Description
Book SynopsisA comprehensive summary of theoretical and practical developments in LTE Heterogeneous Networks
The last decade has witnessed the proliferation of mobile broadband data and the trend is likely to increase in the coming years. Current cellular networks are ill equipped to deal with this surge in demand. To satisfy user demand and maximize profits, a new paradigm to operate networks is needed. Heterogeneous networks, that deploy an overlay of small cells with limited coverage and transmit power, over a macro coverage area is the solution by providing capacity and coverage where it is needed.
This book presents a comprehensive overview of small cell based heterogeneous networks within the framework of 3GPP LTE-Advanced which is the major enabler of current and future heterogeneous networks. The book first establishes the basics of LTE standards 8 -10. Wherever relevant, the underlying theory of wireless communications is explained and the signaling and proto
Table of Contents
About the Authors xi
Foreword xiii
Preface xv
Acknowledgements xvii
List of Acronyms xix
1 An Introduction to Heterogeneous Networks 1
1.1 Introduction 1
1.2 Heterogeneous Network Deployments 3
1.2.1 Distributed Antenna Systems 3
1.2.2 Public Access Picocells/Metrocells 4
1.2.3 Consumer-Grade Femtocells 4
1.2.4 WiFi Systems 5
1.3 Features of Heterogeneous Networks 5
1.3.1 Association and Load Balancing 5
1.3.2 Interference Management 6
1.3.3 Self-Organizing Networks 6
1.3.4 Mobility Management 7
1.4 Evolution of Cellular Technology and Standards 7
1.4.1 3GPP Standardization Process 9
References 10
Part I OVERVIEW
2 Fundamentals of LTE 15
2.1 Introduction 15
2.2 LTE Core Network 17
2.2.1 Control Plane 18
2.2.2 User Plane 19
2.2.3 Practical Implementations of the Core Network 19
2.3 LTE Radio Access Network 20
2.3.1 Control Plane 20
2.3.2 User Plane 23
2.4 Connectivity Among eNodeBs: The X2 Interface 24
2.4.1 Load- and Interference-Related Information 26
2.4.2 Handover-Related Information 26
2.5 Technologies in LTE 27
2.5.1 Orthogonal Frequency Division Multiplexing 27
2.5.2 Multiple Antenna Communications 36
References 42
3 LTE Signal Structure and Physical Channels 45
3.1 Introduction 45
3.2 LTE Signal Structure 45
3.3 Introduction to LTE Physical Channels and Reference Signals 48
3.4 Resource Block Assignment 51
3.5 Downlink Physical Channels 54
3.5.1 Physical Broadcast Channel (PBCH) 55
3.5.2 Physical Downlink Shared Channel (PDSCH) 57
3.5.3 Physical Multicast Channel (PMCH) 58
3.5.4 Physical Control Format Indicator Channel (PCFICH) 58
3.5.5 Physical Hybrid ARQ Indicator Channel (PHICH) 59
3.5.6 Physical Downlink Control Channel (PDCCH) 60
3.6 Uplink Physical Channels 67
3.6.1 Physical Uplink Shared Channel (PUSCH) 67
3.6.2 Physical Uplink Control Channel (PUCCH) 68
3.6.3 Physical Random Access Channel (PRACH) 70
References 71
4 Physical Layer Signal Processing in LTE 73
4.1 Introduction 73
4.2 Downlink Synchronization Signals 73
4.2.1 Primary Synchronization Signal 74
4.2.2 Secondary Synchronization Signal 76
4.3 Reference Signals 77
4.3.1 Downlink Reference Signals 77
4.3.2 Uplink Reference Signals 84
4.4 Channel Estimation and Feedback 85
4.4.1 Basics of Link Adaptation 85
4.4.2 Feedback for MIMO OFDM Channels 88
4.4.3 New Features in LTE-Advanced 92
4.5 Design Paradigm of LTE Signaling 94
4.6 Scheduling and Resource Allocation 94
4.6.1 Scheduling Algorithms 96
4.6.2 Inter-eNodeB Coordination for Resource Allocation in LTE 98
References 100
Part II INTER-CELL INTERFERENCE COORDINATION
5 Release 10 Enhanced ICIC 103
5.1 Introduction 103
5.2 Typical Deployment Scenarios 103
5.2.1 Macro–Pico Deployment Scenario 104
5.2.2 Macro–Femto Deployment Scenario 107
5.3 Time Domain Techniques 110
5.3.1 Almost Blank Subframe 110
5.3.2 ABS Use Cases 113
5.3.3 UE Measurement and Reporting 116
5.3.4 Backhaul Support 118
5.3.5 Simulation Results 119
5.4 Power Control Techniques 123
5.4.1 Target Scenario 123
5.4.2 Power Control Schemes 124
5.4.3 Results from Realistic Deployments 125
5.5 Carrier Aggregation-Based eICIC 127
References 130
6 Release 11 Further Enhanced ICIC: Transceiver Processing 133
6.1 Introduction 133
6.2 Typical Deployment Scenarios 133
6.3 Techniques for Mitigating CRS Interference 136
6.3.1 Receiver-Based Techniques 136
6.3.2 Transmitter-Based Techniques 140
6.4 Weak Cell Detection 142
6.5 Non-Zero-Power ABS 144
References 147
7 Release 11 Further Enhanced ICIC: Remaining Topics 149
7.1 Carrier-Based Interference Coordination 149
7.1.1 Operational Carrier Selection 150
7.1.2 Primary and Secondary Cell Selection 153
7.2 Enhanced PDCCH for Interference Coordination 154
References 159
Part III COORDINATED MULTI-POINT TRANSMISSION RECEPTION
8 Downlink CoMP: Signal Processing 163
8.1 Introduction 163
8.2 CoMP Scenarios in 3GPP 164
8.2.1 Homogeneous Networks with Intra-Site CoMP 164
8.2.2 Homogeneous Networks with High-Power RRHs 165
8.2.3 Heterogeneous Networks with Low-Power RRHs with Cell IDs Different from the Macro 165
8.2.4 Heterogeneous Networks with Low-Power RRHs with Cell IDs the Same as the Macro 166
8.3 CoMP Sets 167
8.3.1 RRM Measurement Set/CoMP Resource Management Set 167
8.3.2 CoMP Measurement Set 168
8.3.3 CoMP Cooperating Set 169
8.4 CoMP Transmission in 3GPP 169
8.4.1 Coordinated Scheduling/Beamforming 169
8.4.2 Dynamic Point Selection 172
8.4.3 Joint Transmission 177
8.5 Comparison of Different CoMP Categories 180
References 182
9 Downlink CoMP: Standardization Impact 185
9.1 Introduction 185
9.2 Modification of Reference Signals 185
9.2.1 Modifications in CSI-RS 185
9.2.2 Modifications in DMRS 186
9.3 CSI Processes 189
9.3.1 UE Processing Complexity and CSI Reference Resources 191
9.3.2 Inheritance and Reference Processes 192
9.4 PDSCH Rate Matching 193
9.5 Quasi-Co-Location of Antenna Ports 195
9.5.1 Quasi-Co-Location Between the Same Antenna Ports 197
9.5.2 Quasi-Co-Location Between Different Antenna Ports 198
9.6 New Transmission Mode and DCI Format 200
9.7 Backhaul Support for CoMP 201
9.8 Summary 203
References 203
Part IV UPCOMING TECHNOLOGIES
10 Dense Small Cell Deployments 207
10.1 Introduction 207
10.2 Evolution of Small Cells 207
10.2.1 Deployment Scenarios 209
10.3 Efficient Operation of Small Cells 212
10.3.1 Dual Connectivity 214
10.3.2 ICIC Mechanism 216
10.3.3 Small Cell Discovery 220
10.4 Control Signaling Enhancement 223
10.4.1 Multi-Subframe Scheduling 223
10.4.2 Cross-Subframe Scheduling 224
10.5 Reference Signal Overhead Reduction 225
10.5.1 Downlink DMRS 225
10.5.2 Uplink DMRS 227
References 228
11 TD-LTE Enhancements for Small Cells 231
11.1 Enhancements for Dynamic TDD 231
11.1.1 TDD UL/DL Reconfiguration Scenarios in 3GPP 232
11.1.2 Interference Mitigation Schemes 234
11.2 FDD-TDD Joint Operation 239
11.2.1 Deployment Scenarios 240
11.2.2 Issues and Potential Solutions 241
References 243
12 Full Dimension MIMO 245
12.1 Introduction 245
12.2 Antenna Systems Architecture: Passive and Active 245
12.3 Antenna Patterns 248
12.3.1 Passive Antenna Element Pattern 248
12.3.2 Active Antenna Systems 250
12.3.3 AAS with Additional Mechanical Tilt 253
12.3.4 Effect of Multipath Fading Channels 253
12.4 FD-MIMO Deployment Scenarios 254
12.4.1 UE-Specific FD-MIMO 254
12.4.2 Cell-Specific FD-MIMO 255
12.4.3 System-Specific FD-MIMO 255
12.5 Conclusion 256
References 256
13 Future Trends in Heterogeneous Networks 257
13.1 Summary 257
13.2 Small Cells and Cloud RAN 258
13.3 Small Cells, Millimeter Wave Communications and Massive MIMO 259
13.4 Small Cells and Big Data 260
13.5 Concluding Remarks 260
References 260
Index 263
