ETSI Workshop on Future Radio Technologies: Air Interfaces

Jian Luo (presenter)Ali A. Zaidi, Jaakko Vihriälä, Domenico Giustiniano, Yinan Qi, Hardy Halbauer, Dimitri Kténas, Richard Weiler, Honglei Miao, Javier Lorca

Sophia‐Antipolis, France , 01/27‐28/2016

mmMAGIC

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Outline

Overview of mm‐wave air‐interface design mm‐Wave specific challenges for air‐interface design KPI’s and design principles Summary and future work

WORK PACKAGE 4

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Air Interface Design for mm‐Wave: Overview

Topics: Waveform Channel code & 

Retransmission Frame 

structure and numerology

Multiple access and duplexing

Initial access

28/01/2016

Directional links

RF impairments

Power efficiency

Channel charact.

Blockage 

Transceiver arch.

Wave‐form

Channel code

Frame Structure

Efficient access schemes

Multi‐antenna tech.

Indoor/Outdoor

Access/Backhaul

Mobility (up to vehicular)

LOS/NLOS

Diverse UE types

Low latency requirements

mm‐wave Challenges mm‐wave Scenarios

Support

SimulationHardware‐in‐the‐Loop Trial

Test and verify

Design and optimize

Design 

constraints

Require

… …

WORK PACKAGE 4

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Outline

Overview of mm‐wave air‐interface design mm‐Wave specific challenges for air‐interface design KPI’s and design principles Summary and future work

WORK PACKAGE 4

mm‐Wave specific Challenges (1)

High free space loss and directional transmission

• Antenna gain must be increased to achieve reasonable coverage → Direc ve links

• Directive links will affect effective channels, interference characteristics, broadcast signaling etc.

Different propagation characteristics

• Sparsity of path clusters

Vunerability to blocking/shadowing• Problem for outdoor to indoor coverage• Coverage holes exist within cell ranges

Channel under mobility• Strong Doppler effect• Beam misalignment• Intermittant link quality

73 GHz @Entrance Hall

WORK PACKAGE 4

mm‐Wave specific Challenges (2)• RF impairments deteriorate 

with increasing frequency• Phase noise• I/Q‐imbalance• Sampling jitter of ADC • Power Amplifier (PA) 

nonlinearity• Reduced PA efficiency• Large bandwidth

• High processing demand, large processing delay, power consumption

Phase noise PA nonlinearity

• Hybrid transceiver• Puts constraints on radio interface design

• Support both backhaul and access• Support stand‐alone and overlay 

networking• Frequency uncertainty

WORK PACKAGE 4

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Outline

Overview of mm‐wave air‐interface design mm‐Wave specific challenges for air‐interface design KPI’s and design principles Summary and future work

WORK PACKAGE 4

Waveform Design Design KPI’s

Peak‐to‐Average‐Power‐Ratio (PAPR)

Robustness against RF impairments 

Spectral efficiency Compatibilty with multi‐antenna 

technologies Implementation complexity Good time localization e.g. short 

decaying time of the signal relative to TDD guard period

Flexibility/adaptability of the waveform

Robustness against Doppler effect Impact on link budget

Waveform Candidates Multi‐carrier family: CP‐OFDM, W‐OFDM, P‐OFDM, UW‐OFDM, UF‐OFDM, FQAM‐OFDM, FBMC‐QAM, FBMC‐OQAM

Single carrier family: (Precoded)‐SC‐FDMA, zero‐tail DFT‐s‐OFDM, SC‐DQAM, SC‐ceCPM

Approach Selection of waveform candidates Software defined RI: Adapt waveform to different

scenarios/channel conditions/requirements Different waveforms and pulse shapes

WORK PACKAGE 4

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Channel Code and Retransmissions Design KPI’s for 

channel code Throughput Throughput per 

hardware resource unit, e.g. per chip area

Latency Error correction 

capability Complexity Power consumption Memory 

consumption Suitability to re‐

transmission schemes

Design KPI’s for retransmissions Latency Complexity Reliability Suitability to forward 

error correction (channel code design)

Flexible round trip time for varying degrees of centralization

Design aspects for channel code and retransmissions Widely varying block lengths and code rates to be supported

Reduced encoding/decoding complexity for ultra‐high data rates

New ARQ/HARQ concepts with tight limits on complexity and latency

Possibility of fast retransmissions under partial FEC decoding mechanisms

WORK PACKAGE 4

Frame Structure and Numerology Main design aspects:

Design against hardware impairments

Frame structure supporting beamforming

Design against mobility Overhead reduction Preamble and RS design Common and dedicated control Joint backhaul and access Stand‐alone and non‐

standalone cases Scalable and hardware agnostic 

air interface

Design KPI’s Throughput Robustness to HW 

impairments and Doppler

Latency Mobility support

Candidates TDD frame structure 

with flexible DL/UL propotion

Separation of control and Data channels

WORK PACKAGE 4

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Multiple Access and Duplexing Schemes

30.11.2015

Design KPI’s Data rate  Connection density Latency Flexible scheduling Scheduling 

complexity Resource usage 

efficiency Robustness to PHY 

imperfections Availability and 

accuracy of context information

Consider extensive use of antenna arrays

Exploit context‐aware information

Consider multiple users with different requirements

Flexible adaptation to dynamic UL/DL traffics

Consider coexistence of different operators, networks and standards

WORK PACKAGE 4

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Initial Access Schemes

30.11.2015

Design KPI’s Access delay Access ratio Overhead Complexity Availability and 

accuracy of context information

Standalone/non‐standalone operations support

Antenna configurations support

Exploit sub‐6 GHz coverage

Exploit contexual information

Coupling beamforming and initial access

Support different transceiver/antenna configurations

mm‐wave beam finding

Assistance from sub‐6 GHz network(If available)

mm‐wave AP

WORK PACKAGE 4

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Outline

Overview of mm‐wave air‐interface design mm‐Wave specific challenges for air‐interface design KPI’s and design principles Summary and future work

WORK PACKAGE 4

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Summary and Furture Work A number of mm‐wave specific challenges summarized

Channel, impairment, bandwidth, transceiver, deployment etc.

KPI’s and design principles identified/derived For topics: waveform, channel code and re‐transmission schemes, frame 

structure and numerology, multiple access and duplexing, initial access

Future works: Develope/evaluate technology components/candidates according to the 

KPI’s and design principles, addressing the challenges Mapp technology components to use cases

28/01/2016

THANK YOU!

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