Lte Communications and Networks: Femtocells and Antenna Design Challenges

ISBN-13: 9781119385226 / Angielski / Twarda / 2018 / 360 str.

Masood Ur Rehman; Ghazanfar Ali Safdar

Spis treści

List of Contributors xv

Preface xvi

1 Introduction 1
Ghazanfar Ali Safdar and Masood Ur Rehman

1.1 Evolution of Wireless and Cellular Communication 2

1.1.1 1 G 3

1.1.2 2 G 3

1.1.3 2.5 G 3

1.1.4 2.75 G 4

1.1.5 3 G 4

1.1.6 3.5 G 4

1.1.7 4 G/LTE 5

1.2 LTE Architecture 5

1.2.1 Communications Perspective Challenges in LTE Networks 8

1.2.1.1 Signalling System 8

1.2.1.2 Backward Compatibility 9

1.2.1.3 BS Efficiency 9

1.2.2 LTE Radio Frame 10

1.3 LTE Antennas 11

1.4 LTE Applications 11

1.4.1 Communications 11

1.4.2 Public Safety 12

1.4.3 Device ]to ]Device Communications 12

1.4.4 Video Streaming 12

1.4.5 Voice over LTE (VoLTE) 12

1.4.6 Internet of Things 13

1.4.7 Wearable Systems 13

1.4.8 Cloud Computing 13

1.5 Book Organization 14

References 16

Part I LTE Femtocells 19

2 LTE Femtocells 21
Ghazanfar Ali Safdar

2.1 Introduction 21

2.1.1 Cross ]Tier Interference 22

2.1.2 Co ]Tier Interference 24

2.1.3 Downlink Interference Modelling 24

2.1.4 Uplink Interference Modelling 25

2.2 Platform for Femtocell Deployment 26

2.3 LTE Architecture Overview 26

2.3.1 LTE Downlink Transmission 27

2.3.2 LTE Uplink Transmission 27

2.4 LTE Femtocell Interference Analysis 28

2.4.1 Scenario 1: Cross ]Tier Interference Analysis 28

2.4.2 Scenario 2: Effects of Femtocell Access Mode Deployment 28

2.4.3 Scenario 3: Co ]Tier Interference Analysis 29

2.4.4 Scenario 4: Effects of Varying FAP Transmit Power Levels on MUEs 29

2.5 Interference Mitigation: Current State of the Art 31

2.5.1 Spectrum Access/Frequency Assignment 31

2.5.2 Power Control 32

2.5.3 Antenna Schemes 33

2.6 Cognitive Femtocells: A Smart Solution to a Complex Problem 33

2.7 Summary 35

References 36

3 Interference Mitigation in Cognitive Radio ]Based LTE Femtocells 38
Ghazanfar Ali Safdar

3.1 Introduction 39

3.2 Femtocells 41

3.2.1 Femtocells Interference versus Deployment 43

3.2.2 Femtocells Typical Interference Mitigation Techniques 46

3.2.2.1 Spectrum Access/Frequency Assignment Schemes 46

3.2.2.2 Power Control (PC) Schemes 46

3.2.2.3 Antenna Schemes 48

3.3 Interference Mitigation in Femtocells using Cognitive Radio 49

3.3.1 Cognitive Interference Mitigation 51

3.3.1.1 Cognitive Interference Mitigation PC 52

3.3.1.2 Cognitive Interference Mitigation Spectrum Access 54

3.3.1.3 Cognitive Interference Mitigation Antenna Schemes 64

3.3.1.4 Cognitive Interference Mitigation Joint Schemes 66

3.3.2 Cognitive Interference Mitigation versus Conventional Interference Mitigation 70

3.4 Summary 74

References 75

4 Coverage Area ]Based Power Control for Interference Management in LTE Femtocells 84
Ghazanfar Ali Safdar

4.1 Introduction 85

4.2 Coverage Radius Based Power Control Scheme (PS) 88

4.2.1 Radius Limit Setting 89

4.2.2 Initial Coverage Radius 89

4.2.3 Self ]Update 89

4.2.4 Final Radius 89

4.3 System Model 90

4.4 Performance Analysis 92

4.4.1 Results and Discussion 93

4.4.1.1 SINR Cross ]Tier (Single Cell) 93

4.4.1.2 SINR Co ]Tier (Single Cell) 94

4.4.1.3 Downlink Throughput (Single Cell) 95

4.4.1.4 Co ] and Cross ]Tier SINR (Single Cell versus Multicell) 96

4.4.1.5 Droppage in SINR (Single Cell versus Multicell) 97

4.4.1.6 Coverage Area Bounds and Impact on SINR (Single Cell versus Multicell) 99

4.5 Summary 100

References 101

5 Energy Management in LTE Femtocells 104
Kapil Kanwal, Ghazanfar Ali Safdar, Masood Ur Rehman and Xiaodong Yang

5.1 Introduction 105

5.2 Architecture of LTE Networks 105

5.2.1 Communications Perspective Challenges in LTE Networks 106

5.2.1.1 Signalling System 106

5.2.1.2 Backward Compatibility 107

5.2.1.3 BS Efficiency 107

5.2.2 Importance of Energy Management in LTE Networks 108

5.3 Classification of ES Schemes 108

5.3.1 Static Power Consumption 109

5.3.2 Dynamic Power Consumption 109

5.4 Energy Efficient Resource Allocation 113

5.4.1 Hybrid FBS and MBS Based Schemes 113

5.4.2 Link Adaptation Schemes 114

5.4.3 Cross Layer Resource Allocation Schemes 115

5.4.4 MBSFN Resource Allocation Scheme 115

5.5 Bandwidth Expansion Schemes 117

5.5.1 CoMP Based Coverage Expansion 117

5.5.2 Time Compression (TCoM) Scheme 118

5.5.3 Bandwidth Expansion Mode (BEM) Scheme 119

5.5.4 Component Carrier Based Schemes 121

5.5.5 Scheduling Based Schemes 122

5.6 Load Balancing Schemes 123

5.6.1 Distance Aware Schemes 123

5.6.2 Coverage Expansion Based Schemes 125

5.6.3 Distributed Schemes 125

5.6.4 Shared Relay Based Schemes 127

5.6.5 CRN Adopted Switching Off of a BS 128

5.6.6 Reduced Early Handover (REHO) Scheme 129

5.7 Comparative Analysis 130

5.8 Open Research Issues 135

5.9 Summary 139

References 140

6 Spectrum Sensing Mechanisms in Cognitive Radio Based LTE Femtocells 150
Tazeen S. Syed and Ghazanfar Ali Safdar

6.1 Fundamentals of Signal Processing 151

6.1.1 Channel Model 151

6.1.1.1 Additive Gaussian Noise Channel 151

6.1.1.2 Linear Filter Channel 152

6.1.1.3 Band Limited Channel 153

6.1.2 Modulation Technique 153

6.1.3 Error Probability 154

6.2 Spectrum Sensing Techniques 155

6.2.1 Primary Transmitter Detection 155

6.2.1.1 Energy Detector 156

6.2.1.2 Matched Filter Detection 158

6.2.1.3 Cyclostationary Feature Detection 159

6.2.1.4 Waveform Detection 160

6.2.1.5 Wavelet Detection 161

6.2.1.6 Hybrid Sensing 162

6.2.1.7 Multi ]Taper Spectrum Sensing 163

6.2.2 Collaborative/Cooperative Detection 163

6.2.3 Interference Temperature Detection 166

6.2.4 Primary Receiver Detection 166

6.3 History Assisted Spectrum Sensing 166

6.4 Model ]and Statistics ]Based Spectrum Sensing Classification 167

6.5 Challenges and Issues 172

6.6 Summary 176

References 177

Part II Antennas for LTE Femtocells 185

7 Antenna Consideration for LTE Femtocells 187
Masood Ur Rehman

7.1 Antenna Fundamentals 187

7.1.1 Input Impedance and Matching 188

7.1.2 Bandwidth 189

7.1.3 Radiation Pattern 190

7.1.4 Directivity and Gain 191

7.1.5 Efficiency 193

7.1.6 Polarization 193

7.2 Antenna Requirements for LTE Femtocells 196

7.2.1 Frequency Bands 197

7.2.2 Form Factor and Size Limitation 201

7.2.3 Impedance Matching, Directivity, Gain and Efficiency 201

7.2.4 Directionality 202

7.2.5 Polarization 203

7.2.6 Human Body Effects and Specific Absorption Rate (SAR) 204

7.2.7 Multiple Input Multiple Output (MIMO) 205

References 206

8 Multiband Antennas for LTE Femtocells 209
Masood Ur Rehman and Xiaodong Yang

8.1 Fundamentals of Multiband Antennas 209

8.1.1 Multiband Techniques 210

8.1.1.1 Higher Order Resonances 210

8.1.1.2 Multiple Resonant Structures 211

8.2 Types of Multiband Antennas 211

8.3 Multiband Antenna Design: Case Studies 214

8.3.1 Multi ]Slot Antenna 215

8.3.1.1 Antenna Geometry 215

8.3.1.2 Antenna Performance Evaluation 215

8.3.2 Patch ]Loop Combination Antenna 220

8.3.2.1 Antenna Configuration 220

8.3.2.2 Antenna Performance 220

8.4 Open Research Issues 227

References 227

9 Reconfigurable Antennas for LTE Femtocells 230
Masood Ur Rehman and Waqas Farooq

9.1 Fundamentals of Reconfigurable Antennas 230

9.1.1 Types of Reconfigurable Antennas 231

9.1.1.1 Use of Switches 232

9.1.1.2 Structural and Mechanical Changes 232

9.1.1.3 Material Changes 234

9.2 Realization of Reconfigurable Antennas 234

9.3 Rectangular Patch Reconfigurable LTE Femtocell Antenna 237

9.3.1 Design Conception 237

9.3.2 Frequency Reconfiguration Mode 239

9.3.3 Antenna Performance Evaluation 240

9.4 Circular Patch Reconfigurable LTE Femtocell Antenna 246

9.4.1 Frequency Reconfiguration Mode 248

9.4.2 Antenna Performance Evaluation 248

9.5 Open Research Issues 253

References 254

10 Multimode Antennas for LTE Femtocells 259
Oluyemi Peter Falade, Xiaodong Chen and Masood Ur Rehman

10.1 Multimode Antennas: Fundamentals and Types 260

10.2 Design of a Compact Multimode LTE Femtocell Antenna for Handheld Devices 261

10.2.1 Numerical Analysis 263

10.2.2 Experimental Investigation 266

10.3 Design of a Multifunctional Compact Antenna for LTE Femtocells and GNSS Systems 268

10.3.1 Numerical Analysis 273

10.3.2 Experimental Investigation 279

10.4 Summary 284

10.5 Open Challenges and Issues 284

References 284

11 Human Body Effects on LTE Femtocell Antennas 289
Masood Ur Rehman and Qammer Hussain Abbasi

11.1 Interaction of the Human Body with Antennas 290

11.2 Numerical Modelling of the Human Body 291

11.2.1 Evaluation and Comparison of Numerical Models of Human Body 294

11.2.1.1 On ]Body Transmission 294

11.2.1.2 Effects on Antenna Radiation Pattern 297

11.2.1.3 Electric Field Distribution 299

11.2.1.4 Specific Absorption Rate (SAR) 300

11.3 Evaluation of Human Body Effects on LTE Femtocell Antennas 305

11.3.1 On ]Body Antenna Placement 308

11.3.2 Antenna ]Body Separation 310

11.3.3 On ]Body LTE Channel Characterization 312

11.3.4 On ]Off Body LTE Channel Characterization 313

11.3.5 Body ]to ]Body LTE Channel Characterization 315

11.4 Open Research Issues 316

References 317

12 The Road Ahead for LTE Femtocells 322
Masood Ur Rehman and Ghazanfar Ali Safdar

12.1 Future Prospects and Challenges 323

12.1.1 Spectrum Sharing 324

12.1.2 Intelligent/Efficient Spectrum Sensing Schemes 324

12.1.3 Primary/Secondary User Issue 325

12.1.4 Energy Saving 325

12.1.5 Security 326

12.1.6 Pilot Power/Coverage Radius Issue 326

12.1.7 Signalling Overhead 326

12.1.8 Proximity Services 326

12.1.9 The Internet ]of ]Things (IoT) 327

12.1.10 The Age of Big Data 328

12.1.11 5G and Femtocells 328

12.1.12 Antenna Design and Channel Modelling 328

References 330

Index 332

 

O autorze

DR. MASOOD UR REHMAN is a Lecturer in Electronic Engineering at the University of Bedfordshire, UK. He has authored four books, eight book chapters, more than eighty technical papers in leading journals and peer–reviewed conferences, and one patent in the area of antennas and RF systems.

DR. GHAZANFAR ALI SAFDAR is a Senior Lecturer in Computer Networking at the University of Bedfordshire, UK. He has authored two books, nine book chapters and approximately sixty research papers in renowned journals and peer–reviewed conferences in the area of wireless communications and networking.

Blurb

A COMPREHENSIVE RESOURCE TO THE LATEST DEVELOPMENTS OF SYSTEM ENHANCEMENT TECHNIQUES OF FEMTOCELLS, POWER MANAGEMENT, INTERFERENCE MITIGATION AND ANTENNA DESIGN

LTE Communications and Networks fills a gap in the literature to offer a comprehensive review of the most current developments of LTE Femtocells and antennas and explores their future growth. With contributions from a group of experts that represent the fields of wireless communications and mobile communications, signal processing and antenna design, this text identifies technical challenges and presents recent results related to the development, integration and enhancement of LTE systems in portable devices.

The authors examine topics such as application of cognitive radio with efficient sensing mechanisms, interference mitigation and power management schemes for the LTE systems. They also provide a comprehensive account of design challenges and approaches, performance enhancement techniques and effects of user′s presence on the LTE antennas. LTE Communications and Networks also highlights the promising technologies of multiband, multimode and reconfigurable antennas for efficient design of portable LTE devices. Designed to be a practical resource, this text:

• Explores the interference mitigation, power control and spectrum management in LTE Femtocells and related issues
• Contains information on the design challenges, different approaches, performance enhancement and application case scenarios for the LTE antennas
• Covers the most recent developments of system enhancement techniques in terms of Femtocells, power management, interference mitigation and antenna design
• Includes contributions from leading experts in the field

Written for industry professionals and researchers, LTE Communications and Networks is a groundbreaking book that presents a comprehensive treatment of the LTE systems in the context of Femtocells and antenna design and covers the wide range of issues related to the topic.