot simply be realized by monitoring the power in some frequency

    band of interest. More sophisticated techniques are required in order to capture

    the temporal and spatial variations in the radio environment and avoid inter-

    ference to other users, the vacant spectrum at a specic time or location can be

    identied through this capability. Consequently, the best spectrum and appro-priate operating parameters can be selected [19].

    •   Recongurability: The cognitive capability provides spectrum awareness

    whereas recongurability enables the radio to be dynamically programmed

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    Spectrum sensing has been identied as a key enabling functionality to ensure

    that SUs would not interfere with PUs, by reliably detecting PU signals. In addition,

    reliable sensing plays a critical role on communication links of SUs since it creates

    spectrum opportunities for them. In order to ef ciently utilize the available

    opportunities, SUs must sense frequently all degrees of freedom (time, frequency,

    and space) while minimizing the time spent in sensing [45–50]. We will introduce

    the spectrum sensing technology for detail in the following subsection.

    1.2.2 Spectrum Management 

    After spectrum sensing, the spectrum management is needed to capture the best 

    available spectrum to satisfy user communication requirements. The spectrum

    management functions mainly include spectrum analysis and spectrum decision.

    In cognitive radio networks (CRN), the available spectrum holes show different 

    characteristics which vary over time. Since the SUs are equipped with the CR based

    physical layer, it is important to understand the characteristics of different spectrum

    bands. Spectrum analysis enables the characterization of different spectrum bands,

    which can be exploited to get the spectrum band appropriate to the user require-

    ments [19].Once all available spectrum bands are characterized, appropriate operating

    spectrum band should be selected for the current transmission considering the QoS

    requirements and the spectrum characteristics. The spectrum decision is about 

    whether and how to access the spectrum. The goal of the spectrum decision is to

    best meet the user communication requirements, while satisfying a set of con-

    straints, e.g., the acceptable interference which can be created to other users in the

    spectrum. The optimization goal, i.e., the outcome that best meets the user 

    requirements, can be a local or a global criterion. Next, it is important that the

    spectrum decision is coordinated through SUs in the network. The classication of the spectrum decision is shown in Fig.  1.2. The spectrum decision can impact the

    future spectrum sensing and hence the amount of    “learning”   the wireless com-

    munication scene [44].

    Transmitter detection area

    Secondary userPrimary base station

    Primary user

    Receiver detection area=

    Interference area

    Fig. 1.1   Detection area with and without interference

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    1.2.3 Spectrum Mobility

    In CRN, spectrum mobility arises when current channel conditions become worse

    or a PU appears. Spectrum mobility gives rise to a new type of handoff in CRN that 

    we refer to as spectrum hand off. The protocols for different layers of the network

    stack must adapt to the channel parameters of the operating frequency. Moreover,

    they should be transparent to the spectrum hand off and the associated latency. As

    pointed out in earlier sections, a CR can adapt to the frequency of operation.

    Therefore, each time a SU changes its frequency of operation, the network proto-

    cols are going to shift from one mode of operation to another. The purpose of 

    spectrum mobility management in CRN is to make sure that such transitions are

    made smoothly and as soon as possible such that the applications running on a SU

    perceive minimum performance degradation during a spectrum hand off. It is

    essential for the mobility management protocols to learn in advance about the

    duration of a spectrum hand off. This information should be provided by the sensing

    algorithm. Once the mobility management protocols learn about this latency, their 

     job is to make sure that the ongoing communications of a SU undergo only min-

    imum performance degradation. Consequently, multi-layer mobility management 

    protocols are required to accomplish the spectrum mobility functionalities. These

    protocols support mobility management adaptive to different types of applications.

    For example, a TCP connection can be put to a wait state until the spectrum hand

    off is over. Moreover, since the TCP parameters may change after a spectrum hand

    off, it is essential to learn the new parameters and ensure that the transitions fromthe old parameters to new parameters are carried out rapidly. For a data commu-

    nication e.g., FTP, the mobility management protocols should implement mecha-

    nisms to store the packets that are transmitted during a spectrum hand off, whereas

    Spectrum decision

    Optimization behaviour Architecture Coordination

    CooperativeNon-

    cooperativeCentralizedDistributed

    Common

    channel

    No common

    channel

    Control only Data channel

    Fig. 1.2   Spectrum decision classication

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    for a real-time application there is no need to store the packets as the stored packets,

    if delivered later, will be stale packets and can not be used by the corresponding

    application [19].

    1.2.4 Spectrum Sharing

    As introduced in the previous section, DSA technology is needed to achieve a better 

    use of the spectrum. DSA is the opposite of the current static spectrum management 

    policy. However, various approaches are possible to make the spectrum manage-

    ment more adaptive, as presented in Fig.  1.3 [44].Dynamic licensing results in a dynamic spectrum allocation that gives exclusive

    use to the technology or network that currently has the most prot of spectrum use.

    It is similar to the current spectrum regulation in that it licenses spectrum bands for 

    exclusive use. This dynamic licensing is, however, much more  flexible, to be able

    to adapt to the wireless communication dynamics [44].

    Ideally, spectrum sharing should adapt very fast to all dynamics present in

    wireless communication, which can be caused by the channel variations or because

    of the burst application demands. Coexistence or dynamic sharing allows such

    sharing, in theory, on a packet per packet basis since it licenses spectrum to net-works simultaneously, while relying on in-network spectrum sharing techniques to

    avoid conflicts. This model for spectrum sharing assumes that all networking nodes

    have equal regulatory status. As a result, this model is also referred to as open

    Dynamic spectrum

    access

    Dynamic licensing

    (Dynamic exclusive use)

    Horizontal sharing

    Dynamic sharing

    (coexistence)

    Vertical sharing

    Heterogeneous

    networks

    Homogeneous

    networksUnderlay Overlay

    Symmetric Asymmetric

    Fig. 1.3   Dynamic spectrum access, classication along regulatory status

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    sharing model [51] or as spectrum commons [52, 53]. Medium access protocols for 

    wireless networks are working according to this model and considerable literature

    can be found on both centrally controlled or distributed access techniques for 

    spectrum sharing between nodes of a single network [44].

    In the above-discussed case for coexistence, both considered networks adapt their transmission schemes as function of the environment. This is because both

    networks can benet from avoiding the mutual interference, and both networks

    have (limited) adaptive or cognitive capabilities. In this case, spectrum sharing can

    be classied as symmetric in nature. This asymmetric spectrum sharing, in which

    only one of the technologies is adaptive, is somewhat similar to vertical spectrum

    sharing [44].

    The initial denition of spectrum sharing assumes the existence of a PU and a

    SU. While the spectrum has been licensed to the PU only, the SU can use it 

    opportunistically provided this does not affect the PUs’   performance. Twoapproaches exist for spectrum access to minimize the interference caused to the PUs

    by the SUs’   communication: spectrum overlay and spectrum underlay. Overlay

    spectrum sharing refers to the spectrum access technique used. More specically, a

    node accesses the network using a portion of the spectrum that has not been used by

    licensed users [19,   54–60]. As a result, interference to the primary system is

    minimized. Underlay spectrum sharing exploits the spread spectrum techniques

    developed for cellular networks [61]. Once a spectrum allocation map has been

    acquired, a SU begins transmission such that its transmit power at a certain portion

    of the spectrum is regarded as noise by the licensed users. This technique requiressophisticated spread spectrum techniques and can utilize increased bandwidth

    compared to overlay techniques.

    1.2.5 Conclusions

    The core idea of CR technology is that the SUs can intelligently detect and analyze

    the spectrum in wireless environment, and then identify the free spectrum inspecic time or specic position. By this way, the SUs can access the selected

    optimal spectrum to realize spectrum sharing and the improved spectrum utilization

    [62–64]. To achieve this goal, the SUs have to implement spectrum sensing to  nd

    the PU and detect the idle spectrum resources. Spectrum analysis is needed after the

    completion of spectrum sensing. The SUs will analyze the characteristics of the

    available spectrum resources in the CRN so that they can determine the appropriate

    frequency bands for radio transmission. The key of spectrum analysis is how to

    select the appropriate spectrum according to the results of the spectrum sensing to

    realize reliable communication. The purpose of the spectrum decision is making

    preparations for spectrum sharing [19,   65] by conrming the access parameters

    (including modulation encoding and the transmitted power) based on the spectrum

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    sensing and the spectrum analysis. Spectrum analysis and spectrum decision

    belongs to the scope of spectrum management. Once the work band is selected, the

    SU can transmit the signal in this band, however, the SU access the spectrum in an

    opportunistic way in CRN, because the available spectrum are changed dynamically

    in different space and time [66–71]. When the PU appears, the SU must release the

    occupied spectrum and switch to other available spectrum to achieve seamless hand

    off, which is called spectrum hand off, named as spectrum shift. In the process of 

    spectrum hand off, how to ensure the continuity and reliability of the SU ’s trans-

    mission and realize the fast seamless hand off are dif cult, which  rstly require that the SU should continuously perform spectrum sensing to detect the availability of 

    the free spectrum resources. Multiple SUs may use the same idle spectrum to

    communicate simultaneously when the idle spectrum is detected, therefore, in order 

    to avoid the SUs interference with each other, spectrum sharing is needed. In the

    spectrum sharing, the SUs’   transmissions can be appropriately coordinated and

    managed by certain resource allocation strategies which are similar to the MAC

    media access protocols in the existing systems [71–73]. The above process usually

    can be described by a cognitive ring, as shown in Fig. 1.4. In short, the goal of CR

    is to provide available spectrum resources for SUs when assuring suf cient pro-tection to the PU. In order to achieve this goal, various aspects of the cognitive ring

    need to be considered, in which the spectrum sensing is the premise and the key of 

    the CR technology. It is very important to study the spectrum sensing technology so

    as to make full use of the limited spectrum resources.

    In summary, the SUs need to search spectrum constantly until the idle spectrum

    are detected in the process of spectrum sensing. When the PU returns to the channel

    which has been occupied by a SU, the SU have to release this channel to avoid

    interference to the PU. However, it is hard to guarantee that the PU signals can be

    detected absolutely up to 100 % in actual. Therefore, the core problem of spectrumsensing technology is how to detect the idle spectrum accurately.

    Fig. 1.4   Cognitive ring

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    1.3 Spectrum Sensing Technology

    1.3.1 Spectrum Sensing Classi   cation

    The spectrum sensing is to detect the unused spectrum bands in order to enable CR

    to adapt its environment. Since there exist multiple SUs in CRN, according to

    whether they implement spectrum sensing collaboratively, the spectrum sensing

    schemes can be categorized as cooperative spectrum sensing scheme and

    non-cooperative spectrum sensing scheme. Further, cooperative spectrum sensing

    can be divided into centralized sensing [74–76], distributed sensing [77] and

    relay-assisted sensing [78–80] on how cooperative CR users share the sensing data

    in the network, as shown in Fig.  1.5 [81].

    In centralized cooperative spectrum sensing, a central identity called fusion

    center (FC) controls the three-step process of cooperative spectrum sensing. Firstly,

    the FC selects a channel or a frequency band of interest for sensing and instructs all

    cooperating SUs to individually perform local sensing. Secondly, all cooperating

    SUs report their sensing results via the control channel. Then the FC combines the

    received local sensing information, determines the presence of PUs, and transmits

    the decision back to cooperating SUs. As shown in Fig.  1.6a, SU0   is the FC and

    SU1–SU5 are cooperating SUs performing local sensing and reporting the results to

    SU0. For local sensing, all SUs are tuned to the selected licensed channel or 

    frequency band where a physical point-to-point link between the PU transmitter and

    each cooperating SU for observing the primary signal is called a sensing channel.For data reporting, all SUs are tuned to a control channel where a physical

    point-to-point link between each cooperating SU and the FC for sending the sensing

    results is called a reporting channel. Note that centralized cooperative spectrum

    sensing can occur in either centralized or distributed CRN. In centralized CRN, a

    Spectrum sensing

    Cooperative

    sensing

    Non-Cooperative

    sensing

    Centalizedsensing

    Distributedsensing

    Relay-assistedsensing

    Fig. 1.5   Spectrum sensing classication

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    CR base station (BS) is naturally the FC. Alternatively, in CR ad hoc networkswhere a CR BS is not present, any SU can act as a FC to coordinate cooperative

    spectrum sensing and combine the sensing information from the cooperating

    neighbors [81].

    Unlike centralized cooperative spectrum sensing, distributed cooperative spec-

    trum sensing does not rely on a FC for making the cooperative decision. In this

    case, SUs communicate among themselves and converge to a unied decision on

    the presence or absence of PUs by iterations. Figure 1.6b illustrates the cooperation

    in the distributed manner. After local sensing, SU1–SU5   share the local sensing

    results with other users within their transmission range. Based on a distributedalgorithm, each SU sends its own sensing data to other users, combines its data with

    the received sensing data, and decides whether or not the PU is present by using a

    local criterion. If the criterion is not satised, SUs send their combined results to

    other users again and repeat this process until the algorithm is converged and a

    decision is obtained. In this manner, this distributed scheme may take several

    iterations to reach the unanimous cooperative decision [81].

    In addition to centralized and distributed cooperative spectrum sensing, the third

    scheme is relay-assisted cooperative spectrum sensing. Since both sensing channel

    and reporting channel are not perfect, a SU who experience a weak sensing channel

    and a strong reporting channel and a SU who experience a strong sensing channel

    and a weak reporting channel, for example, can complement and cooperate with

    each other to improve the performance of cooperative spectrum sensing. In

    Fig.  1.6c, SU1, SU4, and SU5, who observe strong PU signals, may suffer from a

    weak report channel. SU2 and SU3, who have a strong reporting channel, can serve

    as relays to assist in forwarding the sensing results from SU1, SU4, and SU5 to the

    FC. In this case, the reporting channels from SU2  and SU3   to the FC can also be

    called relay channels. Note that although Fig. 1.6c shows a centralized structure, the

    relay-assisted cooperative spectrum sensing can exist in distributed scheme. In fact,

    when the sensing results need to be forwarded by multiple hops to reach the

    destination, all the intermediate hops are relays. Thus, if both centralized and

    distributed structures are one-hop cooperative spectrum sensing, the relay-assisted

    structure can be considered as multi-hop cooperative spectrum sensing. In addition,

    SU5

    PU

    SU2

    SU1

    SU0(FC)

    SU4

    SU3

    SU5

    PU

    SU2

    SU1

    SU0(FC)

    SU4

    SU3

    (Relay)(Relay)

    (a) (b) (c)

    SU5

    PU

    SU2

    SU1

    SU4

    SU3

    Fig. 1.6   Classication of cooperative spectrum sensing

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    the relay for cooperative spectrum sensing here serves a different purpose from the

    relays in cooperative communications [71], where the CR relays are used for for-

    warding the PU traf c [81].

    1.3.2 Spectrum Sensing Method 

    In cooperative spectrum sensing, each SU can utilize the sensing method in

    non-cooperative spectrum sensing to implement the spectrum sensing, the detail

    classication is shown as in Fig. 1.7. The current non-cooperative spectrum sensing

    methods include: the sensing based on PU receiver, the sensing based on inter-

    ference temperature model and the sensing based on the PU transmitter [19]. The

    main idea of the sensing based on the interference temperature model is that in a

    certain frequency band, if all of the energy that the PU received from the inter-

    ference source do not exceed a predened maximum limit (also known as inter-ference temperature limit), the SU can share this band with the PU. The interference

    temperature model manages interference at the receiver through the interference

    temperature limit, which is represented by the amount of new interference that the

    receiver could tolerate. In other words, the interference temperature model accounts

    for the cumulative RF energy from multiple transmissions and sets a maximum

    threshold on their aggregate level. As long as SUs do not exceed this limit by their 

    transmissions, they can use this spectrum band. The dif culty of this detection

    model lies in how to effectively measure the interference temperature. A SU is

    naturally aware of its transmit power level and its precise location with the help of apositioning system. With this ability, however, its transmission could cause sig-

    nicant interference at a neighboring receiver on the same frequency. However,

    currently, there exists no practical way for a cognitive radio to measure or estimate

    Spectrum sensing

    Transmitter Receiver

    Energy detection Matched filter

    Interference

    temperature

    Cyclostationary

    Detection

    Fig. 1.7   Spectrum sensing method

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    the interference temperature on nearby primary receivers. Since primary receivers

    are usually passive devices, a SU cannot be aware of the precise locations of 

    primary receivers. Therefore, if SUs cannot effectively measure their transmission

    on all possible receivers, a useful interference temperature measurement may not be

    feasible [19]. The sensing based on PU receiver is also known as local oscillator leakage detection, in which, whether there exist available spectrum resources are

     judged by detecting the target users who are receiving signal in the authorization

    system, it mainly makes a judgment by using local oscillation leakage energy that 

    released by RF front-end when the PU’s receiving equipment are working, those

    leaked signal energy are often very weak, so this method is only applied to test 

    television receiver at present. In practice, it is dif cult for SU to obtain accurate

    position information of the PU receiver [50, 82–87]. The sensing based on the PU

    transmitter is that the SU determine whether there are idle spectrum by detecting the

    transmitted signal of the PU. This method of spectrum sensing is simple and easy tooperate. Therefore, most existing spectrum sensing algorithms focus on the

    detection of the primary transmitted signal based on the local observations of the

    CR. The typical detection methods based on primary transmitted signal include:

    energy detection, matched  lter detection and cyclostationary detection [19, 71].

    1.3.2.1 Energy Detection

    If prior knowledge of the PU signal is unknown, the energy detection method isoptimal for detecting any zero-mean constellation signals [88]. In the energy

    detection approach, the radio-frequency (RF) energy in the channel or the received

    signal strength indicator is measured to determine whether the channel is idle or not.

    First, the input signal is  ltered with a band-pass   lter to select the bandwidth of 

    interest. The output signal is then squared and integrated over the observation

    interval. Lastly, the output of the integrator is compared to a predened threshold to

    infer the presence or not of the PU signal, as shown in Fig.  1.8. When the spectrum

    is analyzed in the digital domain, fast Fourier transform (FFT) based methods are

    used. Speci

    cally, the received signal   x t ð Þ, sampled in a time window, is 

    rst passed through an FFT device to get the power spectrum   X f ð Þj j2. The peak of thepower spectrum is then located. After windowing the peak of the spectrum, we get 

    Y f ð Þj j2. The signal energy is then collected in the frequency domain. Although theenergy-detection approach can be implemented without any prior knowledge of the

    PU signal, it still has some drawbacks. The   rst problem is that it has poor per-

    formance under low SNR conditions. This is because the noise variance is not 

    accurately known at the low SNR, and the noise uncertainty may render the energy

    detection useless [88]. Another challenging issue is the inability to differentiate the

    Fig. 1.8   Energy detection

    model

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    interference from other secondary users who share the same channel with the PU

    [87]. Furthermore, the threshold used in energy selection depends on the noise

    variance, and small noise power estimation errors can result in signicant perfor-

    mance loss [71]. As energy detection method is simple and easy to realize, it has

    been widely applied in practice.

    1.3.2.2 Matched Filter Detection

    When a SU has a prior knowledge of the PU signal, the optimal signal detection is a

    matched   lter, as it maximizes the signal-to-noise ratio (SNR) of the received

    signal. A matched  lter is obtained by correlating a known signal, or template, with

    an unknown signal to detect the presence of the template in the unknown signal.

    This is equivalent to convolving the unknown signal with a time-reversed versionof the template [71]. So the matched   lter can be considered as an optimal linear 

    lter that maximizes the SNR in the presence of additive noise [50, 89,  90].

    The main advantage of matched  lter is that it needs less time to achieve high

    processing gain due to coherent detection [88]. Another signicant disadvantage of 

    the matched   lter is that it would require a dedicated sensing receiver for all

    primary user signal types. In the CR scenario, however, the use of the matched lter 

    can be severely limited since the information of the PU signal is hardly available at 

    the CRs. The use of this approach is still possible if we have partial information of 

    the PU signal such as pilot symbols or preambles, which can be used for coherent detection [15]. For instance, to detect the presence of a digital television

    (DTV) signal, we may detect its pilot tone by passing the DTV signal through a

    delay-and-multiply circuit. If the squared magnitude of the output signal is larger 

    than a threshold, the presence of the DTV signal can be detected [71].

    1.3.2.3 Cyclostationary Detection

    Cyclostationary detection is more robust to noise uncertainty than energy detection.If the signal of the PU exhibits strong cyclostationary properties, it can be detected

    at very low SNR values by exploiting the information (cyclostationary feature)

    embedded in the received signal. A signal is said to be cyclostationary (in the wide

    sense) if its autocorrelation is a periodic function of time   t  with some period [71,

    91]. The cyclostationary detection can be performed as follows.

    •   First, the cyclic auto-correlation function (CAF) of the observed signal x t ð Þ   is

    calculated as   E x t þ sð Þ x  t    sð Þe j 2pat 

    , where   E   f g   denotes the statistical

    expectation operation and   a   is called the cyclic frequency.

    •   The spectral correlation function (SCF) S f ; að Þ is then obtained from the discreteFourier transformation of the CAF. The SCF is also called cyclic spectrum,

    which is a two-dimension function in terms of frequency f  and cyclic frequency  a.

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    •   The detection is completed by searching for the unique cyclic frequency cor-

    responding to the peak in the SCF plane.

    This detection approach is robust to random noise and interference from other 

    modulated signals because the noise has only a peak of SCF at the zero cyclicfrequency and the different modulated signals have different unique cyclic fre-

    quencies. In [92], the cyclostationary detection method is employed for the

    detection of the Advanced Television Systems Committee DTV signals in wireless

    region-area network systems. Experimental results show superior detection per-

    formance even in very low SNR region. In [93], distributed detection is considered

    for scanning spectrum holes, where each CR employs a generalized likelihood ratio

    test for detecting primary transmissions with multiple cyclic frequencies.

    The above approach can detect the PU signal from other SUs signals over the

    same frequency band provided that the cyclic features of the PU and the CR signals

    differ from each other, which is usually the case, because different wireless systems

    usually employ different signal structures and parameters. By exploiting the distinct 

    cyclostationary characteristics of the PU and the CR signals, a strategy of extracting

    channel-allocation information is proposed in spectrum pooling systems [94], where

    the PU is a GSM network and the CR is an OFDM-based WLAN system. However,

    cyclostationary detection is more complex to implement than the energy detection

    and requires a prior knowledge of PU signal such as modulation format [71].

    1.4 Motivation

    Since there exists the hidden terminal problem in CRN as shown in Fig.  1.9, when

    the channel between the PU and the SU is effected by the shadow of building, the

    SU cannot accurately detect whether the PU is present or not in the interested bands

    of the SU. As a result, the SU may incorrectly detect the PU signal whereas the

    spectrum is idle, which results that the SU can not use this frequency band and thus

    lose the opportunities to access it. On the other hand, when the band is occupied by

    the PU while the PU signal is not detected by the SU, the SU will access this bandwhich causes serious interference to the PU. Accordingly, when the channel

    between the PU and the SU exists multipath fading and shadowing, the PU signal

    PUSUFig. 1.9   The hidden terminal

    problem between the PU and

    the SU

    1.3 Spectrum Sensing Technology 15

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    can not be accurately detected by single-user spectrum sensing. To address this

    issue, multiple CRs can be designed to collaborate in spectrum sensing [15,  71].

    Cooperative communication technology can effectively resist wireless channels’

    fading and greatly improve the transmission reliabilities, which has been regarded

    as one of the ways to deal with the problems of CR technology [95, 96]. References[22, 23, 78, 79] show that the system performance can be improved by introducing

    the cooperative communication into the CR system, in which, both of the advan-

    tages can be utilized. The cooperative spectrum sensing (CSS) is a main application

    in the combination of CR technology and cooperative communication technology.

    Previous studies have shown that the CSS can effectively improve the detection

    performance under fading channels [15,   24,   25,   75,   80,   97–104]. As discussed

    above, from the perspective of the network architecture, the CSS can be divided

    into centralized based CSS and distributed based CSS. In the centralized CSS mode,

    there exist a control channel and a central controller which is also called the FC, inwhich, each SU transmit the sensing result to the FC by the control channel, and

    then the FC makes a   nal decision on whether the PU signal exists or not by

    collecting all of the results from each SU and broadcast the availability of detected

    spectrum in the whole network. In the distributed CSS mode, there is no central

    controller, each SU sharing its local sensing information and decide whether the PU

    signal is present by combining its local sensing information with others’. In the

    distributed CSS mode, each SU will perform information fusion, which results a

    large amount of data computing. From the perspective of spectrum sharing, the FC

    is responsible for allocating the idle spectrum resources in the centralized CSS;while in the distributed CSS, each node is self-centered and mainly satisfy the need

    of itself, it will access the spectrum as long as the idle spectrum is detected without 

    considering about the needs of other SUs’. We mainly concentrate on the cen-

    tralized based CSS in this book.

    References

    1. Federal Communications commission (2002) Spectrum policy task force, ET Docket no.

    02-135 memorandum opinion and order 

    2. Federal Communications commission (2003) Notice of proposed rule making and order, ET

    Docket No 03-222

    3. Federal Communications commission (2003.) Notice of inquiry and notice of proposed

    Rulemaking, ET Docket No. 03-237

    4. Cheng P, Deng RL, Chen JM (2012) Energy-ef cient cooperative spectrum sensing in

    sensor-aided cognitive radio networks. IEEE Wirel Commun 19(6):100–105

    5. McHenry M, Livsics E, Nguyen T et al (2007) XG dynamic spectrum access  eld test results.

    IEEE Commun Mag 45(6):51–57

    6. McHenry MA NSF (2005) Spectrum occupancy measurements project summary. Shared

    Spectrum Company Rep

    7. Deng RL, Chen JM, Yuen C et al (2012) Energy-ef cient cooperative spectrum sensing by

    optimal scheduling in sensor-aided cognitive radio networks. IEEE Trans Veh Technol 61

    (2):716–725

    16 1 Introduction

  • 8/16/2019 Cognitive Wireless Networks Using the CSS Technology

    29/168

    8. Buddhikot MM, Ryan K (2005) Spectrum management in coordinated dynamic spectrum

    access based cellular networks. In: Proceedings of IEEE DySPAN 2005, pp 299–307

    9. Etkin R, Parekh A, Tse D (2005) Spectrum sharing for unlicensed bands. In: Proceedings of 

    IEEE DySPAN 2005, pp 251–258

    10. Grandblaise D, Bourse D, Moessner K, Leaves P (2002) Dynamic spectrum allocation

    (DSA) and recongurability. In: Proceedings of software-dened radio (SDR) Forum

    11. Kamakaris T, Buddhikot MM, Iyer R (2005) A case for coordinated dynamic spectrum

    access in cellular networks. In: Proceedings of IEEE DySPAN 2005, pp 289–298

    12. Leaves P, Moessner K, Tafazoli R, Grandblaise D, Bourse D, Tonjes R, Breveglieri M

    (2004) Dynamic spectrum allocation in composite recongurable wireless networks. IEEE

    Comm Mag 42:72–81

    13. Wang P, Akyildiz IF (2011) Can dynamic spectrum access induce heavy tailed delay? In:

    2011 IEEE symposium on new frontiers in dynamic spectrum access networks (DySPAN),

    Aachen, pp 197–207

    14. Wang P, Akyildiz IF (2012) On the origins of heavy-tailed delay in dynamic spectrum access

    networks. IEEE Trans Mobile Comput 11(2):204–217

    15. Cabric D, Mishra SM, Brodersen RW (2004) Implementation issues in spectrum sensing for cognitive radios. In: Proceedings of 38th Asilomar conferences signals, system, computers.

    United States, pp 772–776

    16. Cabric D, Brodersen RW (2005) Physical layer design issues unique to cognitive radio

    systems. In: Proceedings of IEEE personal indoor and mobile radio communications

    (PIMRC) 2005

    17. Cabric D, Mishra SM, Willkomm D, Brodersen R, Wolisz A (2005) A cognitive radio

    approach for usage of virtual unlicensed spectrum. In: Proceedings of 14th IST mobile and

    wireless communications summit 

    18. Maldonado D, Lie B, Hugine A, Rondeau TW, Bostian CW (2005) Cognitive radio

    applications to dynamic spectrum allocation. In: Proceedings of IEEE DySPAN 2005,

    pp 597–

    60019. Akyildiz IF, Lee WY, Vuran MC et al (2006) Next generation/dynamic spectrum

    access/cognitive radio wireless networks: a survey. Comput Net J 50(13):2127–2159

    20. Shin KG, Hyoil K, Min AW et al (2010) Cognitive radios for dynamic spectrum access: from

    concept to reality. IEEE Wirel Commun 17(6):64–74

    21. Mitola J, Maguit QG (1999) Cognitive radio: making software radios more personal. IEEE

    Pers Commun 6(4):13–18

    22. Simeone O, Gambini J, Bar-Ness Y et al (2007) Cooperation and cognitive radio. In:

    IEEE international conference on proceedings communications, 2007. ICC‘07, Glasgow,

    pp 6511–6515

    23. Scutari G, Palomar D, Barbarossa S (2008) Cognitive MIMO radio. IEEE Signal Process

    Mag 25(6):46–

    5924. Weiss T, Jondral F (2004) Spectrum pooling: an innovative strategy for the enhancement of 

    spectrum ef ciency. IEEE Commun Mag 42(3):S8–S14

    25. Ganesan G, Li Y (2005) Agility improvement through cooperative diversity in cognitive

    radio. In: Proceedings of IEEE global telecommunications conference. GLOBECOM’05,

    St. Louis, MO, United States, pp 2505–2509

    26. Tang JM (2011) Research on transmission performance of cognitive radio system based on

    cooperative communication. Beijing University of Posts and Telecommunications, Beijing

    27. Yan SN (2011) Research on spectrum sharing technologies based on cooperation for 

    cognitive radios. Beijing University of Posts and Telecommunications, Beijing

    28. IEEE 802.22-2011(TM) Standard for cognitive wireless regional area networks (RAN) for 

    operation in TV bands http://www.ieee802.org/22/ . 1 July 201129. IEEE 802.16’s license-exempt (LE) task group, [online]. Available: http://grouper.

    ieee802.0rg/16/e

    30. IEEE P1900 working group [online]. Available:  http://grouper.ieee.org/groups/emc/emc/ 

    1900/index.html

    References 17

    http://www.ieee802.org/22/http://grouper.ieee.org/groups/emc/emc/1900/index.htmlhttp://grouper.ieee.org/groups/emc/emc/1900/index.htmlhttp://grouper.ieee.org/groups/emc/emc/1900/index.htmlhttp://grouper.ieee.org/groups/emc/emc/1900/index.htmlhttp://www.ieee802.org/22/

  • 8/16/2019 Cognitive Wireless Networks Using the CSS Technology

    30/168

    31. Holland O, Muck M, Martigne P et al (2007) Development of a radio enabler for 

    reconguration management within the IEEE P1900.4 working group. IEEE DySPAN

    2007:232–239

    32. Muck M, Buljore S, Martigne P et al (2007) IEEE P1900.B: coexistence support for 

    recongurable, heterogeneous air interfaces. IEEE DySPAN 2007:381–389

    33. Shen J (2004) 3GPP long term evolution: principle and system design. The People ’s Posts

    and Telecommunications Press, Beijing

    34. Si JB (2010) Wireless cooperative transmission and the application in cognitive radio

    networks. Xidian University, Xian

    35. Guo CL, Feng CY, Zeng ZM (2010) Cognitive radio network technologies and application.

    Publishing House of Electronics Industry, Beijing

    36. Haykin S (2005) Cognitive radio: brain-empowered wireless communications. IEEE J Sel

    Areas Commun 23(2):201–220

    37. Zhang GW (2011) Spectrum sensing algorithms for cognitive radio networks. Shandong

    University, Jinan

    38. Brodersen RW et al (2004) Coruvs: a cognitive radio approach for usage of virtual

    unlicensed spectrum. Berkeley Wireless Research Center (BWRC) White paper 39. FP6 End-to-End Recongurability (R2R II) Integrated Project (IP), http://www.ntia.doc.gov/ 

    osmhome/allochrt.pdf 

    40. DAPRA XG WG (2003) The XG Architectural framework V1.0

    41. DAPRA XG WG (2003) The XG Vision RFC V1.0

    42. Thomas RW, DaSilva LA, MacKenzie AB (2005) Cognitive networks. In: Proceedings of 

    IEEE DySPAN 2005, pp 352–360

    43. Jondral FK (2005) Software-dened radio-basic and evolution to cognitive radio,

    EURASIP J Wirel Commun Networking 2005(3):275–283

    44. Hossain E, Bhargava V (2007) Cognitive wireless communication networks. Springer, Berlin

    45. Chen R, Park JM, Bian K (2008) Robust distributed spectrum sensing in cognitive radio

    networks. In: Proceedings of IEEE INFOCOM, Phoenix, pp 1876–

    188446. Wax M, Kailath T (1985) Detection of signals by Information theoretic criteria. IEEE Trans

    Acoust Speech Signal Process 33(2):387–392

    47. Editorial Guest (2007) Adaptive, spectrum agile and cognitive wireless networks. IEEE J Sel

    Areas Commun 25(3):513–516

    48. Varshney PK (1996) Distributed detection and data fusion, 1st edn. Article Book, Springer,

    Berlin pp 1–276

    49. Lehtomaki JJ, Vartiainen J, Juntti M, Saarnisaari H (2006) Spectrum sensing with forward

    methods. In: Proceedings of IEEE MILCOM, Washington, DC, pp 1–7

    50. Dior (2009) Spectrum sensing optimization based on detection and power constraints.

    Huazhong University of Science and Technology, Wuhan

    51. Zhao Q, Sadler BM (2007) Dynamic spectrum access: signal processing, networking andregulatory policy. IEEE Signal Process Mag 55(5):2294–2309

    52. Benkler Y (1998) Overcoming agoraphobia: building the commons of the digitally

    networked environment. Harvard J Law Technol 11:(287)

    53. Lehr W, Crowncroft J (2005) Managing shared access to a spectrum commons. In:

    Proceedings of IEEE DySPAN 2005, pp 420–444

    54. Brik V, Rozner E, Banarjee S, Bahl P, DSAP (2005) A protocol for coordinated spectrum

    access. In: Proceedings of IEEE DySPAN 2005, pp 611–614

    55. Cao L, Zheng H (2005) Distributed spectrum allocation via local bargaining. In: Proceedings

    of IEEE sensor and Ad Hoc communications and networks (SECON) 2005, pp 475–486

    56. Ma L, Han X, Shen CC (2005) Dynamic open spectrum sharing MAC protocol for wireless

    ad hoc network. In: Proceedings of IEEE DySPAN 2005, pp 203–

    21357. Sankaranarayanan S, Papadimitratos P, Mishra A, Hershey S (2005) A bandwidth sharing

    approach to improve licensed spectrum utilization. In: Proceedings of IEEE DySPAN 2