SIST EN 300 961 V7.0.2:2003

Digital cellular telecommunications system (Phase 2+) (GSM); Full rate speech; Transcoding (GSM 06.10 version 7.0.2 Release 1998)

SUBJECT Addition of mu-law (PCS 1900).

Digitalni celični telekomunikacijski sistem (faza 2+) – Govor s polno hitrostjo – Prekodiranje (GSM 06.10, različica 7.0.2, izdaja 1998)

General Information

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI EN 300 961 V7.0.2 (1999-12) - Digital cellular telecommunications system (Phase 2+) (GSM); Full rate speech; Transcoding (GSM 06.10 version 7.0.2 Release 1998)

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital cellular telecommunications system (Phase 2+) (GSM); Full rate speech; Transcoding (GSM 06.10 version 7.0.2 Release 1998)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 300 961 Version 7.0.2SIST EN 300 961 V7.0.2:2003en01-december-2003SIST EN 300 961 V7.0.2:2003SLOVENSKI
STANDARD



SIST EN 300 961 V7.0.2:2003



ETSIEN300961V7.0.2(1999-12)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);Fullratespeech;Transcoding(GSM06.10version7.0.2Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)2(GSM06.10version7.0.2Release1998)ReferenceREN/SMG-110610Q7(8wc03i1c.PDF)KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSIPostaladdressF-06921SophiaAntipolisCedex-FRANCEOfficeaddress650RoutedesLucioles-SophiaAntipolisValbonne-FRANCETel.:[phone]Fax:[phone]SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/[e-mail]ETSIdeliverablecanbedownloadedfromhttp://www.etsi.orgIfyoufinderrorsinthepresentdocument,sendyourcommentto:[e-mail]Ideliverablemaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshouldbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.CopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute1999.Allrightsreserved.SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)3(GSM06.10version7.0.2Release1998)ContentsIntellectualPropertyRights.6Foreword.61Scope.81.1References.81.1.1Abbreviations.91.2Outlinedescription.91.3Functionaldescriptionofaudioparts.91.4PCMFormatconversion.101.5PrinciplesoftheRPE-LTPencoder.101.6PrinciplesoftheRPE-LTPdecoder.111.7Sequenceandsubjectiveimportanceofencodedparameters.112Transmissioncharacteristics.142.1Performancecharacteristicsoftheanalogue/digitalinterfaces.142.2Transcoderdelay.143FunctionaldescriptionoftheRPE-LTPcodec.143.1FunctionaldescriptionoftheRPE-LTPencoder.143.1.1Offsetcompensation.153.1.2Pre-emphasis.153.1.3Segmentation.153.1.4Autocorrelation.153.1.5SchurRecursion.163.1.6TransformationofreflectioncoefficientstoLog.-AreaRatios.163.1.7QuantizationandcodingofLog.-AreaRatios.163.1.8DecodingofthequantizedLog.-AreaRatios.173.1.9InterpolationofLog.-AreaRatios.173.1.10TransformationofLog.-AreaRatiosintoreflectioncoefficients.173.1.11Shorttermanalysisfiltering.173.1.12Sub-segmentation.183.1.13CalculationoftheLTPparameters.183.1.14Coding/DecodingoftheLTPlags.183.1.15Coding/DecodingoftheLTPgains.183.1.16Longtermanalysisfiltering.193.1.17Longtermsynthesisfiltering.193.1.18WeightingFilter.193.1.19AdaptivesampleratedecimationbyRPEgridselection.203.1.20APCMquantizationoftheselectedRPEsequence.203.1.21APCMinversequantization.213.1.22RPEgridpositioning.223.2Decoder.223.2.1RPEdecodingsection.223.2.2LongTermPredictionsection.223.2.3Shorttermsynthesisfilteringsection.223.2.4Post-processing.224Codechoming.264.1Functionaldescription.264.2Definitions.264.3Encoderhoming.274.4Decoderhoming.274.5Encoderhomestate.284.6Decoderhomestate.285ComputationaldetailsoftheRPE-LTPcodec.285.1Datarepresentationandarithmeticoperations.285.2FixedpointimplementationoftheRPE-LTPcoder.30SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)4(GSM06.10version7.0.2Release1998)5.2.0Scalingoftheinputvariable.315.2.1Downscalingoftheinputsignal.315.2.2Offsetcompensation.315.2.3Pre-emphasis.315.2.4Autocorrelation.325.2.5Computationofthereflectioncoefficients.325.2.6TransformationofreflectioncoefficientstoLog.-AreaRatios.335.2.7QuantizationandcodingoftheLog.-AreaRatios.345.2.8DecodingofthecodedLog.-AreaRatios.345.2.9Computationofthequantizedreflectioncoefficients.345.2.9.1InterpolationoftheLARpp[1.8]togettheLARp[1.8].345.2.9.2Computationoftherp[1.8]fromtheinterpolatedLARp[1.8].355.2.10Shorttermanalysisfiltering.355.2.11CalculationoftheLTPparameters.365.2.12Longtermanalysisfiltering.375.2.13Weightingfilter.375.2.14RPEgridselection.385.2.15APCMquantizationoftheselectedRPEsequence.385.2.16APCMinversequantization.395.2.17RPEgridpositioning.395.2.18Updateofthereconstructedshorttermresidualsignaldp[-120.-1].405.3FixedpointimplementationoftheRPE-LTPdecoder.405.3.1RPEdecodingsection.405.3.2Longtermsynthesisfiltering.405.3.3Computationofthedecodedreflectioncoefficients.415.3.4Shorttermsynthesisfilteringsection.415.3.5De-emphasisfiltering.425.3.6Upscalingoftheoutputsignal.425.3.7Truncationoftheoutputvariable.425.4TablesusedinthefixedpointimplementationoftheRPE-LTPcoderanddecoder.436Digitaltestsequences.446.1Inputandoutputsignals.446.2Configurationfortheapplicationofthetestsequences.446.2.1Configuration1(encoderonly).456.2.2Configuration2(decoderonly).456.3Testsequences.466.3.1Testsequencesforconfiguration1.466.3.2Testsequencesforconfiguration2.466.3.3AdditionalTestsequencesforCodecHoming.506.3.3.1Codechomingframes.506.3.3.2Sequenceforanextensivetestofthedecoderhoming.506.3.3.3Sequencesforfindingthe20msframingoftheGSMfullratespeechencoder.506.3.3.4Formatsandsizesofthesynchronizationsequences.51AnnexA(informative):Codecperformance.53A.1PerformanceoftheRPE-LTP.53A.1.1Introduction.53A.1.2Speechperformance.53A.1.2.1Singleencoding.53A.1.2.2Speechperformancewheninterconnectedwithcodingsystemsonananaloguebasis.54A.1.2.2.1Performancewith32kbit/sADPCM(G.721,supersededbyG.726).54A.1.2.2.2PerformancewithanotherRPE-LTPcodec.54A.1.2.2.3PerformancewithencodingotherthanRPE-LTPand32kbit/sADPCM(G.721,supersededbyG.726).54A.1.3Non-speechperformance.55A.1.3.1Performancewithsinglesinewaves.55A.1.3.2PerformancewithDTMFtones.55A.1.3.3Performancewithinformationtones.55A.1.3.4Performancewithvoice-banddata.55SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)5(GSM06.10version7.0.2Release1998)A.1.4Delay.55A.1.5Bibliography.57A.2Subjectiverelevanceofthespeechcoderoutputbits.57A.3Formatfortestsequencedistribution.59A.3.1Typeoffilesprovided.59A.3.2Fileformatdescription.60AnnexB(informative):Testsequencedisks.62AnnexC(informative):ChangeRequestHistory.63History.64SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)6(GSM06.10version7.0.2Release1998)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinSR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinSR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbytheSpecialMobileGroup(SMG).Thepresentdocumentspecifiesthefullratespeechtranscodingwithinthedigitalcellulartelecommunicationssystem.NOTE:ThepresentdocumentisareproductionofrecommendationT/L/03/11"13kbit/sRegularPulseExcitation-LongTermPrediction-LinearPredictiveCoderforuseinthedigitalcellulartelecommunicationssystem".Archive 8wc03i1c.ZIP which accompanies the present document, contains test sequences, as described in clause 6 andannexA.3.Thearchivecontainsthefollowing:Disk1.zipAnnexB:TestsequencesfortheGSMFullRatespeechcodec;TestsequencesSEQ01.xxxtoSEQ05.xxx.(Disk1.zipcontainsLHAcompressedfiles.)Disk2.zipAnnexB:TestsequencesfortheGSMFullRatespeechcodecwithhomingframes;TestsequencesSEQ01H.*toSEQ02H.*.Disk3.zipAnnexB:TestsequencesfortheGSMFullRatespeechcodecwithhomingframes;TestsequencesSEQ03H.*toSYNC159.COD.Disk4.zipAnnexB:8bitA-lawtestsequencesfortheGSMFullRatespeechcodecwithandwithouthomingframes(Disk4.zipcontainsself-extractingfiles).Disk5.zipAnnexB:8bitµ-lawtestsequencesfortheGSMFullRatespeechcodecwithandwithouthomingframes(Disk5.zipcontainsself-extractingfiles).SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)7(GSM06.10version7.0.2Release1998)ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocumentitwillbere-releasedwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7indicatesRelease1998ofGSMPhase2+xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthisEN:3December1999DateoflatestannouncementofthisEN(doa):31March2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2000DateofwithdrawalofanyconflictingNationalStandard(dow):30September2000SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)8(GSM06.10version7.0.2Release1998)1ScopeThetranscodingprocedurespecifiedinthepresentdocumentisapplicableforthefull-rateTrafficChannel(TCH)inthedigitalcellulartelecommunicationssystem.Theuseofthistranscodingschemeforotherapplicationshasnotbeenconsidered.InGSM06.01,areferenceconfigurationforthespeechtransmissionchainofthedigitalcellulartelecommunicationssystemisshown.Accordingtothisreferenceconfiguration,thespeechencodertakesitsinputasa13bituniformPCMsignaleitherfromtheaudiopartofthemobilestationoronthenetworkside,fromthePSTNviaan8bit/A-orµ-law(PCS1900)to13bituniformPCMconversion.TheencodedspeechattheoutputofthespeechencoderisdeliveredtoachannelencoderunitwhichisspecifiedinGSM05.03.Inthereceivedirection,theinverseoperationstakeplace.Thepresentdocumentdescribesthedetailedmappingbetweeninputblocksof160speechsamplesin13bituniformPCMformattoencodedblocksof260bitsandfromencodedblocksof260bitstooutputblocksof160reconstructedspeechsamples.Thesamplingrateis8000sample/sleadingtoanaveragebitratefortheencodedbitstreamof13kbit/s.Thecodingschemeistheso-calledRegularPulseExcitation-LongTermprediction-LinearPredictiveCoder,here-afterreferredtoasRPE-LTP.ThepresentdocumentalsospecifiestheconversionbetweenA-andµ-law(PCS1900)PCMand13bituniformPCM.Performancerequirementsfortheaudioinputandoutputpartsareincludedonlytotheextentthattheyaffectthetranscoderperformance.Thepresentdocumentalsodescribesthecodecdowntothebitlevel,thusenablingtheverificationofcompliancetothepresentdocumenttoahighdegreeofconfidencebyuseofasetofdigitaltestsequences.Thesetestsequencesaredescribedandarecontainedinarchive8wc03i0o.ZIPwhichaccompaniesthepresentdocument.1.1ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.•Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.•Foraspecificreference,subsequentrevisionsdonotapply.•Foranon-specificreference,thelatestversionapplies.•Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.•ForthisRelease1998document,referencestoGSMdocumentsareforRelease1998versions(version7.x.y).[1]GSM01.04:"Digitalcellulartelecommunicationssystem(Phase2+);Abbreviationsandacronyms".[2]GSM05.03:"Digitalcellulartelecommunicationssystem(Phase2+);Channelcoding".[3]GSM06.01:"Digitalcellulartelecommunicationssystem(Phase2+);Fullratespeech;Processingfunctions".[4]GSM11.10:"Digitalcellulartelecommunicationssystem(Phase2+);MobileStation(MS)conformityspecification".[5]ETS300085:"IntegratedServicesDigitalNetwork(ISDN);3,1kHztelephonyteleservice;Attachmentrequirementsforhandsetterminals(CandidateNET33)".[6]ITU-TRecommendationG.711:"Pulsecodemodulation(PCM)ofvoicefrequencies".[7]ITU-TRecommendationG.712:"Transmissionperformancecharacteristicsofpulsecodemodulation".SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)9(GSM06.10version7.0.2Release1998)[8]ITU-TRecommendationG.726:"40,32,24,16kbit/sadaptivedifferentialpulsecodemodulation(ADPCM)".[9]ITU-TRecommendationQ.35:"Technicalcharacteristicsoftonesforthetelephoneservice".[10]ITU-TRecommendationV.21:"300bitspersecondduplexmodemstandardizedforuseinthegeneralswitchedtelephonenetwork".[11]ITU-TRecommendationV.23:"600/1200-bandmodemstandardizedforuseinthegeneralswitchedtelephonenetwork".[12]GSM06.32:"Digitalcellulartelecommunicationssystem(Phase2+);VoiceActivityDetector(VAD)".1.1.1AbbreviationsAbbreviationsusedinthepresentdocumentarelistedinGSM01.04.1.2OutlinedescriptionThepresentdocumentisstructuredasfollows:Subclause1.3containsafunctionaldescriptionoftheaudiopartsincludingtheA/DandD/Afunctions.Subclause1.4describestheconversionbetween13bituniformand8bitA-lawsamples.Subclauses1.5and1.6presentasimplifieddescriptionoftheprinciplesoftheRPE-LTPencodinganddecodingprocessrespectively.Insubclause1.7,thesequenceandsubjectiveimportanceofencodedparametersaregiven.Clause2dealswiththetransmissioncharacteristicsoftheaudiopartsthatarerelevantfortheperformanceoftheRPE-LTPcodec.SometransmissioncharacteristicsoftheRPE-LTPcodecarealsospecifiedinclause2.Clause3presentsthefunctionaldescriptionoftheRPE-LTPcodinganddecodingprocedures,whereasclause4describesthecomputationaldetailsofthealgorithm.ProceduresfortheverificationofthecorrectfunctioningoftheRPE-LTParedescribedinclause5.PerformanceandnetworkaspectsoftheRPE-LTPcodecarecontainedinannexA.1.3FunctionaldescriptionofaudiopartsTheanalogue-to-digitalanddigital-to-analogueconversionwillinprinciplecomprisethefollowingelements:1)Analoguetouniformdigital:-microphone;-inputleveladjustmentdevice;-inputanti-aliasingfilter;-sample-holddevicesamplingat8kHz;-analogue-to-uniformdigitalconversionto13bitsrepresentation.Theuniformformatshallberepresentedintwo'scomplement.2)Uniformdigitaltoanalogue:-conversionfrom13bit/8kHzuniformPCMtoanalogue;-aholddevice;-reconstructionfilterincludingx/sinxcorrection;-outputleveladjustmentdevice;SIST EN 300 961 V7.0.2:2003



ETSIETSIEN300961V7.0.2(1999-12)10(GSM06.10version7.0.2Release1998)-earphoneorloudspeaker.Intheterminalequipment,theA/Dfunctionmaybeachievedeither:-bydirectconversionto13bituniformPCMformat;-orbyconversionto8bit/A-orµ-law(PCS1900)compandedformat,basedonastandardA-orµ-law(PCS1900)codec/filteraccordingtoITU-TRecommendationG.711/714,followedbythe8-bitto13-bitconversionaccordingtotheprocedurespecifiedinsubclause1.4.FortheD/Aoperation,theinverseoperationstakeplace.InthelattercaseitshouldbenotedthatthespecificationsinITU-TrecommendationG.714(supersededbyG.712)areconcernedwithPCMequipmentlocatedinthecentralpartsofthenetwork.Whenusedintheterminalequipment,thisspecificationdoesnotonitsownensuresufficientout-of-bandattenuation.Thespecificationofout-of-bandsignalsisdefinedinsection2betweentheacousticsignalandthedigitalinterfacetotakeintoaccountthatthefilteringintheterminalcanbeachievedbothbyelectronicandacousticaldesign.1.4PCMFormatconversionTheconversionbetween8bitA-orµ-law(PCS1900)compandedformatandthe13-bituniformformatshallbeasdefinedinITU-TRecommendationG.721(supersededbyG.726),subclause4.2.1,sub-blockEXPANDandsubclause4.2.7,sub-blockCOMPRESS.TheparameterLAW=1shouldbeusedforA-lawandLAW=0shouldbeusedforµ-law(PCS1900).1.5PrinciplesoftheRPE-LTPencoderAsimplifiedblockdiagramoftheRPE-LTPencoderisshowninfigure1.1.Inthisdiagramthecodingandquantizationfunctionsarenotshownexplicitly.Theinputspeechframe,consistingof160signalsamples(uniform13bitPCMsamples),isfirstpre-processedtoproduceanoffset-freesignal,whichisthensubjectedtoafirstorderpre-emphasisfilter.The160samplesobtainedarethenanalysedtodeterminethecoefficientsfortheshorttermanalysisfilter(LPCanalysis).Theseparametersarethenusedforthefilteringofthesame160samples.Theresultis160samplesoftheshorttermresidualsignal.Thefilterparameters,termedreflectioncoefficients,aretransformedtolog.arearatios,LARs,beforetransmission.Forthefollowingoperations,thespeechframeisdividedinto4sub-frameswith40samplesoftheshorttermresidualsignalineach.Eachsub-frameisprocessedblockwisebythesubsequentfunctionalelements.Beforetheprocessingofeachsub-blockof40shorttermresidualsamples,theparametersofthelongtermanalysisfilter,theLTPlagandtheLTPgain,areestimatedandupdatedintheLTPanalysisblock,onthebasisofthecurrentsub-blockofthepresentandastoredsequenceofthe120previousreconstructedshorttermresid
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