Abstract: Theapplicationofanamplitudeandphasemeasurementsystembasedonthespreadingcodesislimitedbytherequirementsofcodeorthogonality.Anamplitudephasemeasurementmethodfordigitalbeamformingnetworkbasedonnonorthogonalcodeswasproposedtoovercomethelimitation.Themainsourceoferrorsinthemeasurementsystemwithnonorthogonalcodeswasmultipleaccessinterference(MAI).Therefore,decorrelatingalgorithmwasproposedtosuppresstheMAIatthecostofincreasingthenoiseslightly.Theoreticalanalysisprovidedthetheorylowerboundoftheamplitudeandphasemeasurementandtheeffectofthesystemerrorandmutualcouplingonthemeasurementaccuracy.Simulationresultsdemonstratethattheaccuracyofthemeasurementsystemwithoutdecorrelatingalgorithmisunacceptable.However,theproposedmethodcansatisfytheaccuracyrequirementsof±01dBand±1degreeundertheconditionsthattheinbandsignaltonoiseratio(SNR)ishigherthan10dB.Moreover,thesimulationresultsareingoodagreementwiththoseoftheoreticalanalysis.

Key words: satellitecommunications, digitalbeamformingnetwork, amplitudephasemeasurement, nonorthogonalcodes, multipleaccessinterference, decorrelatingalgorithm