5G New Radio E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 855

Veröffentlichungsjahr: 2020

Beschreibung

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.

Leseprobe

Table of Contents

Cover

List of Contributors

Preface

Acknowledgments

Abbreviations

1 Introduction and Background

1.1 Why 5G?

1.2 Requirements and Targets

1.3 Technology Components and Design Considerations

2 Network Architecture and NR Radio Protocols

2.1 Architecture Overview

2.2 Core Network Architecture

2.3 Radio Access Network

2.4 NR Radio Interface Protocols

3 PHY Layer

3.1 Introduction (Mihai Enescu, Nokia Bell Labs, Finland)

3.2 NR Waveforms (Youngsoo Yuk, Nokia Bell Labs, Korea)

3.3 Antenna Architectures in 5G (Fred Vook, Nokia Bell Labs, USA)

3.4 Frame Structure and Resource Allocation (Karri Ranta-aho, Nokia Bell Labs, Finland)

3.5 Synchronization Signals and Broadcast Channels in NR Beam-Based System (Jorma Kaikkonen, Sami Hakola, Nokia Bell Labs, Finland)

3.6 Physical Random Access Channel (PRACH) (Emad Farag, Nokia Bell Labs, USA)

3.7 CSI-RS (Stephen Grant, Ericsson, USA)

3.8 PDSCH and PUSCH DM-RS, Qualcomm Technologies, Inc. (Alexandros Manolakos, Qualcomm Technologies, Inc, USA)

3.9 Phrase- Tracking RS (Youngsoo Yuk, Nokia Bell Labs, Korea)

3.10 SRS (Stephen Grant, Ericsson, USA)

3.11 Power Control (Mihai Enescu, Nokia Bell Labs, Finland)

3.12 DL and UL Transmission Framework (Mihai Enescu, Nokia, Karri Ranta-aho, Nokia Bell Labs, Finland)

Notes

4 Main Radio Interface Related System Procedures

4.1 Initial Access (Jorma Kaikkonen, Sami Hakola, Nokia Bell Labs, Finland, Emad Farag, Nokia Bell Labs, USA)

4.2 Beam Management (Mihai Enescu, Nokia Bell Labs, Finland, Claes Tidestav, Ericsson, Sweden, Sami Hakola, Juha Karjalainen, Nokia Bell Labs, Finland)

4.3 CSI Framework (Sebastian Faxér, Ericsson, Sweden)

4.4 Radio Link Monitoring (Claes Tidestav, Ericsson, Sweden, Dawid Koziol, Nokia Bell Labs, Poland)

4.5 Radio Resource Management (RRM) and Mobility (Helka-Liina Määttänen, Ericsson, Finland, Dawid Koziol, Nokia Bell Labs, Poland, Claes Tidestav, Ericsson, Sweden)

Note

5 Performance Characteristics of 5G New Radio

5.1 Introduction

5.2 Sub-6 GHz: Codebook-Based MIMO in NR

5.3 NR MIMO Performance in mmWave Bands

5.4 Concluding Remarks

6 UE Features

6.1 Reference Signals

References

Index

End User License Agreement

List of Tables

Chapter 1

Table 1.1 ITU-R requirements for IMT-2020 [5].

Table 1.2 Summary of 5G NR technology components.

Table 1.3 Spectrum bands for low-to-mid frequency (FR1).

Table 1.4 Spectrum bands for high frequency (FR2).

Table 1.5 Scenarios impacting 5G new radio numerology.

Table 1.6 Key performance indicators impacting the new radio numerology.

Table 1.7 5G new radio 5G PHY numerologies for OFDM based waveforms.

Chapter 2

Table 2.1 Summary of different Dual Connectivity architecture options.

Table 2.2 Summary of F1 and E1 protocol functions.

Table 2.3 Summary of the main functions of various NR radio protocol layer's.

Table 2.4 Comparison of different RLC modes.

Table 2.5 Main functions of logical and transport channels in NR.

Table 2.6 NR MAC CEs related to reference signal resource set activation/deac...

Table 2.7 TCI state or spatial relation related MAC CEs.

Table 2.8 CSI related NR MAC CEs.

Table 2.9 Other NR MAC CEs.

Table 2.10 Main attributes of the RRC states in NR system.

Table 2.11 Signaling Radio Bearers in NR description.

Table 2.12 Main characteristics and contents of System Information in NR syst...

Table 2.13 Comparison of message 1 and message 3 based SI request mechanisms.

Table 2.14 Meaning of the NEED codes.

Chapter 3

Table 3.1 Comparison of various candidate waveforms for NR.

Table 3.2 OFDM numerologies.

Table 3.3 Supported nominal carrier bandwidths and maximum BWP sizes for FR1.

Table 3.4 Supported nominal carrier bandwidths and maximum BWP sizes for FR2.

Table 3.5 Data scheduling related information fields of the data-scheduling D...

Table 3.6 Frequency band allocation for SS/PBCH block and Type0-PDCCH CORESET...

Table 3.7 Long sequence preamble formats.

Table 3.8 Long sequence preamble format delay spread.

Table 3.9 Short sequence preamble formats.

Table 3.10 Short sequence preamble format delay spread.

Table 3.11 PRACH Occasion size in frequency domain.

Table 3.12 CSI-RS locations within a slot.

Table 3.13 Main properties of the DM-RS Type 1 and 2.

Table 3.14 PDSCH DM-RS positions for single-symbol (top) and double-symbol (b...

Table 3.15 PUSCH DM-RS positions within a slot for single-symbol DM-RS and in...

Table 3.16 Parameters for PDSCH DM-RS configuration type 2.

Table 3.17 Parameters for PDSCH DM-RS configuration type 2.

Table 3.18 The ratio of PDSCH EPRE to DM-RS EPRE [38.214].

Table 3.19 Size of antenna port DCI field for DCO format 1_1.

Table 3.20 Antenna port(s) signaling for PDSCH and DM-RS Type 1 with maxLengt...

Table 3.21 Size of Antenna Port DCI field for DCO format 0_1.

Table 3.22 Parameters for phase noise models.

Table 3.23 The parameter

.

Table 3.24 PT-RS power boosting value in dB.

Table 3.25 PT-RS symbol mapping.

Table 3.26 PT-RS group pattern as a function of scheduled bandwidth.

Table 3.27 PT-RS scaling factor (β′) when transform coding enabled.

Table 3.28 Example SRS bandwidth configuration for the case of C

SRS

 = 13.

Table 3.29 Cyclic shifts assigned to multiple SRS antenna ports. d

0

is the RR...

Table 3.30 Maximum number of SRS resources that may be multiplexed on the sam...

Table 3.31 DCI formats in 5G NR Release 15.

Table 3.32 Information carrier by the data-scheduling DCI formats.

Table 3.33 RNTI fields used in 5G.

Chapter 4

Table 4.1 Maximum number of candidate SS/PBCH block positions (

L

max

) per carr...

Table 4.2 UL grant fields in random access response (RAR).

Table 4.3 Fields of DCI of PDCCH order.

Table 4.4 PRACH mask index values [38.321].

Table 4.5 TCI states for periodic TRS.

Table 4.6 TCI states for aperiodic TRS.

Table 4.7 TCI states for CSI-RS for CSI acquisition.

Table 4.8 TCI states for CSI-RS for beam management.

Table 4.9 TCI states for DM-RS for PDCCH/PDSCH DM-RS.

Table 4.10 Beam switching mechanism and applicable reference RS for SRS resou...

Table 4.11 Summary for different combinations CSI reporting activation with d...

Table 4.12 Summary of possible combinations of time-domain behaviors of CSI r...

Table 4.13 Limitation on number of CSI-RS ports per CSI-RS resource.

Table 4.14 The four-bit 64QAM CQI table.

Table 4.15 Definition of subband differential CQI.

Table 4.16 Nominal subband sizes.

Table 4.17 Bitfields used for validation of SP-CSI deactivation command.

Table 4.18 Bitfields used for validation of SP-CSI activation command.

Table 4.19 Timing requirement for low latency CSI, high latency CSI and beam ...

Table 4.20 Ultra-low latency CSI timing requirement.

Table 4.21 Example overhead calculation for Type II CSI feedback, assuming 13...

Table 4.22 The maximum number of RLM RSs that can be configured for different...

Table 4.23 Applicability of different measurement quantities and different re...

Table 4.24 Summary of Idle mode procedures tasks division between NAS and AS ...

Chapter 5

Table 5.1 Antenna array parameters for sub-6 GHz performance evaluation.

Table 5.2 System modeling for performance evaluations in sub-6 GHz deployment...

Table 5.3 Downlink MIMO transmission schemes.

List of Illustrations

Chapter 1

Figure 1.1 ITU-R vision for 5G [4].

Figure 1.2 Spectrum bands for low-to-mid frequency (FR1).

Figure 1.3 Spectrum bands for low-to-mid frequency (FR2).

Figure 1.4 Examples of different transceiver and antenna system architectures:...

Figure 1.5 LTE-NR tight interworking architecture optimized for fast roll-out.

Figure 1.6 Illustration of integrated access and backhaul.

Chapter 2

Figure 2.1 Overview of MR-DC connectivity principles with EPC and 5GC.

Figure 2.2 5G Core Network architecture.

Figure 2.3 Overall QoS architecture in 5G system.

Figure 2.4 Example of Service Request procedure.

Figure 2.5 NG-RAN architecture for NR standalone deployment.

Figure 2.6 Functional split between NG-RAN and 5GC nodes.

Figure 2.7 Full NG-RAN architecture.

Figure 2.8 EN-DC architecture.

Figure 2.9 NGEN-DC architecture.

Figure 2.10 NE-DC architecture.

Figure 2.11 Different kind of bearers established by the network.

Figure 2.12 gNB architecture with CU-DU split and UP-CP separation.

Figure 2.13 Protocol stack architecture with CU-DU split.

Figure 2.14 Control plane and User plane protocol stack in NR system.

Figure 2.15 Data flow example through Layer 2 protocol stack in NR system.

Figure 2.16 Data flow example through Layer 2 protocol stack in NR system.

Figure 2.17 PDCP protocol with a split and a non-split bearer.

Figure 2.18 PDCP window example.

Figure 2.19 RLC AM operation example in DL.

Figure 2.20 RLC AM operation example in UL.

Figure 2.21 MAC entity.

Figure 2.22 (De-) multiplexing in MAC.

Figure 2.23 Logical Channel Prioritization example.

Figure 2.24 Example of HARQ entities and processes in a gNB.

Figure 2.25 BWP operation example.

Figure 2.26 Basic DRX operation.

Figure 2.27 SP CSI-RS / CSI-IM Resource Set Activation/Deactivation MAC CE.

Figure 2.28 UE state machine and state transitions between NR/5GC, E-UTRA/EPC,...

Figure 2.29 An example of scheduling of SI broadcast transmissions using SI wi...

Figure 2.30 Choice of the System Information request mechanism depending on th...

Figure 2.31 Unified Access Control procedure executed in the UE.

Figure 2.32 CN-initiated Paging.

Figure 2.33 RAN-initiated Paging.

Figure 2.34 RRC Connection establishment triggered by receiving Paging message...

Figure 2.35 UE capability Enquiry message.

Figure 2.36 Initial AS Security Activation procedure (success).

Figure 2.37 Initial AS Security Activation procedure (failure).

Figure 2.38 Successful RRC reconfiguration.

Figure 2.39 RRC reconfiguration failure.

Figure 2.40 RRC Release procedure.

Figure 2.41 Successful RRC Resume procedure.

Figure 2.42 RRC Resume procedure with fall back to RRC Setup.

Figure 2.43 RRC connection resume rejected by the network.

Figure 2.44 RRC Resume procedure triggered for the sake of the RNA update.

Figure 2.45 Exemplary life-cycle of the UE's RRC connection.

Chapter 3

Figure 3.1 Illustration of multi-service support of 5G new radio.

Figure 3.2 Illustration of ICI among OFDM subcarriers with different numerolog...

Figure 3.3 Generation of enhanced OFDM based waveforms.

Figure 3.4 Link simulation results when desired signal (15 kHz SCS) is transmi...

Figure 3.5 Rx unit performance comparison between matched transceiver with asy...

Figure 3.6 Zero-tail DFT-s-OFDM signal generation.

Figure 3.7 PAPR reduction with π/2-BPSK modulation and spectral shaping.

Figure 3.8 Single beam beamforming – general concept. Left: transmit. Right: r...

Figure 3.9 Multi-beam beamforming antenna array – N beams in a fully connected...

Figure 3.10 Multi-beam beamforming antenna array – N beams in a sub-array conn...

Figure 3.11 Digital antenna array architecture. Left: single beam. Right: mult...

Figure 3.12 Analog antenna array architecture. Left: single beam. Right: multi...

Figure 3.13 Hybrid antenna array architecture with fully-connected beamforming...

Figure 3.14 Hybrid antenna array architecture with sub-array-connected beamfor...

Figure 3.15 A single antenna array panel of cross-polarized antennas (+45° and...

Figure 3.16 Single column antenna virtualization: single column aggregated int...

Figure 3.17 Multi column antenna virtualization: multiple columns aggregated i...

Figure 3.18 Single column antenna virtualization creating elevation ports: sin...

Figure 3.19 Multiple column antenna virtualization creating elevation ports: m...

Figure 3.20 General two-dimensional virtualization.

Figure 3.21 PRB/slot grid.

Figure 3.22 Nested time domain structure.

Figure 3.23 Nested frequency domain structure.

Figure 3.24 Defining a BWP on a common resource block grid.

Figure 3.25 Flexible and dynamic HARQ-ACK feedback and retransmission timing.

Figure 3.26 Multiplexing UEs with different subcarrier spacings in frequency a...

Figure 3.27 Illustration of Type 0 and Type 1 frequency domain resource alloca...

Figure 3.28 Among other things, the DCI carries resource allocation related in...

Figure 3.29 SS/PBCH block structure.

Figure 3.30 Illustration of the frequency location relation of Type0-PDCCH COR...

Figure 3.31 SS/PBCH block and Type0-PDCCH CORESET multiplexing patterns: (a) p...

Figure 3.32 Determination of Type0-PDCCH monitoring slots for multiplexing pat...

Figure 3.33 Illustration of determination of Type0-PDCCH monitoring occasions ...

Figure 3.34 Illustration of determination of Type0-PDCCH monitoring occasions ...

Figure 3.35 Illustration of multiplexing pattern 2 PDCCH monitoring occasions.

Figure 3.36 Illustration of non-default association for OSI delivery.

Figure 3.37 Illustration of PO definition with PO specific offset (a) and with...

Figure 3.38 Cross-correlation of a Zadoff-Chu sequence having a frequency offs...

Figure 3.39 Correlation of a delayed received preamble signal with a reference...

Figure 3.40 Correlation range of each cyclically shifted preamble sequence, wh...

Figure 3.41 Examples showing the range of the main peak, the 1st negative and ...

Figure 3.42 Examples of restricted set Type A preamble sequences for two diffe...

Figure 3.43 Examples showing the range of the main peak, the 1st and 2nd negat...

Figure 3.44 Examples of restricted set Type B preamble sequences for Zhadoff-C...

Figure 3.45 Preamble Format consisting of cyclic prefix followed by K sequence...

Figure 3.46 Preamble format 0.

Figure 3.47 Enumeration of preamble index across cyclic shifts and logical roo...

Figure 3.48 Columns of random access configuration tables ([Tables 6.3.3.2-2/3...

Figure 3.49 Time domain organization of PRACH occasions within a subframe or 6...

Figure 3.50 Frequency domain organization of PRACH occasions frequency divisio...

Figure 3.51 Example of allocation of PRACH subcarriers within the PRACH occasi...

Figure 3.52 Determination of the first subcarrier of the first PUSCH RB of the...

Figure 3.53 Example of CP length of preamble format A2 with subcarrier spacing...

Figure 3.54 Limited time/frequency mapping locations for a CSI-RS resource in ...

Figure 3.55 Exemplary CDM group for CDM4(FD2,TD2) corresponding to antenna por...

Figure 3.56 Achieving full PA utilization through CDM.

Figure 3.57 Exemplary CSI-RS resource configurations for various rows in Table...

Figure 3.58 Exemplary CSI-RS configurations for various rows in Table 3.12: (a...

Figure 3.59 Illustration of antenna port mapping – frequency first, time secon...

Figure 3.60 Periodic, semi-persistent, aperiodic CSI-RS transmission.

Figure 3.61 Exemplary configurations of CSI-IM Pattern 0 and Pattern 1.

Figure 3.62 Exemplary configuration (one period) of CSI-RS for tracking.

Figure 3.63 UE measurement and reporting on a set of CSI-RS resources with rep...

Figure 3.64 UE measurement on a set of CSI-RS resources with repetition = “on....

Figure 3.65 Example of “pipeline processing” enabled by a front-loaded DM-RS p...

Figure 3.66 Front-loaded DM-RS Configuration Type 1.

Figure 3.67 Front-loaded DM-RS configuration Type 2.

Figure 3.68 Definition of l

d

for different mapping Types. For mapping Type A, ...

Figure 3.69 DM-RS patterns for mapping Type A with front-load DM-RS single-sym...

Figure 3.70 DM-RS patterns for mapping Type A with front-load DM-RS double-sym...

Figure 3.71 DM-RS patterns for PDSCH mapping Type B.

Figure 3.72 PUSCH mapping Type A DM-RS with intra-slot frequency hopping enabl...

Figure 3.73 PUSCH mapping Type B DM-RS with intra-slot frequency hopping enabl...

Figure 3.74 Front-load DM-RS location in case of collision of single-symbol DM...

Figure 3.75 Front-load DM-RS location in case of collision of single-symbol DM...

Figure 3.76 Front-load DM-RS location in case of collision of double-symbol DM...

Figure 3.77 NR-LTE Coexistence scenario: When one additional single-symbol DM-...

Figure 3.78 Default DM-RS patterns for PDSCH.

Figure 3.79 The sequence of the PDSCH DM-RS is initialized starting from CRB0,...

Figure 3.80 An example of sequence to subcarrier mapping for DMRS type 1, with...

Figure 3.81 DM-RS type 1 PAPR from the CCDF of the power-to-average power rati...

Figure 3.82 PAPR comparison among π/2 BPSK modulated random PUSCH data, π/2 BP...

Figure 3.83 PAPR comparison among π/2 BPSK modulated random PUSCH data, π/2 BP...

Figure 3.84 Gold sequence based DMRS sequence generation for π/2 BPSK with fil...

Figure 3.85 Comparison of PDSCH spectral efficiency with link and rank adaptat...

Figure 3.86 Comparison of PRG = “Wideband” and PRG = 4 at low geometries.

Figure 3.87 Procedure for determining the PRB bundling value in DCI format 1_1...

Figure 3.88 Example of front-load DM-RS with configuration type 2 with DM-RS o...

Figure 3.89 Impact of local oscillator frequency offset on received constellat...

Figure 3.90 A brief summary of the phase noise level achieved by different fab...

Figure 3.91 Basic structure of a phase-locked loop (PLL) circuit.

Figure 3.92 Illustration of PSD contribution: (a) by oscillator components (b)...

Figure 3.93 PSD of proposed phase noise model at both UE and BS side.

Figure 3.94 Illustration of Thermal noise and phase noise impact for various m...

Figure 3.95 Spectral Efficiency Performance comparison with/without phase nois...

Figure 3.96 Basic structure of PT-RS in NR.

Figure 3.97 Evaluation results for spectral efficiency with CPE compensation w...

Figure 3.98 Illustration of phase noise estimation for CPE and ICI with a give...

Figure 3.99 Comparison of the simulation results of the spectral efficiency wi...

Figure 3.100 Example of block PT-RS structures with different densities.

Figure 3.101 Illustration of PT-RS port mapping to DM-RS port when one or two ...

Figure 3.102 PT-RS time domain allocation for different density when configure...

Figure 3.103 Illustration of PT-RS ports association with DM-RSs for a UE equi...

Figure 3.104 Example of PT-RS design for DFT-s-OFDM (

). (a)

. (b)

.

Figure 3.105 Time and frequency domain location of an SRS resource. In the tim...

Figure 3.106 Transmission comb examples for a single-symbol SRS resource. A co...

Figure 3.107 Aperiodic SRS transmission of 4-symbol resource with b

hop

 = B

SRS

 ...

Figure 3.108 Aperiodic SRS transmission with intra-slot frequency hopping of (...

Figure 3.109 Periodic SRS transmissionwith intra + inter-slot frequency hoppin...

Figure 3.110 Periodic SRS transmission with inter-slot frequency hopping of a ...

Figure 3.111 Mapping of port numbers to combs for two examples of a 4-port, 2 ...

Figure 3.112 2T4R antenna switching and associated SRS resource configuration....

Figure 3.113 Configuration of SS/PBCH and CSI-RS and indication of reference s...

Figure 3.114 Pathloss Computation for PUSCH power control.

Figure 3.115 Transport channels processing in downlink.

Figure 3.116 Diagram for codebook based UL transmission procedure.

Figure 3.117 Diagram for non-codebook based UL transmission procedure.

Figure 3.118 Transport channels processing in uplink.

Chapter 4

Figure 4.1 Mapping of SS/PBCH candidate locations to symbols in slot(s).

Figure 4.2 Mapping of SS/PBCH candidate locations to slot.

Figure 4.3 Four-step contention-based random access procedure 38.300 [10].

Figure 4.4 Random access response (RAR) window.

Figure 4.5 MAC subheader for backoff indicator.

Figure 4.6 MAC subheader for RAPID.

Figure 4.7 MAC subPDU with subheader for RAPID and MAC RAR.

Figure 4.8 MAC random access response (RAR).

Figure 4.9 Contention-free random access procedure [38.300].

Figure 4.10 Example of the indication of the SS/PBCH index and PRACH Mask inde...

Figure 4.11 Quasi-collocation for preamble triggered by PDCCH order and corres...

Figure 4.12 Beam-based transmission in gNB with N beams. SS/PBCH Block (SSB) #...

Figure 4.13 Beam operation during RACH procedure, assuming beam correspondence...

Figure 4.14 Association of preambles within PRACH occasions to contention-base...

Figure 4.15 Example of mapping SS/PBCH Blocks to ROs. In this example, there a...

Figure 4.16 Example of mapping SS/PBCH Blocks to ROs. In this example, one SS/...

Figure 4.17 Example of association of CSI-RS resource to multiple PRACH occasi...

Figure 4.18 Schematics for power control.

Figure 4.19 Two-step RACH procedure.

Figure 4.20 Integrated access and backhaul (IAB) backhaul and access links.

Figure 4.21 Example of IAB backhaul ROs, based on a release 15 PRACH configura...

Figure 4.22 One example of hybrid transceiver architecture.

Figure 4.23 128 antenna array size for 3.5 and 28 GHz.

Figure 4.24 Beam correpondence at gNB and UE.

Figure 4.25 Downlink beam training use cases for linear movement of UE (diagon...

Figure 4.26 Necessity for beam change: movement of the UE (left figure), UE ro...

Figure 4.27 Beam sweeping with wider beams (left figure), beam sweeping with n...

Figure 4.28 Transmission of narrow beams for P2 procedure.

Figure 4.29 Transmission of narrow beams for P2 procedure.

Figure 4.30 Transmission of narrow beams for P3 procedure.

Figure 4.31 Timeline of Px procedures.

Figure 4.32 UL UE beam identification based on SRS transmission and SRI.

Figure 4.33 UL gNB beam identification based on same beam transmission from UE...

Figure 4.34 UL UE beam selection.

Figure 4.35 Example TCI state configuration and its use as QCL source.

Figure 4.36 The TCI states for aperiodic CSI-RS is signaled via the CSI reques...

Figure 4.37 TCI states configuration.

Figure 4.38 TCI timeline configurations for PDSCH.

Figure 4.39 TCI timeline configurations for CSI-RS.

Figure 4.40 UL Beam indication example.

Figure 4.41 Different Beams configured for a PUCCH resource, a single beam is ...

Figure 4.42 Possible spatial relations configurations of periodic, aperiodic a...

Figure 4.43 An example of Class B CSI reporting in LTE-A Rel-13.

Figure 4.44 An example of non-group beam reporting schemes in NR Rel-15.

Figure 4.45 An example of group-based beam reporting scheme with single beam g...

Figure 4.46 An example of group-based beam reporting scheme with two beam grou...

Figure 4.47 An example of non- and differential reporting in Rel-15.

Figure 4.48 Beam blockage due to obstacle.

Figure 4.49 Beam failure recovery procedure steps.

Figure 4.50 Beam failure instance indication.

Figure 4.51 Illustration of beam failure detection procedure.

Figure 4.52 CFRA BFR procedure.

Figure 4.53 CBRA BFR procedure.

Figure 4.54 Illustration of the CSI framework.

Figure 4.55 Illustration of the CSI feedback loop.

Figure 4.56 Hybrid non-precoded/beamformed CSI-RS feedback.

Figure 4.57 Example of port indication for non-PMI feedback.

Figure 4.58 Illustration of CSI reporting band as subset of subbands within th...

Figure 4.59 Illustration of aperiodic trigger states and mapping from a DCI co...

Figure 4.60 Example of partial CSI Part 2 omission.

Figure 4.61 Illustration of CPU occupation.

Figure 4.62 Illustration of the CSI timeline requirement (Z,Z′) symbols.

Figure 4.63 Supported 1D and 2D antenna port layouts for the single panel code...

Figure 4.64 Illustration of position vector in plane wave field.

Figure 4.65 Illustration of time-discrete Fourier transform of space-sampled c...

Figure 4.66 Illustration of beam pattern.

Figure 4.67 Fraction of channel energy captured in the N strongest DFT beams.

Figure 4.68 Illustration of the Type I Single-Panel codebook with subband beam...

Figure 4.69 Illustration of the Type I codebook.

Figure 4.70 Illustration of multi-panel port layout.

Figure 4.71 An example of rotated orthogonal beams expressed as oversampled DF...

Figure 4.72 Illustration of the Type II codebook with wideband amplitude.

Figure 4.73 Reasons for radio link failure. The UE may declare RLF when it det...

Figure 4.74 When the network can reach the UE using UE-specific beamforming, t...

Figure 4.75 UE can be configured with multiple RLM RSs. Only if the quality es...

Figure 4.76 The Q

out

and Q

in

thresholds are defined indirectly by relying on h...

Figure 4.77 RLF declaration based on detection of physical layer problems.

Figure 4.78 Example of a situation where RLF is not declared due to the number...

Figure 4.79 Example of a situation where RLF is not declared due to that N311 ...

Figure 4.80 Random access success and failure. In this example, the maximum nu...

Figure 4.81 RLF declaration due to maximum number of RLC retransmissions.

Figure 4.82 UE procedures after RLF declaration.

Figure 4.83 Example of a successful RLF recovery through RRC connection reesta...

Figure 4.84 Example of unsuccessful RLF recovery (no suitable cell found by th...

Figure 4.85 SCG failure information procedure triggered upon SCG RLF.

Figure 4.86 The SS-RSRP measurement is defined as the linear average of the po...

Figure 4.87 An example of RSSI measurement resources for SS-RSRQ. Note that th...

Figure 4.88 An example of an asynchronous system: the UE would have to measure...

Figure 4.89 An example of a coarsely synchronized system, with an SMTC window....

Figure 4.90 A network deployment with SS/PBCH blocks transmitted on multiple f...

Figure 4.91 Measurement configuration.

Figure 4.92 Event triggering rules taking A1 event as an example.

Figure 4.93 Measurement model for RRC CONNECTED.

Figure 4.94 Inter-gNB handover procedure (Access Management Function (AMF) and...

Figure 4.95 Utilization of beam level measurements for the sake of cell access...

Figure 4.96 An example of usage of rangeToBestCell and absThreshSS-BlocksConso...

Figure 4.97 UE states and state transitions based on cell selection and resele...

Figure 4.98 Relation between cells, RAN notification areas and tracking areas.

Chapter 5

Figure 5.1 Antenna arrays at the gNB for sub-6 GHz performance comparisons: ph...

Figure 5.2 Sector spectral efficiency with full buffer traffic – 2 through 32 ...

Figure 5.3 Edge user (5th-percentile) spectral efficiency with full buffer tra...

Figure 5.4 Mean number of UEs paired with a greedy pairing algorithm in full b...

Figure 5.5 Mean spectral efficiency: Mean UE spectral efficiency with bursty t...

Figure 5.6 Edge UE spectral efficiency (5th percentile) with bursty traffic (a...

Figure 5.7 Resource utilization with bursty traffic (arrival rates 1 through 6...

Figure 5.8 Mean number of co-scheduled users with bursty traffic and full buff...

Figure 5.9 Percent gains in Mean UE spectral efficiency for bursty and full bu...

Figure 5.10 Relative performance of the Type I and Type II configurations in F...

Figure 5.11 Downlink UE throughput at 28 GHz in Urban Macro.

Figure 5.12 Uplink UE throughput at 28 GHz in Urban Macro.

Guide

Cover

Table of Contents

Begin Reading

Pages

iii

iv

xiii

xv

xvi

xvii

xix

xx

xxi

xxii

xxiii

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

419

420

421

422

423

424

425

426

427

428

429

430

431

433

434

435

437

438

439

440

441

442

443

444

445

446

447

448

449

450

5G New Radio

A Beam-based Air Interface

Edited by

Mihai Enescu

This edition first published 2020

© 2020 John Wiley & Sons Ltd

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions.

The right of Mihai Enescu to be identified as the editor of this work has been asserted in accordance with law.

Registered Offices

John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA

John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

Editorial Office

The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com.

Wiley also publishes its books in a variety of electronic formats and by print-on-demand. Some content that appears in standard print versions of this book may not be available in other formats.

Limit of Liability/Disclaimer of Warranty

In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of experimental reagents, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each chemical, piece of equipment, reagent, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

Library of Congress Cataloging-in-Publication Data applied for

Hardback ISBN: 9781119582380

Cover Design: Wiley

Cover Image: © ixpert/Shutterstock

List of Contributors

Mihai Enescu

Nokia Bell Labs, Finland 

Emad Farag

Nokia Bell Labs, USA 

Sebastian Faxér

Ericsson, Sweden 

Stephen Grant

Ericsson, USA 

Sami Hakola

Nokia Bell Labs, Finland 

Jorma Kaikkonen

Nokia Bell Labs, Finland 

Juha Karjalainen

Nokia Bell Labs, Finland 

Timo Koskela

Nokia Bell Labs, Finland 

Dawid Koziol

Nokia Bell Labs, Poland 

Helka-Liina Määttänen

Ericsson, Finland 

Alexandros Manolakos

Qualcomm Technologies, Inc., USA 

Karri Ranta-aho

Nokia Bell Labs, Finland 

Claes Tidestav

Ericsson, Sweden

Fred Vook

Nokia Bell Labs, USA 

Youngsoo Yuk

Nokia Bell Labs, Korea 

Preface

5G New Radio is perhaps the most awaited technology of 2020 promising not only to improve the mobile broadband transmission speed and capacity but also to revolutionize our lives and important industries, allowing for more reliable and fast communications, and for massive machine-type communications. One new development of this technology is the operation in millimeter wave, in carrier frequencies above 3.5 GHz, while the backbone of the design relies on multiple antenna transmission and reception. Indeed, multiantenna transmission is not a development area anymore but becomes a central part of the system design, and this was one of the main motivations for the introduction of this book. The complexity of the 5G specification is higher compared to legacy wireless technologies such as LTE. Understanding the design and functionality of 5G is way harder by reading solely the specification text; hence, the motivation to connect the dots of the existing specifications and explaining in a more formal way how the system works and how the specified technologies are functioning.

The book is written by active participants in the standardization, experts from top companies who have been proposing some of the specified techniques, and have been part of the standardization discussions. Our intention was to present the physical layer structure and procedures by looking at the system design also from the perspective of multiantenna/beam operation. Because of the vast amount of information and its complexity, the book does not cover some of the physical aspects, which might be more beam agnostic, such as channel coding. However, in addition to the physical layer part, the book has a thorough presentation of the related network architecture and NR radio protocols, information which we believe complements the other physical layer aspects. From a timeline perspective of the specification, the book aims at converging what is known in the industry as of Release 15; however, some of the Release 16 developments are also mentioned in various areas of the design.

The structure of this book is as follows.

Chapter 1 takes a general view on the introduction of 5G and its technology components. We present the system requirements and targets and elaborate on the available 5G spectrum. A brief overview of the 5G technology components is presented, with a more in-depth description following in the rest of the book. In this chapter, we touch some of the higher level aspects related to waveforms, multiple access, scalable/multiple numerologies, and multiantenna architectures, interworking with other technologies. Release 16 beam-based technologies are mentioned as well, such as integrated access and backhaul (IAB), NR operation in unlicensed frequency bands (NR-U), ultrareliable and low-latency communications (URLLC), vehicular-to-everything (V2X), positioning and other system enhancements in the area of two-step RACH, cross-link interference (CLI) mitigation, UE power saving, mobility enhancements, multiantenna technologies, and the support for above 52 GHz frequencies.

Chapter 2 provides an overview on 5G core (5GC) network and functionalities by presenting the specified logical network nodes that are the standardized building blocks for the 5GC and by giving an example of a signaling flow between the nodes for connection establishment. We also go through the different dual-connectivity options and related terminologies.

Physical layer components are described in Chapter 3. Waveforms are described first, being at the foundation of the system design. Throughout the description, we are explaining the selected waveforms and the reasons behind these choices. Antenna architectures are described next, highlighting the main possible antenna array architectures: analog, digital, and hybrid. Antenna panels, virtualization, and ports are also described. Frame structures and resource allocation strategies are introduced. These are followed by the detailed description of synchronization signals and broadcast channels that are complemented by the random access channels. The reference symbols of NR are as follows, with a detailed description of reference symbols used for channel sounding in both downlink and uplink, demodulation, and phrase tracking. The chapter closes with a description of power control and a downlink and uplink transmission framework.

The main radio interface-related system procedures are described in Chapter 4. The chapter starts with initial access and continues with one of the core elements of 5G physical layer: beam management. Issues such as beam management procedures, signals quasi-colocation, and beam failure are described in detail. The CSI framework presents not only the ways in which CSI resources are configured and used in the reporting procedure but also details on codebook configurations and operation. Radio link monitoring procedures, radio resource management, and mobility are also covered in Chapter 4.

In standardization, the introduction of system components is usually done based also on performance. In Chapter 5, we look into selected system performance aspects, the overall system performance characteristics being never the less quite large. We are considering some key components based on MIMO, below and above 6 GHz operation, which translated into the utilization of advanced codebook design as well as on the beam-based operation.

Chapter 6 ends the book with a presentation of the UE features. All the UE functionalities used by the 3GPP 5G specifications are defined as UE features and these are mandatory and optional, or mandatory with optional capability. In this chapter, we are trying to give a glimpse of some of the mandatory physical layer parameters.

Acknowledgments

This book is the result of the fruitful cooperation of a team of experts from several companies. The dedication and professionalism are hereby gratefully acknowledged, as well as the support of their companies.

5G New Radio is one of the most complex standards to date, which would have not been possible without the contribution of all the entities participating in the standardization process. Without their work and contribution to the standardization process, this book would have not been possible. We hereby provide our deep thanks to all our colleagues participating in the 3GPP discussions. The help provided by ETSI is also gratefully acknowledged.

Finally, this book is intended to present the 5G New Radio physical layer from a multiantenna perspective; however, the reader should refer to the technical specifications published by 3GPP. Any views expressed in this book are those of the authors and do not necessarily reflect the views of their companies.

Abbreviations

3GPP

Third Generation Partnership Project

ACK

Acknowledgment

ACLR

Adjacent channel leakage ratio

ADC

Analog-to-Digital Converter

BPCH

Broadcast Physical Channel

BSR

Buffer Status Report

BWP

Bandwidth part

BPSK

Binary Phase Shift Keying

BS

Base Station

CBG

Code block group

CCDF

Complementary cumulative distribution function

CCP

Common Control Plane

CDD

Cyclic delay diversity

CDMA

Code Division Multiple Access

CMOS

Complementary Metal-Oxide-Semiconductor.

CN

Core Network

CP

Cyclic prefix

CQI

Channel quality indicator

CPU

CSI processing unit

CRB

Common resource block

CRC

Cyclic redundancy check

C-RNTI

Cell Radio-Network Temporary Identifier

CRI

CSI-RS Resource Indicator

CRS

Common Reference Signals

CSI

Channel state information

CSI-RS

Channel state information reference signal

CS-RNTI

Configured scheduling RNTI

CSI-RSRP

CSI reference signal received power

CSI-RSRQ

CSI reference signal received quality

CSI-SINR

CSI signal-to-noise and interference ratio

CU-DU

Central Unit - Distributed Unit

CW

Codeword

DAC

Digital-to-Analog Converter

DC

Dual Connectivity

DCI

Downlink control information

DFT

Discrete Fourier Transform

DL

Downlink

DM-RS

Dedicated demodulation reference signals

DRX

Discontinuous Reception

DSP

Digital Signal Processing

eMBB

Extreme Mobile Broadband

EIRP

Effective Isotropic Radiated Power

EN-DC

E-UTRA NR Dual-Connectivity

EPC

Evolved Packet Core

EPRE

Energy per resource element

E-UTRA

Evolved UTRA

EVM

Error Vector Magnitude

FDD

Frequency Division Duplex

FDM

Frequency Division Multiplexing

FDMA

frequency division multiple access

FFT

fast Fourier transform

FR1

Frequency Range 1

FR2

Frequency Range 2

FTP

File Transfer Protocol

GaAs

Gallium arsenide

GaN

Gallium nitride

GNSS

Global navigation satellite system

GTP

GPRS Tunneling Protocol

HARQ

hybrid automatic repeat request

HO

Hand Over

IAB

Integrated Access and Backhaul

IM

Interference measurement

IMS

IP Multimedia Subsystem

ITU

International Telecommunications Union

ITU-R

International Telecommunications Union-Radiocommunications Sector

IoT

Internet of Things

KPI

Key Performance Indicator

L1-RSRP

Layer 1 reference signal received power

LCID

Logical Channel Index

LI

Layer Indicator

LOS

Line of Sight

LTE

Long Term Evolution

LSB

Least Significant Bit

MAC

Medium Access Control

MBMS

Multimedia Broadcast Multicast Service

MCS

Modulation and coding scheme

MIB

Master Information Block

MCL

Maximum coupling loss

MTC

Machine Type Communications

mMTC

Massive Machine Type Communications

MIMO

Multiple Input Multiple Output

MMSE

Minimum mean square error

MMTEL

multimedia telephony service

MN

Master Node

MSB

Most Significant Bit

MU-MIMO

Multi-User MIMO

NAK

Negative Acknowledgment

NB-IoT

Narrow Band Internet of Things

NR-DC

New Radio Dual Connectivity

NSA

non-standalone

NR

New Radio

NR-U

New Radio Unlicensed

NZP

Non zero power

NW

Network

OFDM

Orthogonal Frequency Division Multiplexing

OFDMA

Orthogonal Frequency Division Multiplexing Access

PA

Power Amplifier

PAPR

peak-to-average power ratio

PBCH

Physical Broadcast Channel

PCID

Physical Cell Identity

PDCCH

Physical downlink control channel

PDCP

Packet Data Convergence Protocol

PDSCH

Physical downlink shared channel

PDU

Protocol Data Unit

PHY

Physical Layer

PLL

Phase-Locked Loop

PLMN

public land mobile network

PMI

Precoding-Matrix Indicator

PN

Phase Noise

PRACH

Physical Random-Access Channel

PRB

Physical Resource Block

P-RNTI

Paging RNTI

LSB

Least Significant Bit

PSK

Phase Shift Keying

PSS

Primary Synchronisation signal

PUCCH

Physical uplink control channel

PUSCH

Physical uplink shared channel

PBCH

Physical Broadcast Channel

PCID

Physical Cell Identifier

PDCP

Packet Data Convergence Protocol

PHY

Physical Layer

PMI

Precoding Matrix Indicator

PRACH

physical random access channel

PRB

Physical resource block

PRG

Precoding resource block group

PT-RS

Phase-tracking reference signal

QAM

Quadrature Amplitude Modulation

QCI

QoS Class Identifier

QCL

Quasi co-location

QoS

quality of service

QPSK

Quadrature Phase Shift Keying

RACH

random access channel

RAN

Radio Access Network

RA-RNTI

Random Access RNTI

RAT

Radio Access Technology

RB

Resource block

RE

Resource Element

RBG

Resource block group

RDI

DRB mapping Indication

RF

Radio Frequency

RI

Rank Indicator

RIT

Radio Interface Technology

RLC

Radio Link Control

RMSI

Remaining Minimum System Information

RNTI

Radio-Network Temporary Identifier

RIV

Resource indicator value

RS

Reference signal

RRC

radio resource control

RRM

Radio Resource Management

SA

standalone

SIB

System Information Block

SLNR

Signal-to-leakage-and-noise ratio

SNR

Signal to Noise Ratio

SSB

Synchronization Signal Block

SSS

Secondary Synchronization Signal

SFN

Single Frequency network

SLIV

Start and length indicator value

SI

System Information

SiGe

Silicon Germanium

SR

Scheduling Request

SRIT

Set of Radio Interface Technologies

SRS

Sounding reference signal

SS

Synchronisation signal

SS/PBCH

Synchronisation signal Physical Broadcast Channel

SSS

Secondary Synchronisation signal

SS-RSRP

SS reference signal received power

SS-RSRQ

SS reference signal received quality

SS-SINR

SS signal-to-noise and interference ratio

SRB

Signaling radio bearers

SU-MIMO

Single-User MIMO

SDL

Supplemental downlink

SVD

Singular Value Decomposition

SUL

Supplemental uplink

TB

Transport Block

TR

Technical Report

TCI

Transmission Configuration Indicator

TCP

Transmission Control Protocol

TDD

Time Division Duplex

TDM

Time division multiplexing

TD-RA

Time domain resource assignment

TPC

Transmit Power Control

TPMI

Transmit Precoding Indicator

TTI

Transmit Time Interval

TX

Transmitter

UCI

uplink control information

UE

User equipment

UL

Uplink

UMTS

Universal Mobile Telecommunications System

UP-CP

User Plane – Control Plane

URLLC

Ultra Reliable and Low Latency Communications

UTC

Universal Time

VRB

Virtual Resource Block

V2X

Vehicular-to-everything

WG

Working group

1Introduction and Background

Mihai Enescu, and Karri Ranta-aho

Nokia Bell Labs, Finland

1.1 Why 5G?

It is perhaps a reasonable question to ask why we need 5G? Was in fact 4G/LTE and its evolution sufficient? Looking at LTE we note that indeed, we identify a good set of advanced technical components (speaking from the perspective of physical layer): it has multiple antennas scaling to the possibility to use massive MIMO (Multiple Input Multiple Output), it supports emerging connectivity techniques such as device-to-device, NB-IoT, Ultra Reliable and Low Latency Communications (URLLC). So why 5G? Every decade seems to bring a new wave of technology, this was the case with the arrival of 3G and 4G. From this basic perspective, the arrival of 5G strengthens this “rule.” Is there a need for 5G, especially given the fact that LTE and LTE-pro are capable of delivering high data rates and flexible technology? Yes, there is a need for 5G and there are a couple of reasons which we will elaborate next.

Like any evolving system, LTE has reached the limit of being a complicated design, its limitations coming from the fact that the basic design conceived a decade ago cannot be updated further in a simple way and cannot be kept easily compatible with the earlier equipment. The evolution of 3GPP generations has maintained the rule that all new devices are able to function in the older networks and vice versa without loss of functionality. As some of the components introduced at the very beginning of 4G need complicated solutions in order to be optimized, new functionality must be introduced so that compatibility with the old functionality is maintained. To give a simple example, the very first LTE release was designed based on Common Reference Signals (CRSs), up to four ports, which are transmitted all the time, hence they are always ON. However, the system cannot turn these reference signals OFF, nor can scale them when the number of antennas is increasing at the transmitter without causing complications to existing device base. While CRS were a good design at its time, it was also unscalable in the future, by scalability meaning, for example, increasing the number of ports as the number of transmit antennas increases. Perhaps one of the most important lessons learned from LTE is indeed the need for a more flexible and scalable system toward the future. This is an intrinsic characteristic of 5G NR design and we are covering perhaps the most important new development over LTE, the multi-antenna perspective, in this book.

Another reason for 5G is the need for harvesting the spectrum where cellular technology has not been used so far. Spectrum is a costly resource, not easy to handle in a global environment, especially keeping in mind the cost of both devices and network equipment. 4G/LTE has been deployed in the low bands and with these occupied, there is an obvious need and choice to evolve to the areas of unoccupied spectrum to obtain more capacity for the system in general. Most of the first deployments rely on mid band of 3.5/4.5 GHz as well as 28/39 GHz, bands that are mostly unoccupied by LTE in the lower end, and lacking ability for LTE to be even deployed on in on the higher end. While moving to higher frequency bands not earlier used for cellular radio transmissions is not an easy step, it comes with the good news that the antenna form factor gets smaller as the carrier frequency gets higher. However, a lot of other challenges are arising from the fact that the pathloss on higher frequencies is also higher, and the power amplifier technologies need to evolve to support sufficient transmit powers with reasonable energy efficiency in a consumer device price point. As a first step, the 5G NR is designed to operate on bands starting from under 1 GHz and reaching up to 52 GHz, with more design focus to come in the area of 52 GHz and beyond.

The need for this book came from the fact that it seems necessary to link the dots of the existing 5G specifications into a cursive description of what the system is about and why it has been created the way it is. This book has been written by standardization experts who have been and currently are participating actively in 3GPP discussions. Most of them have also been involved in designing the 4G system with the area of expertise reaching back to 2G and 3G. We hope that the description herein will help the reader into getting a better understanding of how the 5G physical layer and related higher layer components are functioning and especially why they were designed to function that way.

While the existing 3GPP standards describe what has been agreed in the meetings, in this book we want to take this one step further and also present the context of some of the discussions and various alternatives which have been discussed but, in the end, not adopted as a standardized solutions.

1.2 Requirements and Targets

The 5G specification work was preceded by a study whose objective [1] was to identify and develop technology components needed for new radio (NR) systems being able to use any spectrum band ranging at least up to 100 GHz. The goal was to achieve a single technical framework addressing all usage scenarios, requirements, and deployment scenarios defined in TR38.913 [2]. This TR was defined to ensure that the ITU-R IMT-2020 requirements [3] will be covered, and additional industry needs are also taken into account in the technical work. Naturally the requirements were not developed in a vacuum but based on the practical understanding of what should also be achievable in real life without the need to violate the laws of physics. The new radio access technology (RAT) was to be designed for inherent forward compatibility to allow specification in multiple phases and cater for the needs of the future that today we can't imagine. This design requirement was also learning from LTE, which had a somewhat rigid setup of always-own full-band CRS and fairly fixed carrier bandwidth structure even if the original LTE design has regardless of these things proven itself to be very capable of integrating new features over a number of subsequent 3GPP releases. The New Radio study item contained technical features needed to meet these objectives set in the said TR38.913 [2]. In addition to very demanding performance requirements the additional functional requirements include:

Tight interworking between the new RAT and LTE

Interworking with non-3GPP systems

Operation in licensed bands (paired and unpaired), and licensed assisted operations in unlicensed bands.

Stand-alone operation in unlicensed bands.

One of the focus areas for the initial work related to defining a fundamental physical layer signal structure for new RAT, the key topics in this area including waveform, frame structure(s), and channel coding scheme(s).

1.2.1 System Requirements

In order to understand how wireless technologies are being created and especially labeled, it is necessary to discuss briefly about IMT-2020. There is indeed a basic question: who is certifying that a particular technology can be called 5G and based on what criteria is this done?

The International Telecommunications Union (ITU), based in Geneva, Switzerland, is a United Nations agency responsible for issues related to the communications technology. The areas of ITU cover Radio communications (ITU-R), Standardization (ITU-T), Development (ITU-D). In order to have a unified certification system on a global scale, technologies must be certified by ITU-R. This is based on ITU-R-crafted requirements, for a technology being labeled as 5G, this needs to pass these ITU requirements. The first NR release is already done, however, in order for this to be called a 5G technology, this design must pass the ITU-R requirements, this evaluation being done during the IMT-2020 discussions. According to the IMT-2020 vision, a 5G technology needs to reach requirements presented in Figure 1.1 [4].

The area of 5G requirements is crafted around the three main development cases: Extreme Mobile Broadband (eMBB), URLLC, and Massive Machine Type Communications (mMTC). eMBB capabilities relate to the maximum achievable data rate in terms of peak data rate (20 Gbps) but also in terms of coverage (1 Gbps), a high speed environment where quality of service (QoS) needs to be met for 500 kmph, an energy efficient operation at least similar to 4G and the possibility for delivering services in dense areas where the total traffic across the coverage area is of 1000 Mbps m−2. URLLC has its own requirements of a very tight latency (round trip time) of 1 ms while the eMBB target of mobility needs also to be met. Finally, mMTC targets a total number of devices per unit area of 10 000 devices per km2.

This vision was worked further, and to some extent in parallel with the 3GPP requirement and evaluation environment definition, and a more thorough requirement document with a very detailed evaluation methodology document were later produced by ITU.R. [5, 6] (summarized in Table 1.1). In some cases, the requirement name alone is insufficient to understand what is required, as what matters is how the detailed definition and the test setup have been defined. E.g. the user experienced data rate refers to a cell edge user defined as a 5th percentile point in the cumulative distribution function in a setup where there are 10 users in each cell of the system all of them having data to be scheduled. This leads to 100% loading in all cells all the time generating both worst case own cell loading and worst possible other cell interference. The simulation scenarios for evaluation are defined in fine detail in [6].

Figure 1.1

ITU-R vision for 5G [

4

].

The 3GPP RAN meeting #70 in December 2015 opened a study on scenarios and requirements for Next Generation Access Technologies [7]. The draft Technical Report of the System Information (SI) [2] released in March 2016 consisted of a large number of requirements that were used as a basis for the physical layer design work. The RAN#71 (in March 2016) also approved a new study on New Radio (NR) Access Technology that tasked the Radio Access Network (RAN) WGs “…to develop an NR access technology to meet a broad range of use cases including enhanced mobile broadband, massive MTC, critical MTC, and additional requirements defined during the RAN requirements study” [8].

The Requirements and Scenarios Technical Report [2] listed a large number of requirements to which the physical layer of the 5G New Radio is to provide solutions, which are summarized in the list below:

A very

diverse set of deployments

ranging from Indoor Hotspot to Extreme Rural coverage

A

wide range of spectrum bands

up to 100 GHz

and bandwidths

up to 1 GHz

Wide range of

device speeds

, up to 500 kmph

Ultra-deep indoor coverage

with tentative target of 164 dB MCL

D2D/V2V links

Target

peak rate of 20 Gbps in downlink and 10 Gbps in uplink

Significantly

improved system capacity, user data rates and spectral efficiency

over LTE

Target

C-plane latency

of 10 ms

Target

U-plane latency

of 4 ms for mobile broadband, and 0.5 ms for

ultra low latency

communication

Target

mobility

-incurred

connection interruption of 0 ms

Table 1.1 ITU-R requirements for IMT-2020 [5].

Requirement name

Minimum requirement

Peak data rate

DL: 20 Gbps, UL: 10 Gbps

Peak spectral efficiency

DL: 30 bps Hz

−1

, UL: 15 bps Hz

−1

User experienced data rate

DL: 100 Mbps, UL: 50 Mbps

5th percentile user spectral efficiency

Indoor hotspot – DL: 0.3 bps Hz

−1

, UL 0.21 bps Hz

−1

Dense urban – DL: 0.225 bps Hz

−1

, UL 0.15 bps Hz

−1

Rural – DL: 0.12 bps Hz

−1

, UL 0.045 bps Hz

−1

Average spectral efficiency

Indoor hotspot – DL: 9 bps Hz

−1

, UL 6.75 bps Hz

−1

Dense urban – DL: 7.8 bps Hz

−1

, UL 5.4 bps Hz

−1

Rural – DL: 3.3 bps Hz

−1

, UL 1.6 bps Hz

−1

Area traffic capacity

10 Mbps m

−2

User plane latency

4 ms for eMBB, 1 ms for URLLC

Control plane latency

20 ms requirement, 10 ms encouraged

Connection density

1 000 000 devices km

−2

Energy efficiency

Network energy efficiency is the capability of a RIT/SRIT to minimize the radio access network energy consumption in relation to the traffic capacity provided. Device energy efficiency is the capability of the RIT/SRIT to minimize the power consumed by the device modem in relation to the traffic characteristics.

Reliability

The minimum requirement for the reliability is 99.999% success probability of transmitting a layer 2 PDU (protocol data unit) of 32 bytes within 1 ms in channel quality of coverage edge for the Urban Macro-URLLC test environment

Mobility link spectral efficiency

Indoor hotspot 10 kmph−1.5 bps Hz

−1

Dense urban 30 kmph–1.12 bps Hz

−1

Rural 120 kmph–0.8 bps Hz

−1

Rural 500 kmph–0.45 bps Hz

−1

Mobility interruption time

0 ms

Bandwidth