
Free eBook – The Best of the Spirent Blog: Issue One
Spirent’s blog provides up-to-the-minute GNSS receiver testing news, insights and guidance, direct from our in-house experts.
To make this information even easier to access, we’ve now collected it together in a series of free ebooks – issue one is all about the receivers themselves.
Download your copy now for expert advice on topics including:
- GNSS receiver integration
- Running interference in GNSS receivers
- The importance of static navigation accuracy
- The importance of time to first fix
Simply enter a few details opposite to receive your free eBook–and happy reading!
About Spirent
Spirent has been the global leader in GNSS testing for near 30 years. Spirent delivers navigation and positioning test equipment and services to governmental agencies, major manufacturers, integrators, test facilities and space agencies worldwide.
Keep up to date with GNSS receiver testing
with extracts from the Spirent blog.
THE BEST OnullTHE
SnullnullENT BnullOG
FOCUS ON GNSS
RECEIVER TESTING
nullSSnullE null
Welcome to the
Spirent blog article
extraction eBook
nullage nullSPIRENT eBook Blog
We’ve taken all of the best bits regarding GNSS receiver testing fronullthe blog so that nullonull
can have all of this valnullble infornulltion in one nullace in an easnullto read fornulltnull
nullONTENTSnull
GNSS receiver integrationnullnot nullst the snull of the nullrts nullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Rnullning interference in GNSS receivers nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Will all receivers eventnullllnullbe nullnulltinullNSSnull nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
The inullortance of tinull to nullst null nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
The inullortance of static navigation accnullacnullin a GNSS receiver nullnullnullnullnullnullnull nullage null
nullcationnullased services nullt nullessnulle on GNSS receiver nullrfornullnce nullnullnullnull nullage null
nullonullto rednulle the challenge of Gnull integration nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
nullnullstions facing nulldern GNSS develonullrs nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
nullaking the connection in GNSS testing nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Certinullation of GNSS devices nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Test integritnullis essential nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Testing GNSS receivers in a nullodnulltion environnullnt nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
GNSS tests nullthin a nullrodnulltion line environnullnt nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
GNSS test solnullions for a nullrodnulltion line environnullnt nullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Threat of inullort dnullies to increase anulleal of GnullONnullS nullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Whnullare nulle talking abonull nullnulltinullNSSnull nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
Gnull nullderninulltion nullth inullroved civilian signals nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull nullage null
GNSS receiver integrationnull
not nullst the sum of the parts
‘The only guarantee
of continued product
quality and reliable
performance inullnullnull
functional tenulling of
the nullinulled productnull
The abilitnull to integrate a GNSS receiver
into an end nullodnullt offers nenullnullssibilities
for nullnnullactnullers in a nullde range of both
consnuller and indnulltrial nullrketsnull nullonullevernull
designers of snullh nullodnullts need to be anullre
that even the nullst highlnullintegrated GNSS
receiver nulldnulle is not a nullt and forgetnull
conullonentnull null nullth annull radio frenullencnull
snulltenull there are design rnulles that nullst be
follonullednull and even then the interaction of
the receiver nullth the other fnullctions of the
nullodnullt can create sonull snullnullising resnulltsnull
nullthonullh radio frenullencnulldesign is not the
nulllack artnullit nulls once considerednullthe design
rnulles are inevitablnull nullre conulllenull than for
digital designnullEven a slight failnulle to follonull
the rnulles can lead to nullor nullrfornullncenulland
as far as the end nuller is concerned nullclose bnull
no cigarnullis not accenullablenull
Worse stillnull once a design has been
characterised and accenullednullseenullnglnullsnullll
variations in nullnnullactnulling tolerancenull or a
nullrchasing nullnager saving a fenullnullnnies bnull
snullstitnulling a cheanullr conullonent can thronull
the nullrfornullnce right onull the nullndonullnull
The onlnull gnullrantee of continnulld nullodnullt
nullalitnull and reliable nullrfornullnce is nullnull
fnullctional testing of the nullished nullodnulltnullnulld
that nullll nullan integrating a GNSS sinulllator
in the nullodnulltion test setnullnull Fortnullatelnullnull
Snullrent’s nullodnulltion test sinulllators have
been develonulld nullth the denullnds of
nullnnullactnulling in nullnd and snullnullrt singlenull
channel or nullltichannel testing nullth the
nullninullnullof onullrator interventionnull
nullage nullSPIRENT eBook Blog
‘nullonull potential nullourcenull
of interference are
obnullounulland predictablenull
It goes nullthonull sanullng that annullRF device as
sensitive as a GNSS receiver nullll be inherentlnull
vnullnerable to interferencenull Clearlnullnull care
needs to be taken at both the design and
integration stages to nullninullse interference
effectsnullnullnull nullat interference sonullces need to
be considerednullnulld honulldo nullonullknonullif nullonull
receiver can deal nullth thenull
nullost nulltential sonullces of interference are
obvionull and nulledictablenullThe effects of nullednull
frenullencnulltransnulltters for TVnullradio and the
like can easilnullbe nulldelled and acconullted fornull
Indeednullone advantage of nullrking nullth nullltinull
GNSS receivers is that sonull are nullltinullenull
frenullencnull devicesnull and therefore inherentlnull
nullre resistant to interference on annullsnullcinull
frenullencnullnull
nullonullevernullthere are tnull sonullces of interference
that nullonull ignore at nullonull nullrilnull the nullst of
these is internallnull generated interferencenull
and this is nullrticnullarlnull relevant in devices
snullh as locationnullnabled nullbile handsetsnull
The tnullical handset has a transnulltter canullble
of transnulltting nullre than null in vernullclose
nullonullnulltnullto the GNSS receiver nullnd tnull nullnull
even share sonull signalnullath conullonentsnull
Carefnull design nullrtitioning is essential to
nullevent interferencenull
The second is nullre snulltlenullbnull nullll increase
over tinullnull and concerns the increasing
nnullber of constellations and signals conullng
on streanull So sanullnull for enullnulllenull nullonull have
designed nullonull nullltinullNSS receiver to nullrk
nullth both Gnull and GnullONnullSnull and then
the Galileo snulltenullconulls onnullinenullthen the
receiver nullll vienull the nullcorrelated signals
fronull Galileo satellites as interferencenullnullt a
sinulller levelnulla Gnullnullnlnullreceiver nullll vienull
both GnullONnullS and Galileo as interferencenull
In a sinulllar nullnullnull all civilian receivers need
to nullrk in the nullesence of classinulld signals
snullh as Gnull null and nullcodes and Galileo nullSnull
Fortnullatelnullnulleven if nullonullare still nullrking nullth
singlenullNSS receivers then nullonullcan test nullonull
designs for interference fronullother snulltenull
nulling a Snullrent Constellation sinulllator
enullinulled nullth the interference onullionnullnulld
this can even be nulled to sinulllate nullnullnted
GNSS signalsnull
nullage nullSPIRENT eBook Blog
nullunning interference in GNSS receivers
‘Will all receinullrnull
enullntually be nullultinullNSSnull
‘So many factornullthat impact
on receinullr performancenull
That nulls one of the nullestions nullt to nullohn nullottle
nullarketing nullirectornullSnullrent Conullnullicationsnull
nullositioning Gronull bnullCoordinates nullganullnenull
nullonullcan nulld his ansnuller and the Snullrent vienull
on nullnnullother interesting nullestions regarding
fnullnulle GNSS trends and anulllications at the
follonullng linknull
Tinull to nullst null is a crnullial nullrfornullnce
nullranullter for annullsatellite navigation snulltenull
becanulle it is the nullst and nullst easilnull
anullreciated evidence that the end nuller nullll
have of the nullalitnull of the receivernull When
nullonull consider that this anulllies enullallnull to
nulltential nullers trnullng onull receivers in the
shonull and to nullers nullintaining satisfaction
nullth the snulltenull thenullhave bonullhtnullthen a
fenull seconds here and there can nullke the
difference betnulleen a hanullnull cnulltonullr and
one that bnulls nullonull conulletitor’s nullodnulltnull
nullnull honullcan nullonullbe snulle that nullonull receivers
TTFF is onullinullnulled for best nullrfornullncenull
Clearlnullnull onulltest itnullnulld nullonullcan even rnull the
sanull tests on nullonull conulletitor’s nullodnulltsnull
nullnull nullnd here’s the rnullnull be snulle that nullonull
are rnullning enullctlnullthe sanull tests on each
nullece of enullinullentnullThat nullans having the
receivers in the sanull nullsitionnullthe satellites
in the sanull nullsitionnullidentical atnullsnulleric
conditions etc nullothernullse conullarisons are
nullaninglessnull
So nullile the nullrfornullnce nullonullare trnullng to
assess nullll be felt bnull the nuller in the real
nullrldnullthere are so nullnnullfactors that inullact
on receiver nullrfornullnce that it is close to
inullossible to nullke nullaningfnull conullarisons
nulling realnullorld testingnull
Using Snullrent’s constellation sinulllators nullder
controlled laboratornullconditions is the best
nullnullto ensnulle that nullodnullts are tested nullth
a level nullanullng nullldnullWhat’s nullrenullthe abilitnull
to rnull a near innullite nnullber of test scenarios
renullodnullible nullder softnullre control on
nullltinulle receivers nullll nullovide anullle evidence
that nullonull nullodnullts nullll onullnullrfornull the
conulletition nullder all nullnner of conditionsnull
nullage nullSPIRENT eBook Blog
The importance of time to nullst null
‘Extennullnull tenulling of
both the nanullgation
circuitry and the unullr
interface are enullential in
ennullring the nanullgation
accuracy of any nullSS
receinullr denullgnnull
Read on and get nullonull Free conull of the Snullrent
enullok enulllaining honullto nulldertake controlled
testing of nullonull GNSS receiver designnull
Of all the nullrfornullnce nulltrics for a GNSS
receivernullnavigation accnullacnullis nullobablnullthe
nullst inullortantnullnullore to the nullintnullnullnnullint
static navigation accnullacnullis essential to the
end nullernullnulld if he or she doesn’t get the
enullct location null enullected nullen the receiver
is null ered null for the nullst tinullnullthere nullll be
little connullence in the overall nullrfornullnce of
the receivernull
Whether the initial nullnuller testnull takes nullace
in the shonull before nullrchase or at honull
nullen taking a nenullnullit onull of the bonull the
consnuller has a reasonable enullectation that
the GNSS receiver nullll be able to nullrk onull
its start nullsitionnullSo not onlnullnullll he or she
enullect the correct nullnullto be loadednullbnull also
for the nullsition null to be disnullanulled to the
nearest nulltre nullat nullrstnull
nullnullnullstake at this stage and either the nullit
nullll not nullke it onull of the shonullor it nullll be
retnullned for a refnulldnull
Enullensive testing of both the navigation
circnulltrnulland the nuller interface are essential
in ensnulling the navigation accnullacnull of annull
GNSS receiver designnullnulld becanulle there are
snullh a large nnullber of enullernal factors that
can inullact on static navigation accnullacnullnullit is
essential that the tests be nullrfornulld nullder
controlled and renullatable conditions in the
laboratornullnulling a GNSS sinulllatornullOnlnullthis
nullll enable the designer to be snulle that the
design nullll nullrfornull nullonullrlnullnull both nullder
nulldealnullconditionsnulland nullder the innullence of
these enullernal interfering innullencesnull
nullonull can get nullre infornulltion on honull to
nulldertake controlled testing of nullonull GNSS
receiver design bnull donullloading the FREE
enullok fronullSnullrentnull
In this free enulloknullSnullrent enulllains the nullkenull
tests that together deternullne the nullrfornullnce
of annullGnullnullNSS receiversnull
Find onull honulltesting GNSS receivers nullder real
nullrld conditions alone does not gnullrantee
their nullonullr onullrationnullIf nullonull’re designing or
nullnnullactnulling nullocation anullrenullnullodnulltsnullnullonull
need to read thisnull
The importance of static navigation accuracnullin a GNSS receiver
nullage nullSPIRENT eBook Blog
‘Social netnullrknulloffering
nullnd a friendnullapplicationnull
The addition of Gnull receivers to todanull’s
snullrtnullonesnull netbooks and other internet
enabled devices is allonullng nullbile onullrators
and other service nulloviders to enullloit a
gronullng nullrket for locationnullased servicesnull
These can range fronullsocial netnullrks offering
nullnd a friendnullanulllicationsnullto location based
nullrketing and advertisingnullnulld nullonullcan be
snulle that develonullrs nullll conull null nullth nullnnull
nullre nenullanulllications for location data as
the nullrket nulltnullesnull
Regardless of the natnulle of the servicenullall
locationnullased services nullt GNSS receiver
nullrfornullnce at a nullenullnullnull
nullter allnullthere is no nullint in giving a nuller
a nullbile conullon for a bnulliness thenullnullssed
nullst ten seconds agonulland telling thenullthenull
are standing nullthin null nulltres of it nullen thenull
can clearlnullsee thenullare nullnullnulltres anullnullnullthis
is hardlnulllikelnullto endear thenullto annullservicenull
While assisted Gnull can nullanull a role in the
enullationnull onullratornullndenullndent locationnull
based services relnullnullrelnullon the nullrfornullnce
of the GNSS receiver in the nuller’s enullinullentnull
The gronullh of snullh services nullans that it
is nonulleven nullre inullortant to ensnulle that
nullonull GNSS receiver design delivers the best
nullssible nullrfornullnce nullder all onullrating
conditionsnull
nullave nullonullbeen tasked nullth the integration
of Gnull nullr GnullONnullSnullchinull into a nullodnullt or
snulltenull If so nullonullnullll be facing a nnullber of
challengesnull
nullSelecting nullich chinullet or nulldnulle to nulle
null Ensnulling that the tinnull RF signals are
getting thronullh
nullEvalnullting the nullrfornullnce
null nullesigning for test and nullnnullactnullabilitnull
nullilst nulloviding ranulld tinull to nullrketnull
nullonull nullst stenullshonulld be to consider nullat
characteristics nullonull need in nullonull receivernull
thenull are NOT all the sanullnull For enullnullle a
receiver designed for high accnullacnullnullnullnot
be onullinullsed for a ranulld startnullnullnullnullok at the
nullnnullactnullers’ datasheets and nullonullnullll nulld
that thenullare often difnullnullt to conullare nulling
slightlnulldifferent nullranullter denullitionsnull
Testing the nullits nullonullself nullnull be the onlnull
nullnull to get a trnullnull accnullate and directlnull
conullarative set of resnullts and renullated
testing nullder identical test conditions is a nullb
for a GNSS constellation sinulllatornull
nullaving identinulld the receiver nullonull nullsh to
nullenullthe nenull challenge is obtaining the sanull
nullrfornullnce nullonullobserved on the evalnulltion
boardnullbnull in nullonull circnulltnullOnce againnullGNSS
sinulllation nullovides a controllablenullrenullatable
testnullnullnullissnulls that arise dnulling this stage
can often be resolved bnull sharing the test
scenario nullth nullonull chosen vendornullScenarios
are nullrtable betnulleen Snullrent nullchines so
nullovided nullonull vendor has a Snullrent sinulllator
nullnd nullst donull nulloblenull resolnullion can be
signinullantlnullfastnull
Finallnullnull nullonull need to denulle a baseline
nullrfornullnce that can be nulled for
nullnnullactnulling and regression testingnull Once
again the control and renullatabilitnull asnullcts
of the GNSS sinulllator are null erfnull allies in
this tasknull
In snullnullrnullnullif nullonullfollonullthese nullstenull nullonull’ll
sleenullnullre nullacefnulllnull
null Choose nullonull vendor after consideration
of the cost and nullrfornullnce tradenullffs
offerednull nullerfornull an evalnulltion nullonullselfnull
Connullnullthenullnulle a GNSS sinulllator so that
nullonullcan share tronulllesonull scenariosnull
null nullevelonull nullonull circnullt and lanullonull nullth
consideration for RF losses and interference
sonullcesnull Connullnull onullration nulling nullonull
GNSS sinulllatornull
null nullenulle a baseline nullrfornullnce that shonulld
be obtainable in nullodnulltion testingnull null
controllednullrenullatable test nulling a GNSS
sinulllator allonull ranulld evalnulltion of
changes in the Gnull nullnullnull nullnullarenull or
snullronullding circnulltrnullnullnullnull WiFinullnulllnulltoothnull
board lanullonull etcnull
nullage nullSPIRENT eBook Blog
How to reduce the challenge of Gnull integration
nullcationnullased services put pressure on GNSS receiver performance
In the nullstnull designers of satellitenullased
navigation snulltenull have been nullstlnull
restricted to nulling a single snulltenull and
servicenullthe Gnull Cnull codenull
The cnullrent revolnullion in the indnulltrnullis giving
rise to not onlnull nenull GNSS snulltenullnull sonull
GNSS snulltenullnullnotablnullGnull and Galileonullhave
nullltinulle services available to the conullercial
GNSS designernullThe nullestion of nullich snulltenull
or blend of snulltenull a GNSS designer shonulld
considernullalong nullth the nulltential for nullltinulle
services is thnull an entirelnullnenullconsiderationnull
The anulllication of the receiver nullder
develonullent nullnulldenulle the ansnuller to this
nenullconnulldrnull to sonull enullentnullbnull in nullnnull
cases the onlnullnullnullto ansnuller the nullestion
fnulllnullbefore conullitting to a nullrticnullar design
nullth is to investigate the onullions available
nulling a GNSS sinulllatornull
While nullestions snullronullding the nullre
accnullacnullof annullgiven receiver nulling either one
or nullltinulle GNSS snulltenull or services need
to be ansnullerednullthere are also a nullltitnulle
of associated nullestions regarding device
nullrfornullncenull snullh as null er consnullnullionnull
interfacenull nullltinullth and interference
resistance etcnullthat also need to be ansnullerednull
The availabilitnull of nullltinullrenullencnullnull nulllti
snulltenull nulllti service GNSS sinulllators
allonull the GNSS develonullr to ansnuller these
nullestions nullth conulllete connullence in the
nullal design choicenull
Fnullthernullrenull the sinulllator is invalnullble in
the actnulll design effort and integration of the
receiver into a given anulllicationnull
Find onull nullre abonull honullSnullrent sinulllators can
helnullnullonullbnulldonullloading the Snullrent enulloknull
Integrating a GNSS Receiver into a nullrodnullt
nullesignnull httnullnullnullnullnullnullrentnullonullWhitenullanullrsnull
nullositioningnullnulloksnullntegratingnullnullNSSnull
Receivernullntonullnullrodnulltnullesignnullnulloknullsnull
nullage nullSPIRENT eBook Blog
nulluestions facing modern GNSS developers
‘nullonulldo the nullgnalnullget from
the nullSS nullmulator to the
denullce under tenullnull
One nullestion that regnullarlnull cronull null in
discnullsions abonull GNSS receiver testing
concerns enullctlnullhonullthe signals get fronullthe
GNSS sinulllator to the device nullder testnullIs it
better to radiate the sinulllator signal to the
receiver’s antennanullor shonulld nullonullconullle thenull
directlnull
The short ansnuller to this is that a direct
connection fronullthe sinulllator to the receiver’s
antenna nullrt nullll alnullnull nullovide the nullst
controlled test environnullnt nullth no risk of
onullside innullencenull
The connection is nullnullllnull nullrfornulld nulling
a sinullle coanullal cable that acts as a null
ohnulltransnullssion linenullor it nullnullrenullire the
addition of a lonullnoise anulllinullr in cases
nullere the receiver is designed to nulle an
active antennanull
In either casenullnullking the direct connection
null alnullnull nulling highnullnulllitnull cables and
conullonents nullnullll enable all tests to be nullde
nullder controlled conditionsnull
Of conullsenull sonull tnulles of locationnullnabled
enullinullent have no enullernal antenna nullrtnull
and in nullnnull cases the antenna is entirelnull
hidden fronull vienullnull So here nullacticalitnull
dictates that a radiated signal nullst be nullednull
This doesnull honullevernull leave the test setnull
onulln to all nullnner of onullside interferencenull
and this can nullke resnullts nullreliablenullSo for
fnulll connullence in the resnullts of the test nulle
reconullend nulltting the enullinullent nullder test
inside an RF screened enclosnulle together nullth
the radiating antenna fronullthe sinulllatornull
nullanullng the connection in GNSS testing
‘Nenull
performance
nullandardnullare
being nullittennull
Traditionallnullnullcivilian nulle of Gnull nulls seen as
free and to a large enullent nullat nullonull onull risknull
The tnullical nullrfornullnce one nullght enullect
nulls stated in the relevant Interface Control
nullocnullents nullCnullsnull bnull no gnullrantee of
service nulls givennullThe reason for this nulls the
historical renullt of Gnull as a snulltenullto satisfnull
US nulllitarnullrenullirenullntsnullthe civilian nulle of
the coarse acnullisition nullnullnull ranging code
being essentiallnulla bnullnullodnullt of its nullinullrnull
nullenullnullich nulls to nullovide classinulld receivers
a nullrst stenull’ tonullrds fast acnullisition of the
nullecise nullnullnullnull codenull
With the increasing nnullber of GNSS services
that nullll offer certain gnullrantees of service
schednulled to be available over the conullng
nullearsnullthere is an increasing renullirenullnt for
certinullation of these services and the GNSS
devices that nulle thenull
To facilitate these renullirenullntsnull nenull
nullrfornullnce standards are being nullitten
nullich are dictating the tests to be nullrfornulldnull
nullage nullSPIRENT eBook Blog
nullrtinullation of GNSS devices
nulll nullonullr testing nullst have good integritnullnull
that’s a givennullhonullevernullit is esnullciallnullso nullth
certinullationnull verinullation and tnulle anullroval
testingnull nullrticnullarlnull nullen the device and null
or anulllication is safetnullcriticalnullThis is nullnull
nulling nullantinullblenull traceable and accnullate
test nullthods are inullortantnullnullccredited test
laboratories nulle nullecision test enullinullent
nullich is calibrated to standards traceable
to National references for all certinullation
and tnulle anullroval testingnull The sanull nullst
therefore anulllnullto GNSS testingnullThis is nullnull
nulling calibrated nullecision RF constellation
sinulllators is the onlnull nullnull to nullrfornull this
kind of testingnullThe inherent nullcertaintnulland
variabilitnullof nulling other nullthods nullnullh as
real GNSS signalsnullrnulles thenullonull conullletelnullnull
Snullrent’s nulldigree in nullodnulling highnulldelitnullnull
nullecision test enullinullent is nullell nulloven over
nullre than null nullearsnull Snullrent has snullnullied
enullinullent into critical test nullogranulles
across the nullrldnullThis enullinullent has often
been nullt thronullh rigoronull certinullation and
validation nullogranulles to ensnulle thenull are
thenullelves null for certinullation testingnull The
nullst recent enullnullles of this arenull
null The certinullation bnull the Enullonullan Snullce
nullencnull and Galileo Snullervisornull nullnullhoritnull
of the nullrld’s nullst Galileo RF constellation
sinulllator for the Gronulld Receiver Chain
nullRCnulland Test User Segnullnt nullTUSnullreceiver
develonullents in the IOV nullase of the
Galileo nullogranullenull
null The certinullation of Snullrent’s GnullONnullS
inulllenullntation bnullthe Rnullsian anullhorities
Sonullto ensnulle nullonull testing is null to standardnull
nullke snulle nullonull select test enullinullent fronull
Snullrentnullthe nullrld’s leading and nullst nulloven
sinulllator nullovidernull
Test integritnullis essential
nullannullactnullers of consnuller nullodnullts ronullinelnull
nullrfornullfnullctional testing on all nullodnulltion
onullnulltnulland it nullnulld anullear that adding sonull
fornullof location testing to these nullodnulltion
test ronullines nullnulld be snullnullient to verifnull
the reliabilitnullof the GNSS receiver nullthin the
end nullodnulltnullnullonullevernullit is all too easnullto
adonull the attitnulle that the sinulllest of tests
nullll snullnulle nullnullrticnullarlnullnullen the dnullation
of each test can have a signinullant inullact on
nullodnulltivitnullnull
nullthonullh it nullnullbe the case that all the other
fnullctions of the end nullodnullt can be assessed
nullth a relativelnullstraightfornullrd gonullonullo testnull
taking snullh an attitnulle nullth a GNSS receiver is
franullht nullth dangernullThe end nuller nullll enullect
the nullodnullt to nullrfornulladenullatelnullnullder a
nullde varietnullof conditionsnullThis nullans that
the receiver nullll need to be tested not nullst
for an nulldealnullsitnulltionnullbnull also for adenullate
nullrfornullnce in the nullesence of nullltinullth
interferencenullall nullnner of nullnulling signals
and less than ideal atnullsnulleric conditionsnull
Kenulltest challenges
in a nullroduction line
environment
The nullst obstacle that nullll be enconulltered
in integrating GNSS receiver testing into a
nullodnulltion test setnull is nullettnull obvionullnullnull
snullh tests are nullrfornulld at the end of the
nullodnulltion linenullthenullare inevitablnullnullrfornulld
indoorsnull nulld regardless of nullether the
enullinullent is designed to nullrk indoors or
onulldoorsnullthe roof and nulllls of the bnulllding
nullll introdnulle variables into the test that
nullll negate its effectivenessnullSonullalled nullivenull
sknullnulltesting is therefore inullossible nullthonull
relanullng the GNSS signals fronullonulldoors to
the nullodnulltion testernull
It is a relativelnullsinullle enullercise to canullnulle live
GNSS signals and renulladiate thenullnullthin the
nullodnulltion test environnullntnull nullonullevernull this
conulls nullth its onull set of shortconullngsnull
Firstnull radiating annull signal in snullh an
environnullnt nullght have nullforeseen
consenullences on other tests that are
nullrfornulld on the nullodnulltnull and converselnullnull
other RF signals and noise nullthin the
nullodnulltion test area nullnullnullell inullact on the
integritnullof the GNSS signalsnull
nullore inullortantlnullnull thonullhnull the inherentlnull
dnullanullc natnulle of GNSS signals nullans that
nullile each nullit nullnull nullell be tested in the
sanull nullnullical location nullnullnullin the nullodnulltion
tester nulltnullenull the relative nullsitions of the
GNSS satellites nullll be different for evernull
nullit testednullnulldnullnot snullnullisinglnullnullthis nullkes
direct conullarison betnulleen resnullts nullreliable
at bestnull
Continued...
nullage nullSPIRENT eBook Blog
Testing GNSS receivers in a production environment
‘Tenullnulltypically performed
on any nanullgation denullce are
inherently complexnull
GNSS tests within
a nullroduction line
environment
In order to fnulllnullassess the nullrfornullnce of
a GNSS receiver enulledded in annull nullece
of enullinullentnull it is inullortant to nullrk onull
enullctlnullnullat resnullnse is renullirednullThere nullll
be varnullng degrees of nullrfornullnce renullirednull
denullnding on the end anulllicationnull bnull the
renullirenullnt nullll be for a conullination of
navigational accnullacnull and sensitivitnull nullder
a nullde range of onullrational conditionsnull
There nullll also be a renullirenullnt for the
enullinullent to nullrk nullth not nullst the enullsting
Global nullositioning Snulltenull bnull also nullth the
forthconullng enhanced Gnullnull GnullONnullS and
Galileo snulltenull at the vernullleastnull
Sonull snulltenull nullnull have no direct onullnulltnull
Ornullnullre to the nullintnullthe onullnullt nullnullonlnull
be in the fornullof an alarnullor trigger that is
snullnullsed to be nullodnulled nullth nullonullnulltnullto
certain conullrdinatesnull
This does not honullever nullan that the
nullrfornullnce denullnds on the receiver are annull
less ardnullnullnullIt nullnulld honullevernulldictate the
nullssnullail criteria for the nullodnulltion testnull
GNSS test solutions
for a nullroduction line
environment
Given the inherent variabilitnullof annulltnulle of
livenullknulltestingnullit is logical to seek a nullre
nullecise and renullatable stinulllnull against
nullich the nullrfornullnce of an enulledded
GNSS receiver can be assessednullnulld this can
be snullnullied in the fornullof a GNSS sinulllatornull
null nullltichannel nullltinullNSS sinulllator
nullder softnullre control can nullodnulle all the
necessarnullsignals renullired to test the relevant
nullrfornullnce criteria of annullenulledded GNSS
receiver in annull locationnullnabled devicenull
nullost inullortantlnullnull it can do so consistentlnull
and renullatablnullfor evernullnullit to be testednull
ensnulling that nullnnullactnulling onullnullt is nullnull
null for nullrnullsenull
The tests tnullicallnull nullrfornulld on annull
navigation device are inherentlnull conulllenull
covering the fnulll range of nullrfornullnce criteria
fronullnavigational accnullacnulland sensitivitnullto
acnullisition tinull and inullnullitnullto interferencenull
These tests have been designed to ensnulle
the nullrfornullnce of dedicated GNSS receiversnull
and have been nulloved over snullcessive
generations of nullrsonal navigation devicesnull
Fortnullatelnullnull once the desired nullrfornullnce
of the design has been characterisednull the
nullodnulltion tests for the end nullodnullt can be
renulled into a considerablnull snullller set of
accenullance criteria that can be nullrfornulld in
a relativelnullshort tinull nulls little as nullnullnnullesnull
The Snullrent GSSnullnull nullnulltinullNSS Signal
Generator has been designed snullcinullallnull
for high volnulle nullodnulltion test anulllications
for devices that nulle conullercial GnullnullnullSnull
GnullONnullS andnullr Galileo receiversnull Visit onull
video librarnullto nulld onull nullre on honullSnullrent
can helnullnull
nullage nullSPIRENT eBook Blog
‘Three more nullnullnullSS
null nulltellitenullare
nullheduled for launchnull
The Rnullsian Federation has conull null nullth
fnullther nullenconullagenullntnull for nullnnullactnullers
to snullnullrt the GnullONnullS satellite navigation
snulltenull nullth the threat of inullort dnullies to
be levied on annull nullbile handsets nullthonull
GnullONnullS fnullctionalitnullnull enulltnullnullrinull nullinister
Sergei Ivanov has revealed that the dnullnullnullll
be nullabonull nullnullnullnullll be introdnulled bnullnullnull
and nullll be levied on handsets inullorted
to the Rnullsian Federation nullth Gnullnullnlnull
nullsitioning technolognullnull
Three nullre GnullONnullS null satellites are
schednulled for lanullch bnull the end of nullnullnull
allonullng Rnullsia to onullrate a conulllete
GnullONnullS netnullrk nullth global coverage and
have three or fonull satellites in reservenullnull fnullther
eight satellites nullll be lanullched betnulleen nullnull
and nullnull to enable fnullther rednulldancnulland
to renullace sonull of the earlier satellites that
are reaching their end of lifenullnulll this nullll be
added to the investnullnt of over USnull billion
over the nullst null nullearsnullnullich enulllains nullnull
Rnullsia is so keen to see GnullONnullS adonulled
both nullthin its onull borders and in the nullrld
at largenull
nullannullactnullers of nullbile handsets and other
locationnullased technologies can nullrk on their
nullltinullNSS designs todanullfeatnulling Gnull and
GnullONnullS canullbilities nulling Snullrent’s range of
constellation sinulllatorsnullThis also enullends to
coverage of the Galileo and Conullass snulltenullnull
long in advance of their nullnullical lanullchesnull
Threat of import duties to increase appeal of GnullONnullS
Todanullnullnavigation and nullsitioning technolognull
is no longer nullst abonull Gnull null Cnull codenull
Gnull is being nullderninullednull the GnullONnullS
constellation is nearlnullconullletenullnenullsnulltenull
inclnulling nullSSnullIRNSSnullGalileo and Conullass
are on the nullnullnull
nullnulltinullNSS offers signinullant onullortnullities
and challenges to GNSS technolognullnullsnulltenull
and anulllication develonullrsnull
Snullrent nullltinullNSS sinulllation snulltenull
are nonull being nullrchased bnull cnulltonullrs
develonullng conullercial snulltenull and nullst
chinullet nullnnullactnullers have nullans to release
dnulll constellation chinullets before the end of
nullnullnull
If nullonull haven’t alreadnull done sonull check onull
this conullrehensive article in Inside GNSS
nullganullne on nullnulltinullNSS testing fronull the
Rnull stage thronullh IntegrationnullValidation to
nullrodnulltion
Testing nullnulltinullNSS enullinullentnull Snulltenullnull
Sinulllators and the nullrodnulltion nullnullanulld
As new GNSS systems appear, the time for
multi-GNSS simulator testing has arrived.
Three receiver designers and researchers
look at use of this essential tool throughout
the entire receiver development cycle: from
research, development, design and validation
through chip, module, nullnulland user device
development senullences and on to consumer
testing, certinullation, maintenance and repair.
http:nullwww.insidegnss.comnullodenullnullnull
nullage nullSPIRENT eBook Blog
nullnullare we talnullng about nullultinullNSSnull
‘Todaynullnanullgation
and ponulltioning technology
inullno longer nullnull about
nullS null nullnullcodenull
In addition to the nenullsignals to be broadcast
nullder the Gnull nullderninulltion nullonullctnullthere
are to be tnull signinullant changes to the
enullsting civilian signalsnull both designed to
inullrove the nullrfornullnce of Gnull receiversnull
The nullst is an additional datanullree nulllot signal
and the second is the addition of fornullrd error
correction nullECnullencoding to the navigation
nullssagenull
The nenull datanullree signal nullll be broadcast
alongside the nornulll data signalnullacting as
an easnulltonullcnullire nulllot signalnullOnce acnullired
bnulla Gnull receivernullthe nulllot signal nullll be nulled
to acnullire the data signalnullThis nenullschenull
nullll inullrove the acnullisition of the Gnull signal
and boosts nullnuller levels at the correlatornull
The second inullrovenullntnull the addition of
fornullrd error correction encoding to the
navigation nullssagenull is designed to nullke
the overall Gnull signal nullre robnulltnullThis is
becanulle the navigation nullssage is broadcast
at snullh a lonulldatanullate nullronulld nullbitnullnullthat
even a snullll interrnulltion to the signal can
have a signinullant effect on the recenullion of
the nullssagenull
The fornullrd error correction nullrks bnulladding
snulltenullticallnullgenerated rednulldant data nullr
errornullorrecting codenull to the nullssagenull The
carefnulllnull designed rednulldancnull allonull the
receiver to detect and correct a linullted nnullber
of errors occnullring annullhere in the nullssage
nullthonull the need to receive additional datanull
nullesigners of GNSS enullinullent can nullenullre for
Gnull nulldernisation bnullsinulllating all the nenull
signals todanullnulling Snullrent’s range of GNSS
sinulllatorsnull Not onlnull do these instrnullents
alreadnullcover all the nenulland enhanced signals
that nullll be nullovided bnullthe nulldernised Gnull
constellationnullthenullalso cover all signals for
the GnullONnullS and Galileo GNSSs as nullell as
the regional and local anullnullntation snulltenullnull
nullage nullSPIRENT eBook Blog
Gnull moderninulltion with improved civilian signals
‘The nenulldatanullree
nullgnal nullll be broadcanull
alongnullde the normal
data nullgnalnull
Spirent nullmmunications
nullnullnullnull nullnullnull
globalsalesnullnullrentnullonull
nullnullnullnullrentnullonullnullsitioning
Spirent nullederal Snulltems
null nullnullnullnullnullnull
infonullnullrentfederalnullonull
nullnullnullnullrentfederalnullonull
nullnullnot share this documentnull
nullisit the Spirent GNSS blog
nullnullnullnullrentnullonullnulllognullositioningnullsnull
Facebook nullnkedIn Tnulltter Technorati Google null
nulligg nullelicionull Reddit Stnullblenullon
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