Self-Interference in Full-Duplex 2×2 MIMO Transceivers: Channel Characterization and RF/Analog ...

127 Pages·2017·6.71 MB·English

Self-Interference in Full-Duplex 2×2 MIMO
Transceivers: Channel Characterization and
RF/Analog Cancellation
Fei Chen
Department of Electrical & Computer Engineering
McGill University
Montreal, Canada
April 2017
AthesissubmittedtoMcGillUniversityinpartialfulfillmentoftherequirementsforthedegree
ofMasterofEngineering.
(cid:13)c 2017FeiChen
2017/04/07
i
Tomyparents,
withallmylove.
ii
Abstract
Spectrum resources become more and more scarce over last few decades, leading to the sig-
nificance of effectively utilizing and allocating spectrum. Recently, in-band full-duplex (FD)
operation has gained more attention as a potential approach of enhancing spectrum efficiency by
simultaneous transmission and reception over the same frequency. One of the most challenging
problemsinFDcommunicationsistheexistingstrongself-interference(SI)fromtransmitterand
co-locatedreceiver. TheSImustbesuppressedtoasufficientlylowlevelbyacombinationofan-
tenna,radiofrequency(RF)andbasebandcancellationstagessothattheintendedsignalreceived
from the distant transmitter can be reliably demodulated. In this work, we study the SI-channel
characteristicsanddevelopahighperformanceRF/Analogself-interferencecanceller(SIC)fora
2×2MIMOFDtransceiver.
Firstofall,SIcancellationtechniquerequiresknowledgeofSIpropagationcharacteristicsand
models. We investigate of the wideband SI-channel propagation characteristics of a 2×2 MIMO
with dual-polarized antennas. The SI-channels are measured at center frequency of 2.45GHz
with 500MHz bandwidth in various environments: anechoic chamber, laboratory room, and cor-
ridor. ThemeasurementresultsshowthattheSI-channelcanberepresentedbyamultipathmodel
composting of two segments: a quasi-static internal SI-sub-channel due to the particular Tx/Rx
antennastructureandatime-varyinganddynamicexternalSI-sub-channelduetopossiblereflec-
tions from the surrounding objects. Also, the external SI-channel exhibits cluster arrival features
andcanbedescribedbyamodifiedSaleh-Valenzuela(S-V)model.
Inaddition,weadevelopRF/AnalogSICtosuppressthequasi-staticinternalSI-sub-channel.
We discuss SIC design considerations at the system level. Specifically, we consider coupler se-
lection to minimize the noise-figure increase and derive the linearity requirements of RF/Analog
SIC, including the component linearity requirements, so that the nonlinear distortion introduced
by RF/Analog SIC will not significantly degrade SNR after all the cancellation stages. We pro-
posehigh-linearRF/AnalogSICwithcustom-madecomponents. Measurementsandsimulations
with followed digital cancellation stages show that proposed RF/Analog SIC can provide 60-
80dBcancellationandnegligibleSNRdegradation(0.3dB)duetononlineardistortion.
Moreover, we specifically focus on the study and design of delay/phase shift module, to
meet the RF/Analog SIC linearity requirements. This delay/phase shift module is composed of
a RF switched true time Delay line (switched TTD) and an analog variable reflective type phase
shifter (RTPS). Measurement results show significant improvement over off-the-shelf products,
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andotherexistingprototypes,intermsoflinearity.
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Sommaire
Lesressourcesduspectresontdeplusenplusraresaucoursdesdernie`resde´cennies,cequicon-
duit a` l’importance d’utiliser et d’allouer efficacement le spectre. Re´cemment, la transmission
en duplex inte´gral (FD) a gagne´ une grande d’attention comme une me´thode qui peut poten-
tielle ame´liorer l’efficacite´ spectrale par la transmission et la re´ception simultane´e sur la meˆme
fre´quence. L’un des proble`mes majeurs de la transmission en FD est l’auto-interfe´rence (self-
interferenceouSI)fortere´sultantedel’e´metteuretlere´cepteurco-situe´. LaSIdoiteˆtrere´duitea`
unniveausuffisammentfaibleencombinantdestechniquesdere´ductionauniveaudesantennes,
au niveau radio fre´quence (RF) et en bande de base pour graduellement atte´nuer la SI. Dans ce
travail, nous e´tudions les caracte´ristiques du canal de la SI et nous de´veloppons un me´canisme
d’annulationdelaSIope´rantdansledomaineRF/Analogiquepourune´metteur-re´cepteura` deux
antennes(2×2MIMO).
Tout d’abord, la technique d’annulation de la SI requiert la connaissance et la caracte´risation
du canal de propagation de la SI que nous e´tudions pour un syste`me MIMO 2x2 large bande
avec des antennes a` polarisation double. Les canaux SI sont mesure´s pour une fre´quence cen-
trale de 2,45GHz avec une bande passante de 500 MHz dans divers environnements: chambre
ane´cho¨ıque, salle de laboratoire et couloir. Les re´sultats de mesure montrent que le canal de la
SIpeuteˆtrerepre´sente´ pardescomposantsmultitrajetsa` deuxsegments: unecomposanteinterne
quasi-statiquede´pendantedelastructuredesantenneetunecomposanteprovenantdesre´flexions
a` partir des objets environnants. De plus, nous montrons que ces re´flexions peuvent eˆtre de´crit
parunmode`lemodifie´ deSaleh-Valenzuela(S-V).
En outre, nous de´veloppons un sche´ma d’annulation de la SI (SIC) en RF/Analogique pour
supprimerlaSIre´sultantedureflextioninternequasi-statique. Nousdiscutonsdesconside´rations
de la conception du SIC au niveau du syste`me. En particulier, nous e´tudions la se´lection du
coupleurdanslebut deminimiserdelafiguredebruitet nousde´rivonslanonline´arite´ introduite
parleRF/AnalogiqueSIC,pourde´terminerlecaracte`renonline´airedescomposantes,quigarantie
que le RF/Analogique SIC ne de´gradera pas le SNR. Nous proposons un SIC RF/Analogique
hautement line´aire avec des composants sur mesure. Des mesures et des simulations avec des
e´tages d’annulation nume´riques suivis montrent que le RF/Analogique SIC propose´ peut fournir
uneannulationde60-80dBetunede´gradationne´gligeabledelaSNR(0.3dB)duea` unedistorsion
non-line´aire.
De plus, nous nous concentrons particuliairement sur l’e´tude et la conception du module de
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de´lai/de´phasage, pour re´pondre aux exigences de la line´arite´ du RF/Analogique SIC. Ce mod-
ule de de´lai/de´phasage est compose´ d’une ligne de temporisation a` temps re´el commute´e RF
(TTDcommute´e)etd’unde´phaseurdetypeanalogiquea` re´flexionvariable(RTPS).Lesre´sultats
des mesures montrent une ame´lioration significative par rapport aux solutions disponibles sur le
marche´ etauxautresprototypesexistants,entermesdeline´arite´.
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Acknowledgments
I would like to express my deepest and sincere gratitude to my supervisor, Professor Tho Le-
Ngoc, for his patience, excellent guidance, encouragement during my M.Eng. studies at McGill
University. Particularly, I appreciate his devotion to this research, his broad knowledge, sharp
judgment,enthusiasm.
My deep appreciation goes to the Broadband Communications Research Lab (BCRL) Man-
ager/Engineer, Mr.Robert Morawski, for his patient and productive research coaching and col-
laboration in assisting me to complete this research work. He has helped me countless times in
practical issues of my research and I have learned a great deal from him. I also would like to
thankMr.ThanhNgonTranforhiskindassistanceandhelpfuldiscussions.
I would like to thank financial support received from the Natural Sciences and Engineering
ResearchCouncilofCanada(NSERC)andHuaweiTechnologies.
I am deeply grateful to all my colleagues and friends in BCRL. They made my journey at
McGill unforgettable. I would like to thank Hak Hyun Lee, Ruozhu Li, Ruikai Mai, Ahmed
Masmoudi,SeonghwanKim,XiaoweiWang,PragyanHazarika. Iamalsothankfultomyfriends
at McGill and in Montreal, especially, Bonan Zhang, Ge Li, Ziyin Chen, Zheng Liu, Yue Cai,
BaoguangXu,YiqingXiao,RandyLi,YuhaoMao.
Finally, my deepest and sincere gratitudes are devoted to my parents and my beloved girl-
friendforalltheirimmenselove,presenceandsupport.
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Contents
1 Introduction 1
1.1 Full-DuplexWirelessCommunicationsandKeyChallenges . . . . . . . . . . . . 1
1.2 ApplicationsofFull-DuplexCommunications . . . . . . . . . . . . . . . . . . . 4
1.2.1 Full-duplexBaseStationorRelay . . . . . . . . . . . . . . . . . . . . . 4
1.2.2 Device-to-Device(D2D)Communication . . . . . . . . . . . . . . . . . 4
1.2.3 Two-TierCognitiveRadioNetworks . . . . . . . . . . . . . . . . . . . . 5
1.2.4 ImproveSecurityofWirelessDataTransfer . . . . . . . . . . . . . . . . 5
1.2.5 OtherApplications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 ThesisContributionsandOrganization . . . . . . . . . . . . . . . . . . . . . . . 6
2 SIChannelCharacteristicsandSICancellationTechniques: AReview 8
2.1 Self-InterferenceChannelCharacteristicsandModeling . . . . . . . . . . . . . . 8
2.2 Self-InterferenceCancellationTechniques . . . . . . . . . . . . . . . . . . . . . 9
2.2.1 AntennaorPropagationDomainSuppression . . . . . . . . . . . . . . . 11
2.2.2 RFDomainSelf-InterferenceCancellation . . . . . . . . . . . . . . . . 12
2.2.3 BasebandDomainSelf-interferenceCancellation . . . . . . . . . . . . . 16
2.3 ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3 SIChannelCharacterizationandModeling 18
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2 MeasurementSetup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.1 Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.2 WidebandChannelSoundingSystemandDataAcquisition . . . . . . . . 22
3.2.3 MeasurementEnvironments . . . . . . . . . . . . . . . . . . . . . . . . 23
3.2.4 MeasurementProcedure . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Contents viii
3.3 MeasurementResultsandSI-channelModeling . . . . . . . . . . . . . . . . . . 26
3.3.1 SI-channelPDP Trends . . . . . . . . . . . . . . . . . . . . . . . . . 26
TR
3.3.2 SI-ChannelImpulseResponseModelsandParameters . . . . . . . . . . 27
3.3.3 TimeDispersionCharacteristics . . . . . . . . . . . . . . . . . . . . . . 35
3.4 ConcludingRemarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4 RF/AnalogSelf-InterferenceCancellerfor2×2MIMOFull-DuplexTransceiver 40
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.2 Multi-TapDelayLineRF/AnalogSICStructureandDesignConsiderations . . . 42
4.2.1 Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.2 CouplerConsideration . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.3 NonlinearityConsideration . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.4 TuningAlgorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.5 Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.2.6 QuantizationEffectsofcomponentsinRF/AnalogSIC . . . . . . . . . . 53
4.3 ImplementedPrototypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.3.1 Prototype1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.3.2 Prototype2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.4 MeasurementResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.4.1 AnechoicChamberMeasurements . . . . . . . . . . . . . . . . . . . . . 63
4.4.2 IndoorEnvironmentMeasurements . . . . . . . . . . . . . . . . . . . . 64
4.4.3 NonlinearDistortionCharacteristicMeasurements . . . . . . . . . . . . 66
4.5 ConcludingRemarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
5 High-PerformanceTunableDelay/PhaseShiftModule 70
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.2 Delay/PhaseShiftmoduleArchitecturesandTopologies . . . . . . . . . . . . . . 71
5.2.1 SwitchedTrueTimeDelay(SwitchedTTD)PhaseShifter . . . . . . . . 71
5.2.2 HighPass-LowPassTypePhaseShifter . . . . . . . . . . . . . . . . . . 73
5.2.3 Reflective-TypePhaseShifter(RTPS) . . . . . . . . . . . . . . . . . . . 73
5.2.4 PeriodicallyLoadedLinephaseshifter . . . . . . . . . . . . . . . . . . . 76
5.3 TargetSpecifications,DesignTopologiesSelections,andConsiderations . . . . . 78
5.3.1 SwitchedTTDPhaseShifter . . . . . . . . . . . . . . . . . . . . . . . . 80
Contents ix
5.3.2 RTPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.4 ImplementedPrototypeandCharacterizations . . . . . . . . . . . . . . . . . . . 84
5.4.1 SwitchedTTDMeasurements . . . . . . . . . . . . . . . . . . . . . . . 84
5.4.2 VariableRTPSMeasurements . . . . . . . . . . . . . . . . . . . . . . . 87
5.5 ConcludingRemarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6 Conclusions 92
6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.2 PotentialFutureResearch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
A OIP3,IIP3andIIP3DerivationforSICrequirements 95
A.1 OIP3andIIP3Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
A.2 IIP3DerivationforSICrequirements . . . . . . . . . . . . . . . . . . . . . . . . 96
B GroupDelayMeasurementAccuracy 98
References 100