A guide to the 3GPP-specified 5G physical layer with a focus on the new beam-based dimension in the radio system
5G New Radio: A Beam-based Air Interface is an authoritative guide to the newly 3GPP-specified 5G physical layer. The contributors - noted experts on the topic and creators of the actual standard - focus on the beam-based operation which is a new dimension in the radio system due to the millimeter wave deployments of 5G. The book contains information that complements the 3GPP specification and helps to connect the dots regarding key features.
The book assumes a basic knowledge of multi-antenna technologies and covers the physical layer aspects related to beam operation, such as initial access, details of reference signal design, beam management, and DL and UL data channel transmission. The contributors also provide a brief overview of standardization efforts, IMT-2020 submission, 5G spectrum, and performance analysis of 5G components. This important text:
- Contains information on the 3GPP-specified 5G physical layer
- Highlights the beam-based operation
- Covers the physical layer aspects related to beam operation
- Includes contributions from experts who created the standard
Written for students and development engineers working with 5G NR, 5G New Radio: A Beam-based Air Interface offers an expert analysis of the 3GPP-specified 5G physical layer.
Table of Contents
List of Contributors xiii
Preface xv
Acknowledgments xvii
Abbreviations xix
1 Introduction and Background 1
Mihai Enescu and Karri Ranta-aho
1.1 Why 5G? 1
1.2 Requirements and Targets 2
1.2.1 System Requirements 3
1.2.2 5G Spectrum 7
1.3 Technology Components and Design Considerations 10
1.3.1 Waveform 12
1.3.2 Multiple Access 13
1.3.3 Scalable/Multi Numerology 13
1.3.3.1 Motivation for Multiple Numerologies 13
1.3.3.2 5G NR Numerologies 13
1.3.4 Multi-antenna 17
1.3.5 Interworking with LTE and Other Technologies 18
1.3.6 5G Beam Based Technologies Across Release 15 and Release 16 19
1.3.6.1 Integrated Access and Backhaul 19
1.3.6.2 NR Operation on Unlicensed Frequency Bands (NR-U) 20
1.3.6.3 Ultra-Reliable and Low Latency Communications 21
1.3.6.4 Vehicular-to-everything (V2X) 21
1.3.6.5 Positioning 22
1.3.6.6 System Enhancements 22
2 Network Architecture and NR Radio Protocols 25
Dawid Koziol and Helka-Liina Määttänen
2.1 Architecture Overview 25
2.2 Core Network Architecture 26
2.2.1 Overview 26
2.2.2 Service Request Procedure 29
2.3 Radio Access Network 31
2.3.1 NR Standalone RAN Architecture 31
2.3.2 Additional Architectural Options 32
2.3.3 CU-DU and UP-CP Split 37
2.4 NR Radio Interface Protocols 41
2.4.1 Overall Protocol Structure 41
2.4.2 Main Functions of NR Radio Protocols 44
2.4.3 SDAP Layer 47
2.4.4 PDCP Layer 47
2.4.4.1 PDCP Packet Transmission 48
2.4.4.2 PDCP Duplication 49
2.4.4.3 Access Stratum (AS) Security 50
2.4.4.4 Robust Header Compression (ROHC) 50
2.4.5 RLC 50
2.4.5.1 Segmentation and Concatenation 51
2.4.5.2 RLC Reordering 51
2.4.5.3 ARQ Retransmissions and Status Reporting 52
2.4.6 MAC Protocol 53
2.4.6.1 Overview 53
2.4.6.2 Multiplexing and Demultiplexing 53
2.4.6.3 Logical Channel Prioritization 54
2.4.6.4 Hybrid Automatic Repeat Request (HARQ) 57
2.4.6.5 BWP Operation 58
2.4.6.6 Scheduling Request 60
2.4.6.7 Semi Persistent Scheduling and Configured Grants 60
2.4.6.8 Discontinuous Reception (DRX) 60
2.4.6.9 Buffer Status Reports 62
2.4.6.10 Timing Advance Operation 62
2.4.6.11 MAC Control Elements 63
2.4.7 Radio Resource Control (RRC) 67
2.4.7.1 Overview 67
2.4.7.2 RRC State Machine 68
2.4.7.3 Cells, Cell Groups, and Signaling Radio Bearers 70
2.4.7.4 System Information 71
2.4.7.5 Unified Access Control (UAC) 78
2.4.7.6 Connection Control 79
2.4.7.7 NAS Information Transfer 87
2.4.7.8 UE Assistance Information 87
2.4.7.9 RRC PDU Structure 89
3 PHY Layer 95
Mihai Enescu, Youngsoo Yuk, Fred Vook, Karri Ranta-aho, Jorma Kaikkonen, Sami Hakola, Emad Farag, Stephen Grant, and Alexandros Manolakos
3.1 Introduction (Mihai Enescu, Nokia Bell Labs, Finland) 95
3.2 NRWaveforms (Youngsoo Yuk, Nokia Bell Labs, Korea) 96
3.2.1 Advanced CP-OFDM Waveforms for Multi-Service Support 96
3.2.2 Low PAPR Waveform for Coverage Enhancement 102
3.2.3 Considerations on the Waveform for above 52.6 GHz 104
3.3 Antenna Architectures in 5G (Fred Vook, Nokia Bell Labs, USA) 105
3.3.1 Beamforming 105
3.3.2 Antenna Array Architectures 108
3.3.3 Antenna Panels 110
3.3.4 Antenna Virtualization 111
3.3.5 Antenna Ports 113
3.3.6 Beamforming for a Beam-Based Air Interface 115
3.4 Frame Structure and Resource Allocation (Karri Ranta-aho, Nokia Bell Labs, Finland) 115
3.4.1 Resource Grid 115
3.4.2 Data Scheduling and HARQ 118
3.4.3 Frequency Domain Resource Allocation and Bandwidth Part 119
3.4.4 Time Domain Resource Allocation 123
3.5 Synchronization Signals and Broadcast Channels in NR Beam-Based System (Jorma Kaikkonen, Sami Hakola, Nokia Bell Labs, Finland) 125
3.5.1 SS/PBCH Block 125
3.5.2 Synchronization Signal Structure 126
3.5.3 Broadcast Channels 128
3.5.3.1 PBCH 128
3.5.3.2 SIB1 129
3.5.3.3 Delivery of Other Broadcast Information and Support of Beamforming 135
3.6 Physical Random Access Channel (PRACH) (Emad Farag, Nokia Bell Labs, USA) 139
3.6.1 Introduction 139
3.6.2 Preamble Sequence 140
3.6.2.1 Useful Properties of Zhadoff-Chu Sequences 140
3.6.2.2 Unrestricted Preamble Sequences 142
3.6.2.3 Restricted Preamble Sequences 144
3.6.3 Preamble Formats 147
3.6.3.1 Long Sequence Preamble Formats 148
3.6.3.2 Short Sequence Preamble Formats 149
3.6.4 PRACH Occasion 150
3.6.5 PRACH Baseband Signal Generation 155
3.7 CSI-RS (Stephen Grant, Ericsson, USA) 159
3.7.1 Overview 159
3.7.1.1 CSI-RS Use Cases 159
3.7.1.2 Key Differences with LTE 161
3.7.2 Physical Layer Design 162
3.7.2.1 Mapping to Physical Resources 162
3.7.2.2 Antenna Port Mapping 167
3.7.2.3 Sequence Generation and Mapping 167
3.7.2.4 Time Domain Behavior 168
3.7.2.5 Multiplexing with Other Signals 169
3.7.3 Zero Power CSI-RS 170
3.7.4 Interference Measurement Resources (CSI-IM) 170
3.7.5 CSI-RS Resource Sets 171
3.7.5.1 CSI-RS for Tracking 171
3.7.5.2 CSI-RS for L1-RSRP Measurement 173
3.8 PDSCH and PUSCH DM-RS, Qualcomm Technologies, Inc. (Alexandros Manolakos, Qualcomm Technologies, Inc, USA) 176
3.8.1 Overview 176
3.8.1.1 What is DM-RS Used for? 176
3.8.1.2 Key Differences from LTE 176
3.8.2 Physical Layer Design 178
3.8.2.1 Mapping to Physical Resources 178
3.8.2.2 Default DM-RS Pattern for PDSCH and PUSCH 189
3.8.2.3 Sequence Generation and Scrambling 193
3.8.3 Procedures and Signaling 200
3.8.3.1 Physical Resource Block Bundling 200
3.8.3.2 DM-RS to PDSCH and PUSCH EPRE Ratio 205
3.8.3.3 Antenna Port DCI Signaling 207
3.8.3.4 Quasi-Colocation Considerations for DM-RS of PDSCH 209
3.9 Phrase- Tracking RS (Youngsoo Yuk, Nokia Bell Labs, Korea) 210
3.9.1 Phase Noise and its Modeling 210
3.9.1.1 Phase Noise in mm-Wave Frequency and its Impact to OFDM System 210
3.9.1.2 Principles of Oscillator Design and Practical Phase Noise Modeling 211
3.9.2 Principle of Phase Noise Compensation 216
3.9.3 NR PT-RS Structure and Procedures 221
3.9.3.1 PT-RS Design for Downlink 221
3.9.3.2 PT-RS Design for Uplink CP-OFDM 224
3.9.3.3 PT-RS Design for Uplink DFT-s-OFDM 225
3.10 SRS (Stephen Grant, Ericsson, USA) 228
3.10.1 Overview 228
3.10.1.1 SRS Use Cases 228
3.10.1.2 Key Differences with LTE 229
3.10.2 Physical Layer Design 230
3.10.2.1 Mapping to Physical Resources 230
3.10.2.2 Antenna Port Mapping 237
3.10.2.3 Sequence Generation and Mapping 239
3.10.2.4 Multiplexing with Other UL Signals 243
3.10.3 SRS Resource Sets 244
3.10.3.1 SRS for Downlink CSI Acquisition for Reciprocity-Based Operation 244
3.10.3.2 SRS for Uplink CSI Acquisition 245
3.10.3.3 SRS for Uplink Beam Management 246
3.11 Power Control (Mihai Enescu, Nokia Bell Labs, Finland) 246
3.12 DL and UL Transmission Framework (Mihai Enescu, Nokia, Karri Ranta-aho, Nokia Bell Labs, Finland) 249
3.12.1 Downlink Transmission Schemes for PDSCH 249
3.12.2 Downlink Transmit Processing 250
3.12.2.1 PHY Processing for PDSCH 250
3.12.2.2 PHY Processing for PDCCH 251
3.12.3 Uplink Transmission Schemes for PUSCH 254
3.12.3.1 Codebook Based UL Transmission 254
3.12.3.2 Non-Codebook Based UL Transmission 255
3.12.4 Uplink Transmit Processings 255
3.12.4.1 PHY Processing for PUSCH 255
3.12.5 Bandwidth Adaptation 256
3.12.5.1 Overview 256
3.12.5.2 Support for Narrow-Band UE in a Wide-Band Cell 257
3.12.5.3 Saving Battery with Bandwidth Adaptation 257
3.12.5.4 Spectrum Flexibility 260
3.12.6 Radio Network Temporary Identifiers (RNTI) 260
4 Main Radio Interface Related System Procedures 261
Jorma Kaikkonen, Sami Hakola, Emad Farag, Mihai Enescu, Claes Tidestav, Juha Karjalainen, Timo Koskela, Sebastian Faxér, Dawid Koziol, and Helka-Liina Määttänen
4.1 Initial Access (Jorma Kaikkonen, Sami Hakola, Nokia Bell Labs, Finland, Emad Farag, Nokia Bell Labs, USA) 261
4.1.1 Cell Search 261
4.1.1.1 SS/PBCH Block Time Pattern 262
4.1.1.2 Initial Cell Selection Related Assistance Information 265
4.1.2 Random Access 265
4.1.2.1 Introduction 265
4.1.2.2 Higher Layer Random Access Procedures 266
4.1.2.3 Random Access Use Cases 274
4.1.2.4 Physical Layer Random Access Procedures 274
4.1.2.5 RACH in Release 16 283
4.2 Beam Management (Mihai Enescu, Nokia Bell Labs, Finland, Claes Tidestav, Ericsson, Sweden, Sami Hakola, Juha Karjalainen, Nokia Bell Labs, Finland) 287
4.2.1 Introduction to Beam Management 287
4.2.2 Beam Management Procedures 289
4.2.2.1 Beamwidths 291
4.2.2.2 Beam Determination 291
4.2.3 Beam Indication Framework for DL Quasi Co-location and TCI States 296
4.2.3.1 QCL 296
4.2.3.2 TCI Framework 297
4.2.4 Beam Indication Framework for UL Transmission 303
4.2.4.1 SRS Configurations 305
4.2.4.2 Signaling Options for SRS Used for UL Beam Management 306
4.2.4.3 Beam Reporting from a UE with Multiple Panels 306
4.2.5 Reporting of L1-RSRP 307
4.2.6 Beam Failure Detection and Recovery 312
4.2.6.1 Overview 312
4.2.6.2 Beam Failure Detection 313
4.2.6.3 New Candidate Beam Selection 314
4.2.6.4 Recovery Request and Response 315
4.2.6.5 Completion of BFR Procedure 316
4.3 CSI Framework (Sebastian Faxér, Ericsson, Sweden) 317
4.3.1 Reporting and Resource Settings 318
4.3.2 Reporting Configurations and CSI Reporting Content 323
4.3.2.1 The Different CSI Parameters 323
4.3.2.2 CSI-RS Resource Indicator (CRI) 323
4.3.2.3 SSB Resource Indicator 324
4.3.2.4 Precoder Matrix Indicator (PMI) and Rank Indicator (RI) 324
4.3.2.5 Channel Quality Indicator (CQI) 325
4.3.2.6 Layer Indicator (LI) 327
4.3.2.7 Layer-1 Reference Signal Received Power (L1-RSRP) 327
4.3.2.8 Reporting Quantities 327
4.3.2.9 Frequency-Granularity 331
4.3.2.10 Measurement Restriction of Channel and Interference 332
4.3.2.11 Codebook Configuration 333
4.3.2.12 NZP CSI-RS Based Interference Measurement 333
4.3.3 Triggering/Activation of CSI Reports and CSI-RS 334
4.3.3.1 Aperiodic CSI-RS/IM and CSI Reporting 334
4.3.3.2 Semi-Persistent CSI-RS/IM and CSI Reporting 335
4.3.4 UCI Encoding 337
4.3.4.1 Collision Rules and Priority Order 338
4.3.4.2 Partial CSI Omission for PUSCH-Based CSI 339
4.3.5 CSI Processing Criteria 340
4.3.6 CSI Timeline Requirement 341
4.3.7 Codebook-Based Feedback 344
4.3.7.1 Motivation for the Use of DFT Codebooks 346
4.3.7.2 DL Type I Codebook 349
4.3.7.3 DL Type II Codebook 352
4.4 Radio Link Monitoring (Claes Tidestav, Ericsson, Sweden, Dawid Koziol, Nokia Bell Labs, Poland) 356
4.4.1 Causes of Radio Link Failure 357
4.4.1.1 Physical Layer Problem 357
4.4.1.2 Random Access Failure 363
4.4.1.3 RLC Failure 364
4.4.2 Actions After RLF 365
4.4.2.1 RLF in MCG 365
4.4.2.2 RLF in SCG 368
4.4.3 Relation Between RLM/RLF and BFR 368
4.5 Radio Resource Management (RRM) and Mobility (Helka-Liina Määttänen, Ericsson, Finland, Dawid Koziol, Nokia Bell Labs, Poland, Claes Tidestav, Ericsson, Sweden) 370
4.5.1 Introduction 370
4.5.2 UE Mobility Measurements 371
4.5.2.1 NR Mobility Measurement Quantities 372
4.5.2.2 SS/PBCH Block Measurement Timing Configuration (SMTC) 374
4.5.2.3 SS/PBCH Block Transmission in Frequency Domain 376
4.5.3 Connected Mode Mobility 376
4.5.3.1 Overview of RRM Measurements 378
4.5.3.2 Measurement Configuration 378
4.5.3.3 Performing RRM Measurements 383
4.5.3.4 Handover Procedure 384
4.5.4 Idle and Inactive Mode Mobility 388
4.5.4.1 Introduction 388
4.5.4.2 Cell Selection and Reselection 389
4.5.4.3 Location Registration Udate 393
4.5.4.4 Division of IDLE Mode Tasks between NAS and AS Layers 396
5 Performance Characteristics of 5G New Radio 397
Fred Vook
5.1 Introduction 397
5.2 Sub-6 GHz: Codebook-Based MIMO in NR 398
5.2.1 Antenna Array Configurations 398
5.2.2 System Modeling 399
5.2.3 Downlink CSI Feedback and MIMO Transmission Schemes 399
5.2.4 Traffic Models and Massive MIMO 401
5.2.5 Performance in Full Buffer Traffic 401
5.2.6 Performance in Bursty (FTP) Traffic 404
5.2.7 Performance of NR Type II CSI 411
5.3 NR MIMO Performance in mmWave Bands 413
5.4 Concluding Remarks 416
6 UE Features 419
Mihai Enescu
6.1 Reference Signals 422
6.1.1 DM-RS 422
6.1.2 CSI-RS 423
6.1.3 PT-RS 424
6.1.4 SRS 424
6.1.5 TRS 425
6.1.6 Beam Management 426
6.1.7 TCI and QCL 428
6.1.8 Beam Failure Detection 428
6.1.9 RLM 429
6.1.10 CSI Framework 429
References 433
Index 437
