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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
| 2
▪ 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
| 3
▪ 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
| 4
▪ 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
| 5
▪ 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
| 6
[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
| 7
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
| 8
▪ 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
| 9
▪ 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
| 10
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
| 18
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?