Yinan Qi

Samsung Electronics R&D Institute UK, Staines, Middlesex TW18 4QE, UK

5G NR: Key Features and EnhancementsAn overview of 5G NR key technical features and enhancements

for massive MIMO, mmWave, etc.

18th September, CW TEC 2018 - The

inevitable automation of Next Generation

Networks

▪ 5G NR Phase I overview: timeline, spectrum and use cases.

▪ Key features and enhancements

▪ Flexibility

o Numerology

o Frame structure

▪ Millimetre wave

o Beam management

o Massive MIMO

o Phase tracking

▪ UE specific design

o Bandwidth part (BWP)

o Reference signal design

▪ 5G NR Phase II overview: SID/WID, enhancements, etc.

Outline

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▪ Much faster than 4G: 48 months→ 27 months

▪ 5G NR timeline

▪ 3GPP Rel-14: focuses on 4G LTEupgrades but a starting point for5G NR phase I

▪ 3GPP Rel-15: dedicated tobuilding the world’s first global 5Gstandards

▪ 3GPP Rel-16: maintenance of 5GNR phase I features and phase IIenhancements

5G NR Phase I: Timeline

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▪ A wide range of frequency bands:both below and above 6 GHz

▪ Below 6 GHZ: 2.5 and 3.5 GHz withwider bandwidth

▪ Above 6 GHz (millimetre wave):ultra-high frequency bands like28GHz and 39GHz are required for5G standards to provide high speeddata transmission.

▪ Each country has its own rules andallocation policies: bands rangingfrom a few hundred MHz to 1GHz.

▪ Licensed/Shared/Unlicensed bands.

5G NR Phase I: Spectrum

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▪ Enhanced Mobile Broadband (eMBB):exceptionally fast data speeds

▪ Ultra Reliable and Low LatencyCommunications (URLLC): real-time servicesthat require extremely low latency andprompt responses

▪ Massive Machine-Type Communications(mMTC): million homes and industrial IoTdevices within 1 km2 can be connected

5G NR Phase I: Use Cases

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▪ HD video: more than 40 times fasterdownloading speed

▪ Autonomous vehicles: emergency brakedistance reduced 2.8 cm

▪ IoT devices: 100,000 → 1,000,000

▪ Scalable numerology

▪ Numerology parameters:

▪ Subcarrier Spacing

o 15 kHz to 60 kHz for below 6 GHz

o 60 kHz to 120 kHz for above 6 GHz

o 240 kHz for synchronization

▪ Cyclic Prefix

o 60 kHz can be configured with extended CP

▪ Larger subcarrier spacing for above 6 GHz

▪ Latency: shorter symbol duration

▪ ICI: phase noise

▪ Support multiplexing of differentnumerologies

5G NR Flexibility: Numerology

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[kHz] 152 = f

▪ Length of one radio frame is fixed to 10ms andthe length of 1 subframe is fixed to 1ms.

▪ Different Numerologies will be then translatedin the number of slots per sub-frame: higherthe Subcarrier spacing → higher the numberof slots per sub-Frame.

▪ Slot: 14 OFDM symbols

▪ 15 kHz: 1 slot per subframe

▪ 30 kHz: 2 slots per subframe

▪ 60 kHz: 4 slots per subframe

▪ 120 kHz: 8 slots per subframe

▪ Two slot configurations:

▪ Slot configuration 0: 14 OFDM symbols, appliedto all numerologies

▪ Slot configuration 1: containing 7, 4 or 2 OFDMsymbols, applied only for certain numerologies.

5G NR Flexibility: Frame Structure

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1 Slot, 14 Symbols, Slot duration 1 ms15 kHz

1 Slot, 14 Symbols, Slot duration 0.5

ms30 kHz

1 Slot, 14 Symbols,

Slot duration 0.25 ms60 kHz

1 Slot, 14

Symbols, Slot

duration 0.125

ms120 kHz

Subframe (1ms)

▪ High frequency bands: small coverage and low penetration rate.

▪ Beamforming

▪ Strong concentrated signals in one particular direction

▪ Enables mmWave frequencies to travel far with less interference from other signals.

▪ More the antenna elements → sharper the beam shape → concentrated energy.

5G NR Millimetre Wave: Beamforming

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▪ A significant challenge: beam paringbetween the base stations and UEs,especially for fast-moving UEs

▪ Beam management

▪ Objective: establish and retain a suitablebeam pair, i.e., beam direction of thetransmitter and beam direction of thereceiver jointly aligned

▪ DL BM as focus of Rel-15

o P-1 : Beam Selection for TRP Tx/UE Rx.

o P-2 : Beam Reselection(Beam Change) forTRP Tx beam.

o P-3 : Beam Reselection(Beam Change) forUE Rx beam.

▪ UL BM: U1/2/3

5G NR Millimetre Wave: Beam Management

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▪ General procedure

▪ Beam measurement: RSRP

▪ Beam reporting

▪ Initial beam establishment

▪ A beam pair is initially established in the DL and ULtransmission directions.

▪ Beam sweeping: associate synchronization signal withdifferent beams

▪ Wider beam/coverage

▪ Beam adjustment

▪ After initial beam pair establishment

▪ Re-evaluate the beam pair due to movements/rotations

▪ Refinement of the beam shape using CSI-RS for datatransmission → narrow beam

5G NR Millimetre Wave: Beam Management

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Beam sweeping

Beam adjustment

▪ From 2/4/8 to massive number ofantennas, e.g., 256 or 1024

▪ mmWave antennas with smaller antennasize

▪ Main benefits

▪ Capacity gains

▪ Spectral efficiency

▪ Energy efficiency

▪ Support up to 8 layers for SU-MIMO andup to 12 layers for MU-MIMO

▪ More accurate CSI feedback: type I andtype II CSI

▪ UL supports both CB and NCB

5G NR Massive MIMO

▪ Type I CSI: Different codebooks assuming differentantenna configurations.

▪ Type I single-panel CSI

o Single panel with N1×N2 cross-polarized antenna elements

o Precoding matrix can be expressed as the production oflong-term frequency-independent precoding matrix andshort-term frequency-dependent precoding matrix

▪ Type I multi-panel CSI

o Same principle but long-term frequency-independentprecoding matrix can reflect beam per panel

▪ Type II CSI

▪ CSI with significantly higher spatial granularity

▪ Target MU-MIMO

5G NR Massive MIMO: CSI

▪ mmWave devices and network access points suffer from severe phase noise mainly due tothe mismatch of transmitter and receiver frequency oscillators.

▪ Worse with higher frequency

▪ Phase noise causes ICI and CPE

5G NR Millimetre Wave: Phase Noise

▪ New reference signal: Phase tracking reference signal (PT-RS)

▪ There is a trade-off between phase tracking accuracy and signaling overhead.

▪ If the density of PT-RS is high, phase tracking accuracy is high and CPE can be better compensated to achieve better performance.

▪ However, higher PT-RS density also means larger signaling overhead.

▪ PT-RS density in the time domain: a function of modulation order.

▪ PT-RS density in the frequency domain: a function of BW.

5G NR Millimetre Wave: PT-RS

▪ BWP

▪ A group of contiguous PRBs

▪ Each BWP has its own numerology

▪ Multiple BWPs can be configured to a singleUE but only one can be active at one time

▪ Use cases

▪ Smaller UE BW capacity

▪ Reduced UE energy

▪ FDM of multiple numerology

▪ Non-contiguous spectrum

▪ Forward compatability

5G NR UE Specific Design: Bandwidth Part

Carrier

BWP

Carrier

BWP

Carrier

BWP

Carrier

BWP

Carrier

BWP

?

▪ LTE

▪ Synchronization: SS

▪ Demodulation: DMRS

▪ Channel estimation:

o Cell specific RS: always on

o CSI-RS: UE specific RS

o SRS: UL

▪ 5G NR

▪ Synchronization: SS

▪ Demodulation: front-loaded DMRS

▪ Phase tracking

o PT-RS

▪ Channel estimation

o CSI-RS

▪ Fine time and frequency tracking

o TRS: one port CSI-RS

5G NR UE Specific Design: Referene Signals

▪ DMRS

▪ Front loaded

▪ Two different DMRS patterns

▪ Additional DMRS symbols can be configured

▪ CSI-RS

▪ X-port CSI-RS REs span N adjacent/non-adjacent OFDM symbols

▪ Three types of component CSI-RS RE patterns are supported:

o (Y,Z) ∈ {(2,1), (2,2), (4,1)}

o A component CSI-RS RE pattern is defined within a single PRB as Y adjacent REs in the frequency domain and Zadjacent REs in the time domain

▪ Three types of CDM patterns are supported:

o FD-CDM2, CDM4 (FD2, TD2), CDM8 (FD2, TD4)

5G NR UE Specific Design: Referene Signals

Adjacent/non-adjacent

▪ Enhancements ofphase I▪ MIMO MIMO

▪ DC and CA

▪ Mobility

▪ 5G NR Phase IISID/WID

5G NR Phase II

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WID Title WI/SI WGCompletion

dateRP-181453 New WID: NR MIMO enhancements WI R1 Dec 2019

RP-181480 New SID: NR V2X SI R1 Mar 2019

RP-181399 New SID: Study on NR positioning support SI R1 Mar 2019

RP-181430 New SID: Study on remote interference management for NR SI R1 Dec 2018

RP-181431 New WID: Cross Link Interference (CLI) handling and Remote Interference Management (RIM) for NR

WI R1 Mar 2019

RP-181463 New SID: NR Power Consumption WI R1 Jun 2019

RP-181370 New SID: Solutions for NR to support Non Terrestrial Networks SI R1 Dec 2019

RP 181477 New SID: NR URLLC Enhancements SI R1 Mar 2019

RP-181479 New SID: NR support for Industrial IOT SI R2 Dec 2018

RP-181459 New SID: Optimisations on UE radio capability signalling - NR/E-UTRA SI R2 Mar 2019

RP-181469 New WID: DC and CA enhancements WI R2 Dec 2019

RP-181433 New WID: NR mobility enhancements WI R2 Dec 2019

RP-181456 New SID: RAN-centric Data Collection and Utilization SI R3 Jun 2019

RP-181467 New SID: 2Rx requirements for vehicle mounted NR UE SI R4 Dec 2018

RP-181402 New SID: Radiated test methodology for the verification of multi-antenna reception performance of NR UEs

SI R4 Dec 2019

RP-181435 New SID: NR design above 52.6GHz SI RAN Sep 2019

Thank you for your attention

Questions?