5GandIoT ChallengestoAntennasandWirelessSystems

ProfY.JayGuoFTSEFIEEEFIETDirector,GlobalBigDataTechnologiesCentreDistinguishedProfessorUniversityofTechnologySydney(UTS)

• UTS:GBDTC

• Key5GChallengesandPHYTechnologies

• BaseStationAntennas

• MassiveAntennaArrays

• ReconfigurableAntennas

• In-BandFullDuplex

• Conclusions

2

Outline

No.1younguniversityinAustralia.Ranked#14intheworld.

Fastgrowingbyattractingtalents

GlobalBigDataTechnologies Centre uts.edu.au

UTS– ModernandCool

• Bigdata,especially non-transactionaldata,oftenneedstobe:• Acquiredremotely• Transmittedreliably• Processedefficiently• Storedeffectively• Sharedsafely• Exploitedfully• Usedwithduecareofprivacy

Ø BIGDATATechnologies– fromdataacquisitiontodecisionsupport

GlobalBigDataTechnologies Centre uts.edu.au

BigDataTechnologies

bdt.uts.edu.au

Sensors(Wirelessandoptical)

Networking(PlanningandDeployment)

Communications(Spectrum,bandwidth&

connectivity)

Datastorage,privacyandsecurity

Dataanalytics,machinelearninganddecision

support

Theproblemspace– InternetofThings(IoT)and5G

BigDataTechnologies

bdt.uts.edu.au

CentreDirector

MobileSensing&Communications

mmWave&THzSystems

UAVCommunicationLab

ElectromagneticInformatics

BigVisualDataAnalytics

SurveillanceLab

ComputerVisionandPatternRecognition

Lab

MultimediaandDataAnalyticsLab

MachineLearningLab

IoTCommunications&

Networking

5G&IoT Lab

SoftwareDefinedNetworksLab

NetworkSecurityLab

CentreManager

CentreCo- Director

GBDTCStructure

• DistinguishedProfessorY.JayGuo• DistinguishedProfessorRichardZiolkowski• DistinguishedVisitingProfessorTrevorBird• AdjunctProfessorBevanJones(formerCTOofArgusTechnology)• DrPeiyuanQin,SeniorLecturer• DrCanDing,Lecturer• 3 postdocs• AnumberofPhDstudents

8

ElectromagneticInformaticsLab

AntennaResearch@EILab

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ØReconfigurableantennas

ØReconfigurableantennaarrays

ØReconfigurablereflectarrays &transmitarrays

ØReconfigurabletightlycoupledarrays

ØReconfigurableleaky-waveantennas

ØReconfigurableconformalantennas

ØMultibandbasestationantennas

Ø Integratedantennasystems

ØElectricallysmallantennas

ØMeta-materialinspiredantennas

ØReconfigurablemm-wavefrontendsusingHTSdevices

Key5GChallengesandPHYTechnologies

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• MassiveSystemCapacity:Tosupportlargenumberofdeviceswithvariousbandwidth requirements.• HighDataRates:AchieveDataratesof100Mbpsto10Gbpsfordifferent scenarios.• VeryLowLatency(1ms)andUltra-High Reliability:Toenabletheintegration ofmission-critical applicationandservices.• Ultra-efficient DeviceandNetworkEnergyEfficiency

Key5GChallenges

5GPHYTechnologies

• HigherFrequency:10G- 50GHz,60-80GHz…• Widerbandwidths: 500MHzto3GHz(below50GHz)• NewPHYtechnologies:e.g.GFDM,FBMC,UFMC,

BFDM,NOMA• MassiveMIMOantennas• In-BandFullDuplex….

BaseStationAntennas

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BackgroundA station antenna is required to provide a full coverage of a geographic area. This isusually realized by 3 vertical high gain arrayswith each array covering a sector.

ChallengingSpecificationsImpedance Matching:

Frequency bands: 698 MHz – 960 MHz (31.6%) or/and 1710 MHz to 2690 MHz(44.5%)VSWR: < 1.5

Horizontal Beamwidth:3dB Beamwidth: 60o± 5o10dB Beamwidth: < 110o

Polarization:± 45oPolarization Isolation:> 25 dBCross Polarization level:

< -20 dB @ 0o< -10 dB @ ±60o

Front Back Ration: > 25 dBVertical 3dB beamwidth: < -15 degreeSide Lobe Level:< -18 dB

CommonBaseStationAntennas

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TheChallenge isMiniaturization!

MultibandAntennas

Meta-surface placed beneath the antenna tosuppress surface wave and to lower theantenna height.

Meta-surfaces placed between the antenna elements to improveisolation.

Programmedmeta-surfacewall

AntennasforMassiveMIMO

• Likelyatmm-wavefrequencies• Powerhandlingrequirementforeachelementreduced• Highlevelintegrationrequiredtomeettheoverallcostrequirement• Antennas+filters+duplexers+…• Multi-disciplinaryefforts• Potentiallychangetheindustrylandscape

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MassiveAntennaArrays

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MassiveAntennaArrays

•MassiveArray• Forverylargeantennaarrays,beamforming gainsaresolargethatinter-cellandinter-streaminterferencecanbeverylow

• So,massiveMIMOcandeliververyhighdatarateandimprovelinkreliability,coverageandpowerefficiency

• Implementation Issues– CostinRF– Costinpackaging– Costinsignalprocessing

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HybridAntennaArray– aTradeoffbetweenPerformanceandCost

Y.J.Guo,J.Bunton,V.Dyadyuk,andX.Huang,“HybridAdaptiveAntennaArray,”PatentAU2009900371P,02/02/2009J.

X.Huang,Y.JayGuo,andJ.Bunton,“Ahybridadaptiveantennaarray,”IEEETransactionsonWirelesscommunications,Vol.9,No.5,pp.1770-1779,May2010.

X.HuangandY.JayGuo,“Frequency-domainAoA estimationandbeamformingwithhybridantennaarray,”IEEETransactionsonWirelessCommunications,Vol.10,No.8,pp.2543-2553,August2011.

J.A.Zhang,X.Huang,V.Dyadyuk,andY.JayGuo,“Massivehybridantennaarrayformillimeter-wavecellularcommunications,”IEEEWirelessCommunicationsMagazine,pp.79– 87,February2015.

•Eachsubarray isananalogarray,consistingofantennasconnectedwithtunablephaseshiftersintheRFchain

•Eachsubarray isconnectedtoabasebandprocessorviaaDACinthetransmitteroranADCinthereceiver

MassiveHybridArrayArchitectures

a)Hybridarrayarchitectureforatransmitterandreceiver;b)twotypesofarrayconfigurationsforahybriduniformsquarearray:interleaved(upper)andlocalized(bottom)configurations.

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HybridArraySolution

• Combiningmultipleantennastoformananaloguesub-array– Analoguebeamforming withpartoftheantennaarray

• Combiningmultipleanaloguesubarrays toformahybridarray,followedbyadigitalbeamformer

• Advantages• ReducesthecostoftheRFdevices(lowerpower/device), andthecostandcomplexityofthedigitalbeamformer

• Generateshighlevelsoftransmitpowerforlongerrangeoperation(solidstatepowersourcesareavailablebutatlowpowerlevels)

• Enablesthesmartantennatechnologytobeappliedtooptimizethesystemperformance

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ReconfigurableAntennas

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FromtheGreekstoPlayingLego

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EquationtoobtaintherequiredphasedistributionfortheelementsofareflectarrayΦ",$%&'()*+ ,*-./0'12*/3$0' ×/3$5')

1ReflecarraywithFixedBeamdirection

1Y.J.GuoandS.K.Barton,“Phasecorrectingzonalreflectorincorporatingrings”,IEEET-AP,vol.43,no.4,Apr.19951Y.J.GuoandS.K.Barton,“Phaseefficiencyofthereflectivearrayantenna”,IEEProc.Micro.AntennaandPropag.Vol.142,no.2,Apr.1995

2Initial“reconfigurable”reflectarrayantennabyusingLEGOsasthecellelement.

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P.-Y.Qin,F.Wei,Y.J.Guo,“AWidebandtoNarrowbandTunableAntennaUsingAReconfigurableFilter”,IEEETransactionsonAntennasandPropagation,vol.63,no.5,pp.2282- 2285,May2015

WidebandtonarrowbandfrequencyRA

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Dual-bandPolarizationRADual-bandpolarizationRAamongtwoorthogonallinearand45degreepolarizations

ØTM10 and TM30 modes are selected tomake the antenna operate in the 2.4 GHzand 5.8 GHz bands.ØThe center of each edge of the patch isconnected to ground via a PIN diode forpolarization switching.

ØByswitchingPINdiodes,theantennacanradiateeitherhorizontal,vertical,or45linearpolarizationinthetwofrequencybands.

P.-Y.Qin,Y.J.Guo,C.Ding,IEEET-AP,vol.61,no.11,pp.5706- 5713,Nov.2013.

Multi-linearPolarizationRAwithshortingposts

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Antennastructure

• PatchlayerandBiasinglayer• Shortingpostsand8Metallicvias• Agroundplane

(a)Patchlayer (b)Biasing layer

(c)Sideview

AntennaPrototype

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Patchlayer Biasinglayer

v Approach to enhance the gain of Pattern RAsØ Employing superstrateatopthepatternRAstoformPRS

antenna

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Beam-steeringReconfigurablePRSAntenna

1) PhasedArraySource

aperture-coupling-fedantenna array

feed network ground plane

Lr

Rogers4003

λg/4 PRS FR4

y

z

θ

microstrip patch

aperture

network

150 mm

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BeamSteeringPRSAntennaDesigns

2. Employing Phase-Varying PRS Structure• Uniform PRS structure Broadside Beam

• Non-uniform PRS structure Tilted Beam

Γ

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Γ Γ1 Γ2

ApproachesforPRSAntennastoRealizeBeamSteering

ReconfigurablePRSStructureandBiasingBiasing Pad 15 nH Inductor PIN diode

Inductive striplines

Part I

Gnd

V

Part II

x

y

33

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L.Y.Ji,Y.J.Guo,P.Y.Qin,S.X.Gong,andR.Mittra,“AReconfigurablePartiallyReflectiveSurface(PRS)AntennaforBeamSteering,”IEEETransactionsonAntennasandPropagation,vol.63,no.6,pp.2387-2395,Jun.2015.

In-BandFullDuplex

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CurrentHalfDuplexRadioCommunications

• Self-interference ismillionstobillions(60-90dB)timesstrongerthanreceivedsignal• Itisgenerallynotpossibleforradiostoreceiveandtransmitinthesamefrequencybandsimultaneouslyduetotheinterferencethatresults.

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InBandFullDuplex– GeneralConcept

• Iftheself-interferencecanbecancelled,wirelesssystemscantransmitandreceivesimultaneouslyoverthesamefrequencyband• Itoffersthepotential todoublethespectralefficiencyofcurrentsystems• Beyondspectralefficiency,IBFDcanalsoenablenewcapabilities,forexample,collisiondetectionwhiletransmitting, instantaneousfeedbackfromotherterminals,…

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ThreeSICancellationTechniques• Digitalcancellationo Upto30-35dBcancellationo Noisyestimateoftheself-interference channelandnoisycomponentsoftheself-interferer cannotbecancelled

• Analogcancellationo Cancellationperformanceupto60dBo Alltransmitterimpairmentscanbecancelledo Relaxtherequirementsondigitalsignalprocessing• Mixed-signalcancellation:thedigitalTXsignalisprocessedandconvertedtoanalogRF,wheresubtractionoccurs.o Thisrequiresadedicatedadditionalup-convertor,whichinpracticeintroducesitsownnoiseanddistortion

o limitsitscancellationto35dB

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TheSourcesofSelf-Interference

• InternalInterference• Antennacoupling• Nearfieldreflection

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Self-InterferenceCancellationRequirements

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Analog DomainSuppression

• Aimtosuppressself-interference intheanaloguereceivechainbeforetheADC• Toreducethedistortionduetotransmitternonlinearityandphasenoise,analoguedomainsuppressionisbettertobeimplementedatRFfrontendascloseaspossibletothetransmitandreceiveantennas• Analoguedomainsuppressioncanbeeitherchannel-awareorchannel-unaware.Channel-awaretechniquesattempttocancelboththedirectandreflectedpathinterference,whereaschannelunawaretechniquescanonlycancelthedirectpathinterference• Weaknesses: analogue-domainsignalprocessingcanbeverydifficultespeciallyforwidebandreflected-path interference

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DigitalDomainSuppression

• Aimtocancelself-interference afterADCbyapplyingsophisticatedDSPtechniquestothereceivedsignal• Theadvantageofdigitaldomainapproachesisthatthesignalprocessingisrelativelyeasyandmature• Themostimportanttaskfordigitaldomaintechniques istobuildadiscrete-timeinterferencemodeltocaptureeverythingbetweenDACandADC• Weaknesses: theADCdynamicrangelimitstheinterferencereductionperformance.Therefore, digitaldomaincancellationisthelastresorttocanceltheself-interference leftoverfromthepropagationdomainandanaloguedomainapproaches

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SICbyAnalogFIRFilters

• Implemented atRFfrontend• Tappingtheoutgoingsignalascloseaspossibletothetransmitantenna• Placingthecancellationpointascloseaspossibletothereceiveantenna• Itischannel-aware,sothatbothdirect-pathandreflected-pathinterferencecanbecancelled

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X.HuangandY.JayGuo,“RadioFrequencySelf-interferenceCancellationwithAnalogLeastMeanSquareLoop,”IEEETransMTT,Issue99,2017.

ExistingSICTechniquesbyAnalogFIRFilters(1)

• Itconsistsofseveralparalleldelaylinesandtunable attenuators,eachprovidingacopyofthetransmittedsignal• Multiplecopiesarecombinedtointerpolatetheself-interference• However,directinterpolationofanRFsignalrequiresveryfinelydetermineddelays(comparabletotheinverseoftheRFcarrierfrequency)• Thetuneableattenuatorsalsoneedtobedynamicallydetermined byadditionaldigitallyimplementedoptimizationalgorithm

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ExistingSICTechniquesbyAnalogFIRFilters(2)

• ThetappeddelaylinesareusedtogetherwithphaseshifterswhichprovideorthogonalcopiesoftheRFsignal

• Thedelaybetweentapsiscomparabletotheinverseofthesignalbandwidth

• Thetapcoefficientsaredeterminedbyanalogueleastmeansquare(ALMS)circuitsimplemented atbaseband

• However, idealintegratorsarenecessaryintheALMScircuits

• Additionaldown-conversion circuitsandmoreanaloguemultipliersarerequired

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NovelSICbyALMSLoop

• WeightingcoefficientsareautomaticallyadaptedbyALMSloopwithsimpleRCcircuits• Implemented directlyatRFnotbaseband• Wehaveprovedthattheinterferencesuppressionratio(ISR)isdetermined bytheloopgain(includingLNAin)andtransmittedsignalpower(giventhemultiplierconstants)– theoreticallimits

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Tx

T

T

LPF LPF LPF LPF

T

T

LPF LPF

LNA

HPA

90o

Rx

LNA Gain 2µ

Tx

LNA

HPA

Rx

90o

LPF

LPF

90o

90o

LPF

LPF

90o

90o

LPF

LPF

90o

T

T

LNA Gain 2µ

X.HuangandY.JayGuo,“RadioFrequencySelf-interferenceCancellationwith AnalogLeastMeanSquareLoop,”IEEETransMTT,Issue99,2017.

In-depthAnalysisofALMSLoop

• ThebehavioursoftheALMSlooparealsoanalysedatbothmicroandmacroscales,consideringsignal’sbothcyclostationary andstationaryproperties

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FutureResearchChallenges

• I/Qimbalanceandphasenoisedirectlyimpacttheperformance• Widebandnearperfectlymatchedantennas• Highperformancelowcostandcompactcirculators• Physicallayeralgorithmdesign• Networkprotocoldesign• Fundamentalperformance limits• ….

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Conclusions

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• 5G and IoT are posing new challenges toantennas and wireless systems

• Majority of the new research will be at higherfrequenciesand on multi-band systems

• New solutionswill be inter-disciplinary§ Materials and devices§ Antennas and microwave/mm-wavecircuits§ Digital signal processing and analogue

systems§ Joint communications and sensing

ThankYou!

Jay.Guo@uts.edu.au