1、 ETSI TS 126 441 V14.0.0 (2017-04) Universal Mobile Telecommunications System (UMTS); LTE; Codec for Enhanced Voice Services (EVS); General overview (3GPP TS 26.441 version 14.0.0 Release 14) TECHNICAL SPECIFICATION ETSI ETSI TS 126 441 V14.0.0 (2017-04)13GPP TS 26.441 version 14.0.0 Release 14Refer
2、ence RTS/TSGS-0426441ve00 Keywords LTE,UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The
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5、hat the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at https:/portal.etsi.org/TB/ETSIDeliverableStatus.aspx If you find errors in the present document, please send your comment to one of the following servic
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7、l not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2017. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for
8、 the benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TS 126 441 V14.0.0 (2017-04)23GPP TS 26.441 version 14.0.
9、0 Release 14Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellect
10、ual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including
11、 IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Specification (TS) has be
12、en produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables. The cross refer
13、ence between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. Modal verbs terminology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in c
14、lause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TS 126 441 V14.0.0 (2017-04)33GPP TS 26.441 version 14.0.0 Release 14Contents Intellectual Property Rights 2
15、g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 References 5g33 Abbreviations . 5g34 General . 6g35 Transcoding functions 8g36 ANSI C-code 9g37 Test vectors 9g38 Discontinuous transmission (DTX) 10g39 Voice activity detection 10g310 Comfort noise insertion 10g311 Error concealm
16、ent of lost frames . 11g312 Frame structure . 11g313 RTP Payload Format 11g314 Jitter Buffer Management . 11g315 Performance characterization . 11g3Annex A (informative): Change history . 12g3History 13g3ETSI ETSI TS 126 441 V14.0.0 (2017-04)43GPP TS 26.441 version 14.0.0 Release 14Foreword This Tec
17、hnical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released
18、by the TSG with an identifying change of release date and an increase in version number as follows: Version x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is in
19、cremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third digit is incremented when editorial only changes have been incorporated in the document. ETSI ETSI TS 126 441 V14.0.0 (2017-04)53GPP TS 26.441 version 14.0.0 Release 141 Scope The present docu
20、ment is an introduction to the audio processing parts of the Enhanced Voice Services coder. A general overview of the audio processing functions is given, with reference to the documents where each function is specified in detail. 2 References The following documents contain provisions which, throug
21、h reference in this text, constitute provisions of the present document. - References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. - For a specific reference, subsequent revisions do not apply. - For a non-specific reference, the late
22、st version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document. 1 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 2 3GPP TS 26.445: “Code
23、c for Enhanced Voice Services (EVS); Detailed Algorithmic Description“. 3 3GPP TS 26.442: “Codec for Enhanced Voice Services (EVS); ANSI C code (fixed-point)“. 4 3GPP TS 26.443: “Codec for Enhanced Voice Services (EVS); ANSI C code (floating point)“. 5 3GPP TS 26.444: “Codec for Enhanced Voice Servi
24、ces (EVS); Test Sequences“. 6 3GPP TS 26.446: “Codec for Enhanced Voice Services (EVS); AMR-WB Backward Compatible Functions“. 7 3GPP TS 26.447: “Codec for Enhanced Voice Services (EVS); Error Concealment of Lost Packets“. 8 3GPP TS 26.448: “Codec for Enhanced Voice Services (EVS); Jitter Buffer Man
25、agement“. 9 3GPP TS 26.449: “Codec for Enhanced Voice Services (EVS); Comfort Noise Generation (CNG) Aspects“. 10 3GPP TS 26.450: “Codec for Enhanced Voice Services (EVS); Discontinuous Transmission (DTX)“. 11 3GPP TS 26.451: “Codec for Enhanced Voice Services (EVS); Voice Activity Detection (VAD)“.
26、 12 3GPP TS 26.114: “IP Multimedia Subsystem (IMS); Multimedia telephony; Media handling and interaction“. 13 3GPP TS 26.131: “Terminal acoustic characteristics for telephony; Requirements“. 14 3GPP TR 26.952: “Codec for Enhanced Voice Services (EVS); Performance Characterization“. 3 Abbreviations F
27、or the purposes of the present document, the abbreviations given in TR 21.905 1 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 1. ACELP Algebraic Code-Excited Linear Prediction AMR-WB Adapti
28、ve Multi Rate Wideband (codec) ETSI ETSI TS 126 441 V14.0.0 (2017-04)63GPP TS 26.441 version 14.0.0 Release 14CNG Comfort Noise Generator DTX Discontinuous Transmission EVS Enhanced Voice Services FB Fullband FEC Frame Erasure Concealment IP Internet Protocol JBM Jitter Buffer Management MSB Most Si
29、gnificant Bit MTSI Multimedia Telephony Service for IMS NB Narrowband PS Packet SwitchedPSTN Public Switched Telephone Network SAD Sound Activity Detection SC-VBR Source Controlled - Variable Bit Rate SID Silence Insertion Descriptor SWB Super Wideband VAD Voice Activity Detection WB Wideband WMOPS
30、Weighted Millions of Operations Per Second 4 General The Enhanced Voice Services coder consists of the multi-rate audio coder optimized for operation with voice and music/mixed content signals, a source controlled rate scheme including a voice/sound activity detector and a comfort noise generation s
31、ystem, and an error concealment mechanism to combat the effects of transmission errors and lost packets. Jitter buffer management is also provided. The EVS coder also provides enhanced interoperation with AMR-WB over all nine source bit rates from 6,6 kbit/s to 23,85 kbit/s. The EVS speech coder is
32、capable of switching its bit-rate every 20 ms speech frame upon command. A reference configuration where the various speech processing functions are identified is given in Figure 1. In this figure, the relevant specifications for each function are also indicated. In Figures 1 - evaluation of the bac
33、kground acoustic noise on the TX side, in order to transmit characteristic parameters to the RX side; - generation of comfort noise on the RX side during periods when no normal speech frames are received. The transmission of comfort noise information to the RX side is achieved by means of a Silence
34、Descriptor (SID) frame, which is sent at regular intervals. - a Source-Controlled Variable Bit Rate operational mode (SC-VBR) operating at 5,9 kbit/s is also provided to reduce the operational bit rate still further for NB and WB speech services. 9 Voice activity detection The Enhanced Voice Service
35、s codec VAD function is described in 2 - the noise parameter encoding (SID frames) and decoding, and - the generation of comfort noise in the receiver. ETSI ETSI TS 126 441 V14.0.0 (2017-04)113GPP TS 26.441 version 14.0.0 Release 14The comfort noise processes and the algorithm for updating the noise
36、 parameters during speech pauses are defined in detail in 2, and the corresponding C-code is defined in 3 & 4. 11 Error concealment of lost frames The EVS coder error concealment of erroneous or lost frames is described in 2 & 7. Frames may be erroneous due to transmission errors or frames may be lo
37、st or delayed due to packet loss in a transport network. The methods described in 2 & 7 may be used as a basis for error concealment. In order to mask the effect of isolated erroneous/lost frames, the decoder shall be informed about erroneous/lost frames and the error concealment actions shall be in
38、itiated, whereby a set of predicted parameters are used in the speech synthesis. Insertion of speech signal independent silence frames is not allowed. 12 Frame structure The EVS coder frame structure is described in 2. 13 RTP Payload Format The EVS coder RTP Payload Format for media handling and int
39、eraction is described in 2. 14 Jitter Buffer Management The EVS coder Jitter Buffer Management is described in 8. 15 Performance characterization The EVS coder performance characterization is described in 14. ETSI ETSI TS 126 441 V14.0.0 (2017-04)123GPP TS 26.441 version 14.0.0 Release 14Annex A (in
40、formative): Change history Change history Date TSG # TSG Doc. CR Rev Subject/Comment Old New 06-2014 64 SP-140208 Presented to TSG SA#64 for information 1.0.0 09-2014 65 SP-140457 Presented to TSG SA#65 for approval 1.0.0 2.0.0 09-2014 65 Approved a TSG SA#65 2.0.0 12.0.0 12-2014 66 SP-140723 0001 T
41、ypographical correction 12.0.0 12.1.0 12-2015 70 Version for Release 13 12.1.0 13.0.0 Change history Date Meeting TDoc CR Rev Cat Subject/Comment New version 2017-03 75 Version for Release 14 14.0.0 ETSI ETSI TS 126 441 V14.0.0 (2017-04)133GPP TS 26.441 version 14.0.0 Release 14History Document history V14.0.0 April 2017 Publication
