5G NR: The Next Generation Wireless Access Technology

Copyright Page

Contents

Preface

Acknowledgments

Abbreviations and Acronyms

1 What Is 5G?

1.1 3GPP and the Standardization of Mobile Communication

1.2 The Next Generation—5G/NR

1.2.1 The 5G Use Cases

1.2.2 Evolving LTE to 5G Capability

1.2.3 NR—The New 5G Radio-Access Technology

1.2.4 5GCN—The New 5G Core Network

2 5G Standardization

2.1 Overview of Standardization and Regulation

2.2 ITU-R Activities From 3G to 5G

2.2.1 The Role of ITU-R

2.2.2 IMT-2000 and IMT-Advanced

2.2.3 IMT-2020 Process in ITU-R WP5D

2.3 5G and IMT-2020

2.3.1 Usage Scenarios for IMT-2020

2.3.2 Capabilities of IMT-2020

2.3.3 IMT-2020 Performance Requirements and Evaluation

2.4 3GPP Standardization

2.4.1 The 3GPP Process

2.4.2 Specification of 5G in 3GPP as an IMT-2020 Candidate

3 Spectrum for 5G

3.1 Spectrum for Mobile Systems

3.1.1 Spectrum Defined for IMT Systems by the ITU-R

3.1.2 Global Spectrum Situation for 5G

3.2 Frequency Bands for NR

3.3 RF Exposure Above 6GHz

4 LTE—An Overview

4.1 LTE Release 8—Basic Radio Access

4.2 LTE Evolution

4.3 Spectrum Flexibility

4.3.1 Carrier Aggregation

4.3.2 License-Assisted Access

4.4 Multi-Antenna Enhancements

4.4.1 Extended Multi-antenna Transmission

4.4.2 Multipoint Coordination and Transmission

4.4.3 Enhanced Control Channel Structure

4.5 Densification, Small Cells, and Heterogeneous Deployments

4.5.1 Relaying

4.5.2 Heterogeneous Deployments

4.5.3 Small-Cell On/Off

4.5.4 Dual Connectivity

4.5.5 Dynamic TDD

4.5.6 WLAN Interworking

4.6 Device Enhancements

4.7 New Scenarios

4.7.1 Device-To-Device Communication

4.7.2 Machine-Type Communication

4.7.3 Latency Reduction—sTTI

4.7.4 V2V and V2X

4.7.5 Aerials

5 NR Overview

5.1 Higher-Frequency Operation and Spectrum Flexibility

5.2 Ultra-Lean Design

5.3 Forward Compatibility

5.4 Transmission Scheme, Bandwidth Parts, and Frame Structure

5.5 Duplex Schemes

5.6 Low-Latency Support

5.7 Scheduling and Data Transmission

5.8 Control Channels

5.9 Beam-Centric Design and Multi-Antenna Transmission

5.10 Initial Access

5.11 Interworking and LTE Coexistence

6 Radio-Interface Architecture

6.1 Overall System Architecture

6.1.1 5G Core Network

6.1.2 Radio-Access Network

6.2 Quality-Of-Service Handling

6.3 Radio Protocol Architecture

6.4 User-Plane Protocols

6.4.1 Service Data Adaptation Protocol (SDAP)

6.4.2 Packet-Data Convergence Protocol (PDCP)

6.4.3 Radio-Link Control

6.4.4 Medium-Access Control

6.4.4.1 Logical Channels and Transport Channels

6.4.4.2 Scheduling

6.4.4.3 Hybrid ARQ With Soft Combining

6.4.5 Physical Layer

6.5 Control-Plane Protocols

6.5.1 RRC State Machine

6.5.2 Idle-State and Inactive-State Mobility

6.5.2.1 Tracking the Device

6.5.2.2 Paging Message Transmission

6.5.3 Connected-State Mobility

7 Overall Transmission Structure

7.1 Transmission Scheme

7.2 Time-Domain Structure

7.3 Frequency-Domain Structure

7.4 Bandwidth Parts

7.5 Frequency-Domain Location of NR Carriers

7.6 Carrier Aggregation

7.6.1 Control Signaling

7.7 Supplementary Uplink

7.7.1 Relation to Carrier Aggregation

7.7.2 Control Signaling

7.8 Duplex Schemes

7.8.1 Time-Division Duplex (TDD)

7.8.2 Frequency-Division Duplex (FDD)

7.8.3 Slot Format and Slot-Format Indication

7.9 Antenna Ports

7.10 Quasi-Colocation

8 Channel Sounding

8.1 Downlink Channel Sounding—CSI-RS

8.1.1 Basic CSI-RS Structure

8.1.2 Frequency-Domain Structure of CSI-RS Configurations

8.1.3 Time-Domain Property of CSI-RS Configurations

8.1.4 CSI-IM—Resources for Interference Measurements

8.1.5 Zero-Power CSI-RS

8.1.6 CSI-RS Resource Sets

8.1.7 Tracking Reference Signal (TRS)

8.1.8 Mapping to Physical Antennas

8.2 Downlink Measurements and Reporting

8.2.1 Report Quantity

8.2.2 Measurement Resource

8.2.3 Report Types

8.3 Uplink Channel Sounding—SRS

8.3.1 SRS Sequences and Zadoff–Chu Sequences

8.3.2 Multiport SRS

8.3.3 Time-Domain Structure of SRS

8.3.4 SRS Resource Sets

8.3.5 Mapping to Physical Antennas

9 Transport-Channel Processing

9.1 Overview

9.2 Channel Coding

9.2.1 CRC Attachment Per Transport Block

9.2.2 Code-Block Segmentation

9.2.3 Channel Coding

9.3 Rate Matching and Physical-Layer Hybrid-ARQ Functionality

9.4 Scrambling

9.5 Modulation

9.6 Layer Mapping

9.7 Uplink DFT Precoding

9.8 Multi-Antenna Precoding

9.8.1 Downlink Precoding

9.8.2 Uplink Precoding

9.9 Resource Mapping

9.10 Downlink Reserved Resources

9.11 Reference Signals

9.11.1 Demodulation Reference Signals for OFDM-Based Downlink and Uplink

9.11.2 Demodulation Reference Signals for DFT-Precoded OFDM Uplink

9.11.3 Phase-Tracking Reference Signals (PT-RS)

10 Physical-Layer Control Signaling

10.1 Downlink

10.1.1 Physical Downlink Control Channel

10.1.2 Control Resource Set

10.1.3 Blind Decoding and Search Spaces

10.1.4 Downlink Scheduling Assignments—DCI Formats 1–0 and 1–1

10.1.5 Uplink Scheduling Grants—DCI Formats 0–0 and 0–1

10.1.6 Slot Format Indication—DCI Format 2–0

10.1.7 Preemption Indication—DCI Format 2–1

10.1.8 Uplink Power Control Commands—DCI Format 2–2

10.1.9 SRS Control Commands—DCI Format 2–3

10.1.10 Signaling of Frequency-Domain Resources

10.1.11 Signaling of Time-Domain Resources

10.1.12 Signaling of Transport-Block Sizes

10.2 Uplink

10.2.1 Basic PUCCH Structure

10.2.2 PUCCH Format 0

10.2.3 PUCCH Format 1

10.2.4 PUCCH Format 2

10.2.5 PUCCH Format 3

10.2.6 PUCCH Format 4

10.2.7 Resources and Parameters for PUCCH Transmission

10.2.8 Uplink Control Signaling on PUSCH

11 Multi-Antenna Transmission

11.1 Introduction

11.2 Downlink Multi-Antenna Precoding

11.2.1 Type I CSI

11.2.1.1 Single-Panel CSI

11.2.1.2 Multipanel CSI

11.2.2 Type II CSI

11.3 NR Uplink Multiantenna Precoding

11.3.1 Codebook-Based Transmission

11.3.2 Non-codebook-Based Precoding

12 Beam Management

12.1 Initial Beam Establishment

12.2 Beam Adjustment

12.2.1 Downlink Transmitter-Side Beam Adjustment

12.2.2 Downlink Receiver-Side Beam Adjustment

12.2.3 Uplink Beam Adjustment

12.2.4 Beam Indication and TCI

12.3 Beam Recovery

12.3.1 Beam-Failure Detection

12.3.2 New-Candidate-Beam Identification

12.3.3 Device Recovery Request and Network Response

13 Retransmission Protocols

13.1 Hybrid-ARQ With Soft Combining

13.1.1 Soft Combining

13.1.2 Downlink Hybrid-ARQ

13.1.3 Uplink Hybrid-ARQ

13.1.4 Timing of Uplink Acknowledgments

13.1.5 Multiplexing of Hybrid-ARQ Acknowledgments

13.2 RLC

13.2.1 Sequence Numbering and Segmentation

13.2.2 Acknowledged Mode and RLC Retransmissions

13.3 PDCP

14 Scheduling

14.1 Dynamic Downlink Scheduling

14.1.1 Bandwidth Adaptation

14.1.2 Downlink Preemption Handling

14.2 Dynamic Uplink Scheduling

14.2.1 Uplink Priority Handling

14.2.2 Scheduling Request

14.2.3 Buffer Status Reports

14.2.4 Power Headroom Reports

14.3 Scheduling and Dynamic TDD

14.4 Transmission Without a Dynamic Grant

14.5 Discontinuous Reception

15 Uplink Power and Timing Control

15.1 Uplink Power Control

15.1.1 Baseline Power Control

15.1.2 Beam-Based Power Control

15.1.2.1 Multiple Path-Loss-Estimation Processes

15.1.2.2 Multiple Open-Loop-Parameter Sets

15.1.2.3 Multiple Closed-Loop Processes

15.1.3 Power Control for PUCCH

15.1.4 Power Control in the Case of Multiple Uplink Carriers

15.2 Uplink Timing Control

16 Initial Access

16.1 Cell Search

16.1.1 The SS Block

16.1.2 Frequency-Domain Position of SS Block

16.1.3 SS Block Periodicity

16.1.4 SS Burst Set: Multiple SS Blocks in the Time Domain

16.1.5 Details of PSS, SSS, and PBCH

16.1.5.1 The Primary Synchronization Sequence (PSS)

16.1.5.2 The Secondary Synchronization Sequence (SSS)

16.1.5.3 PBCH

16.1.6 Providing Remaining System Information

16.2 Random Access

16.2.1 Preamble Transmission

16.2.1.1 Characteristics of Preamble Transmission

16.2.1.2 RACH Resources

16.2.1.3 Basic Preamble Structure

16.2.1.4 Long vs Short Preambles

16.2.1.5 Beam Establishment During Initial Access

16.2.1.6 Preamble Power Control and Power Ramping

16.2.2 Random-Access Response

16.2.3 Message 3: Contention Resolution

16.2.4 Message 4: Contention Resolution and Connection Set Up

16.2.5 Random Access for Supplementary Uplink

17 LTE/NR Interworking and Coexistence

17.1 LTE/NR Dual-Connectivity

17.1.1 Deployment Scenarios

17.1.2 Architecture Options

17.1.3 Single-TX Operation

17.2 LTE/NR Coexistence

18 RF Characteristics

18.1 Spectrum Flexibility Implications

18.2 RF Requirements in Different Frequency Ranges

18.3 Channel Bandwidth and Spectrum Utilization

18.4 Overall Structure of Device RF Requirements

18.5 Overall Structure of Base-Station RF Requirements

18.5.1 Conducted and Radiated RF Requirements for NR BS

18.5.2 BS Types in Different Frequency Ranges for NR

18.6 Overview of Conducted RF Requirements for NR

18.6.1 Conducted Transmitter Characteristics

18.6.2 Conducted Receiver Characteristics

18.6.3 Regional Requirements

18.6.4 Band-Specific Device Requirements Through Network Signaling

18.6.5 Base-Station Classes

18.7 Conducted Output Power Level Requirements

18.7.1 Base-Station Output Power and Dynamic Range

18.7.2 Device Output Power and Dynamic Range

18.8 Transmitted Signal Quality

18.8.1 EVM and Frequency Error

18.8.2 Device In-Band Emissions

18.8.3 Base-Station Time Alignment

18.9 Conducted Unwanted Emissions Requirements

18.9.1 Implementation Aspects

18.9.2 Emission Mask in the OOB Domain

18.9.2.1 Base-Station Operating Band Unwanted Emission Limits

18.9.2.2 Device Spectrum Emission Mask

18.9.3 Adjacent Channel Leakage Ratio

18.9.4 Spurious Emissions

18.9.5 Occupied Bandwidth

18.9.6 Transmitter Intermodulation

18.10 Conducted Sensitivity and Dynamic Range

18.11 Receiver Susceptibility to Interfering Signals

18.12 Radiated RF Requirements for NR

18.12.1 Radiated Device Requirements in FR2

18.12.2 Radiated Base-Station Requirements in FR1

18.12.3 Radiated Base-Station Requirements in FR2

18.13 Ongoing Developments of RF Requirements for NR

18.13.1 Multistandard Radio Base Stations

18.13.2 Multiband-Capable Base Stations

18.13.3 Operation in Non-contiguous Spectrum

19 RF Technologies at mm-Wave Frequencies

19.1 ADC and DAC Considerations

19.2 LO Generation and Phase Noise Aspects

19.2.1 Phase Noise Characteristics of Free-Running Oscillators and PLLs

19.2.2 Challenges With mm-Wave Signal Generation

19.3 Power Amplifier Efficiency in Relation to Unwanted Emission

19.4 Filtering Aspects

19.4.1 Possibilities of Filtering at the Analog Front-End

19.4.2 Insertion Loss (IL) and Bandwidth

19.4.3 Filter Implementation Examples

19.4.3.1 PCB Integrated Implementation Example

19.4.3.2 LTCC Filter Implementation Example

19.5 Receiver Noise Figure, Dynamic Range, and Bandwidth Dependencies

19.5.1 Receiver and Noise Figure Model

19.5.2 Noise Factor and Noise Floor

19.5.3 Compression Point and Gain

19.5.4 Power Spectral Density and Dynamic Range

19.5.5 Carrier Frequency and mm-Wave Technology Aspects

19.6 Summary

20 Beyond the First Release of 5G

20.1 Integrated Access-Backhaul

20.2 Operation in Unlicensed Spectra

20.3 Non-orthogonal Multiple Access

20.4 Machine-Type Communication

20.5 Device-To-Device Communication

20.6 Spectrum and Duplex Flexibility

20.7 Concluding Remarks

References

Index

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