1、 ETSI TS 126 171 V15.0.0 (2018-07) Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Speech codec speech processing functions; Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; General description (3GPP TS 26.171 version 15.0.0 R
2、elease 15) TECHNICAL SPECIFICATION ETSI ETSI TS 126 171 V15.0.0 (2018-07)13GPP TS 26.171 version 15.0.0 Release 15Reference RTS/TSGS-0426171vf00 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 56
3、2 00017 - NAF 742 C Association 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 a
4、ny electronic and/or print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the print of the Portable Document For
5、mat (PDF) version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that 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/ETS
6、IDeliverableStatus.aspx If you find errors in the present document, please send your comment to one of the following services: https:/portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, i
7、ncluding photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. ETSI 2018. All rights reserved. DEC
8、TTM, PLUGTESTSTM, UMTSTMand the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETMare trademarks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M logo is protected for the benefit of its Members. GSMand the GS
9、M logo are trademarks registered and owned by the GSM Association. ETSI ETSI TS 126 171 V15.0.0 (2018-07)23GPP TS 26.171 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 infor
10、mation 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: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the
11、ETSI Secretariat. Latest updates are available on the ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including 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
12、 updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Trademarks The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners. ETSI claims no ownership of these except for any which are indicated
13、 as being the property of 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 Spe
14、cification (TS) has been 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 deliver
15、ables. The cross reference 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 interpr
16、eted as described in clause 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 126 171 V15.0.0 (2018-07)33GPP TS 26.171 version 15.0.0 Release 15Contents Intellec
17、tual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 Normative references . 5g33 Definitions and abbreviations . 5g33.1 Abbreviations 5g34 General . 6g35 Adaptive Multi-Rate Wideband speech codec transcoding functions 8g36 Adaptive Multi-Rate Wideband speech co
18、dec ANSI C-code 8g37 Adaptive Multi-Rate Wideband speech codec test vectors 8g38 Adaptive Multi-Rate Wideband speech codec source controlled rate operation 9g39 Adaptive Multi-Rate Wideband speech codec voice activity detection . 9g310 Adaptive Multi-Rate Wideband speech codec comfort noise insertio
19、n . 10g311 Adaptive Multi-Rate Wideband speech codec error concealment of lost frames 10g312 Adaptive Multi-Rate Wideband speech codec frame structure 10g313 Adaptive Multi-Rate Wideband speech codec interface to RAN . 10g314 Adaptive Multi-Rate Wideband speech codec performance characterisation 11g
20、3Annex A (informative): Change history . 12g3History 13g3ETSI ETSI TS 126 171 V15.0.0 (2018-07)43GPP TS 26.171 version 15.0.0 Release 15Foreword This Technical Specification has been produced by the 3GPP. The present document is an introduction to the speech processing parts of the wideband telephon
21、y speech service employing the Adaptive Multi-Rate Wideband (AMR-WB) speech coder within the 3GPP system. 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 this TS, it will be re-rele
22、ased 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 Indicates TSG approved document under change control. y the second digit is incremen
23、ted 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 specification; ETSI ETSI TS 126 171 V15.0.0 (2018-07)53GPP TS 26.171 version 15.0.0 Release 151 Scope The present docum
24、ent is an introduction to the speech processing parts of the wideband telephony speech service employing the Adaptive Multi-Rate Wideband (AMR-WB) speech coder. A general overview of the speech processing functions is given, with reference to the documents where each function is specified in detail.
25、 2 Normative references This TS incorporates by dated and undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of
26、 these publications apply to this TS only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. 1 GSM 03.50 : “Digital cellular telecommunications system (Phase 2); Transmission planning aspects of the speech service in t
27、he GSM Public Land Mobile Network (PLMN) system“. 2 3GPP TS 26.190 : “AMR Wideband Speech Codec; Transcoding functions“. 3 3GPP TS 26.173 : “AMR Wideband Speech Codec; ANSI-C code“. 4 3GPP TS 26.174 : “AMR Wideband Speech Codec; Test sequences“. 5 3GPP TS 26.193 : “AMR Wideband Speech Codec; Source
28、Controlled Rate operation“. 6 3GPP TS 26.194 : “AMR Wideband Speech Codec; Voice Activity Detection (VAD)“. 7 3GPP TS 26.192 : “AMR Wideband Speech Codec; Comfort Noise Aspects“. 8 3GPP TS 26.191 : “AMR Wideband Speech Codec; Error Concealment of Lost Frames. 9 3GPP TS 26.201 : “AMR Wideband Speech
29、Codec; Frame Structure“. 10 3GPP TS 26.202 : “AMR Wideband Speech Codec; Interface to RAN“. 11 3GPP TR 26.976 : “Performance characterization of the Adaptive Multi-Rate Wideband (AMR-WB) speech codec“. 3 Definitions and abbreviations 3.1 Abbreviations For the purposes of this TS, the following abbre
30、viations apply: ACELP Algebraic Code Excited Linear Prediction AMR Adaptive Multi-Rate AMR-WB Adaptive Multi-Rate Wideband BFI Bad Frame Indication CHD Channel Decoder CHE Channel EncoderGSM Global System for Mobile communications ITU-T International Telecommunication Union Telecommunication standar
31、disation 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 TransmitETSI ETSI TS 126 171 V15.0.0 (2018-07)63GPP TS 26.171 version 15.0.0 Re
32、lease 15UE User Equipment (terminal) 4 General The AMR-WB speech coder consists of the multi-rate speech coder, a source controlled rate scheme including a voice activity detector and a comfort noise generation system, and an error concealment mechanism to combat the effects of transmission errors a
33、nd lost packets. The multi-rate speech coder is a single integrated speech codec with nine source rates from 6.60 kbit/s to 23.85 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 configurat
34、ion 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 Figure 1, the audio parts including analogue to digital and digital to analogue conversion are included, to show the complete sp
35、eech path between the audio input/output in the User Equipment (UE) and the digital interface of the network. The detailed specification of the audio parts is not within the scope of this document. These aspects are only considered to the extent that the performance of the audio parts affect the per
36、formance of the speech transcoder. ETSI ETSI TS 126 171 V15.0.0 (2018-07)73GPP TS 26.171 version 15.0.0 Release 15Figure 1: Overview of audio processing functions 1) 8-bit A-law or g541-law PCM (ITU-T recommendation G.711), 8000 samples/s 2) 14-bit uniform PCM, 16 000 samples/s 3) Voice Activity Det
37、ector (VAD) flag 4) Encoded speech frame, 50 frames/s, number of bits/frame depending on the AMR-WB codec mode 5) Silence Descriptor (SID) frame. 6) TX_TYPE, 3 bits, indicates whether information bits are available and if they are speech or SID information 7) Information bits delivered to the 3G AN
38、8) Information bits received from the 3G AN 9) RX_TYPE, the type of frame received quantized into three bits 10) Silence Descriptor (SID) flag 8bit / A-lawto14-bituniformLPF A/D12MS side onlyBSS side only(narrowband speech)TS 26.190GSM 03.50TRANSMIT SIDESpeechEncoderComfortNoiseTXFunctionsVoiceActiv
39、ityDetectorDTXControlandOperation364567SID frameSpeech frameVAD14-bituniformto8bit / A-lawLPFD/A18MS side onlyBSS side only (narrowband speech)GSM 03.50RECEIVE SIDESpeechDecoderSpeechframesubstitutionDTXControlandOperation45910SID frameSpeech frameComfortNoiseRXFunctions112SPflagInfo.bitsBFIInfo.bit
40、sSIDTAFUpsampling1:2BSS side only (wideband speech)14-bituniform2TS 26.190TS 26.190TS 26.190TS 26.192TS 26.192TS 26.194214-bituniformBSS side only (wideband speech)Downsampling2:1TS 26.191TS 26.193TS 26.193ETSI ETSI TS 126 171 V15.0.0 (2018-07)83GPP TS 26.171 version 15.0.0 Release 1511) Time Alignm
41、ent Flag (TAF), marks the position of the SID frame within the SACCH multiframe 5 Adaptive Multi-Rate Wideband speech codec transcoding functions The adaptive multi-rate wideband speech codec is described in 2. As shown in Figure 1, the speech encoder takes its input as a 14-bit uniform Pulse Code M
42、odulated (PCM) signal either from the audio part of the UE or from the network side TBD or from the Public Switched Telephone Network (PSTN) via an narrowband 13-bit A-law or -law to wideband 14-bit uniform PCM conversion. An upsampling by factor of 2 has to be performed between narrowband and wideb
43、and speech signals. The encoded speech at the output of the speech encoder is packetized and delivered to the network interface. In the receive direction, the inverse operations take place. The detailed mapping between input blocks of 320 speech samples in 14-bit uniform PCM format to encoded blocks
44、 (in which the number of bits depends on the presently used codec mode) and from these to output blocks of 320 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-WB
45、speech codec capable UE shall support all source rates listed in Table 1. Table 1: Source codec bit-rates for the AMR-WB codec Codec mode Source codec bit-rate AMR-WB_23.85 23.85 kbit/sAMR-WB_23.05 23.05 kbit/sAMR-WB_19.85 19.85 kbit/s AMR-WB_18.25 18.25 kbit/s AMR-WB_15.85 15.85 kbit/s AMR-WB_14.25
46、 14.25 kbit/s AMR-WB_12.65 12.65 kbit/s AMR-WB_8.85 8.85 kbit/sAMR-WB_6.60 6.60 kbit/sAMR-WB_SID 1.75 kbit/s * (*) Assuming SID frames are continuously transmitted 6 Adaptive Multi-Rate Wideband speech codec ANSI C-code The ANSI C-code of the speech codec, VAD and CNG system are described in 3. The
47、ANSI C-code is mandatory. 7 Adaptive Multi-Rate Wideband speech codec test vectors A set of digital test sequences is specified in 4, thus enabling the verification of compliance, i.e. bit-exactness, to a high degree of confidence. The test sequences are defined separately for: - The speech codec de
48、scribed in 2, - The VAD described in 6, - The CN generation described in 7. The adaptive multi-rate wideband 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 inpu
49、t ETSI ETSI TS 126 171 V15.0.0 (2018-07)93GPP TS 26.171 version 15.0.0 Release 15sequence always with the corresponding bit exact output sequence, provided that the internal state variables are also always exactly in the same state at the beginning of the test. The 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
