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1、ISSUE 1USER TECHNOLOGY REPORT2016Issue 1More information on the European Union is available on the Internet(http:/europa.eu).Luxembourg:Publications Office of the European Union,2016ISBN 978-92-9206-029-9doi:10.2878/760803Copyright European GNSS Agency,2016Information contained in the document may b
2、e excerpted,copied,printed and provided to third parties only under the condition that the source and copyright owner is clearly stated as follows:“Source:GNSS User Technology Report,Issue 1,copyright European GNSS Agency,2016”.For reproduction or use of photos and any other artistic material,permis
3、sion must be sought directly from the copyright holder.The designations employed,the presentation of the materials and the views expressed by authors,editors,or expert groups do not necessarily represent the opinions,decisions or the stated policy of neither GSA nor the European Commission.The menti
4、on of specific companies or of certain manufacturers products does not imply that they are endorsed or recommended by the GSA in preference to others of a similar nature that are not mentioned.Errors and omissions excepted,the names of proprietary products and copyright holders are distinguished by
5、initial capital letters.The present document is being distributed without warranty of any kind,either express or implied in relation to its content and/or use.In no event shall the GSA be liable for damages arising from the content and use of the present document.This document and the information co
6、ntained in it is subject to applicable copyright and other intellectual property rights under the laws of the Czech Republic and other states.No part of this document,including any part of the information contained therein,in whichever format,whether digital or otherwise,may be altered,edited or cha
7、nged without prior express and written permission of the European GNSS Agency,to be requested via https:/www.gsa.europa.eu/contact-us,clearly stating the element(document and/or information)and term of use requested.Should you become aware of any breach of the above terms of use,please notify the Eu
8、ropean GNSS Agency immediately,through the above mentioned contact site.Any breach of these terms of use may be made subject to legal proceedings,seeking monetary damages and/or an injunction to stop the unlawful use of the document and/or any information contained therein.By downloading,forwarding,
9、and/or copying this document or any parts thereof,in whichever format,whether digital or otherwise,the user acknowledges and accepts the above terms of use as applicable to him/her.2016Issue 1GNSS USER TECHNOLOGY REPORTISSUE 1GNSS User Technology Report|Issue 1,2016Dear Reader,In recent years,GNSS t
10、echnology,both on the side of global constellations and user receivers,has been developing considerably.European systems EGNOS and Galileo are increasingly present in GNSS receivers,providing enhanced performance to their users in Europe and worldwide.Despite increased deployment of other positionin
11、g technologies,GNSS remains at their core and is today the most widespread and cost effective source of location information.In view of the changing user needs in terms of expected positioning experiences,the appearance of new and modernised GNSS signals,and advances in semiconductor technologies,we
12、 felt the need to take a closer look at the impact these changes will have on user technology and the role of GNSS in positioning solutions of the future.I am pleased to introduce the GSAs first GNSS User Technology Report.As a sister publication to our well recognised GNSS Market Report,this Report
13、 zeros in on the state-of-the-art GNSS receiver technology,along with analysing the trends that are sure to change the entire GNSS landscape.In the following pages,you will get an in-depth analysis of GNSS user technology as it pertains to three key macrosegments:mass market solutions;transport safe
14、ty and liability-critical solutions and high precision,timing and asset management solutions.In addition,we also provide a general overview of the latest GNSS receiver technology,common to all application areas,along with a supplement on location technologies that looks beyond GNSS in the positionin
15、g landscape.This publication was written with the contribution of leading GNSS receiver and chipset manufacturers,and is meant to serve as a valuable tool to support your planning and decision-making with regard to developing,purchasing and using GNSS user technology.We look forward to receiving you
16、r feedback and working with you in continuing this exciting E-GNSS evolution.Carlo des DoridesExecutive DirectorThe European GNSS Agency(GSA)Prague,October 20164FOREWORDGNSS User Technology Report|Issue 1,2016EXECUTIVE SUMMARY5The Technology in GNSS user equipment today is more diversified than ever
17、 before;ranging from miniaturised,low power chips found in IoT networks nodes to much larger,more powerful(and expensive)receivers fitted in passenger aircraft.Furthermore,new models are being introduced at an unprecedented rate,driven by the growing performance requirements of innovative appli-cati
18、ons,developments in the semiconductor industry and to take advantage of the enhanced capabilities offered by new and modernised GNSS systems and services.In this rapidly evolving landscape,three primary dimensions of change can be identified for user positioning technology:ubiquity(continuous access
19、 to the location information everywhere),automation and ambient intelligence(e.g.enabling autonomous vehicles that can sense their environment and adapt to it)and the provision of more robust,secure solutions(resistant to interference and respecting the privacy of the users).These drivers impact all
20、 aspects of receiver design,from antenna frequency range to signal proces-sing channels.The implementation of disruptive techniques,such as vector and cloud processing,is making it possible to achieve greater performance while preserving battery life.Furthermore,other positioning technologies and si
21、gnals of opportunity are used alongside GNSS to offer enhanced experiences.The sensor technology is advancing in parallel,making the vision of smart dust(a widely deployed network of low power,low cost microsensors)closer to becoming a rea-lity.GNSS antenna designers are expected to complement the s
22、olution with more robust,smaller,multi-purpose antennas.Some of these innovations are already becoming accessible,as confirmed by leading GNSS technology providers,featuring their latest solutions in this report.Changes in receiver design are not obviously affecting all application segments in the s
23、ame way,or at the same pace.GSA analysis of more than 400 receivers,chipsets and modules currently on the market shows that nearly 65%of them support multiple constellations,and this percentage should reach nearly 100%of new devices within the next few years.Mass market receivers and high accuracy p
24、rofessional receivers are leading this trend,with nearly 30%of them already capable of using the 4 available global constellations.On the other hand,receivers targeting safety-critical applications,such as aviation,must wait for the new technologies to be proven and new standards or regulations to b
25、ecome available prior to implementing them.In terms of supported frequencies,GSA analysis shows that 30%of all receivers implement more than one of them,mostly in high precision.The adoption is lower than that of multi-constellation due to many factors,such as cost,complexity,power draw and the rela
26、tive novelty of open signals on multiple frequencies.In the coming years,the ever increasing demand for a better resilience observed across all applications,and the higher accuracy and integrity needed for automation,will undoubtedly foster a much wider adoption of dual frequency(E1/L1+E5/L5)solutio
27、ns.This is supported by the fact that satellites broadcasting a high quality open signal on L5/E5 are launched at a faster rate and their promising performance in urban canyons is awaking growing interest for double frequency in mass market.Finally,new capabilities are introduced at a GNSS system an
28、d/or receiver level to provide users with an improved performance in terms of robustness and accuracy to better serve applications that require it.Examples include GNSS signal authentication,which is expected to play an important role for liability critical applications;and triple frequency real tim
29、e precise point positioning,such as found in the Galileo commercial service for high accuracy applications.Industry and research organisations are the main actors of these developments.In mass market,the chipset supply chain is extremely consolidated with few players worldwide driving the innovation
30、.In liability and safety,critical transport solutions,a consolidated industry with important European presence,is dominating innovation in automotive,maritime and aviation,while new players may emerge in new applications,such as autonomous vehicles.In high pre-cision,timing and asset management,the
31、suppliers are specialised in various professional fields(e.g.surveying,machine control,timing),however their products are based on a relatively low number of GNSS chipsets.To conclude,the GNSS user technology is,now more than ever,experiencing a rapid and exciting evolution,answering to the needs of
32、 ubiquity,automation and secure positioning.This report explores in details of all these new developments,and how they will bring continuous accuracy,integrity and robustness to the main application domains.GNSS User Technology Report|Issue 1,205262FOREWORDEXECUTIVE SUMMARY INTRODUCTIONGN
33、SS USER TECHNOLOGY OVERVIEW MASS MARKET SOLUTIONS TRANSPORT SAFETY&LIABILITY CRITICAL SOLUTIONS HIGH PRECISION,TIMING AND ASSET MANAGEMENT SOLUTIONS EDITOR S SPECIAL:GNSS AND OTHER POSITIONING TECHNOLOGIES ANNEXES73KEY PERFORMANCE PARAMETERS 74ACRONYMS75SENSORS&COMPONENTS TABLES 76METHODOLOGY78ABOUT
34、 THE AUTHORS 796TABLE OF CONTENTSGNSS User Technology Report|Issue 1,2016No one-size-fits-allNo single positioning method or technology,or magic combination thereof,can serve as the answer.After all,the technology thats right for pedestrian navigation probably isnt the best fit for use with an unman
35、ned vehicle.This is because all positioning requirements exist within a given context,including the physical and radio-electrical environment,user dynamics,and power,size and weight constraints.It is this context that determines what positioning technologies are required.As a result,the most advance
36、d positioning systems can evaluate the context of their intended use and deliver an optimised positioning solution.In the era of the Internet of Things(IoT)and Big Data,trends in geo-positioning and information technology(IT)are inseparable.After all,IoT is built on the premise that it will know whe
37、re the things are.In fact,already today nearly half of all available mobile applications use location infor-mation a significance that will only continue to increase.In writing this report,our goal was twofold.On the one hand,we have tried to foresee how location will be used in the years to come an
38、d,on the other,how it will influence the design of positioning systems.The future we see goes something like this:You will set your morning alarms based on real-time traffic estimates and your coffee will be brewed accordingly,ready and waiting for you as you head out the door.Gone will be the days
39、of forgetting to send mom flowers on Mothers Day,as your phone will send an automatic reminder and provide your autonomous car with directions to the nearest floral shop.Or perhaps you dont have time to go to the shop?No worries,with just a simple command a drone will deliver the flowers for you.But
40、 this future can only become a reality if the positioning systems of the future provide:nUbiquitous positioning:the ability to choose the optimal combination of sensors and networks to become environment-independent.Here technology works in the background to provide seamless indoor and outdoor posit
41、ioning and navigation at any time.nAutomation and ambient intelligence:sufficient reliability to enable such autonomous oper-ations as driving,sailing,parking,landing,etc.,by sensing the environment and adapting to it in real time.nSecurity:not only in the sense of a solutions reliability and safety
42、,but also by responding to growing concerns about privacy.If the positioning system knows where you and your assets are at all times,it better keep this information to itself.Welcome to the futureINTRODUCTION7Source:ThinkstockPositioningSystemsGNSS User Technology Report|Issue 1,2016GNSS is by far t
43、he most cost-effective outdoor positioning technology currently available and will remain so for the foreseeable future.Already today GNSS is the main source for outdoor location information,which is especially important for large scale applications and when working away from urban areas.GNSS will n
44、ot,however,be used as standalone solution.In order to work across an array of contexts,ubiquitous positioning requires the use of several positioning networks and sensors.For this reason,todays GNSS chipsets use other radio networks and Micro-Electro-Mechanical Systems(MEMS)to provide enhanced posit
45、ioning,and dedicated networks like LoRaWAN,ZigBee and Sigfox to provide additional connectivity to IoT tags.The next generation of chipsets will allow users to simultaneously connect to several wireless access technologies(WiFi,Universal Mobile Telecommunications System(UMTS),Enhanced Data Rates for
46、 GSM Evolution(EDGE),smart-radio,among others)and to seamlessly move between them.By 2020,all new GNSS receivers will be multi-constellation capable,providing sound benefits for product innovation and achieving enhanced performance in many GNSS applications.Based on a GSA analysis of more than 400 r
47、eceivers,chipsets and modules currently on the market,already around 65%of receivers implement multi-constellation support,and more than 20%integrate four constellations into a single product.The most popular combination is GPS and Glonass,followed by GPS and Galileo.Although power consumption and p
48、rocessing capability may somewhat limit the number of satellites used,thus imposing a choice at the receiver level,advances in other technical fields will compensate for these issues.Multi-frequency is already widely used by professional applications,with the mass market expected to follow.Overall,o
49、ut of the 400 receivers analysed,20%use double frequency,and 10%integrate three frequencies.This trend is fuelled by the need for greater accuracy in active driver assistance and for the additional protection against interference that frequency diversity provides.As to the latter point,the vulnerabi
50、lity of location services to interference or spoofing is a growing concern.However,the developments towards GNSS signal authentication may increase robustness against spoofing,and could even support applications using geo-fencing,such as mobile payments.3D MappingSLAMCo-operative positioning(Peer to
51、 Peer)Smart DustPervasive networks SOOPMEMS integrationCamerasVisual perceptionMulti-constellation multi-frequency GNSSPositioning User TechnologyMain areas of innovationInnovation areas and emerging concepts likely to influence future positioning,navigation and timing(PNT)systems8INTRODUCTIONGNSS U
52、ser Technology Report|Issue 1,2016For your reading convenience,this report has been divided into three parts.In the first part,we take a general look at the recent developments and future trends of GNSS user technology.Our focus is on receiver design,innovative signal processing techniques,changes i
53、mpacting antennas,and GNSS vulnerabilities and what is being done to miti-gate them.We also take a close look at how changes in user needs,GNSS systems,and underlying technologies are all having an impact on receiver design.In the second part,we present specific developments and solutions that are t
54、ypical for a given application area.Like our Market Report,this report considers all GNSS applications in these segments:Location Based Services,Agriculture,Transportation(Aviation,Maritime,Rail,Road),Surveying and Timing*.We have further grouped these applications into three macrosegments:1.Mass ma
55、rket consumer solutions:high volume chipsets typically used in smartphones,tablets and other consumer devices,alongwith emerging solutions for IoT,in-vehicle navigation,consumer unmanned aerial vehicles(UAVs),general aviation Visual Flight Rules(VFRs)and solutions for leisure maritime.These solution
56、s are characterised by requiring a fast time to first fix and high availability,but not being very demanding in terms of accuracy.2.Transport liability-critical and safety-critical solutions:location solutions for Road User Charging,Emergency Caller Location(such as eCall),Advanced Driver Assistance
57、,Smart Tachograph,Civil Aviation,Prosumer UAVs,Control Command and Signalling solutions in Rail,Ship Navigation in Maritime(including Vessel Traffic Management),and Anti-Collision systems.These applications are characterised by requiring more robust positioning and navigation information,secured by
58、integrity and authentication.Solutions usually must comply with safety requirements and standards.3.High precision,Timing and Asset Management solutions:Business to Business(B2B)technology solutions for tractor guidance;VariableRate Technology in agriculture;geodesy and other surveying applications;
59、all asset management solutions(e.g.container tracking,fleet management);and the timing and synchronisation solutions used by telecom operators,financial services and energy providers.High precision solutions are characterised by their demand for accuracy of both position and time.In the final part,w
60、e provide a comprehensive overview of all positioning technologies,looking at what lies beyond GNSS in the positioning landscape.A closer look is taken at such augmentation systems as SBAS,PPP solutions,other radio location technologies(LPWAN,Wi-Fi,UWB)and non-radio positioning techniques such as vi
61、sion-aided navigation.*Defence and public utilities solutions are out of scope in this report.Search and Rescue solutions are only partially covered,providing basicinformation on SAR system architecture and the contribution of GNSS to SAR missions.How to read this report:many applications,three macr
62、osegmentsINTRODUCTION9Mass Market Consumer SolutionsTransport Liability-Critical and Safety-Critical SolutionsHigh Precision,Timing and Asset Management SolutionsGNSS User Technology Report|Issue 1,2016GNSS user technology overviewLocalOscillatorRFRFFront-EndAnalogueto DigitalconverterAntennaAnalogu
63、eIFDigitalIFInputs/OutputsUser InterfaceBasebandProcessing PVTProcessingRaw Data&Nav.messagePowerSupplynFactors affecting the evolution of GNSS technology:Changing user needs and requirementspage 11-12GNSS constellations,frequencies,services and their evolutionspage 13-14Evolution of semiconductors
64、and other underlying technologiespage 15-16nReceiver design,signal processing trends,antennas page 17-20nSupported frequencies/constellations by GNSS receivers page 21-22nTesting of multi-constellation page 23nGNSS vulnerabilities,their mitigation and testing page 24-26nEuropean Research and Develop
65、ment page 27-2910GNSS USER TECHNOLOGY OVERVIEWGNSS User Technology Report|Issue 1,2016GNSS TECHNOLOGY EVOLUTIONBQs Aquaris X5 Plus smartphone,2016First European smartphone with Galileo capability.TI-4100 NAVSTAR GPS Receiver,1981One of the first commercial GPS receivers.Magellan NAV 1000 GPS,1988Wor
66、lds first handheld GPS receiver.Benefon Esc!,2001Worlds first personal navigation phone with mobile maps.Fitbit Blaze,2016One of the most popular wearable devices,which includes GNSS,a heart rate monitor and a battery life of up to one week.For many years,the most important evolution in GNSS receive
67、rs has been the reduction of their size,weight,power use and cost,to such an extent that GNSS is now considered a utility.Although todays evolutions may not be as spectacular,they are nonetheless equally important.At the same size and cost,todays receivers deliver ever increasing capabilities for a
68、better user experience.Thanks to the use of multiple constellations and new services,this includes not only improved availability and accuracy,but also improved confidence.What differences can be found between GNSS receivers?GNSS is used for many types of applications,each requiring different servic
69、e levels.The type of technology used depends on such user needs as the desired quality of service.This results in a large variety of user terminals.Some key features of a receiver are:nSupported GNSS constellation(s),frequencies and signals and augmentation system(s).nComplementary technologies in u
70、se.nSuch factors as size,weight,power consumption,etc.Factors affecting the evolution of GNSS user technologyThe evolution of GNSS user technology is influenced by three major factors:nChanging trends in users behaviour and expectations.nEvolution of GNSS infrastructure,such as the appearance of new
71、 signals and frequencies.nEvolution of underlying technologies,largely driven by the IT&Communications industries.The market drivers and trends derived from changing user needs are analysed in depth in sister publication“GNSS Market Report”(see next page).The other two factors impacting receiver des
72、ign are discussed in following sections of this report.The evolution of GNSS user technology is driven by user needs,GNSS infrastructure and underlying technologies GNSS USER TECHNOLOGY OVERVIEW11GNSS User Technology Report|Issue 1,2016The GSA continuously monitors and analyses changing user needs a
73、nd market trends,thanks to the GSAs well-established internal market monitoring and forecasting process.The results of this process are published in the GSAs GNSS Market Report.With in-depth information on specific market segments,the Market Report serves as a comprehensive source of knowledge and i
74、nformation on the GNSS global market and trends at the user level.Whereas the GNSS User Technology Report focuses on the technology trends and drivers at the receiver level,the GNSS Market Report provides a deep insight into current markets and forecasts the future shipments,installed bases and reve
75、nues.Together,they form a comprehensive source of information on GNSS downstream sector.The current version of the GSAs GNSS Market Report can be downloaded free of charge at:https:/www.gsa.europa.eu/market/market-reportThe 5th edition of the GSAs GNSS Market Report is set for publication in 2017.Ch
76、anges in user needs definethe innovation roadmapMarch 2015Issue 4ISSUE 4W It h an an alyS I S o f G n SS US E r t E ch n o lo GyISSN 2443-5236GNSS MARKET REPORTISSUE 1October 2010 GSA GNSS Market Report Issue 1May 2012GSA GNSS Market Report Issue 2October 2013GNSS Market Report Issue 3GNSS TECHNOLOG
77、Y EVOLUTION12GNSS USER TECHNOLOGY OVERVIEWGNSS User Technology Report|Issue 1,2016All GNSS infrastructure providers are currently working on further developing their systems,either in terms of modernisation or initial deployment.For example,GPS and the Russian GLONASS navi-gation system,both operati
78、onal,are currently being modernised,while Galileo is in the deployment phase and set to be fully operational by 2020.Meanwhile,China is in the process of expanding its regional BeiDou Navigation Satellite System into a global one,also by 2020.The Indian Regional Navigation Satellite System(IRNSS)and
79、 Japanese Quasi-Zenith Satellite System(QZSS),which provide regional coverage,are scheduled to become operational in the coming years.As for the satellite based augmentation systems(SBAS),the American Wide Area Augmentation System(WAAS),the European Geostationary Navigation Overlay System(EGNOS)and
80、the Indian GPS Aided Geo Augmentation Navigation(GAGAN)are all planning upgrades to improve perfor-mance,while the Russian System for Differential Corrections and Monitoring(SDCM)and the Chinese Satellite Navigation Augmentation(SNAS)systems are currently under development.All GNSS infrastructure pr
81、oviders are developing new and improved servicesSYSTEMPROVIDERSIGNAL2001920202021SATELLITE NAVIGATION SYSTEMSGLOBAL COVERAGEGPSL1FOC(30)L1 C(0-30)L2FOC(30)L2 CIOC(19-30)FOC(30)L5(12-30)GALILEOE1IS(12-26)ES(26-30)FOC(30)E5IS(12-26)ES(26-30)FOC(30)E6IS(12-26)ES(26-30)FOC(30)GLONASSL1 FDMAFO
82、C(24)L1 CDMA(0-24)L2 FDMAFOC(24)L2 CDMA(0-24)L3 CDMA(0-24)L5 CDMA(0-24)BEIDOUB1(12-35)FOC(35)B2(12-35)FOC(35)B3(12-35)FOC(35)REGIONAL COVERAGQZSS(1-4)IOC(4-7)IRNSSL5IOC(7)FOC(7)S-BandIOC(7)FOC(7)SATELLITE AUGMENTATION SYSTEMSREGIONAL COVERAGEWAASL1FOC(2+1)L5Under development EGNOSL1FOC(2+1)L5Under d
83、evelopmentSDCML1FOC(3)L3FOC(3)L5FOC(3)SNASB1B1CFOC(3)B2AFOC(3)GAGANL1FOC(3)L5Under developmentMSASL1FOC(2)QZSSL1FOC(4)L5Under developmentDevelopment plansThe figures below show the current devel-opment plans for each satellite navigation system over the next five years.The signal sets,status and num
84、ber of satellites are reported as follows:No service Initial services(IOC:Initial Operational Capabilities,IS:Initial Services,ES:Enhanced Services)Full services (FOC:Full Operational Capabilities)Signal statusNumber of satellites(X)GNSS TECHNOLOGY EVOLUTIONGNSS USER TECHNOLOGY OVERVIEW13Disclaimer:
85、Planning based upon publicly available information as of July 2016.GNSS User Technology Report|Issue 1,2016With the modernisation plans of GPS and GLONASS on one hand,and the deployment of Galileo and the Chinese BeiDou on the other,users will soon have access to a wealth of open signals broadcasted
86、 on multiple frequencies.This raises several questions,with no easy answers:Which GNSS/RNSS?All systems,both GNSS and Regional Navigation Satellite Systems(RNSS)are designed to be interoperable and use the same frequency bands.Their signals,however,are different.As a result,some have a better immuni
87、ty to multipath or measurement accuracy,while others provide faster acquisition or require less processing power.In other words,there is no“best”signal or combination of signals only signals better suited for a particular use case or context.How many satellites?Soon there will be approximately 120 s
88、atellites broadcasting signals on L1/E1 with even more on L5/E5 meaning a GNSS receiver could potentially receive signals from as many as 50 satellites.Having this many visible satellites allows for further improvements,including the possibility to reject low quality measurements(non-line of sight,m
89、ultipath contamination,low elevation,etc.)without compromising Geometric Dilution Of Precision(GDOP).The net overall effect is better position accu-racy,and the key to achieving this is the capability to properly assess the quality of observations.To cope with this reality,GNSS receivers will have t
90、o implement selection(or rejection)strategies.Which frequencies to use?For many low to medium accuracy applications,one frequency is sufficient.This single-frequency is currently L1/E1,but as can be seen in the table,L5/E5 could be a viable alternative in the future.High accuracy applications,howeve
91、r,often require the use of dual-frequency observations in order to compensate the ionospheric propagation delays and/or to resolve“carrier phase ambiguities”encountered in such specific processing strategies as Real Time Kinematic(RTK)or Precise Point Positioning(PPP).Currently,L1+L2 observations ar
92、e used,but L5 may soon become the“second frequency of choice”as it will be present on more satellites and is less prone to interferences.High accuracy applications can also benefit from a third frequency to facilitate the ambiguity resolution through techniques known as Three Carrier Ambiguity Resol
93、ution(TCAR)or Extra-wide laning.For safety-critical applications,where redundancy and resistance to jamming is important,dual-fre-quency(L1/E1+L5/E5)is undoubtedly the best choice.GNSS evolution offers enhanced performances,but also raises new questions Which services?Some services offer unique feat
94、ures not available on all GNSS.For instance,Galileo offers:nA Commercial Service that provides subscribed users with such enhanced performance as a very high accuracy or a signal authentication at the spreading code level.nNavigation Message Authentication(NMA)on the Open Service(OS),an innovation t
95、hat allows OS users to benefit from better protection against spoofing.L5/L5OC/E5a/B2aL2/L2C/L2OCE6/LEXL1/L1OC/E1 /B1GPS303030GLONASS242424Galileo303030BeiDou353535QZSS3333IRNSS7129ARNS*Bands122 Frequency band used by the system,with N=number of satellites Frequency band not used by the system*ARNS=
96、Aeronautical Radio Navigation Service:Frequency bands allocated worldwide to GNSS on a primary basis,granting a better protection against interferenceFuture GNSS/RNSS common frequencies,showing the potential of E5a/L5 and of E1/L1 combinationGNSS TECHNOLOGY EVOLUTION14GNSS USER TECHNOLOGY OVERVIEWGN
97、SS User Technology Report|Issue 1,2016Advances in semiconductor technologyAccording to Moores Law,“the number of transistors on a chip roughly doubles every two years.”Over time,performance and power consumption have followed the same trend,thanks to a reduc-tion in the transistors feature size.This
98、 is known as“Dennard scaling”,and it gives Moores law its full strength since physically smaller areas require less power,can operate at higher frequencies as there is a lower delay;and more transistors can be squeezed into the same area.This rapid evolution in chip size,density and efficiency has l
99、ed to a huge increase in the capability of Application-Specific Integrated Circuit(ASIC)devices,enabling unprecedented increases in the complexity of such electronic products as smartphones and GNSS receivers.Current and predicted slow downSince around 2005,predictions of Dennard scaling could no lo
100、nger be achieved at the previous rate,and the increase in transistors has been maintained only through a switch to multi-core processors.The figure above perfectly illustrates this issue.One can see that growth in transistors count is constant,but only because the number of cores is increasing,whils
101、t clock frequency and power consumption have plateaued.Developments in semiconductor technologies will directly impact GNSS receiver performanceIncreased processing powerThe reduction in transistor size directly leads to an increase in the number of transistors on a chip and in the clock rate of pro
102、cessors.Together,these two factors enable a substantial increase in processing power.However,as a result of the slowdown described above,two challenges confront any continued increase in performance:nDevelopment of software that can effectively deploy multi-core.nDevelopment of alternative technolog
103、ies to the transistor in the longer term.Better power efficiencyA reduction in transistor size also causes a significant decrease in power required for comparable processing power,as the power required by a processor stays in proportion to area,both in terms of voltage and current.Over the last deca
104、de all types of electronics have enjoyed drastic reductions in power consumption,and the progress of GNSS modules power consumption reflects this trend.Whereas in the past a basic GPS chip may have consumed 200mW,a modern equivalent will consume 20mW and be capable of processing more channels over m
105、ore constellations.From ever more processing power to lowest possible power usagePossibly because of the end of Dennard scaling,the semiconductor industry has shifted its focus from“raw processing power”to concepts like MtM scaling,improving power efficiency and device utilisation.While the gains wi
106、ll be smaller than historically observed,they may also occur in more interesting areas.For GNSS receivers,this potentially means more progress on the RF side,more accessible Software Defined Radio(SDR)or a combination of both.The short term:More than Moore(MtM)scalingThe goal of MtM scaling is to ex
107、tend the same design principles that have driven digital device scaling for decades over to analogue circuitry and to integrate these technologies on-die within a System on Chip(SoC)or System in Package(SiP).The proposal behind MtM states that it is the heterogeneous integration of digital and non-d
108、igital functionalities into compact systems that will be the key driver for a wide variety of application fields,such as communication,automotive,environmental control,healthcare,security and entertainment.(European Nanoelectronics Initiative Advisory Council,ENIAC).At the same time,MtM aims to conv
109、ert analogue circuits to digital ones,bringing the benefits of Moores Law to Radio Frequency(RF)circuits and,ultimately,making digital RF practical for SoC integration.Source:https:/ Years of Microprocessor Trend DataGNSS TECHNOLOGY EVOLUTIONGNSS USER TECHNOLOGY OVERVIEW15GNSS User Technology Report
110、|Issue 1,2016Advances in software and algorithmsA new trend,driven by advances in general processing power,is using software to approach problems that traditionally required dedicated hardware.Advances in algorithms enabling new positioning techniquesToday algorithm designers have access to more sen
111、sors and data than ever before,enabling novel positioning techniques by fusing said inputs.Although these techniques can overcome the challenges of unfavourable contexts encountered e.g.in location based service(LBS),they pose a problem when it comes to quantifying performance.As such,they must firs
112、t mature significantly before they can be used for any safety or liability-critical applications.Software defined GNSS receivers&simulatorsGNSS software receivers use the antenna and frontend hardware of a conventional receiver;and their host platforms digital computing capabilities to perform all o
113、ther tasks(signal processing;navigation solution processing)usually performed by a dedicated GNSS Application Specific Inte-grated Circuit(ASIC).They can be seen as the GNSS receiver equivalent of a software-defined radio.Software defined GNSS receivers offer significant increases in flexibility ove
114、r hardware receivers,yet this comes at the cost of decreased efficiency(power usage and computational load on the host system).Thus,their use tends to be currently limited to development tools.Along these same lines are GNSS simulators,which utilise Software Defined Radio for rapid proto-typing of n
115、ew positioning algorithms.A key question in the near to medium term evolution of GNSS receiver technology is whether advances in digital signal processing will allow software receivers to go mainstream,meaning we will see GNSS functions switch from ASIC to a software implementation.Considering the e
116、volution in semiconductor technology in the recent years,particularly those pertaining to digital processing,such a move seems rather likely albeit probably not in the next five years.Advances in sensors technologyThe“More than Moore”revolution has happened,and semiconductor manufacturing processes
117、are no longer exclusive to the integrated circuit(IC)industry.In fact,innovation in sensor technology is being driven by automotive positioning systems,smartphones and tablets.This is resulting in a proliferation of combined sensor packages(combos),sensor hubs(dedicated processors)and“intelligent se
118、nsors”(integrating sensor fusion software)and is benefiting such products as MEMS,sensors,LEDs,power devices,3D assembly and heterogeneous integration solutions.The largest share of the industry,at least for consumer products,is owned by inertial sensors(accelerometers and gyroscopes).These are most
119、 often integrated in 6 or,with the addition of magnetometers,9 axis combos and named“motion sensors”.As a result of a drastic decrease in their size,cost and power consumption,they have seen an increased uptake in smartphones,wearables and various IoT markets.Besides inertial sensors,the automotive
120、Advanced Driver Assistance Systems(ADAS)and develop-ments in the driverless car foster the availability of cheaper and/or higher performance cameras,Infra Red,Complementary Metal Oxide Semiconductor(CMOS)image and ultra sound sensors.Still images and video cameras are not only found in our smartphon
121、es,many cars equipped with parking assistance or similar ADAS function also use these cameras as sensors and they may well become one of the most widely used sensors for location purposes.With respect to reference oscillators,Chip Scale Atomic Clocks(CSAC)are commercially available today,and researc
122、h continues to improve their performance/cost ratio.Along with the drastic reduction in the size and power of GNSS receivers,the energy density of batteries has increased,typically doubling every decade,with a parallel cost reduction.This combination means consumers can keep their hand-held devices
123、on for days.Furthermore,these devices are also getting progressively smaller,which enables new applications many of which are as yet unknown.Developments towards software-defined GNSS receivers promise more flexibilityGNSS TECHNOLOGY EVOLUTIONRFFront-EndASICPVT(&App)processingDigital IFDigital ASIC/
124、SoCRFAntennaUser interfaceBasebandprocessingI/ORFFront-EndASICDigital IFRFAntennaUser interfaceHostDSPI/O16GNSS USER TECHNOLOGY OVERVIEWConventional GNSS receiverSoftware GNSS receiver GNSS User Technology Report|Issue 1,2016All components of GNSS receiver design are evolving The evolution of receiv
125、er design has been driven forward by technological developments,including increased power to enable the processing of more GNSS channels and the develop-ment of low-cost MEMS sensors that allow tighter coupling with different sensors and bringing positioning to GNSS-deprived locations.Simultaneously
126、,market pressures have exerted a pull towards increased accuracy,improved performance in difficult environments and reduced time to first fix(TTFF).This diagram presents in a simplified manner the building blocks of a typical GNSS receiver,together with their main characteristics(the most important
127、or rapidly evolving ones being highlighted in red).RECEIVER DESIGN1.Antenna(+preamplifier)Receives,amplifies and band-pass filters GNSS signals.Dimensions:SelectivityNoise factorGainDiagramPhase Centre BandwidthMultipath rejectionSingle or multiple antenna inputsJamming mitigation6.Input/Output inte
128、rfacesConverts data produced in internal formats into such recognised formats as NMEA.After reformatting,the data is output over a suitable data interface such as RS-232 Serial data,Ethernet,Bluetooth or a combination of several.The selection of the interface is often application domain specific.Loc
129、alOscillatorRFRFFront-EndAnalogueto DigitalconverterAntennaAnalogueIFDigitalIFInputs/OutputsUser InterfaceBasebandProcessing PVTProcessingRaw Data&Nav.messagePowerSupply1234562.RF down convertorDown-converts and filters RF signals to an intermediate frequency(IF)compatible with analogue-to-digital c
130、onverter(ADC)acceptable input.Dimensions:Input frequency/iesPhase noiseLinearityAutomatic Gain Control(AGC)Isolation3.Analogue to Digital converterConverts the analogue IF signal into a digital replica.Dimensions:LinearityNumber of bits/Dynamic range JitterBandwidthInterface to baseband4.Baseband pr
131、ocessingAcquires and tracks incoming signals,demodulates navigation data.Dimensions:Number of channelsMeasurement rateMeasurement noise(C/N0)Multipath immunitySignals/modulations processedDynamicsInterference cancellationJamming mitigation5.PVT(&Application)processingComputes the estimated position
132、and receiver time offset relative to the constellations reference time.Dimensions:Solution type(GNSS,Differential GNSS,Real Time Kinematic(RTK),Precise Point Positioning(PPP),)Single or Multi constellationUpdate rateLatencyGNSS USER TECHNOLOGY OVERVIEW17GNSS User Technology Report|Issue 1,2016Signal
133、s and Bandwidth considerationsThe specific signals that a given receiver supports will usually depend upon its targeted market.For example,a composite signal like Galileo E1 uses both Binary Offset Carrier(BOC)1,1 and BOC 6,1 modulations,allowing receiver designers to choose whether to process the w
134、hole signal or just the inner BOC1,1 part.Their decision is driven by device complexity,power consumption and performance trade-offs,as the power consumption of a given receiver is generally proportional to the processing bandwidth and,hence,signal bandwidth.On the other hand,the use of higher proce
135、ssing bandwidths delivers more accurate observations and greater immunity to multipath.Thus,precision receivers,particularly those without power consumption constraints,tend to process the full signal bandwidth,whilst mass market receivers,such as smartphone GNSS receivers,tend to only process the n
136、ecessary minimum bandwidth.Vector trackingAlmost all GNSS receivers employ what we now call scalar tracking,a naming adopted to differ-entiate them from the more advanced design concept of vector tracking.In scalar tracking,carrier and code tracking takes place independently for each signal.Vector t
137、racking tracks all satellite signals in one navigation filter,and is seen as a promising approach to minimise the effect of multipath interference and aid Non Line of Sight(NLOS)detection,both major error sources when using GNSS in urban environments.Vector tracking combines the signal acquisition a
138、nd tracking function with the position solution function,all within one algorithm.Whilst significantly increasing the processing power needed through increased algorithmic complexity and a ten or more fold increase in the rate at which the position is computed,vector tracking is expected to further
139、improve sensitivity,provide an ability to bridge short signal outages and provide a greater immunity to interference.Despite its promised benefits,vector tracking has yet to be embodied into commercial products.It can however be expected that future generations of GNSS receivers will adopt this stra
140、tegy once microprocessor capabilities have increased sufficiently to make it viable,which may take place in the next five years or so.Cloud GNSS processing and snapshot receiversCloud GNSS processing is the ultimate evolution of the software GNSS receiver concept.Instead of using the host devices pr
141、ocessing capabilities,cloud GNSS receivers use cloud based processing services,thus offloading(most)processing and energy consuming tasks to the cloud where such resources are virtually unlimited.Snapshot or single shot positioning is designed to work with only a few milliseconds of raw GNSS signal.
142、A snapshot is a short recording of the raw data after signal conditioning(pre-amplification,down-conversion,filtering and analogue to digital conversion)in the front-end.Snapshots are then passed to the host platform processor,(like a software receiver),stored for later processing(like a GNSS sensor
143、/tracker)or sent to the cloud.This technique is specifically designed for scenarios when continuous Signal in Space(SiS)tracking is not possible(e.g.indoors),not required or not desirable.Because snapshot positioning works with pure signal acquisition and no signal tracking,it does not permit naviga
144、tion message extraction.For this reason,it is impossible to synchronise measurements to any time stamp of the navigation message,as in conventional GNSS positioning.However,via coarse time positioning,specific algorithms can derive a position solution from the snapshots and assistance data.Snapshot
145、positioning has many attractive features:nThe GNSS receivers tasks are reduced to measuring the spreading code phases.Because they do not need to track satellites or decode navigation messages(all computationally intense and energy demanding tasks),power consumption is drastically reduced.nInstead o
146、f tracking satellites for tens of seconds to decode the navigation message,only mil-liseconds of information are required.Therefore,the GNSS receiver can be aggressively duty cycled,further reducing energy needs.nGalileo makes it possible to leverage pilot signals on E1.Pilot codes have improved cro
147、ss-corre-lation protection for near-far situations(processing weak signals in presence of a strong one),allow for very long coherent integration times and therefore arbitrarily high sensitivity(only limited to the local oscillator stability),and ambiguity-free ranging(lifting the constraint of preci
148、se timing assistance).By combining snapshot GNSS positioning and cloud based processing some researchers and vendors claim energy savings of several orders of magnitude a very interesting combination for such uses as“drop and forget”and the Smart Dust concept.Innovative signal processing means integ
149、ration of new signals and reduction of power usage This architecture enables the development of very advanced receivers requiring a high computational load that would otherwise be impractical,or very low power and low-cost entry level receivers,particularly when associated with GNSS snapshot techniq
150、ues.CommunicationAcquisitionTrackingPVT processingRFFront-EndASICRFAntennaBuffer/StorageDigital IFsamplesSIGNAL PROCESSING18GNSS USER TECHNOLOGY OVERVIEWCloud-based GNSS receiver architectureGNSS User Technology Report|Issue 1,2016Antennas,which are responsible for capturing L-band signals transmitt
151、ed from space,serve as the link between the GNSS Space Segment(satellite constellations)and User Segment(GNSS receivers).They are characterised by frequency range,gain,pattern,phase centre variations,capa-bility to reject multipath and interference,and by size,shape and environmental constraints.As
152、sensitivity and selectivity are key parameters for satellite navigation,antennas are usually active,meaning Low Noise Amplifiers(LNAs)and filters can typically be found very close to the radiating element feed.Antenna designers must make trade-offs between antenna efficiency,bandwidth and level of m
153、iniaturisationGNSS Antenna TypeTypeForm factorApplicationsFixed ReferenceExternalChoke ringReference stationGeological monitoring Other fixed location applicationsHigh Performance ExternalSpiral ArrayReference station(temporary and permanent)SurveyingGround mappingAgriculture Construction and mining
154、 Certified CompactExternalPatchAircraft certified for navigation but suitable for any mobile application.Highly portable and suitable for a variety of environments and applications.CompactExternalPatchRoadRailwayMaritimeOEM EmbeddedPatch Monopole Dipole HelixRoadRailwaySurveyLBS,PND&IoTDesign Exampl
155、eDescriptionPatchSquare microstrip patch antennas over high permittivity dielectric substrate to reduce the antenna size.HelixQuadrifilar helical antennas have monopole-like appearance without the need for a supporting ground plane,making them most useful for mobile and handheld devices.ArraySet of
156、antenna elements arranged in an array pattern,usually designed to provide direction of arrival determination for cancelling or suppressing multipath or interferences.SpiralPlanar spiral antennas are inherently circularly polarized and wideband with a hemispherical pattern.DipoleTwo orthogonal dipole
157、s over a ground plane excited in quadrature produce a hemispherical CP pattern.Similar to the one obtained by a micro strip patch antenna,but with larger dimensions.Choke ringCentral element with several concentric conductive rings,enclosed in a protective dome.The objective is to reduce the edge di
158、ffraction of a limited size ground plane to produce a better hemispherical pattern.MonopoleDielectric resonator antennas(DRA)consist of a block of ceramic material of various shapes,the dielectric resonator mounted on a metal surface,and a ground plane.1 The radiating element:responsible for antenna
159、 bandwidth and radiating characteristics.2 The radome:dielectric physical element that protects the radiating element.3 The ground plane:conditions the radiation pattern shape,foremost at low elevation angles.4 The amplifier:LNA(Low Noise Amplifier)that sets the receiver noise figure.Scheme of GNSS
160、AntennaTypical applications for commercial GNSS antenna designGNSS antenna design examples and description3421GNSS ANTENNASGNSS USER TECHNOLOGY OVERVIEW19Photo source:ec-Photo source:Photo:Photo source:toptech-Photo source:TPhoto source:Photo source:.trGNSS User Technology Report|Issue 1,2016Multi-f
161、requencyMass market applications require single-frequency receivers in their large majority,explaining why single band antennas still account for nearly 60%of all antenna models.The percentage of antennas with multi-frequency capabilities has not significantly increased over recent years,although mu
162、lti-frequency antennas are attracting a growing interest in professional applications.MultipurposeRecently,the GNSS downstream industry has shifted from designing antennas on a case-by-case basis to a scenario where antenna manufacturers supply modules that can be easily integrated into OEM manufact
163、urers proprietary products.On top of specifically designed antennas for niche applications,manufacturers now provide numerous embedded and compact antenna designs offering different form factors,choices of housing,mounting,connectors and supply voltage.MiniaturisationAll classes of antennas have see
164、n a move towards miniaturisation.For applications where miniaturisation is the main driver,such as LBS,miniature monopole-like solutions are much more widespread than patches and spirals.These applications require a very small and nearly omnidirectional antenna,and sufficient performance is achieved
165、 even with linearly polarised antennas.Approaches are based in incorporating Electromagnetic bandgap structured(EBG)or metamaterial inspired structures.RobustnessThere is a growing interest in using adaptive antennas as a countermeasure to jamming and non-intentional interferences.Adaptive antennas
166、exploit spatial diversity and can discriminate received signals when they come from different directions than expected.Adaptive techniques cannot be supported solely by the antennas,which are limited to the radiating element and the LNA(Low Noise Amplifier),but require the use of additional electron
167、ic components that process the RF signal.Basic perfor-mancesAntenna gain and noise figures have remained constant over recent years,and show no sign of needing improvement.Receiver sensitivity,however,has improved significantly,relaxing the pressure to have better antennas in many“low perfor-mance”a
168、pplications,thus widening the use of miniature monopole-like antennas.Integration with other antennasGNSS devices are being increasingly integrated into devices supporting other wireless communication technologies,including short range data transmission(Bluetooth,WiFi,RFID)and cellular or satellite
169、communication networks.Advances in antenna design will pave the way for miniature,multipurpose antennas.Capable of oper-ating with various types of receivers,these antennas should be used in heterogeneous applications and market segments,thus maximising the advantages of the economies of scale.Minia
170、turisationAntennas are most efficient when their dimensions are the same as the wavelength at the relevant frequency band(19 cm at E1).Although some applications(e.g.Aviation)allow,or even impose,technical specifications that focus on their radio electrical performance,the majority of GNSS antennas
171、are designed to best meet the needs of GNSS integrators.As a result,they are well-suited to address automotive and LBS applications,for example,where size and cost are the main drivers albeit at the expense of performance.Miniaturisation techniques can be used to reduce antenna dimensions,such as th
172、e folding of the antenna wire or the use of antenna dielectrics with high permittivity.However,the drawback is the reduction of bandwidth wherein the antenna operates most efficiently.Multiple-frequency antennasThe availability of new wider band GNSS signals,the possible migration of multiple freque
173、ncy techniques towards mass market applications and the increasing need to offer better multipath and interference immunity are raising new demands on antenna characteristics,such as increased bandwidth.Such requirements may be in contradiction with the miniaturisation trend.The challenge for antenn
174、a manufacturers is to achieve an optimal trade-off between antenna effi-ciency,bandwidth and miniaturisation.More multipath&interference resilient antenna designsResilience against multipath and interferences is a demand for the whole GNSS reception channel,including the antennas.This aspect of ante
175、nna design is identified by the manufacturers as a most promising research area for professional applications,as well as for mass market ones.The multi-frequency and multi-constellation concepts contribute to increasing this resilience thanks to the higher redundancy and diversity of the signals off
176、ered by the new constellations and bands.Within this context,adaptive antennas are positioned as a very powerful tool against jamming and non-intentional interferences.That being said,the commercial adaptive antenna landscape remains limited to military grade null-steering antennas.Innovative,concur
177、rent designs compatible with civilian market needs will undoubtedly come to market in the coming years.The use of independent antenna elements improves gain and allows Direction of Arrival(DoA)measurements.As a result,multiple input multiple output(MIMO)antenna designs already exist as mature techno
178、logy for use in telecommunications and 4G LTE modems.More robust,smaller and multi-purpose GNSS antennas are on demandGNSS ANTENNA TRENDS20GNSS USER TECHNOLOGY OVERVIEWSummary of current status and trends of GNSS antennasGNSS User Technology Report|Issue 1,2016The past decade has seen the emergence
179、of GNSS receivers supporting multiple constellations a trend that exists even in markets where cost is the dominant factor.However,due to developments in the underlying technologies,the lifecycle of a given generation of receivers is typically only a few years.As a result,manufacturers only seriousl
180、y address each new constellation or signal when it nears its full operational capabilities(FOC)status.Nearly 65%of GNSS receivers available today are multi-constellation,with more than 20%supporting four constellations.The most common combination remains GPS+GLONASS,followed by GPS+Galileo.More than
181、 60%of receivers also include SBAS,either for higher accuracy or integrity.Regional systems,such as QZSS and IRNSS,are also becoming more common.The benefits of supporting multiple constellations:nIncreased availability:*particularly in areas with shadowing.nIncreased accuracy*and integrity:*more sa
182、tellites in view improves accuracy through a better GDOP and integrity through more efficient Receiver Autonomous Integrity Monitoring(RAIM)procedures.nImproved robustness*:as independent systems are harder to spoof.Analysis of GNSS receivers capabilitiesThe GSA independent analysis assesses the cap
183、abilities of nearly 400 receivers,chipsets and modules currently available on the market*.For the analysis,each device is weighted equally,regardless of whether it is a chipset or a receiver and no matter what its sales volume is.The results should therefore be interpreted not as the split of conste
184、llations utilised by end users,but rather the split of constellations available in manufacturers offerings.Disclaimer:The above graphs reflect manufacturers publicly available claims regarding their products domain(s)of use and NOT their actual suitability for specific applications as can be demonst
185、rated e.g.by a certification(when standards and regulations are existing)or actual usage.Multi-constellation feature becoming standard across all applicationsRECEIVERS CAPABILITIESSupported constellations by GNSS receivers22 shows percentage of receivers capable of tracking 1,2,3 or all the 4 GNSS c
186、onstellationsConstellation capability of GNSS receivers11 shows percentage of receivers capable of tracking each constellation0%20%40%60%80%100%GPSSBASGalileo GLONASSGNSS,RNSS and SBAS constellationsBeidouQZSSIRNSS0%5%10%15%20%25%30%35%40%45%123Number of constellations4AllGPS+GLONASS+BeiDouGPS+Galil
187、eo+BeiDou GPS+BeiDouGPS+Galileo+GLONASSGPS+GLONASSGPS+GalileoGPS only*The Key Performance Parameters are defined in Annex I*For details see Annex IVGNSS USER TECHNOLOGY OVERVIEW21GNSS User Technology Report|Issue 1,2016From their inception,new GNSS like Galileo and BeiDou support open multi-frequenc
188、y signals,which helps drive the introduction of dual and triple-frequency commercial receivers.Today,the adoption of multi-frequency tends to only be found in the high precision receivers that demand higher accuracy.There are several research activities happening around dual frequency receivers for
189、mass market and automotive,however no real large scale deployment could be observed so far.As a result,nearly 70%of GNSS receivers remain single-frequency(with the remaining 20%supporting two and 10%three frequencies).The most common combination is L1/E1 and L2,followed by L1/E1,L2 and L5/E5.Not sur
190、prisingly,all GNSS receivers use L1/E1 frequency.Furthermore,around 30%have L2 capability,10%L5/E5,and 1%E6.(For more see charts below).The benefits of supporting multiple frequencies:nImproved accuracy:Dual-frequency capable devices can estimate and compensate for iono-spheric delays.Multi-frequenc
191、y common today only in high precisionnAccess to RTK and PPP techniques:Although theoretically possible for single-frequency receivers,RTK or real time PPP techniques practically require dual-frequency receivers.Further-more,the use of triple-frequency receivers will likely enable further improvement
192、 of the ambi-guity resolution algorithms,e.g.through the TCAR technique.nImproved robustness:Although rarely advertised,frequency diversity is a basic but very efficient protection against jamming.New signal designs also bring significant benefits:nImproved accuracy:New modulations and higher chip r
193、ates enable more precise range measurements.nImproved multipath mitigation:New modulations and higher chip rates provide additional mitigation for multipath issues.nImproved sensitivity:Pilot signals(i.e.dataless signals)enable higher sensitivity receivers through longer integration times.RECEIVERS
194、CAPABILITIESAnalysis of GNSS receivers capabilitiesThe GSA independent analysis assesses the capabilities of nearly 400 receivers,chipsets and modules currently available on the market*.For the analysis,each device is weighted equally,regardless of whether it is a chipset or a receiver and no matter
195、 what its sales volume is.The results should therefore be interpreted not as the split of constellations utilised by end users,but rather the split of constellations available in manufacturers offerings.Disclaimer:The above graphs reflect manufacturers publicly available claims regarding their produ
196、cts domain(s)of use and NOT their actual suitability for specific applications as can be demonstrated e.g.by a certification(when standards and regulations are existing)or actual usage.Supported frequencies by GNSS receivers22 shows percentage of receivers capable of tracking 1,2,3 or all the 4 freq
197、uenciesFrequency capability of GNSS receivers11 shows percentage of receivers supporting each frequency band0%20%40%60%80%100%L1/E1L2L5/E5Frequency bandsE60%20%10%30%40%50%60%70%80%90%100%1234Number of frequenciesAllL1/E1+L2+L5/E5L1/E1+L5/E5L1/E1+L2L1/E1 Only*For details see Annex IV22GNSS USER TECH
198、NOLOGY OVERVIEWIn an OPEN SKY environment,GPS-only acquisition and accuracy is as good as MULTI-CONSTELLATION.In difficult to extreme live environments(e.g.bridges)the MULTI-CONSTELLATION solution always outper-forms GPS-only,making it a MUST HAVE.GNSS User Technology Report|Issue 1,2016 MULTI-CONST
199、ELLATION TESTINGIn preparation for the declaration of Galileo Initial Services,the GSA,along with the European Space Agency(ESA)organised a test campaign of GNSS chipsets to assess the readiness of consumer devices to support Galileo signals.The tests were executed between mid-2014 and early 2016,wi
200、th participation of nine leading mass market manufacturers.In addition to supporting the industry for testing and fine-tuning their Galileo capable products,the campaign also highlighted the performance improvements enabled by multi-constellation capability.The test campaign included a mixture of si
201、mulator-based,RF-replay-based and live tests.Labo-ratory-based tests were based on either RF simulator signals conducted with“on the air”(OTA)RF testing or via scenarios recorded using an RF data recorder.This allowed for meaningful comparisons between receivers or between the various firmware versi
202、ons of a given receiver.As for receivers,several manufacturers used this campaign to compare and fine tune concurrent implementations of their Galileo and multi-GNSS functionality.The test scenarios were designed to assess chipset performance under nominal(open sky)and degraded(sub-urban and urban)e
203、nvironments.They included both static and dynamic conditions,and used various combinations of GPS(used as the reference),GLONASS and Galileo signals.The main performance parameters evaluated were accuracy and Time to First Fix(TTFF).Accuracy:The addition of one or two constellations to GPS only marg
204、inally improves accuracy in open sky conditions.However,as an environment becomes worse(physically and/or radio electrically),Galileos benefits become more obvious.For example,in the urban scenarios,the addition of Galileo signals always improved accuracy,with an observed improvement of the Circular
205、 Error Probable(CEP)between 15 and 20%.The best performing receiver reached a CEP of 3.9 m with GPS and Galileo.The combination GPS+GLONASS(with 7-8 GLONASS satellites)and GPS+Galileo(with only 2-3 Galileo In-Orbit Validation(IOV)satellites)led to a very similar average horizontal position error.TTF
206、F:TTFF was assessed in the same live environments used for accuracy.Like accuracy,improve-ments in TTFF are mostly visible in worst case(urban)scenarios.The average improvement among tested receivers was around 1s in hot start and 20s in cold start TTFF,with the cold start average TTFF expected to s
207、how significant reduction when the number of Galileo satellites in view becomes equal to or greater than four.However,as in the accuracy tests,some large differences between receivers were observed,most likely due to different implementation choices,acquisition strategies and allocation of resources
208、.Galileo testing campaign demonstrates benefits of multi-GNSSLIVE scenarios executed to analyse different user environmentsUrbanSuburbanMotorwayGNSS USER TECHNOLOGY OVERVIEW23Source:ESAGNSS User Technology Report|Issue 1,2016GNSS VULNERABILITIESDue to the nature of GNSS(signals received with very lo
209、w power level),these systems are vulnerable to either natural(e.g.ionospheric scintillation)or man-made(e.g.radio interferences of all sorts)phenomena that may severely disrupt their operation up to a partial or total interruption of service.Such phenomena can be deliberate(jamming and spoofing atta
210、cks),but can also be unwanted(spu-rious radiation of other radio devices,GNSS multipath propagation).Regardless of their nature,these phenomena threaten GNSS and must be protected against.Jamming,spoofing and meaconing threaten GNSS signals and must be coped withDeliberate RF Interference(Jamming):A
211、lthough GNSS jammers are illegal to market,sell and use in most countries,they can nevertheless be bought by the public on the internet.A typical motivation for using a jammer is to fool devices used in asset tracking.However,such jammers often disrupt GNSS over a much larger area than advertised,tr
212、ansforming an alleged“privacy protection device”into a major public nuisance.Unintentional RF Interference:Multipath:a multipath effect is,by definition,a self-interference occurring when the direct path GNSS signal is combined with a delayed replica of itself.It affects phase as well as code measur
213、e-ments.However,by knowing the nature of the interfering signal one can devise specific mitigation strategies.Other RF Interferences:These are unpredictable events,due to abnormal spurious adjacent band or harmonics radiations.Reported incidents have implied sources as diverse as microwave devices,a
214、irport radars and TV transmitters.Generating a forged GNSS signal:Data Bit Generation:There are two approaches to data bit generation,namely navigation mes-sages replica and forgery:nNavigation messages replica:data from space is replayed to reuse the authentic data and/or the ephemeris of the live
215、signal.nNavigation messages forgery:the attacker can theoretically forge the navigation message to achieve a desired PVT at the receiver.If message authentication is used,the authentication tag must also be forged.Spreading code and carrier generation:a GNSS system modulates the data with direct-seq
216、uence spread spectrum(DSSS).For all open services,these sequences are published in the systems Interface Control Documents(ICDs),and may be used to construct a simulated signal.Such a forged signal may then be broadcast with or without synchronising the simulated and real-satellite spreading sequenc
217、es and at various power levels.Replay attacks(Meaconing):Real-time signal replica:signals from space can be delayed and replayed with appropriate hardware,e.g.by using cables that introduce delays into the propagation times,allowing errors in the order of 100 to 200 metres to be introduced in the po
218、sition solution.Even if this approach isnt sufficient to simulate a desired PVT or trajectory,a user might use it to cheat unprotected liability-critical applications(self-spoofing).Record-and-replay:this attack is performed using already commercially available products.The typical architecture of t
219、hese devices consists of a down-converter and analogue-to-digital con-verter(ADC),glue-logic,digital storage(hard disk),and a digital-to-analogue converter(DAC)and up-converter for the retransmission of the signal.Spoofing is a more sophisticated and malicious form of attack than jamming(successful
220、spoof-ing goes undetected).Although jamming is a well-known threat,the classification of deception interferences that affect GNSS signals is not straightforward,with the following parameters being vulnerable to attack(independently or not):timing information,ranging information,ephemeris data,almana
221、c data,corrections data,integrity data,service parameters and authentication data.MultipathOthers RFIDeliberate(Jamming)UnintentionalDenial of Service(Interferences)Deception of Service(Spoofing)Forged signalgenerationReplay attacks(Meaconing)Data Bits GenerationSpreading Sequence&Carrier Generation
222、Real-Time ReplicaRecord and ReplayGNSS Threats24GNSS USER TECHNOLOGY OVERVIEWA simplified taxonomy of man-made RF threats to GNSSGNSS User Technology Report|Issue 1,2016PROTECTING GNSSAnti-SpoofingGNSS may implement several layers of defence against spoofing.The most widely known is to control acces
223、s to the signals by encrypting the ranging codes(“NAVSEC”)and navigation messages(“COMSEC”).This is what the GPS Precise Positioning Service(PPS)and Galileo Public Regulated Service(PRS)services do,only granting access to authorised users.Another approach is GNSS signal authentication.Although here
224、all receivers can process the authenticated signals,these signals include“markers”that can only be interpreted(and in some cases detected)by enabled receivers using a cryptographic feature.This authentication capability may theoretically concern the navigation messages,the ranging codes,or both.In t
225、he near future,Galileo plans to implement such a capability:nThe Navigation Message Authentication(NMA)for the Galileo Open Service signals will be freely available to all users and will offer a“COMSEC”protection against spoofing.nIn addition to NMA,the Galileo Commercial Service will also offer an
226、encrypted ranging code to subscribed users,thus adding“NAVSEC”protection.Mitigation of GNSS vulnerabilities is the subject of intense R&DInterference mitigationAll RF InterferenceDetecting and mitigating jamming can be achieved by:nSuch antenna techniques as array-antennas and array processing algor
227、ithms:Beamforming NullsteeringnDetermining the signal of interests DoA(Direction of Arrival)by exploiting available information from spatial separation.nDetermining the source of interference and spoofing(Direction of Interference DoI).nFront-end Techniques,such as detection techniques based on Comp
228、ressed Sensing.nPre-and Post-Correlation Receiver Techniques,such as pulse blanker,Continuous Wave(CW)nulling,notch filtering,etc.Multipath specific countermeasuresMultipath can be mitigated at different levels by using:nGood antenna design:rejecting LHCP(Left Hand Circularly Polarised)signal becaus
229、e the GNSS signal is RHCP(Right Hand Circularly Polarised),including such specific antenna designs as the choke ring antennas(see page 19).nAdvanced correlator techniques that are now commonly used in higher performance receivers,such as the narrow correlator,Multipath Estimating Delay Lock Loop(MED
230、LL),double delta techniques and gating functions.nSignal processing techniques that estimate the multipath and the ones that attempt to mitigate without estimating it.Carrier phase smoothing of code observations is one of the first methods that has been used.nImproved navigation algorithms that empl
231、oy post-processing methods to analyse receiver-sat-ellite measurements or to correct the solution itself.Advanced Interference Mitigation(AIM+)in Septentrios high-precision receiversWith four global satellite constellations transmitting on at least three different frequencies,users have come to expe
232、ct high-precision positioning in environments that would previously have been off limits.However,as the RF spectrum fills up with satellite transmissions so it also fills up with other communication signals thus increasing the possibility of interference.Low levels of interference can lead to degrad
233、ation in position quality and in the worst cases,to complete loss of signal tracking.At Septentrio,the AIM+approach to combating the effects of interference is twofold:real-time mon-itoring of the RF signal in the spectrum plot to assess type of interference followed by interference mitigation.Three
234、 Adaptive Notch Filters against narrowband interference for signals up to 1 MHz and,against interferers such as chirp jammers with bandwidths greater than 1 MHz,the Wideband Interference Mitigation Unit(WIMU)can be deployed.AIM+has already established itself as a powerful tool in detecting and mitig
235、ating the effects of interference and is included as standard on the following Septentrio products:PolaRx5,AsteRx4,AsteRx-U and the Altus APS3G.Testimonial provided by the company.GNSS USER TECHNOLOGY OVERVIEW25GNSS User Technology Report|Issue 1,2016TESTING ROBUSTNESSProfessional receivers are thos
236、e requiring the highest accuracy,between decimetre and millimetre level accuracies that require multi-frequency,multi-constellation standalone(Precise Point Positioning PPP)or differential code and carrier phase processing.Here design is driven not by size,weight and power,but by the quality and spe
237、cifications of analogue components and the computational capability of the digital processing units.Such GNSS receivers should be compared with calibrated RF laboratory instrumentation,and it is not uncommon to find them used as ground infrastructure to monitor and measure the performance of the spa
238、ce segment itself.As a consequence,the purity of the observations produced is just as important as their availability.To assess the level of readiness and compliance of these professional receivers for Galileo Open Service signals(also in comparison with GPS,Glonass and Beidou)the Joint Research Cen
239、tre(JRC)conducted an in-depth testing cam-paign in 2014 and 2015.The purpose of the campaign was not to benchmark the tested receivers,but to characterise their behaviour in the presence of a signal in space,both nominal and subject to such anomalies as interference and multipath,and to compare comb
240、ined Galileo observables and positioning performance with standalone GPS figures.The tests considered different types of radio frequency interferences(RFI):nContinuous Wave(CW,typical of unwanted oscillator harmonics).nChirp(typical of low-cost jammers).nWideband noise(typical of leakage from neighb
241、ouring high-power signals).Specific tests were carried out for each class of RFI on each band,with observations collected for both measurement level and the position domain.At measurement level,the degradation of Pseudo-Range(PR),Range Rate(RR)and Carrier Phase(CP)was observed through a comparison b
242、etween the interfered/jammed measurements and the reference measurements obtained without interference.In the position domain,GNSS receiver performance was analysed in Single Point Positioning(SPP)mode in terms of mean and Standard Deviation(STD)for both horizontal and vertical components independen
243、tly computing a classical least-squares PVT solution.The tests showed that in a nominal scenario with no interference,the variance of the residuals is highest on GPS L1 C/A,and significantly smaller on Galileo E1B/C.However,the performance on L5 and E5a is similar,as the same BPSK(10)modulation is u
244、sed by GPS and Galileo(similar performance is obtained with E6).The campaign links well with the current adjacent band compatibility studies carried out in the US by the Federal Communications Commission(FCC)under the push of Ligado(formerly Lightsquared).In Europe,in the framework of the Radio Equi
245、pment Directive(RED),this work might be re-used(or re-produced)to provide scientific back-up to the application of the regulation to the precision-receivers market(e.g.surveying,construction,mapping).A testing campaign on GNSS professional receivers assessed their robustness against interference26GN
246、SS USER TECHNOLOGY OVERVIEWSource:Joint Research Centre,EC GNSS User Technology Report|Issue 1,2016EUROPEAN R&DEuropean GNSS Downstream IndustrySince the early days of Satellite Navigation in the 2000s,European industry has shown a great interest in GNSS technology and markets for Galileo&EGNOS appl
247、ications.Today,European GNSS downstream Industry is at the forefront of technological innovation in many areas.It has been an outstanding actor in the transition from pure GPS to multi-GNSS multi-frequency solutions and more widely to connected PNT solutions leveraging hybridization or sensor fusion
248、.Europe industry ranges all domains,from chipset design to manufacturing,integration and certi-fication of major systems and provision of innovative services.In particular,European industry has a leading position in GNSS security and resilience domains.Galileo Services communityGalileo Services(GS)a
249、nd Oregin federate the most active and representative players of GNSS industry and research supporting the Galileo and EGNOS Programmes.This growing network includes actors from the whole GNSS value chain:R&D,equipment manu-facturers,service providers,integrators,software developers,data content and
250、 map providers,chip producers,telecom manufacturers,etc.These organisations are excelling in all kinds of applications in all domains.GS and Oregin members have made substantial investments in and have been conducting research projects on the development of E-GNSS applications for many years.They ar
251、e also directly involved in the definition of E-GNSS services.GS community works every day for an early and wide adoption of E-GNSS services in all domains.Galileo Services(GS)is a non-profit organisation founded in 2002 to support the European GNSS down-stream industry interest.GS network represent
252、s more than 180 member organisations ranging from SMEs to large companies and Academia.Europes industrial contribution to GNSS innovation“We see that there is a strong interestfrom European industry to provide solutions for European GNSS applications globally.”“Notably,we see members of Galileo Serv
253、ices and Oregin that already have or are developing receivers for a broad range of applications,in particular building on Galileo differentiators,”Gard Ueland,GS Chairman.For further information:www.galileo-services.orgGNSS USER TECHNOLOGY OVERVIEW27GNSS User Technology Report|Issue 1,2016EUROPEAN R
254、&DGNSS academic research is alive and well in Europe,making an impressive impact on global innovation.It involves many universities and institutes across all European countries,with some formalising their collaboration under the Satellite Navigation University Network(SUN).SUN,which started in 2010,
255、is now part of the GSA-supported Horizon 2020 e-KnoT project.Its objectives include:nBringing together providers of GNSS univer-sity education to facilitate the development of joint educational programmes.nIncreasing co-operation between partners and industry and between national and European organi
256、sations like the GSA,EC and ESA.nIdentifying the needs of GNSS education and improving its process and curricula.nDeveloping strategies for the current net-work of GNSS universities exploring new educational programmes and methods.Academic research in GNSS is very active in EuropeAalborg Universitet
257、Aalborg University conducts research on the applications of GNSS in surveying and mapping.cole Nationale de LAviation Civile(ENAC)French Civil Aviation Universitys research activities on navigation and positioning focus on such critical transport applications as aviation,road and rail.It encompasses
258、 GNSS integrity monitoring,receiver signal processing,multi-sensor navigation and precise positioning.Hochschule fr Ange-wandte Wissenschaf-ten MnchenResearch at the Faculty of Geoinformatics at the Munich University of Applied Sciences comprises of UAV-Photogrammetry,Remote Sensing,Computer Vision,
259、Navigation and Machine Learning.In particular,research is focused on object-based segmentation and classification for 3D vegetation mapping.Institut Suprieur de lAronautique et de lEspace(ISAE)GNSS education is part of the graduate and postgraduate programmes at ISAEs Aerospace Electronics&Communica
260、tions Pro-grammes.Short courses are organised for professional training.PhD and research activities focus on improving the performance of positioning systems in adverse environment(e.g.cities)via low-cost sensors fusion(e.g.MEMS),antenna processing,multi-con-stellation receivers,etc.ISAE is one of t
261、he founding members of the GNSS Test Laboratory GUIDE.Istituto Superiore Mario Boella(ISMB)The Navigation Technologies Research Area at ISMB focuses on GNSS software receiver technologies and algorithms.It co-organises the Specialising Master on Navigation and Related Applications with the Polytechn
262、ic University of Turin.Politecnico di Torino(POLITO)The Polytechnic University of Turin is involved in GNSS activities through the Department of Electronics and Telecommunications Engineering,where it is developing advanced signal processing algorithms for receivers,and through the Department of Env
263、i-ronment,Land and Infrastructure Engineering where it is studying geomatics applications.Teaching of specific GNSS courses at the University is implemented at MSc level and at specialising masters level.Sveuilite u RijeciUniversity of Rijeka,Faculty of Maritime Studies(Navigational GNSS and Space W
264、eather Laboratory),operates multi-GNSS per-formance and ionospheric dynamics observatories in Rijeka and Baka,and develops a regional space weather impact model and GNSS SDR applications.Tampereen Teknillinen YliopistoThe Tampere University of Technology focuses on signal processing for GNSS receive
265、rs,modulation design in GNSS transmitters,GNSS channel modelling,orbit predictions,implementation and simulation issues on GNSS receiver prototyping,and hybrid localisation solutions involving GNSS and non-GNSS.Technische Universitt GrazThe GNSS research at Graz University of Technology mainly focus
266、es on GNSS-based trajectory determination(PPP,RTK),fusion of GNSS and INS,together with filtering(Kalman filter,particle filter).Universit degli Studi di PadovaUniversity of Padova specialises in regional GNSS permanent networks for application to geodesy,mapping,deformation mon-itoring in seismic/s
267、ubsident areas and research on multi-GNSS interoperability and receiver calibration.It is a regional provider of RTCM/RTK correction signals.Universit di BolognaGNSS-related research at the University of Bologna focuses mainly on code acquisition subsystems;GNSS interference detection,localisation,a
268、nd mitigation;cooperative algorithms;and integration between GNSS and inertial navigation systems.Universitt der Bundeswehr MnchenActivities at the Institute of Space Technology and Space Applications(ISTA)at the Federal Armed Forces University of Munich focuses on teaching and research in the areas
269、 of navigation,signal processing,satellite methodologies,satellite communication,geophysics and geodynamic.The university also has expertise and experience in GNSS and integration with INS.Universitat Politcnica de Catalunya(UPC)The GNSS-related activity of Research group of Astronomy and GEomatics(
270、gAGE)at Polytechnic University of Catalonia includes new algorithms for Wide Area navigation and Fast Precise Point Positioning at the centimetre-level of accuracy using GPS/Galileo signals,SBAS and GBAS studies,and precise ionospheric and tropospheric sounding.University of NottinghamNottingham Geo
271、spatial Institute(NGI)is a cross-disciplinary research and postgraduate teaching institute at The University of Nottingham.Fields of specialisation include satellite navigation and positioning systems,remote sensing photogrammetry,sensor integration,geospatial information science and location based
272、services.28GNSS USER TECHNOLOGY OVERVIEWGNSS User Technology Report|Issue 1,2016EUROPEAN R&DGNSS Downstream R&D programmes in EuropeTo foster the adoption of Galileo and EGNOS-powered services across all market segments,the GSA supports two complementary R&D funding mechanisms:Horizon 2020(H2020)enc
273、ourages the adoption of Galileo and EGNOS via content and applica-tion development.It also supports the integration of their services into devices,along with their eventual commercialisation.Fundamental Elements focuses on supporting the development of innovative chipsets,receivers and other associa
274、ted technologies that integrate Galileo and EGNOS into competitive devices for dedicated user communities/target markets.Research programmes prior to H2020From 2007 to 2013,European GNSS Downstream R&D was funded under the Transport Theme of the 7th Framework Programme for Research and Technological
275、 Development(FP7).The GSA managed a portfolio of 86 R&D GNSS projects,with an average budget of 1.2 million.The total budget for the period was 66 million.FP7 projects covered a wide range of market segments:Road,LBS,Precision,Professional and Sci-entific Applications,International Cooperation,Aviat
276、ion,Rail,Maritime.There was a strong focus on SMEs,with 40%of GNSS funds awarded to SMEs amongst the 425 beneficiaries.Most importantly,the programme generated tangible results:115 demonstrations of E-GNSS applications,45 products,80 prototypes and 13 patents/trademarks.Information about all GNSS pr
277、ojects funded under FP7 can be found here:http:/www.gsa.europa.eu/r-d/gnss-project-portfolioHorizon 2020Horizon 2020 is the current EU Research and Innovation programme,offering nearly 80 billion in funding for the 2014 2020 period.European GNSS applications are part of the Space Theme,having synerg
278、ies with topics on societal challenges.Two E-GNSS calls were successfully con-cluded with a budget of 38 million and 25 million respectively.A third call is planned to be open in November 2016 and run until March 2017.Actions under H2020-Galileo address the development of innovative products,applica
279、tions,feasibility studies and market tests that will have a substantial impact on growing and strength-ening European innovation and know-how,along with the economy and strategic sectors.More information can be found here:http:/www.gsa.europa.eu/gnss-h2020-projects The Fundamental Elements of Europe
280、an GNSSWith a budget of 111 million for the 2015 2020 timeframe,“Fundamental Elements”aims to develop market-ready GNSS chipsets,receivers and antennas.The markets targeted by these end-products include,in varying proportions,all segments:Aviation,Location Based Services(LBS),Agriculture,Surveying,R
281、ail,Road,Maritime,Timing and Synchronisation and PRS.The financial instruments for funding Fundamental Elements-supported activities include grants and tenders/procurements.Grants are the preferred financial instrument,with funding generally provided to beneficiaries for up to 70%of the total budget
282、 of the grant agreements(up to 100%for the tenders/procurements).More information can be found here:http:/www.gsa.europa.eu/r-d/gnss-r-d-programmes/fundamental-elementsEU-funded GNSS downstream R&D covers receiver technology and application development GNSS USER TECHNOLOGY OVERVIEW29GNSS User Techno
283、logy Report|Issue 1,2016Mass market solutionsnMacrosegment characterisation and key performance parameters for user technology page 31nIndustry landscape page 32nSupported frequencies/constellations by GNSS receivers page 33nTypical state-of-the-art receiver specifications and analysis page 34nFutur
284、e drivers and trends page 35-38nE-GNSS added value page 3930Source:ThinkstockGNSS User Technology Report|Issue 1,2016Characterisation of mass market solutionsThis chapter discusses GNSS receivers dedicated to:nLocation Based Services(LBS):Smartphones/tablets,portable devices,wearable devices.nIntern
285、et of Things(IoT):Autonomous devices that require long availability(years)but infrequent uses.nAutomotive in-dash navigation/infotainment systems.nPortable Navigation Devices(PND)and other handheld devices for driving,walking,cycling and outdoors activities.nOther consumer equipment used in:Consumer
286、 grade drones General Aviation(GA)operating under Visual Flight Rules(VFR)Recreational sailingLBS remains the predominant use in terms of volume and value,followed by IoT.PNDs are gradually losing ground to in-vehicle systems and smartphones.Meanwhile,other consumer devices which tend to benefit fro
287、m technological developments in the three key application areas,generally do not justify specific designs at the GNSS core level.Market acceptance of LBS devices is conditioned on the availability and cost of the service,which in turn constrains such location sub-systems as high sensitivity GNSS or
288、hybrid GNSS/MEMS solu-tions that allow indoor use.On the other hand,the vast majority of these listed use cases imply the use of a connected device,thus facilitating the use of Assisted GNSS(A-GNSS)or,in the most extreme cases,of distributed receiver architecture with cloud based processing.Key Perf
289、ormance Parameter(KPP)*Mass MarketAvailabilityAccuracyContinuityIntegrityRobustnessIndoor penetrationTime To First Fix(TTFF)LatencyPower consumptionAnother commonality seen here is that,in general,these devices are battery powered,meaning they must remain small and lightweight.Consequently,another p
290、riority for GNSS receiver design is to minimise power consumption.Finally,with the notable exception of navigation applications,these applications require“on demand”rather than continuous location information.This often allows setting the GNSS receiver in idle or sleep mode to save energy,although t
291、his imposes a quasi-immediate availability(shortest possible TTFF)when the user or the application requests a position.Key performance parameters for mass market*nAvailability:the positioning information is needed“everywhere,every time”and as quickly as possible when requested by the user or the app
292、lication.nPower consumption:most devices are mobile and restricted to battery power.As a result,low power consumption positioning technologies remain a priority.nTTFF:typical usage is over a short period of time.As the user typically has other means of locating themselves,if the time to acquire thei
293、r position is too long,they will not use the device.nIndoor penetration:many applications are used indoors or in urban areas where there is restricted visibility or attenuated signals.MACROSEGMENT CHARACTERISTICS31High availability and low power consumption are key for mass market receivers*The Key
294、Performance Parameters are defined in Annex I Low priority High priority GNSS User Technology Report|Issue 1,2016Mass market receivers are produced in very high volume and sold at a limited price,with hundreds of millions of units going to smartphones and tablets and tens of millions for in-car GNSS
295、 systems every year.Largely dominated by the LBS segment(IT industry model),mass market receivers have a relatively short life cycle(in the 10s of months).Although this gives them the advantage of being able to rapidly adopt new features,it also means that time to market is of essence.Adopting a new
296、 fea-ture too early or too late,even if by just a few months,could impact the products entire life cycle.Mass market receivers also enjoy a very high innovation rate.For example,high-end consumer devices have been in the past early adopters of dual constellation capability,prior to deployment to ent
297、ry level as well and the same will undoubtedly holds true for the adoption of currently in deployment systems like Galileo.However,this trend towards innovation tends to be limited to a few very large players who can ensure sufficient economies of scale.There are challenges,however.For example,parti
298、cular to the design of mass market receivers is the requirement for a position to be available quasi-instantaneously and everywhere.This challenge is addressed by such techniques as:nReducing the signal level needed to acquire the signal(high sensitivity).nHybridisation with other radio technologies
299、(Wi-Fi fingerprinting,cellular network positioning,use of Signals of Opportunity)or non-radio based ones(MEMS).nSpecial techniques devised to provide a more accurate position estimate in the presence of severe multipath and/or non-line of sight(NLOS)signals.nUse of vector tracking techniques.nAdvanc
300、es in such algorithms as satellite shadow matching.Clearly,the development,validation and deployment of such techniques require a high investment.Furthermore,the power,size and cost constraints result in a high-scale integration of both the GNSS and the communications(Wi-Fi,Bluetooth,LTE,FM)into a s
301、ingle chip,to allows for high volume production and a minimal bill of materials for the LBS devices.This in turn has led to a consolidation of the industry,which has as principal actors only eight companies around the world(see table above).None of these actors is a“pure play”GNSS one,with all of th
302、em having a scope of activities encompassing at least wireless communication and positioning.Mass market chipset supply is extremely consolidated,with few global playersAn important feature of mass market consumer solutions is that most receivers are connected ones,with a large proportion of them be
303、ing smartphones or tablets.This in turn means that the supplier of the devices operating system has also an important role to play in the collection,aggregation,processing and delivery of location related information.Thus the description of the background industrial landscape would not be complete i
304、f it were to omit major players/influencers such as Google(for Android based terminals)and Apple(for iOS based terminals),although none of these companies is a supplier of GNSS components.Leading components manufacturersBROADCOMNorth AINTELNorth AMEDIATEKAsia-PQUALCOMMNorth ASPREADTRUMAsia-PSTMICROE
305、LECTRONICSEUTEXAS INSTRUMENTSNorth AU-BLOXNon-UE28 Europewww.u-blox.chDisclaimer:Note that some key industry players do not appear in this list which does not include system or terminal integrators.INDUSTRY LANDSCAPE32GNSS User Technology Report|Issue 1,2016RECEIVER CAPABILITIESMulti-constellation i
306、mproves performance in urban environmentsMulti-constellations adoptionWith Galileo,QZSS,BeiDou,GPS-L1C,and GLONASS-CDMA all on their way,the market continues to develop towards fully flexible,multi-constellation mass market receivers.The uptake of multi-constellation receivers is driven by devices m
307、eant for use in urban canyons and indoors.Although cell/Wi-Fi and related positioning techniques provide some help,GNSS remains the core posi-tioning technology within such environments.As a result,over 70%of all currently available mass market chipsets are multi-constellation capable.The main obsta
308、cles to multi-constellation adoption are the additional costs in terms of price,processing load and energy consumption it may add.Thus,designers must balance the benefits of multi-constellation capability against its costs and,based on this,find the optimal number of channels for the chipset.However
309、,thanks to recent innovations,this choice has become easier.Through the use of architectures that allow a specific channel to process signals originating from different constellations,it is now possible to implement constellation-specific functionality into firmware.This allows the final product man
310、ufacturer to implement constel-lation-specific designs or to configure a given hardware implementation to function with different combinations of constellations as a means of targeting specific sub-markets.It is also worth noting that 65%of these receivers support space based augmentation systems(SB
311、AS),although this figure can be misleading as SBAS functionalities are activated in a much smaller proportion of the end products(due to their requirement for continuous operation,imposing a severe drain on battery operated devices).Multi-frequency adoptionAlthough only the L1/E1 signals are current
312、ly used in mass market prod-ucts,the uptake of E5/L5 signals is expected in the coming years as further explained in section“drivers and trends”on page 36.Disclaimer:The above graphs reflect manufacturers publicly available claims regarding their products domain(s)of use and NOT their actual suitabi
313、lity for specific applications as can be demonstrated e.g.by a certification(when standards and regulations are existing)or actual usage.Frequency capability of GNSS receivers1Supported frequencies by GNSS receivers31 shows percentage of receivers supporting each frequency band3 shows percentage of
314、receivers capable of tracking 1,2,3 or allthe 4 frequenciesConstellation capability of GNSS receivers2Supported constellations by GNSS receivers42 shows percentage of receivers capable of tracking each constellation4 shows percentage of receivers capable of tracking 1,2,3 or all the 4 GNSS constella
315、tions0%20%40%60%80%100%L1/E1L2L5/E5Frequency bandsE60%20%10%30%40%50%60%70%80%90%100%1234Number of frequenciesAllL1/E1+L2+L5/E5L1/E1+L5/E5L1/E1+L2L1/E1 Only0%20%40%60%80%100%GPSSBASGalileo GLONASSGNSS,RNSS and SBAS constellationsBeidouQZSSIRNSS0%5%10%15%20%25%30%35%40%45%123Number of constellations4
316、AllGPS+GLONASS+BeiDouGPS+Galileo+BeiDou GPS+BeiDouGPS+Galileo+GLONASSGPS+GLONASSGPS+GalileoGPS only33GNSS User Technology Report|Issue 1,2016All chipsets or modules in the mass market consumer applications group are single-frequency(E1/L1)receivers(although with the IRNSS system reaching operational
317、 capability in 2016,some products supporting E5/L5 could appear).For increased sensitivity,shorter TTFF and lower power requirements,these chipsets are also all A-GNSS capable.The latest GNSS modules coming from the LBS segment are designed with multi-constellation capability.They provide high sensi
318、tivity and minimal acquisition times while maintaining low system power.In addition,they are optimised for cost sensitive applications,providing optimal performance and easier RF integration.Furthermore,nominal form factor allows for easy migration,and sophisticated RF-architecture and interference
319、suppression ensure maximum performance even in GNSS-hostile environments.In the near future,expect to see an internal flash memoryadded to allow simple firmware upgrades to support additional GNSS features.Typically not pure GNSS modules,these systems on chip(SoC)often integrate communications(Wi-Fi
320、,Bluetooth,LTE,FM)and MEMS accelerometers/gyros,along with other functions.IoT chipsets are the worlds smallest GNSS modules offering embedded flash and full GPS compli-ance(although other constellations may become supported,this uptake is limited by the extremely low power requirements of these dev
321、ices which limits their number of channels).These chips are commonly provided with a plastic package designed to minimise their total footprint.Their low power-processing core delivers several customisable power-saving modes meant to optimise current draw for the desired use.IoT chipsets support bot
322、h local and server-based A-GNSS,thus improving TTFF and minimising power requirements.Portable Navigation Devices(PND)chipsets generally merge the satellite information with data from MEMS inertial sensors to provide continuous location information.These chipsets provide a unified platform comprised
323、 of navigation engines,3D positioning capability and motion sensors.The firmware is usually loaded onto the receivers,with the option of being updated when addi-tional features are needed.SBAS corrections from WAAS,EGNOS,MSAS,and GAGAN are normally supported at chipset level and can be used to incre
324、ase positioning accuracy,according to user needs.Products dedicated to other consumer applications such as recreational sailing and general aviation typically benefit from chipsets developed for the PND market,which fully meet their needs.Mass market chipsets can be classified into LBS,IoT and autom
325、otive with different specsFeaturesLBSIoTPNDDimensions15 x 15 x 3 mm7 x 7 x 2 mm10 x 10 x 1.5 mmWeight1.6 g0.5 g1 gTemperature rangeOperating temperature-40 to+85C-40 to+85C-40 to+85CStorage temperature-40 to+105C-40 to+85C-40 to+85CPower supply2.5-3.6 V1.75-1.85 V3.0-3.6 VCurrent consumptionHibernat
326、e10 mA28 uA30 uAAcquisition100 mA56 mA10 mATracking100 mA39 mA8 mANumber of channels80840Time-To-First-FixCold start26 s 35 s 40 sHot start1 s1 s1 sAided starts2 sN/A2.5 sSensitivityTracking&Navigation167 dBm165 dBm159 dBmAcquisition160 dBm146 dBm146 dBmCold start148 dBm130 dBm150 dBmHot start156 dB
327、m130 dBm150 dBmMax navigation update rate5 HzN/A30 HzVelocity accuracy0.05 m/s0.01 m/s0.03 m/sHorizontal position accuracyAutonomous2.5 m1.2 m2 mSBAS2.0 mN/AN/AAccuracy of time pulse signalRMS30 ns30 ns99%60 ns60 nsFrequency of time pulse signal0.25 Hz10 MHzOperational limitsDynamics4 g3 gAltitude50
328、,000 m50,000 mVelocity500 m/s300 m/sDisclaimer:The above specifications are reflecting manufacturers commercial literature.Furthermore,they concern their most recent products.Conse-quently,discrepancies may exist between the installed receivers characteristics and those stated above.Typical state of
329、 the art receiver specifications for the mass market segmentRECEIVER FORM FACTOR34Sensor fusion evolves for a better positioning experienceWith the emergence of the smartphone,theres been an increasing demand for more sophisticated and more accurate LBS applications.In answer to this demand,smartpho
330、nes are increasingly coming equipped with GNSS-complementary technologies that enable them to deliver a per-situation optimised positioning solution.As GNSS remains the main source of outdoor positioning information,these complementary technologies aim to expand the location capabilities in urban ca
331、nyons and indoor environments.Of course this dependency on GNSS alone increases the risks in the event that GNSS signals become unusable.To mitigate this risk,GNSS is oftentimes augmented by sensors(MEMS).With sensors,such inner variables as accelerometer biases,gyro drift and 3D inertial velocity a
332、re estimated by combining inertial navigation system(INS)information with an absolute external source that provides absolute reference information.In addition,some indoor navigation systems rely on Signals of Opportunity(SOOPs)to aid an INS in the absence of GNSS signals,enabling a navigation soluti
333、on with bounded errors.SOOPs are transmitted at a wide range of frequencies and directions,making them an attractive supplement to GNSS signals to improve the accuracy of a navigation solution.An alternative approach involves the use of machine learning techniques.For instance,Simultaneous Location And Mapping(SLAM)algorithms allow a device to develop a consistent map of its environment while simu