Joydeep Acharya received his PhD degree in Electrical Engineering from Rutgers University in 2009. Currently he is a staff research engineer at Hitachi America's Wireless Systems Research Lab (WSRL) where he is involved in physical layer research and standardization in LTE-Advanced. Previously, he had worked as a research consultant in GS Sanyal School of Telecommunications, Indian Institute of Technology Kharagpur on Physical Layer design of WCDMA. He has been participating in 3GPP RAN 1 and 2 meetings since 2009. He is the author of several IEEE conference and journal papers and inventor of several patents filed worldwide. His research topics include MIMO signal processing, base station coordination, massive MIMO and spectrum regulation and resource allocation for wireless systems.Long Gao received his B.S. degree from Beijing Jiaotong University, Beijing, China, in 2003 and his M.S. degree from Beijing University of Posts and Telecommunications, Beijing, China, in 2006, both in Electrical Engineering. He received his Ph.D. degree in Electrical Engineering from Texas A&M University, College Station, TX and joined Hitachi America, Ltd, Santa Clara, CA, in 2010. Since then, he has been involved in 3GPP LTE/LTE-Advanced standardization activities with focus on cooperative communication and heterogeneous networks. He has published several IEEE papers and submitted several technical contributions to 3GPP RAN1 conference. He has served as a TPC member in major IEEE conferences such as Globecom 2010-2013. He has presented tutorials on LTE-Advanced heterogeneous network in VTC 2012 and WCNC 2013.Sudhanshu Gaur has over 10 years of research and industry experience in the field of wireless communications. He is currently the Principal Research Engineer at Hitachi America's Wireless System Research Lab (WSRL) where he leads LTE-Advanced standardization activities. Earlier he was also involved with IEEE 802.11aa standardization and contributed to Hitachi's wireless HD video system which was demonstrated in CES 2008. Prior to joining Hitachi, he attended Georgia Institute of Technology for PhD degree (2005) and received M.S and B.Tech degrees from Virginia Tech (2003) and Indian Institute of Technology, Kharagpur (2000), respectively. He is a Senior Member of IEEE, has authored several peer reviewed publications in wireless communications, and holds several patents.

• About the Authors xiForeword xiiiPreface xvAcknowledgements xviiList of Acronyms xix1 An Introduction to Heterogeneous Networks 11.1 Introduction 11.2 Heterogeneous Network Deployments 31.2.1 Distributed Antenna Systems 31.2.2 Public Access Picocells/Metrocells 41.2.3 Consumer-Grade Femtocells 41.2.4 WiFi Systems 51.3 Features of Heterogeneous Networks 51.3.1 Association and Load Balancing 51.3.2 Interference Management 61.3.3 Self-Organizing Networks 61.3.4 Mobility Management 71.4 Evolution of Cellular Technology and Standards 71.4.1 3GPP Standardization Process 9References 10Part I OVERVIEW2 Fundamentals of LTE 152.1 Introduction 152.2 LTE Core Network 172.2.1 Control Plane 182.2.2 User Plane 192.2.3 Practical Implementations of the Core Network 192.3 LTE Radio Access Network 202.3.1 Control Plane 202.3.2 User Plane 232.4 Connectivity Among eNodeBs: The X2 Interface 242.4.1 Load- and Interference-Related Information 262.4.2 Handover-Related Information 262.5 Technologies in LTE 272.5.1 Orthogonal Frequency Division Multiplexing 272.5.2 Multiple Antenna Communications 36References 423 LTE Signal Structure and Physical Channels 453.1 Introduction 453.2 LTE Signal Structure 453.3 Introduction to LTE Physical Channels and Reference Signals 483.4 Resource Block Assignment 513.5 Downlink Physical Channels 543.5.1 Physical Broadcast Channel (PBCH) 553.5.2 Physical Downlink Shared Channel (PDSCH) 573.5.3 Physical Multicast Channel (PMCH) 583.5.4 Physical Control Format Indicator Channel (PCFICH) 583.5.5 Physical Hybrid ARQ Indicator Channel (PHICH) 593.5.6 Physical Downlink Control Channel (PDCCH) 603.6 Uplink Physical Channels 673.6.1 Physical Uplink Shared Channel (PUSCH) 673.6.2 Physical Uplink Control Channel (PUCCH) 683.6.3 Physical Random Access Channel (PRACH) 70References 714 Physical Layer Signal Processing in LTE 734.1 Introduction 734.2 Downlink Synchronization Signals 734.2.1 Primary Synchronization Signal 744.2.2 Secondary Synchronization Signal 764.3 Reference Signals 774.3.1 Downlink Reference Signals 774.3.2 Uplink Reference Signals 844.4 Channel Estimation and Feedback 854.4.1 Basics of Link Adaptation 854.4.2 Feedback for MIMO OFDM Channels 884.4.3 New Features in LTE-Advanced 924.5 Design Paradigm of LTE Signaling 944.6 Scheduling and Resource Allocation 944.6.1 Scheduling Algorithms 964.6.2 Inter-eNodeB Coordination for Resource Allocation in LTE 98References 100Part II INTER-CELL INTERFERENCE COORDINATION5 Release 10 Enhanced ICIC 1035.1 Introduction 1035.2 Typical Deployment Scenarios 1035.2.1 Macro–Pico Deployment Scenario 1045.2.2 Macro–Femto Deployment Scenario 1075.3 Time Domain Techniques 1105.3.1 Almost Blank Subframe 1105.3.2 ABS Use Cases 1135.3.3 UE Measurement and Reporting 1165.3.4 Backhaul Support 1185.3.5 Simulation Results 1195.4 Power Control Techniques 1235.4.1 Target Scenario 1235.4.2 Power Control Schemes 1245.4.3 Results from Realistic Deployments 1255.5 Carrier Aggregation-Based eICIC 127References 1306 Release 11 Further Enhanced ICIC: Transceiver Processing 1336.1 Introduction 1336.2 Typical Deployment Scenarios 1336.3 Techniques for Mitigating CRS Interference 1366.3.1 Receiver-Based Techniques 1366.3.2 Transmitter-Based Techniques 1406.4 Weak Cell Detection 1426.5 Non-Zero-Power ABS 144References 1477 Release 11 Further Enhanced ICIC: Remaining Topics 1497.1 Carrier-Based Interference Coordination 1497.1.1 Operational Carrier Selection 1507.1.2 Primary and Secondary Cell Selection 1537.2 Enhanced PDCCH for Interference Coordination 154References 159Part III COORDINATED MULTI-POINT TRANSMISSION RECEPTION8 Downlink CoMP: Signal Processing 1638.1 Introduction 1638.2 CoMP Scenarios in 3GPP 1648.2.1 Homogeneous Networks with Intra-Site CoMP 1648.2.2 Homogeneous Networks with High-Power RRHs 1658.2.3 Heterogeneous Networks with Low-Power RRHs with Cell IDs Different from the Macro 1658.2.4 Heterogeneous Networks with Low-Power RRHs with Cell IDs the Same as the Macro 1668.3 CoMP Sets 1678.3.1 RRM Measurement Set/CoMP Resource Management Set 1678.3.2 CoMP Measurement Set 1688.3.3 CoMP Cooperating Set 1698.4 CoMP Transmission in 3GPP 1698.4.1 Coordinated Scheduling/Beamforming 1698.4.2 Dynamic Point Selection 1728.4.3 Joint Transmission 1778.5 Comparison of Different CoMP Categories 180References 1829 Downlink CoMP: Standardization Impact 1859.1 Introduction 1859.2 Modification of Reference Signals 1859.2.1 Modifications in CSI-RS 1859.2.2 Modifications in DMRS 1869.3 CSI Processes 1899.3.1 UE Processing Complexity and CSI Reference Resources 1919.3.2 Inheritance and Reference Processes 1929.4 PDSCH Rate Matching 1939.5 Quasi-Co-Location of Antenna Ports 1959.5.1 Quasi-Co-Location Between the Same Antenna Ports 1979.5.2 Quasi-Co-Location Between Different Antenna Ports 1989.6 New Transmission Mode and DCI Format 2009.7 Backhaul Support for CoMP 2019.8 Summary 203References 203Part IV UPCOMING TECHNOLOGIES10 Dense Small Cell Deployments 20710.1 Introduction 20710.2 Evolution of Small Cells 20710.2.1 Deployment Scenarios 20910.3 Efficient Operation of Small Cells 21210.3.1 Dual Connectivity 21410.3.2 ICIC Mechanism 21610.3.3 Small Cell Discovery 22010.4 Control Signaling Enhancement 22310.4.1 Multi-Subframe Scheduling 22310.4.2 Cross-Subframe Scheduling 22410.5 Reference Signal Overhead Reduction 22510.5.1 Downlink DMRS 22510.5.2 Uplink DMRS 227References 22811 TD-LTE Enhancements for Small Cells 23111.1 Enhancements for Dynamic TDD 23111.1.1 TDD UL/DL Reconfiguration Scenarios in 3GPP 23211.1.2 Interference Mitigation Schemes 23411.2 FDD-TDD Joint Operation 23911.2.1 Deployment Scenarios 24011.2.2 Issues and Potential Solutions 241References 24312 Full Dimension MIMO 24512.1 Introduction 24512.2 Antenna Systems Architecture: Passive and Active 24512.3 Antenna Patterns 24812.3.1 Passive Antenna Element Pattern 24812.3.2 Active Antenna Systems 25012.3.3 AAS with Additional Mechanical Tilt 25312.3.4 Effect of Multipath Fading Channels 25312.4 FD-MIMO Deployment Scenarios 25412.4.1 UE-Specific FD-MIMO 25412.4.2 Cell-Specific FD-MIMO 25512.4.3 System-Specific FD-MIMO 25512.5 Conclusion 256References 25613 Future Trends in Heterogeneous Networks 25713.1 Summary 25713.2 Small Cells and Cloud RAN 25813.3 Small Cells, Millimeter Wave Communications and Massive MIMO 25913.4 Small Cells and Big Data 26013.5 Concluding Remarks 260References 260Index 263

Joydeep Acharya received his PhD degree in Electrical Engineering from Rutgers University in 2009. Currently he is a staff research engineer at Hitachi America's Wireless Systems Research Lab (WSRL) where he is involved in physical layer research and standardization in LTE-Advanced. Previously, he had worked as a research consultant in GS Sanyal School of Telecommunications, Indian Institute of Technology Kharagpur on Physical Layer design of WCDMA. He has been participating in 3GPP RAN 1 and 2 meetings since 2009. He is the author of several IEEE conference and journal papers and inventor of several patents filed worldwide. His research topics include MIMO signal processing, base station coordination, massive MIMO and spectrum regulation and resource allocation for wireless systems.Long Gao received his B.S. degree from Beijing Jiaotong University, Beijing, China, in 2003 and his M.S. degree from Beijing University of Posts and Telecommunications, Beijing, China, in 2006, both in Electrical Engineering. He received his Ph.D. degree in Electrical Engineering from Texas A&M University, College Station, TX and joined Hitachi America, Ltd, Santa Clara, CA, in 2010. Since then, he has been involved in 3GPP LTE/LTE-Advanced standardization activities with focus on cooperative communication and heterogeneous networks. He has published several IEEE papers and submitted several technical contributions to 3GPP RAN1 conference. He has served as a TPC member in major IEEE conferences such as Globecom 2010-2013. He has presented tutorials on LTE-Advanced heterogeneous network in VTC 2012 and WCNC 2013.Sudhanshu Gaur has over 10 years of research and industry experience in the field of wireless communications. He is currently the Principal Research Engineer at Hitachi America's Wireless System Research Lab (WSRL) where he leads LTE-Advanced standardization activities. Earlier he was also involved with IEEE 802.11aa standardization and contributed to Hitachi's wireless HD video system which was demonstrated in CES 2008. Prior to joining Hitachi, he attended Georgia Institute of Technology for PhD degree (2005) and received M.S and B.Tech degrees from Virginia Tech (2003) and Indian Institute of Technology, Kharagpur (2000), respectively. He is a Senior Member of IEEE, has authored several peer reviewed publications in wireless communications, and holds several patents.

• About the Authors xiForeword xiiiPreface xvAcknowledgements xviiList of Acronyms xix1 An Introduction to Heterogeneous Networks 11.1 Introduction 11.2 Heterogeneous Network Deployments 31.2.1 Distributed Antenna Systems 31.2.2 Public Access Picocells/Metrocells 41.2.3 Consumer-Grade Femtocells 41.2.4 WiFi Systems 51.3 Features of Heterogeneous Networks 51.3.1 Association and Load Balancing 51.3.2 Interference Management 61.3.3 Self-Organizing Networks 61.3.4 Mobility Management 71.4 Evolution of Cellular Technology and Standards 71.4.1 3GPP Standardization Process 9References 10Part I OVERVIEW2 Fundamentals of LTE 152.1 Introduction 152.2 LTE Core Network 172.2.1 Control Plane 182.2.2 User Plane 192.2.3 Practical Implementations of the Core Network 192.3 LTE Radio Access Network 202.3.1 Control Plane 202.3.2 User Plane 232.4 Connectivity Among eNodeBs: The X2 Interface 242.4.1 Load- and Interference-Related Information 262.4.2 Handover-Related Information 262.5 Technologies in LTE 272.5.1 Orthogonal Frequency Division Multiplexing 272.5.2 Multiple Antenna Communications 36References 423 LTE Signal Structure and Physical Channels 453.1 Introduction 453.2 LTE Signal Structure 453.3 Introduction to LTE Physical Channels and Reference Signals 483.4 Resource Block Assignment 513.5 Downlink Physical Channels 543.5.1 Physical Broadcast Channel (PBCH) 553.5.2 Physical Downlink Shared Channel (PDSCH) 573.5.3 Physical Multicast Channel (PMCH) 583.5.4 Physical Control Format Indicator Channel (PCFICH) 583.5.5 Physical Hybrid ARQ Indicator Channel (PHICH) 593.5.6 Physical Downlink Control Channel (PDCCH) 603.6 Uplink Physical Channels 673.6.1 Physical Uplink Shared Channel (PUSCH) 673.6.2 Physical Uplink Control Channel (PUCCH) 683.6.3 Physical Random Access Channel (PRACH) 70References 714 Physical Layer Signal Processing in LTE 734.1 Introduction 734.2 Downlink Synchronization Signals 734.2.1 Primary Synchronization Signal 744.2.2 Secondary Synchronization Signal 764.3 Reference Signals 774.3.1 Downlink Reference Signals 774.3.2 Uplink Reference Signals 844.4 Channel Estimation and Feedback 854.4.1 Basics of Link Adaptation 854.4.2 Feedback for MIMO OFDM Channels 884.4.3 New Features in LTE-Advanced 924.5 Design Paradigm of LTE Signaling 944.6 Scheduling and Resource Allocation 944.6.1 Scheduling Algorithms 964.6.2 Inter-eNodeB Coordination for Resource Allocation in LTE 98References 100Part II INTER-CELL INTERFERENCE COORDINATION5 Release 10 Enhanced ICIC 1035.1 Introduction 1035.2 Typical Deployment Scenarios 1035.2.1 Macro–Pico Deployment Scenario 1045.2.2 Macro–Femto Deployment Scenario 1075.3 Time Domain Techniques 1105.3.1 Almost Blank Subframe 1105.3.2 ABS Use Cases 1135.3.3 UE Measurement and Reporting 1165.3.4 Backhaul Support 1185.3.5 Simulation Results 1195.4 Power Control Techniques 1235.4.1 Target Scenario 1235.4.2 Power Control Schemes 1245.4.3 Results from Realistic Deployments 1255.5 Carrier Aggregation-Based eICIC 127References 1306 Release 11 Further Enhanced ICIC: Transceiver Processing 1336.1 Introduction 1336.2 Typical Deployment Scenarios 1336.3 Techniques for Mitigating CRS Interference 1366.3.1 Receiver-Based Techniques 1366.3.2 Transmitter-Based Techniques 1406.4 Weak Cell Detection 1426.5 Non-Zero-Power ABS 144References 1477 Release 11 Further Enhanced ICIC: Remaining Topics 1497.1 Carrier-Based Interference Coordination 1497.1.1 Operational Carrier Selection 1507.1.2 Primary and Secondary Cell Selection 1537.2 Enhanced PDCCH for Interference Coordination 154References 159Part III COORDINATED MULTI-POINT TRANSMISSION RECEPTION8 Downlink CoMP: Signal Processing 1638.1 Introduction 1638.2 CoMP Scenarios in 3GPP 1648.2.1 Homogeneous Networks with Intra-Site CoMP 1648.2.2 Homogeneous Networks with High-Power RRHs 1658.2.3 Heterogeneous Networks with Low-Power RRHs with Cell IDs Different from the Macro 1658.2.4 Heterogeneous Networks with Low-Power RRHs with Cell IDs the Same as the Macro 1668.3 CoMP Sets 1678.3.1 RRM Measurement Set/CoMP Resource Management Set 1678.3.2 CoMP Measurement Set 1688.3.3 CoMP Cooperating Set 1698.4 CoMP Transmission in 3GPP 1698.4.1 Coordinated Scheduling/Beamforming 1698.4.2 Dynamic Point Selection 1728.4.3 Joint Transmission 1778.5 Comparison of Different CoMP Categories 180References 1829 Downlink CoMP: Standardization Impact 1859.1 Introduction 1859.2 Modification of Reference Signals 1859.2.1 Modifications in CSI-RS 1859.2.2 Modifications in DMRS 1869.3 CSI Processes 1899.3.1 UE Processing Complexity and CSI Reference Resources 1919.3.2 Inheritance and Reference Processes 1929.4 PDSCH Rate Matching 1939.5 Quasi-Co-Location of Antenna Ports 1959.5.1 Quasi-Co-Location Between the Same Antenna Ports 1979.5.2 Quasi-Co-Location Between Different Antenna Ports 1989.6 New Transmission Mode and DCI Format 2009.7 Backhaul Support for CoMP 2019.8 Summary 203References 203Part IV UPCOMING TECHNOLOGIES10 Dense Small Cell Deployments 20710.1 Introduction 20710.2 Evolution of Small Cells 20710.2.1 Deployment Scenarios 20910.3 Efficient Operation of Small Cells 21210.3.1 Dual Connectivity 21410.3.2 ICIC Mechanism 21610.3.3 Small Cell Discovery 22010.4 Control Signaling Enhancement 22310.4.1 Multi-Subframe Scheduling 22310.4.2 Cross-Subframe Scheduling 22410.5 Reference Signal Overhead Reduction 22510.5.1 Downlink DMRS 22510.5.2 Uplink DMRS 227References 22811 TD-LTE Enhancements for Small Cells 23111.1 Enhancements for Dynamic TDD 23111.1.1 TDD UL/DL Reconfiguration Scenarios in 3GPP 23211.1.2 Interference Mitigation Schemes 23411.2 FDD-TDD Joint Operation 23911.2.1 Deployment Scenarios 24011.2.2 Issues and Potential Solutions 241References 24312 Full Dimension MIMO 24512.1 Introduction 24512.2 Antenna Systems Architecture: Passive and Active 24512.3 Antenna Patterns 24812.3.1 Passive Antenna Element Pattern 24812.3.2 Active Antenna Systems 25012.3.3 AAS with Additional Mechanical Tilt 25312.3.4 Effect of Multipath Fading Channels 25312.4 FD-MIMO Deployment Scenarios 25412.4.1 UE-Specific FD-MIMO 25412.4.2 Cell-Specific FD-MIMO 25512.4.3 System-Specific FD-MIMO 25512.5 Conclusion 256References 25613 Future Trends in Heterogeneous Networks 25713.1 Summary 25713.2 Small Cells and Cloud RAN 25813.3 Small Cells, Millimeter Wave Communications and Massive MIMO 25913.4 Small Cells and Big Data 26013.5 Concluding Remarks 260References 260Index 263

Joydeep Acharya received his PhD degree in Electrical Engineering from Rutgers University in 2009. Currently he is a staff research engineer at Hitachi America's Wireless Systems Research Lab (WSRL) where he is involved in physical layer research and standardization in LTE-Advanced. Previously, he had worked as a research consultant in GS Sanyal School of Telecommunications, Indian Institute of Technology Kharagpur on Physical Layer design of WCDMA. He has been participating in 3GPP RAN 1 and 2 meetings since 2009. He is the author of several IEEE conference and journal papers and inventor of several patents filed worldwide. His research topics include MIMO signal processing, base station coordination, massive MIMO and spectrum regulation and resource allocation for wireless systems.Long Gao received his B.S. degree from Beijing Jiaotong University, Beijing, China, in 2003 and his M.S. degree from Beijing University of Posts and Telecommunications, Beijing, China, in 2006, both in Electrical Engineering. He received his Ph.D. degree in Electrical Engineering from Texas A&M University, College Station, TX and joined Hitachi America, Ltd, Santa Clara, CA, in 2010. Since then, he has been involved in 3GPP LTE/LTE-Advanced standardization activities with focus on cooperative communication and heterogeneous networks. He has published several IEEE papers and submitted several technical contributions to 3GPP RAN1 conference. He has served as a TPC member in major IEEE conferences such as Globecom 2010-2013. He has presented tutorials on LTE-Advanced heterogeneous network in VTC 2012 and WCNC 2013.Sudhanshu Gaur has over 10 years of research and industry experience in the field of wireless communications. He is currently the Principal Research Engineer at Hitachi America's Wireless System Research Lab (WSRL) where he leads LTE-Advanced standardization activities. Earlier he was also involved with IEEE 802.11aa standardization and contributed to Hitachi's wireless HD video system which was demonstrated in CES 2008. Prior to joining Hitachi, he attended Georgia Institute of Technology for PhD degree (2005) and received M.S and B.Tech degrees from Virginia Tech (2003) and Indian Institute of Technology, Kharagpur (2000), respectively. He is a Senior Member of IEEE, has authored several peer reviewed publications in wireless communications, and holds several patents.

• About the Authors xiForeword xiiiPreface xvAcknowledgements xviiList of Acronyms xix1 An Introduction to Heterogeneous Networks 11.1 Introduction 11.2 Heterogeneous Network Deployments 31.2.1 Distributed Antenna Systems 31.2.2 Public Access Picocells/Metrocells 41.2.3 Consumer-Grade Femtocells 41.2.4 WiFi Systems 51.3 Features of Heterogeneous Networks 51.3.1 Association and Load Balancing 51.3.2 Interference Management 61.3.3 Self-Organizing Networks 61.3.4 Mobility Management 71.4 Evolution of Cellular Technology and Standards 71.4.1 3GPP Standardization Process 9References 10Part I OVERVIEW2 Fundamentals of LTE 152.1 Introduction 152.2 LTE Core Network 172.2.1 Control Plane 182.2.2 User Plane 192.2.3 Practical Implementations of the Core Network 192.3 LTE Radio Access Network 202.3.1 Control Plane 202.3.2 User Plane 232.4 Connectivity Among eNodeBs: The X2 Interface 242.4.1 Load- and Interference-Related Information 262.4.2 Handover-Related Information 262.5 Technologies in LTE 272.5.1 Orthogonal Frequency Division Multiplexing 272.5.2 Multiple Antenna Communications 36References 423 LTE Signal Structure and Physical Channels 453.1 Introduction 453.2 LTE Signal Structure 453.3 Introduction to LTE Physical Channels and Reference Signals 483.4 Resource Block Assignment 513.5 Downlink Physical Channels 543.5.1 Physical Broadcast Channel (PBCH) 553.5.2 Physical Downlink Shared Channel (PDSCH) 573.5.3 Physical Multicast Channel (PMCH) 583.5.4 Physical Control Format Indicator Channel (PCFICH) 583.5.5 Physical Hybrid ARQ Indicator Channel (PHICH) 593.5.6 Physical Downlink Control Channel (PDCCH) 603.6 Uplink Physical Channels 673.6.1 Physical Uplink Shared Channel (PUSCH) 673.6.2 Physical Uplink Control Channel (PUCCH) 683.6.3 Physical Random Access Channel (PRACH) 70References 714 Physical Layer Signal Processing in LTE 734.1 Introduction 734.2 Downlink Synchronization Signals 734.2.1 Primary Synchronization Signal 744.2.2 Secondary Synchronization Signal 764.3 Reference Signals 774.3.1 Downlink Reference Signals 774.3.2 Uplink Reference Signals 844.4 Channel Estimation and Feedback 854.4.1 Basics of Link Adaptation 854.4.2 Feedback for MIMO OFDM Channels 884.4.3 New Features in LTE-Advanced 924.5 Design Paradigm of LTE Signaling 944.6 Scheduling and Resource Allocation 944.6.1 Scheduling Algorithms 964.6.2 Inter-eNodeB Coordination for Resource Allocation in LTE 98References 100Part II INTER-CELL INTERFERENCE COORDINATION5 Release 10 Enhanced ICIC 1035.1 Introduction 1035.2 Typical Deployment Scenarios 1035.2.1 Macro–Pico Deployment Scenario 1045.2.2 Macro–Femto Deployment Scenario 1075.3 Time Domain Techniques 1105.3.1 Almost Blank Subframe 1105.3.2 ABS Use Cases 1135.3.3 UE Measurement and Reporting 1165.3.4 Backhaul Support 1185.3.5 Simulation Results 1195.4 Power Control Techniques 1235.4.1 Target Scenario 1235.4.2 Power Control Schemes 1245.4.3 Results from Realistic Deployments 1255.5 Carrier Aggregation-Based eICIC 127References 1306 Release 11 Further Enhanced ICIC: Transceiver Processing 1336.1 Introduction 1336.2 Typical Deployment Scenarios 1336.3 Techniques for Mitigating CRS Interference 1366.3.1 Receiver-Based Techniques 1366.3.2 Transmitter-Based Techniques 1406.4 Weak Cell Detection 1426.5 Non-Zero-Power ABS 144References 1477 Release 11 Further Enhanced ICIC: Remaining Topics 1497.1 Carrier-Based Interference Coordination 1497.1.1 Operational Carrier Selection 1507.1.2 Primary and Secondary Cell Selection 1537.2 Enhanced PDCCH for Interference Coordination 154References 159Part III COORDINATED MULTI-POINT TRANSMISSION RECEPTION8 Downlink CoMP: Signal Processing 1638.1 Introduction 1638.2 CoMP Scenarios in 3GPP 1648.2.1 Homogeneous Networks with Intra-Site CoMP 1648.2.2 Homogeneous Networks with High-Power RRHs 1658.2.3 Heterogeneous Networks with Low-Power RRHs with Cell IDs Different from the Macro 1658.2.4 Heterogeneous Networks with Low-Power RRHs with Cell IDs the Same as the Macro 1668.3 CoMP Sets 1678.3.1 RRM Measurement Set/CoMP Resource Management Set 1678.3.2 CoMP Measurement Set 1688.3.3 CoMP Cooperating Set 1698.4 CoMP Transmission in 3GPP 1698.4.1 Coordinated Scheduling/Beamforming 1698.4.2 Dynamic Point Selection 1728.4.3 Joint Transmission 1778.5 Comparison of Different CoMP Categories 180References 1829 Downlink CoMP: Standardization Impact 1859.1 Introduction 1859.2 Modification of Reference Signals 1859.2.1 Modifications in CSI-RS 1859.2.2 Modifications in DMRS 1869.3 CSI Processes 1899.3.1 UE Processing Complexity and CSI Reference Resources 1919.3.2 Inheritance and Reference Processes 1929.4 PDSCH Rate Matching 1939.5 Quasi-Co-Location of Antenna Ports 1959.5.1 Quasi-Co-Location Between the Same Antenna Ports 1979.5.2 Quasi-Co-Location Between Different Antenna Ports 1989.6 New Transmission Mode and DCI Format 2009.7 Backhaul Support for CoMP 2019.8 Summary 203References 203Part IV UPCOMING TECHNOLOGIES10 Dense Small Cell Deployments 20710.1 Introduction 20710.2 Evolution of Small Cells 20710.2.1 Deployment Scenarios 20910.3 Efficient Operation of Small Cells 21210.3.1 Dual Connectivity 21410.3.2 ICIC Mechanism 21610.3.3 Small Cell Discovery 22010.4 Control Signaling Enhancement 22310.4.1 Multi-Subframe Scheduling 22310.4.2 Cross-Subframe Scheduling 22410.5 Reference Signal Overhead Reduction 22510.5.1 Downlink DMRS 22510.5.2 Uplink DMRS 227References 22811 TD-LTE Enhancements for Small Cells 23111.1 Enhancements for Dynamic TDD 23111.1.1 TDD UL/DL Reconfiguration Scenarios in 3GPP 23211.1.2 Interference Mitigation Schemes 23411.2 FDD-TDD Joint Operation 23911.2.1 Deployment Scenarios 24011.2.2 Issues and Potential Solutions 241References 24312 Full Dimension MIMO 24512.1 Introduction 24512.2 Antenna Systems Architecture: Passive and Active 24512.3 Antenna Patterns 24812.3.1 Passive Antenna Element Pattern 24812.3.2 Active Antenna Systems 25012.3.3 AAS with Additional Mechanical Tilt 25312.3.4 Effect of Multipath Fading Channels 25312.4 FD-MIMO Deployment Scenarios 25412.4.1 UE-Specific FD-MIMO 25412.4.2 Cell-Specific FD-MIMO 25512.4.3 System-Specific FD-MIMO 25512.5 Conclusion 256References 25613 Future Trends in Heterogeneous Networks 25713.1 Summary 25713.2 Small Cells and Cloud RAN 25813.3 Small Cells, Millimeter Wave Communications and Massive MIMO 25913.4 Small Cells and Big Data 26013.5 Concluding Remarks 260References 260Index 263