EfficientSystemDesignsforSingleand Multi-User Spatial Modulations
by
cIbrahimOsamaIbrahim MahmoudAl-Nahhal AdissertationsubmittedtotheSchoolofGraduateStudies
inpartialfulfillmentoftherequirementsforthedegreeof
DoctorofPhilosophy
FacultyofEngineeringandAppliedScience MemorialUniversityofNewfoundland
October2020 St.John’s,Newfoundland
Abstract
Spatialmodulation(SM)andquadratureSM(QSM)arepromisingversionsofthesingle-user multiple-inputmultiple-output(MIMO)systemthatovercometheproblemofinter-channel- interferencewhichoccursinconventional MIMOsystems.BothSMandQSMexploitthe indexoftheactivatedantenna(s)tocarryadditionalinformationtoenhancethetotalspectral efficiencyofthesystemtransmission.Inthedetection,theSMandQSMsystemsjointly detecttheindexoftheactivatedantenna(s)aswellasthetransmittedmodulationsymbol, whichisanexhaustiveprocessespeciallyforhigherordermodulationsandlargesystem dimensions.Thisexhaustiveprocesscontradictsthedemandsoffuturewirelessnetworks thatrequirelow-powerconsumptionandlowcommunicationlatency.
Tofulfillthedemandoflow-complexdecodersatthereceiversideforfuturewireless networks,Iproposethreedifferentlow-complexitydecodersforsingle-userSMandQSM MIMOsystems.Thesealgorithmsarebasedontheconceptofspheredecodingforthe tree-searchstructure.Thefirstproposedalgorithmprovidesasignificantreductioninthe decodingcomplexitywithoptimalbiterrorrate(BER)performance.Thesecondproposed algorithmprovidesanextrareductioninthedecodingcomplexitywithoutsacrificingthe optimalityoftheBERperformance.Finally,thethirdalgorithmprovidesaflexibletrade-off betweencomplexityandBERperformancetobesuitableformosthardwareimplementations. TheproposedalgorithmsarestudiedintermsofBERperformanceandexpecteddecoding complexityforthesingle-userSMandQSM MIMOsystems.
Formulti-userSM-MIMO,alow-costsystemisproposedusingthesparsecodemul- tipleaccess(SCMA)technique.Theproposedlow-costSM-SCMAsystemsignificantly reducestherequirednumberoftransmitantennaswithalmostnolossintermsoftheBER performanceanddecodingcomplexity,comparedwiththeconventionalSM-SCMA.Atthe receiver,themessagepassingalgorithm(MPA)isemployedtodetectthetransmittedsignals, whichsuffersfromhighdecodingcomplexityinpracticalimplementations.Toaddressthis issue,threelow-complexitydecodingalgorithmsareproposedfortheSM-SCMAsystem. Thefirstalgorithmprovidesthebenchmarkforthedecodingcomplexityattheexpenseofthe BERperformance.Thesecondalgorithmslightlyincreasesthedecodingcomplexitywitha significantimprovementintheBERperformance.Finally,thethirdalgorithmprovidesa near-optimumBERperformancewithaconsiderabledecodingcomplexityreductionwhen comparedtothe MPAdecoder. Moreover,itsupportstheparallelhardwareimplementation andstrikesatrade-offbetweendecodingcomplexityandBERperformance.
Morespecifically,thethreelow-complexityreceiversforthesingle-userSMandQSM MIMOsystemsareintroducedinChapters2,3,4and5.InChapter2,thefirstlow- complexityalgorithmforsingle-userQSM-MIMOsystemisproposed.Thesecondlow- complexityalgorithmforSM-MIMOsystemisintroducedinChapter3,andisanalyzedin Chapter4.Thereliabledecoderforsingle-userSM-MIMOsystemisproposedinChapter5. Formulti-userSM-SCMA,thelow-costsystemisproposedinChapter6;atthereceiverside, thethreelow-complexitydecodersfortheSM-SCMAsystemareproposedandanalyzedin Chapter7.
Tomyfatherandmother... Tomylovelywifeandkids... Tomytwosistersandtwobrothers...
Tomyentirefamilyandfriends...
Acknowledgments
PraisebetoAllah,theCherisherandSustaineroftheWorlds.AfterthankingAlmighty
"ALLAH"forhisblessingandguidancetocompletethiswork,Iwouldliketooffermy sincerethankstomysupervisorsProf.OctaviaDobreandDr.SalamaIkkifortheirvaluable guidanceandadvice.IwouldliketoexpressmydeepappreciationtoProf. Octaviafor herprofessionalismandpersonalcaringforherstudentsbeforeandafterthestudy;Iwas luckytobeherstudent,andIencouragehard-workergraduatestudentstogothroughthis amazingexperiencewithher.Iwouldliketoacknowledgethefinancialsupportprovidedby mysupervisors,theFacultyofEngineeringandAppliedScience,theSchoolofGraduate Studies,andtheNaturalScienceandEngineeringResearchCouncilofCanada(NSERC). IwouldliketothankmyEgyptianuniversity,Al-AzharUniversityinCairo,forletting metrythisfruitfulexperience.SinceasignificantpartofmyeducationwasinEgyptandmy foundationswerelaidinschoolsoftheZagazigandCairocities,Iwouldliketothankmy elementaryschoolteachers,myuncleHosnywhotaughtmemathatsecondaryandhigh schools,myB.Sc.professors,andmy M.Sc.thesissupervisorProf. MasoudAlghoniemy whoputmeontherightpathofscientificresearchandhasbeenstillintouchwithme.
Thefinalwordofacknowledgmentisreservedtomyparentsfortheirunconditional support,tomytwosistersandtwobrothersfortheirlove,tomyfriendsallovertheworld, tomysweetheartandlovelywifeIsraaandourkidsfortheirpatienceandformotivatingme. Finally,Iwouldliketosaythat“Iamnothingwithoutyouall.”
Co-AuthorshipStatement
I,IbrahimAl-Nahhal,holdaprincipleauthorstatusforallthemanuscriptchapters(Chapters 2-7)inthisdissertation. However,eachmanuscriptisco-authoredbymysupervisors andco-researchers,whosecontributionshavefacilitatedthedevelopmentofthisworkas describedbelow.
•Paper1inChapter2:I.Al-Nahhal,O.A.Dobre,andS.Ikki,“QuadratureSpatial ModulationDecodingComplexity:StudyandReduction,”IEEE WirelessCommuni- cationsLetters,vol.6,pp.378-381,Jun.2017.
Iwastheprimaryauthor,withauthors2and3contributingtotheidea,itsformulation anddevelopment,andrefinementofthepresentation.
•Paper2inChapter3:I.Al-Nahhal,O.A.Dobre,andS.Ikki,“LowComplexityDe- codersforSpatialandQuadratureSpatial Modulations,”inProceedingIEEEVehicle TechnologyConference(VTC-Spring),2018,pp.1–5.
Iwastheprimaryauthor,withauthors2and3contributingtotheidea,itsformulation anddevelopment,andrefinementofthepresentation.
•Paper3inChapter4:I.Al-Nahhal,E.Basar,O.A.Dobre,andS.Ikki,“Optimum Low-ComplexityDecoderforSpatial Modulation,”IEEEJournalonSelectedAreas inCommunications,vol.37,no.9,pp.2001-2013,Jul.2019.
anddevelopment,andrefinementofthepresentation.
•Paper4inChapter5:I.Al-Nahhal,O.A.Dobre,andS.Ikki,“ReliableDetection forSpatial ModulationSystems,”accepted,IEEEVehicleTechnologyConference (VTC-Fall),2020.
Iwastheprimaryauthor,withauthors2and3contributingtotheidea,itsformulation anddevelopment,andrefinementofthepresentation.
•Paper5inChapter6:I.Al-Nahhal,O.A.Dobre,E.Basar,andS.Ikki,“Low-Cost UplinkSparseCode MultipleAccessforSpatial Modulation,”IEEETransactions VehicleTechnology,vol.68,no.9,pp.9313-9317,Jul.2019.
Iwastheprimaryauthor,withauthors2-4contributingtotheidea,itsformulation anddevelopment,andrefinementofthepresentation.
•Paper6inChapter7:I.Al-Nahhal,O.A.Dobre,andS.Ikki,“OntheComplexity ReductionofUplinkSparseCode MultipleAccessforSpatial Modulation,”accepted, IEEETransactionsonCommunications,Aug.2020.
Iwastheprimaryauthor,withauthors2and3contributingtotheidea,itsformulation anddevelopment,andrefinementofthepresentation.
IbrahimAl-Nahhal Date
TableofContents
Abstract ii
Acknowledgments v
Co-AuthorshipStatement vi
TableofContents viii
ListofTables xiv
ListofFigures xv
ListofAbbreviations xix
1 Introduction 1
1.1 Background... 1
1.2 MIMOSystems... 2
1.3 Single-UserSpatial Modulation ... 3
1.3.1 SMFunctionality... 4
1.3.2 TheQSM-MIMOSystem ... 4
1.4 Multi-UserSM... 6
1.4.1 SCMAFunctionality... 7
1.4.2 TheSM-SCMASystem ... 9
1.5 PotentialApplicationsofSMtoEmergingCommunicationSystems.... 9
1.6 MotivationandOutline... 11
1.7 Contributions... 12
References... 14
2 QuadratureSpatial ModulationDecodingComplexity:StudyandReduction 20 2.1 Abstract... 20
2.2 Introduction... 21
2.3 TheQSMSystem Model... 22
2.4 TheQSM-MLDecoderComplexity... 23
2.5 Reduced-ComplexityQSMAlgorithm... 24
2.6 ComplexityanalysisoftheQSM-RC... 26
2.7 Numericalresults... 28
2.8 Conclusion ... 30
2.9 APPENDIX:Proofof(2.8)... 30
References... 33
3 LowComplexityDecodersforSpatialandQuadratureSpatial Modulations 36 3.1 Abstract... 36
3.2 Introduction... 37
3.3 SMandQSMSystem Models ... 38
3.3.1 Spatial Modulation... 38
3.3.2 QuadratureSpatial Modulation... 39
3.3.3 TheTree-SearchStructureConcept... 40
3.4 Proposedm-MLow-ComplexityAlgorithm... 40
3.5 ComplexityAnalysis... 43
3.6 UnionBoundErrorProbabilityAnalysis... 45
3.7 Numericalresults... 47
3.8 Conclusion ... 49
References... 49
4 OptimumLow-ComplexityDecoderforSpatial Modulation 54 4.1 Abstract... 54
4.2 Introduction... 55
4.3 System Model... 57
4.3.1 SM Modulator... 57
4.3.2 SM-MLDemodulation... 58
4.4 Minimum-Distanceof Maximum-LengthAlgorithm... 60
4.5 ComplexityAnalysis... 64
4.5.1 PerfectChannelStateInformationattheReceiver... 66
4.5.2 ImperfectChannelStateInformationattheReceiver... 68
4.6 OptimalityofBERPerformance... 70
4.7 NumericalResultsandDiscussions... 72
4.7.1 BERComparison... 73
4.7.2 AnalyticalComplexityAssessment ... 74
4.7.3 ComplexityComparison... 75
4.7.4 ComplexityReductionSensitivity... 76
4.7.5 Discussions... 77
4.8 Conclusion ... 79
References... 79
5 ReliableDetectionforSpatial ModulationSystems 95 5.1 Abstract... 95
5.2 Introduction... 96
5.3 System Model... 97
5.4 TheProposedRSDAlgorithm... 99
5.5 TheoreticalAnalysis ...101
5.5.1 BERUpperBoundAnalysis...101
5.5.2 ExpectedComplexityAnalysis...103
5.6 SimulationResults...105
5.6.1 AssessmentofExpectedComplexityfortheRSDAlgorithm....105
5.6.2 ComparisonswithLiteratureAlgorithms ...106
5.7 Conclusion ...107
References...107
6 Low-CostUplinkSparseCode MultipleAccessforSpatial Modulation 114 6.1 Abstract...114
6.2 Introduction...115
6.3 Related Workand Motivation...116
6.4 RGSM-SCMASystem Model ...117
6.5 RGSM-SCMASignalDetection...119
6.5.1 MLDecoder...120
6.5.2 MAPDecoder ...120
6.5.3 MPADecoder...122
6.5.4 MPAComplexityAnalysis...123
6.6 SimulationResults...124
6.7 Conclusion ...125
References...127
7 OntheComplexityReductionofUplinkSparseCode MultipleAccessforSpa-
tial Modulation 131
7.1 Abstract...131
7.2 Introduction...132
7.3 System Model...135
7.3.1 TransmittedandReceivedSignal...135
7.3.2 SignalDetection...137
7.3.2.1 MLDecoder...138
7.3.2.2 MPADecoder...138
7.4 TheProposedDecodingAlgorithms...140
7.4.1 TheSUDAlgorithm...141
7.4.2 The MSUDAlgorithm...142
7.4.3 TheFCSDAlgorithm...144
7.4.3.1 SM-SCMATree-search...144
7.4.3.2 TheFCSDAlgorithm...147
7.5 ComplexityAnalysis...150
7.5.1 TheSUDAlgorithm...150
7.5.2 The MSUDAlgorithm...151
7.5.3 TheFCSDAlgorithm...152
7.6 SimulationResultsandDiscussions ...152
7.6.1 ParametersSensitivity...153
7.6.2 BERPerformanceAssessment...157
7.6.3 DecodingComplexityAssessment...158
7.7 Conclusions...158
References...159
8 ConclusionsandPotentialDirectionsofFutureInvestigation 171
8.1 Conclusions...171
8.2 PotentialDirectionsofFutureInvestigation...172
References 174 Chapter1...174
Chapter2...178
Chapter3...179
Chapter4...181
Chapter5...185
Chapter6...186
Chapter7...188
ListofTables
6.1 TheRGSM-SCMAantennagroupingvectorlookuptableforNt=5,Na=2, Nc=8,andηus=3bpcu...118 6.2 Therealoperationsofthe MPAdecodersfortheSM-SCMAandRGSM-SCMA
systems...124
ListofFigures
1.1 TridimensionalconstellationdiagramoftheSM-MIMOsystemfor4trans- mitantennasand4modulationsymbols... 5 1.2 Exampleofinputbit-streammappingintheSM-MIMOsystemfor4transmit
antennasand4modulationsymbols... 5 1.3 TridimensionalconstellationdiagramoftheQSM-MIMOsystemfor4
transmitantennasand4modulationsymbols... 6 1.4 BasicconceptofSCMAtechniquefor6usersand4subcarriers... 8 1.5 ExampleofSCMAtechniquefor6usersand4subcarriers... 8 2.1 Thetree-searchstructurefortheQSM-RCdecoderforη=4bit/sec/Hz,
Nr=3,Nt=2andMQSM=4. ... 25 2.2 ComplexityreductioncomparisonofdifferentQSMdecodersforMQSM=4,
η=6bit/sec/Hz,Nt=4andNr=4... 29 2.3 NumberofVNscomparisonofdifferentQSMdecodersforMQSM=4,SNR
=10dBandNr=8... 29 2.4 BER-performancecomparisonofdifferentQSMdecodersforη=8bit/sec/Hz,
Nr=4,Nt=4,MSM=64andMQSM=16. ... 31 2.5 ComplexityreductioncomparisonofdifferentQSMdecodersforη=
8bit/sec/Hz,Nr=4,Nt=4,MSM=64andMQSM=16. ... 31
3.1 Thetree-searchstructurefortheSM-SDalgorithmforηSM=4b/s/Hz, Nr=3,Nt=2andMSM=2... 41 3.2 ReductionincomplexitybetweentheSM-MLandproposedm-Malgorithms
forη=6b/s/Hzandη=10b/s/Hz. ... 48 3.3 ReductionincomplexitybetweentheQSM-MLandproposedm-Malgo-
rithmsforη=6b/s/Hzandη=10b/s/Hz... 48 3.4 Complexitygainwhenusingtheproposedm-MovertheSM-SDalgorithms
in[5]and[8],forη=6b/s/Hzandη=10b/s/Hz... 50 3.5 Complexitygainwhenusingtheproposedm-MovertheQSM-SDalgo-
rithmsin[5]and[8],forη=6b/s/Hzandη=10b/s/Hz... 50 3.6 BERperformancecomparisonofdifferentSMdecodersforη=6b/s/Hz
andη=10b/s/Hz. ... 51 4.1 SMtree-searchdecoderforM =2,Nt=2,andNr=3withfourbranches. ... 60 4.2 Anumericalexampleforthem-Malgorithm(3×4SM-MIMOsystemandM =2).62 4.3 AveragenumberofNoMofthem-Mwalgorithmfor8×8SM-MIMOand8-QAM.72 4.4 BERcomparisonofdeterminedSM-MIMOsystemfordifferentdecoders. .... 80 4.5 BERcomparisonofunder-determinedSM-MIMOsystemfordifferentdecoders. . 80 4.6 BERcomparisonofover-determinedSM-MIMOsystemfordifferentdecoders... 81 4.7 ComplexityofdeterminedSM-MIMOsystemfortheproposedm-Malgorithm... 82 4.8 Complexityofunder-determinedSM-MIMOsystemfortheproposedm-Malgorithm.83 4.9 Complexityofover-determinedSM-MIMOsystemfortheproposedm-Malgorithm.84 4.10ComplexityreductioncomparisonofdeterminedSM-MIMOsystemfordifferent
decoders.... 85 4.11Complexityreductioncomparisonofunder-determinedSM-MIMOsystemfor
differentdecoders. ... 86
4.12Complexityreductioncomparisonofover-determinedSM-MIMOsystemfordiffer- entdecoders.... 87 4.13Complexityreductionoftheproposedm-MalgorithmforNt= Nr=16and
variableM.... 88 4.14Complexityreductionoftheproposedm-MalgorithmforM = Nr=16and
variableNt.... 88 4.15Complexityreductionoftheproposedm-MalgorithmforNt= M =16and
variableNr.... 89 5.1 Tree-searchofSM-MIMOforM =2,Nt=4,andNr=6.... 98 5.2 AveragenumberofvisitednodesoftheproposedRSDalgorithmfor16-QAMand
8×8SM-MIMOsystem....108 5.3 AveragenumberofvisitednodesoftheproposedRSDalgorithmfor16-QAMand
16×16SM-MIMOsystem....108 5.4 BERcomparisonforthe16-QAMand8×8SM-MIMOsystem....109 5.5 BERcomparisonforthe16-QAMand16×16SM-MIMOsystem....109 5.6 Complexityreductioncomparisonforthe16-QAMand8×8SM-MIMOsystem..110 5.7 Complexityreductioncomparisonforthe16-QAMand16×16SM-MIMOsystem.110 6.1 UplinkRGSM-SCMAblockdiagramfortheu-thuser...117 6.2 BERperformancecomparison...126 6.3 ExtracomplexitycomparisonbetweenSM-SCMAandRGSM-SCMA. ..126 6.4 NtcomparisonbetweenSM-SCMAandRGSM-SCMA...127 7.1 MPAfactorgraphoftheSM-SCMAforU=6andR=4...139 7.2 Theproposedtree-searchfortheSM-SCMAsystem...146 7.3 ConvergenceoftheproposedMSUDdecoderforNr×4MIMOSM-SCMA
system. ...154
7.4 NoMofdifferentvaluesofρrforηu=3bpcu. ...159 7.5 NoMofdifferentvaluesofρrforηu=4bpcu. ...160 7.6 BERperformancecomparisonof2×4MIMOwith M =2(i.e.,ηu=3
bpcu)...160 7.7 BERperformancecomparisonof4×4MIMOwith M =2(i.e.,ηu=3
bpcu)...161 7.8 BERperformancecomparisonof6×4MIMOwith M =2(i.e.,ηu=3
bpcu)...161 7.9 BERperformancecomparisonof2×4MIMOwith M =4(i.e.,ηu=4
bpcu)...162 7.10BERperformancecomparisonof4×4MIMOwith M =4(i.e.,ηu=4
bpcu)...162 7.11BERperformancecomparisonof6×4MIMOwith M =4(i.e.,ηu=4
bpcu)...163 7.12RealadditionscomparisonofdifferentSM-SCMAdecodersforηu=3bpcu.163 7.13RealmultiplicationscomparisonofdifferentSM-SCMAdecodersforηu=3
bpcu...164 7.14RealadditionscomparisonofdifferentSM-SCMAdecodersforηu=4bpcu.164 7.15RealmultiplicationscomparisonofdifferentSM-SCMAdecodersforηu=4
bpcu...165
ListofAbbreviations
AWGN Additive WhiteGaussianNoise b/s/Hz Bit/Second/Hertz
BER BitErrorRate
bpcu BitsPerChannelUse BPSK BinaryPhase-Shift-Keying CDF CumulativeDistributionFunction CS CompressiveSensing
CSIR ChannelStateInformationattheReceiverSide DA Data-Aided
DSP DigitalSignalProcessor
EBCS EnhancedBayesianCompressiveSensing ED EuclideanDistance
ExCo ExtraComplexity
FCSD Fixed-ComplexitySphereDecoder
FES FullyExpandedStage flops FloatingPointOperations FN FunctionNodes
GSM GeneralizedSpatial Modulation IAS Inter-AntennaSynchronization ICI Inter-ChannelInterference
m-M Minimum-Distanceof Maximum-Length MAP MaximumaPosterioriProbability
MIMO Multiple-Input Multiple-Output ML Maximum–Likelihood
mmWave Millimeter-Wave
MPA MessagePassingAlgorithm
MSUD ModifiedSuccessiveUserDetection NoM Numberof Misses
NOMA Non-Orthogonal MultipleAccess ORE OrthogonalResourceElement PAM PulseAmplitude Modulation pdf ProbabilityDensityFunction
PSK PhaseShiftKeying
QAM QuadratureAmplitude Modulation QSM QuadratureSpatial Modulation RC Reduced-Complexity
RF RadioFrequency
RGSM RotationalGeneralizedSpatial Modulation S/P Serial-to-Parallel
SCMA SparseCode MultipleAccess SD sphereDecoder
SE SpectralEfficiency SES SingleExpandedStage SM Spatial Modulation SNR Signal-to-NoiseRatio SUD SuccessiveUserDetection
UBCR UpperBoundoftheComplexityReduction VLC VisibleLightCommunication
VN VariableNodes VN VisitedNode
Chapter1
Introduction
1.1 Background
In1874,GuglielmoMarconi,thefatherofradiofrequency(RF)signals,wasborninItaly.At anearlyage,hewasinfluencedbyHeinrichHertzwhotriedtotransmittheelectromagnetic wavesthroughtheair.Followingnumerousunsuccessfulattempts, Marconiwasfinallyable tosendawirelesssignalacrosstheAtlanticin1901,drawingtheworld’sattentiontoa groundbreakingfieldoftechnology.Thesiteof Marconi’sexperimentisstillavenuefor touristsattheSignalHillinSt.John’s,Newfoundland,andcontinuestobeawitnesstoone oftheremarkableinventionsforhumanity.AboutthreeyearsafterMarconi’sexperiment, specificallyin1904,JohnFleminginventedthethermionicdiodewhichhasbecomean essentialcomponentinwirelessdevices. MarconiandFlemingneverknewthattheywere abouttoforeverchangethefaceoftheworld.Sincethen,numerousuniversities,researchlabs andindustrialcompanieshavededicatedresourcestoimprovethewirelesscommunication systems.
Currently,wirelesstechnologyisanessentialpartoflife.Peoplerelyheavilyontech- nologyformostoftheirdailylife,suchasforecastingtheweather,followingthenewsall
