Abstract: Sofar,computersimulationisthemainevaluationmethodforthecompatibilityperformanceofthesatellitenavigationsignals.Themodelingwasusedtosimulatethemeasuringconditionandstep，butitisimpossibletoreproducetheoperatingconditionoftherealnavigationsystem.Anyparameterchangewillleadtotheresimulation，averylargeamountofcomputationandanalysis，andlargeerrors.Basedonthesatellitenavigationreceiver，thecompatibilityofthenavigationsignalwasstudied.Firstly,themodelwasdeducedbytheratiooftheoutputsignalpowerofinstantcorrugatortothesumofthenoisepowerandtheinterferencepower，accordingtotheeffectoftheinterferencesignalonGNSSreceivercapture，carriertrackinganddataconditioning.Toobtaintheoptimalassessmentoftheinference，theequivalentcarriertonoiseratiomodelwasestablishedbyarelativelysimpleformula，basedonaspectralisolationfactor.Secondly，thepower，theantennagainandtheconstellationpowergainofthenavigationsignalswereanalyzedconcretelywhensignalarrivedatthegroundastheGPSC/Acodeself-disturbed.Finally，theattenuationtestingresultoftheequivalentcarriertonoiseratiowasshownwhentheGPSC/Acodeself-disturbed.Itprovidesreferenceforthesignaldesignofthenewsatellitenavigationsystem.

Key words: Globalsatellitenavigationsystem, Compatibility, Assessment, EquivalentCNR, Spectrumseparationcoefficient