1、 ETSI TS 126 071 V15.0.0 (2018-07) Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Mandatory speech CODEC speech processing functions; AMR speech Codec; General description (3GPP TS 26.071 version 15.0.0 Release 15) TECHNICAL SPECI
2、FICATION ETSI ETSI TS 126 071 V15.0.0 (2018-07)13GPP TS 26.071 version 15.0.0 Release 15Reference RTS/TSGS-0426071vf00 Keywords GSM,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 Associ
3、ation but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be downloaded from: http:/www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print
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9、stered and owned by the GSM Association. ETSI ETSI TS 126 071 V15.0.0 (2018-07)23GPP TS 26.071 version 15.0.0 Release 15Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information pertaining to these
10、 essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest u
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13、ETSI, and conveys no right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Specification (TS) has been p
14、roduced 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 reference
15、 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 claus
16、e 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 126 071 V15.0.0 (2018-07)33GPP TS 26.071 version 15.0.0 Release 15Contents Intellectual Property Rights 2g3Fo
17、reword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 References 5g33 Definitions and abbreviations . 6g33.1 Abbreviations . 6g34 General . 6g35 Adaptive Multi-Rate speech codec transcoding functions . 8g36 Adaptive Multi-Rate speech codec ANSI C-code 8g37 Adaptive Multi-Rate speech code
18、c test vectors 8g38 Adaptive Multi-Rate speech codec source controlled rate operation . 9g39 Adaptive Multi-Rate speech codec voice activity detection 9g310 Adaptive Multi-Rate speech codec comfort noise insertion . 9g311 Adaptive Multi-Rate speech codec error concealment of lost frames 10g312 Adapt
19、ive Multi-Rate speech codec frame structure . 10g313 Adaptive Multi-Rate speech codec interface to RAN 10g314 Adaptive Multi-Rate speech codec performance characterisation . 10g3Annex A (informative): Change history 11g3History 12g3ETSI ETSI TS 126 071 V15.0.0 (2018-07)43GPP TS 26.071 version 15.0.0
20、 Release 15Foreword This Technical 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 docum
21、ent, it will be re-released 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 contr
22、ol. y the second digit is incremented 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 126 071 V15.0.0 (2018-07)53GPP TS 26.071 version 15.0.0 Releas
23、e 151 Scope The present document is an introduction to the speech processing parts of the narrowband telephony speech service employing the Adaptive Multi-Rate (AMR) speech coder. A general overview of the speech processing functions is given, with reference to the documents where each function is s
24、pecified in detail. 2 References The following documents contain provisions which, through 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 specif
25、ic reference, subsequent revisions do not apply. - For a non-specific reference, the latest 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
26、document. 1 GSM 03.50: “Digital cellular telecommunications system (Phase 2); Transmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) system“. 2 3GPP TS 26.090: “Transcoding functions“. 3 3GPP TS 26.073: “Adaptive Multi-Rate (AMR); ANSI C source code“. 4 3GPP
27、 TS 26.074: “Adaptive Multi-Rate (AMR); Test sequences“. 5 3GPP TS 26.093: “Source Controlled Rate operation“. 6 3GPP TS 26.094: “AMR Speech Codec; Voice Activity Detector“. 7 3GPP TS 26.092: “Mandatory Speech Codec speech processing functions; AMR Speech Codec; Comfort noise aspects“. 8 3GPP TS 26.
28、091: “Mandatory Speech Codec speech processing functions; AMR Speech Codec; Error concealment of lost frames“. 9 3GPP TS 26.101: “Frame Structure“. 10 3GPP TS 26.102: “AMR Speech Codec; Interface to Iu snd Uu“. 11 3GPP TS 26.901: “AMR wideband speech codec feasibility study report “. 12 ITU-T Recomm
29、endation G.711: “Pulse code modulation (PCM) of voice frequencies“. 13 ITU-T Recommendation H.324: “Terminal for low bit-rate multimedia communication“. ETSI ETSI TS 126 071 V15.0.0 (2018-07)63GPP TS 26.071 version 15.0.0 Release 153 Definitions and abbreviations 3.1 Abbreviations For the purposes o
30、f this TS, the following abbreviations apply: ACELP Algebraic Code Excited Linear Prediction AMR Adaptive Multi-Rate BFI Bad Frame Indication CHD Channel Decoder CHE Channel EncoderGSM Global System for Mobile communications ITU-T International Telecommunication Union Telecommunication standardisati
31、on sector (former CCITT) PCM Pulse Code Modulation PLMN Public Land Mobile Network PSTN Public Switched Telephone Network RX Receive SCR Source Controlled Rate SPD SPeech Decoder SPE SPeech Encoder TC Transcoder TX TransmitUE User Equipment (terminal) 4 General The AMR speech coder consists of the m
32、ulti-rate speech coder, a source controlled rate scheme including a voice activity detector and a comfort noise generation system, and an error concealment mechansim to combat the effects of transmission errors and lost packets. The multi-rate speech coder is a single integrated speech codec with ei
33、ght source rates from 4.75 kbit/s to 12.2 kbit/s, and a low rate background noise encoding mode. The speech coder is 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. I
34、n this figure, the relevant specifications for each function are also indicated. In Figure 1, the audio parts including analogue to digital and digital to analogue conversion are included, to show the complete speech path between the audio input/output in the User Equipment (UE) and the digital inte
35、rface of the network. The detailed specification of the audio parts is not within the scope of the present document. These aspects are only considered to the extent that the performance of the audio parts affect the performance of the speech transcoder. ETSI ETSI TS 126 071 V15.0.0 (2018-07)73GPP TS
36、 26.071 version 15.0.0 Release 158bit / A-lawto13-bituniformLPF A/D12MS side onlyBSS side only GSM 06.60.AMRGSM 03.50TRANSMIT SIDESpeechEncoderComfortNoiseTXFunctionsVoiceActivityDetectorDTXControlandOperation364567GSM 06.82.AMR GSM 06.81.AMRGSM 06.60.AMRGSM 06.62.AMRSID frameSpeech frameVAD13-bitun
37、iformto8bit / A-lawLPFD/A18MS side onlyBSS side only GSM 06.60.AMRGSM 03.50RECEIVE SIDESpeechDecoderSpeechframesubstitutionDTXControlandOperation45910GSM 06.61.AMRGSM 06.81.AMRGSM 06.60.AMRGSM 06.62.AMRSID frameSpeech frameComfortNoiseRXFunctions112SPflagInfo.bitsBFIInfo.bitsSIDTAFFigure 1: Overview
38、 of audio processing functions 1) 8-bit A-law or g541-law PCM (ITU-T Recommendation G.711 12 ), 8 000 samples/s; 2) 13-bit uniform PCM, 8 000 samples/s; 3) Voice Activity Detector (VAD) flag; 4) Encoded speech frame, 50 frames/s, number of bits/frame depending on the AMR codec mode; 5) SIlence Descr
39、iptor (SID) frame; 6) TX_TYPE, 2 bits, indicates whether information bits are available and if they are speech or SID information; 7) Information bits delivered to the 3G AN; 8) Information bits received from the 3G AN; 9) RX_TYPE, the type of frame received quantized into three bits. ETSI ETSI TS 1
40、26 071 V15.0.0 (2018-07)83GPP TS 26.071 version 15.0.0 Release 155 Adaptive Multi-Rate speech codec transcoding functions The adaptive multi-rate speech codec is described in 2. The technical content is identical to that of 3GPP TS 26.090. As shown in Figure 1, the speech encoder takes its input as
41、a 13-bit uniform Pulse Code Modulated (PCM) signal either from the audio part of the UE or on the network side, from the Public Switched Telephone Network (PSTN) via an 8-bit A-law or g541-law to 13-bit uniform PCM conversion. The encoded speech at the output of the speech encoder is packetized and
42、delivered to the network interface. In the receive direction, the inverse operations take place. The detailed mapping between input blocks of 160 speech samples in 13-bit uniform PCM format to encoded blocks (in which the number of bits depends on the presently used codec mode) and from these to out
43、put blocks of 160 reconstructed speech samples is described in 2. The coding scheme is Multi-Rate Algebraic Code Excited Linear Prediction. The bit-rates of the source codec are listed in Table 1. An AMR speech codec capable UE shall support all source rates listed in Table 1. Table 1: Source codec
44、bit-rates for the AMR codec. Codec mode Source codec bit-rate AMR_12.20 12,20 kbit/s (GSM EFR) AMR_10.20 10,20 kbit/sAMR_7.95 7,95 kbit/sAMR_7.40 7,40 kbit/s (IS-641) AMR_6.70 6,70 kbit/s (PDC-EFR) AMR_5.90 5,90 kbit/sAMR_5.15 5,15 kbit/sAMR_4.75 4,75 kbit/s AMR_SID 1,80 kbit/s (see note 1) NOTE 1:
45、Assuming SID frames are continously transmitted NOTE 2: GSM-EFR is the 3GPP TS 26.090 Enhanced Full Rate Speech Codec (also identical to the TIA TDMA-US1 Enhanced speech codec) NOTE 3: IS-641is the TIA/EIA IS-641 TDMA Enhanced Full Rate Speech Codec NOTE 4: PDC-EFR is the ARIB 6.7 kbit/s Enhanced Fu
46、ll Rate Speech Codec 6 Adaptive Multi-Rate speech codec ANSI C-code The ANSI-C code of the speech codec, VAD and CNG system are described in 3. The ANSI C-code is mandatory. The ANSI C-code is identical to that of 3GPP TS 26.073 3. 7 Adaptive Multi-Rate speech codec test vectors A set of digital tes
47、t sequences is specified in 4, thus enabling the verification of compliance, i.e. bit-exactness, to a high degree of confidence. The test vectors are identical to those of 3GPP TS 26.074 4. The test sequences are defined separately for: - The speech codec described in 2, - The VAD described in 6, -
48、The CN generation described in 7. The adaptive multi-rate speech transcoder, VAD, SCR system and comfort noise parts of the audio processing functions (see Figure 1) are defined in bit exact arithmetic. Consequently, they shall react on a given input sequence always with the corresponding bit exact
49、output sequence, provided that the internal state variables are also always exactly in the same state at the beginning of the test. ETSI ETSI TS 126 071 V15.0.0 (2018-07)93GPP TS 26.071 version 15.0.0 Release 15The input test sequences provided shall force the corresponding output test sequences, provided that the tested modules are in their home-state when starting. The modules may be set into their home states by provoking the appropriate homing-functions. NOTE: This is normally done during reset (initialisation of the codec).
