Simplified AltBOC Receiver Performance Analysis Aerospace Engineering

112 Pages·2016·2.54 MB·English

by  Andre C. Marta

Simplified AltBOC Receiver Performance Analysis
Rui Filipe Duarte Nunes
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisor(s): Prof. António José Castelo Branco Rodrigues
Eng. Tiago Roque Peres
Examination Committee
Chairperson: Prof. João Manuel Lage de Miranda Lemos
Supervisor: Eng. Tiago Roque Peres
Member of the Committee: Prof. José Eduardo C. R. da Cunha Sanguino
May 2016
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Acknowledgments
This thesis would not be possible without the constant effort and incentive of helpful people all around
me. Beingwithscientificknowledge, moralsupportorgeneraladvice, thisroadwasthrillednotonlyby
anindividualbutbymanysupportivehelpinghands.
IwanttogiveaspecialthankstomyDEIMOSsupervisorTiagoPereswhoseknowledgeonthematter
and availability were always a positive force and to my IST supervisor Anto´nio Rodrigues for all the
cooperativework.
IalsowanttoexpressmygratitudetoDEIMOSpersonalstafffortheircompanionship,especiallytoJoa˜o
SilvaandPedroFreirewhoalwaysshowedinterestandmadeallofthispossible.
These working months were hard at times but my family were an invaluable support throughout all the
way. Specifically my father whose scientific knowledge and life experience were always positive inputs
and helped me push forward at all times, my mother who could always have a kind word to boost the
moraleandmysisterwhoinspiredmetobemoreandbetter.
Finally I need to thank all my university and out of school friends, specially my girlfriend who I knew I
couldalwayscounton.
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Resumo
O sinal E5 AltBOC e´ um sinal de transmissa˜o de informac¸a˜o complexo e exo´tico usado nos sate´lites
Galileo que permite obter um valor preciso da posic¸a˜o do recetor. Sendo um sinal relativamente novo,
ha´ muito terreno inexplorado em relac¸a˜o a este assunto, nomeadamente a arquitetura do recetor que
melhorseenquadranesteproblema.
EstetrabalhotemcomoobjetivoimplementarumrecetordeE5AltBOCcapazdedesmodularinformac¸a˜o
de ambas as bandas E5a e E5b em conjunto (Dual Sideband ou DSB) ou em separado (Single Side-
bandouSSB)ecompararosseusresultados.
Este trabalho concentra a sua pesquisa nos blocos de seguimento onde a frequeˆncia de Doppler e o
atraso de co´digo devem ser alinhados entre um sinal gerado localmente e o sinal recebido para fun-
cionarcorretamente.
A parte inovadora desta tese e´ a implementac¸a˜o de um recetor Dual Sideband que usa correladores
complexos na sua arquitetura que conseguem processar simultaneamente a informac¸a˜o de ambos os
canais de dados e piloto de ambas as bandas E5a e E5b. No cap´ıtulo dos resultados deste docu-
mentosa˜oapresentadososresultadoscomparativosentreDSBeSSBparava´riascondic¸o˜esincluindo
avariac¸a˜odarelac¸a˜opoteˆnciadaportadora-ru´ıdo.
Palavras-chave:
Galileo,SinalE5,Modulac¸a˜oAltBOC,Receptor,Seguimento
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Abstract
TheE5AltBOCsignalisacomplexandexotictransmissionsignalusedinGalileosatellitestoenablethe
computationofaprecisevalueforthereceiverposition. Sincethissignalisrelativelynew,thereisalot
ofunexploredterrainregardingthissubjectnamelythereceiverarchitecturethatbestsuitstheproblem.
ThisworkaddressesimplementationaspectsofanE5AltBOCreceiverreadytodemodulatedatafrom
bothbandsE5aandE5btogetherasDualSideband(DSB)orseparatelyasSingleSideband(SSB)and
compareitsresults.
This work focus its research on the tracking block where a Doppler frequency and code delay must be
alignedbetweenthelocallygeneratedreplicaandthereceivedsignaltooperateproperly.
The innovating part of this thesis is the implementation of a Dual Sideband receiver that uses complex
correlatorsinitsarchitecturethatcanprocesssimultaneouslytheinformationofbothE5aandE5bdata
andpilotchannels. Intheresultschapterofthisdocument,wepresentthecomparativeresultsbetween
DSBandSSBforvariousconditionsincludingthevariationofthecarrierpowertonoiseratio.
Keywords:
Galileo,E5Signal,AltBOCmodulation,Receiver,Tracking
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Contents
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Resumo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
1 Introduction 1
1.1 State-of-the-art . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 ThesisOutline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 GNSSConcept 5
2.1 BasicConcept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 ActiveNavigationSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 GNSSSignals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.1 BPSK-R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.2 BOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.3 MBOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 GNSSNavigationEquation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.6 SourcesofSignalDegradation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 E5Signal 15
3.1 GalileoServices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 E5transmittedsignal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3 E5equivalentrepresentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.4 RangingE5Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.4.1 PrimaryCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.4.2 SecondaryCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.5 AutocorrelationFunctionandPowerSpectralDensity . . . . . . . . . . . . . . . . . . . . . 22
3.5.1 AutocorrelationFunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
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3.5.2 PowerSpectralDensity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.6 ReceivedSignalPowerandSNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4 GNSSReceivers 27
4.1 GNSSReceiverArchitecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.1 Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.1.2 FrontEnd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.1.3 BasebandProcessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1.4 ApplicationProcessing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2 SignalAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3 SignalTracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.3.1 PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.3.2 DLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.3.3 DataDemodulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.4 NoisePerformance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.5 Multipath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5 ReceiverarchitecturesforAltBOCsignals 45
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.2 FilteredAltBOCsignals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.3 Single-sidebandAltBOCreceiver(withbasebandprocessing) . . . . . . . . . . . . . . . . 50
5.3.1 PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.3.2 DLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.4 Double-sidebandAltBOCreceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
5.4.1 PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.4.2 DLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.4.3 Sidebandtranslator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6 ImplementationandResults 61
6.1 MonteCarloSimulationAspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.2 SimulationProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.2.1 Parametrization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.2.2 Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
6.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.3.1 C/N Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
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6.4 InterferenceTest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
7 FinalRemarks 75
7.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
7.2 Futurework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
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