1、 ETSI TS 126 290 V15.0.0 (2018-07) Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Audio codec processing functions; Extended Adaptive Multi-Rate - Wideband (AMR-WB+) codec; Transcoding functions (3GPP TS 26.290 version 15.0.0 Rele
2、ase 15) TECHNICAL SPECIFICATION ETSI ETSI TS 126 290 V15.0.0 (2018-07)13GPP TS 26.290 version 15.0.0 Release 15Reference RTS/TSGS-0426290vf00 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 0
3、0017 - 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 any
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9、ogo are trademarks registered and owned by the GSM Association. ETSI ETSI TS 126 290 V15.0.0 (2018-07)23GPP TS 26.290 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 informat
10、ion 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 ETS
11、I 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 up
12、dates 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 as
13、 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 Specif
14、ication (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 deliverabl
15、es. 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 interprete
16、d 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 126 290 V15.0.0 (2018-07)33GPP TS 26.290 version 15.0.0 Release 15Contents Intellectua
17、l Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 6g31 Scope 7g32 References 7g33 Definitions and abbreviations . 7g33.1 Definitions 7g33.2 Abbreviations . 9g34 Outline description . 9g34.1 Functional description of audio parts . 9g34.2 Preparation of input samples 10g34.3 Pri
18、nciples of the extended adaptive multi-rate wideband codec . 10g34.3.1 Encoding and decoding structure 11g34.3.2 LP analysis and synthesis in low-frequency band. 13g34.3.3 ACELP and TCX coding 13g34.3.4 Coding of high-frequency band 13g34.3.5 Stereo coding 13g34.3.6 Low complexity operation 13g34.3.
19、7 Frame erasure concealment. 13g34.3.8 Bit allocation . 13g35 Functional description of the encoder 15g35.1 Input signal pre-processing. 15g35.1.1 High Pass Filtering . 16g35.1.2 Stereo Signal Downmixing/Bandsplitting 16g35.2 Principle of the hybrid ACELP/TCX core encoding 17g35.2.1 Timing chart of
20、the ACELP and TCX modes . 17g35.2.2 ACELP/TCX mode combinations and mode encoding 18g35.2.3 ACELP/TCX closed-loop mode selection 19g35.2.4 ACELP/TCX open-loop mode selection. 20g35.3 Hybrid ACELP/TCX core encoding description 24g35.3.1 Pre-emphasis . 24g35.3.2 LP analysis and interpolation 24g35.3.2
21、.1 Windowing and auto-correlation computation 24g35.3.2.2 Levinson-Durbin algorithm . 24g35.3.2.3 LP to ISP conversion . 24g35.3.2.4 ISP to LP conversion . 24g35.3.2.5 Quantization of the ISP coefficient . 24g35.3.2.6 Interpolation of the ISPs 25g35.3.3 Perceptual weighting. 25g35.3.4 ACELP Excitati
22、on encoder . 25g35.3.4.1 Open-loop pitch analysis . 25g35.3.4.2 Impulse response computation 25g35.3.4.3 Target signal computation . 25g35.3.4.4 Adaptive codebook 25g35.3.4.5 Algebraic codebook 26g35.3.4.5.1 Codebook structure 26g35.3.4.5.2 Pulse indexing . 26g35.3.4.5.3 Codebook search . 26g35.3.4.
23、6 Quantization of the adaptive and fixed codebook gains 26g35.3.5 TCX Excitation encoder . 27g35.3.5.1 TCX encoder block diagram . 27g35.3.5.2 Computation of the target signal for transform coding . 29g35.3.5.3 Zero-input response subtraction 29g3ETSI ETSI TS 126 290 V15.0.0 (2018-07)43GPP TS 26.290
24、 version 15.0.0 Release 155.3.5.4 Windowing of target signal . 30g35.3.5.5 Transform 31g35.3.5.6 Spectrum pre-shaping 31g35.3.5.7 Split multi-rate lattice VQ . 32g35.3.5.8 Spectrum de-shaping . 37g35.3.5.9 Inverse transform 37g35.3.5.10 Gain optimization and quantization 37g35.3.5.11 Windowing for o
25、verlap-and-add . 38g35.3.5.12 Memory update . 38g35.3.5.13 Excitation signal computation . 38g35.4 Mono Signal High-Band encoding (BWE) 38g35.5 Stereo signal encoding 41g35.5.1 Stereo Signal Low-Band Encoding . 41g35.5.1.1 Principle 42g35.5.1.2 Signal Windowing . 42g35.5.1.3 Pre-echo mode . 43g35.5.
26、1.4 Redundancy reduction . 43g35.5.2 Stereo Signal Mid-Band Processing . 43g35.5.2.1 Principle 43g35.5.2.2 Residual computation 43g35.5.2.3 Filter computation, smoothing and quantization . 44g35.5.2.4 Channel energy matching 44g35.5.3 Stereo Signal High-Band Processing 45g35.6 Packetization 45g35.6.
27、1 Packetization of TCX encoded parameters . 45g35.6.1.1 Multiplexing principle for a single binary table 46g35.6.1.2 Multiplexing in case of multiple binary tables 47g35.6.2 Packetization procedure for all parameters . 49g35.6.3 TCX gain multiplexing . 51g35.6.4 Stereo Packetization 52g36 Functional
28、 description of the decoder 52g36.1 Mono Signal Low-Band synthesis 52g36.1.1 ACELP mode decoding and signal synthesis . 52g36.1.2 TCX mode decoding and signal synthesis 53g36.1.3 Post-processing of Mono Low-Band signal 56g36.2 Mono Signal High-Band synthesis . 58g36.3 Stereo Signal synthesis . 61g36
29、.3.1 Stereo signal low-band synthesis 62g36.3.2 Stereo Signal Mid-Band synthesis 63g36.3.3 Stereo Signal High-Band synthesis . 64g36.3.4 Stereo output signal generation . 64g36.4 Stereo to mono conversion . 64g36.4.1 Low-Band synthesis 64g36.4.2 High-Band synthesis. 64g36.5 Bad frame concealment 64g
30、36.5.1 Mono . 64g36.5.1.1 Mode decoding and extrapolation . 64g36.5.1.2 TCX bad frame concealment. 67g36.5.1.2.1 Spectrum de-shaping . 67g36.5.1.2.2 Spectrum Extrapolation . 67g36.5.1.2.3 Amplitude Extrapolation . 67g36.5.1.2.4 Phase Extrapolation . 68g36.5.2 Stereo 68g36.5.2.1 Low-band 69g36.5.2.2
31、Mid-band. 70g36.6 Output signal generation 70g37 Detailed bit allocation of the Extended AMR-WB codec 71g38 Storage and Transport Interface formats 77g38.1 Available Modes and Bitrates 77g38.2 AMR-WB+ Transport Interface Format . 80g3ETSI ETSI TS 126 290 V15.0.0 (2018-07)53GPP TS 26.290 version 15.0
32、.0 Release 158.3 AMR-WB+ File Storage Format 82g3Annex A (informative): Change history . 84g3History 85g3ETSI ETSI TS 126 290 V15.0.0 (2018-07)63GPP TS 26.290 version 15.0.0 Release 15Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). This docume
33、nt describes the Extended Adaptive Multi-Rate Wideband (AMR-WB+) 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 the present document, it will be re-re
34、leased 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 digi
35、t 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 126 290 V15.0.0 (2018-07)73GPP TS 26.290 version 15.0.0 Release 151 Scope This Tele
36、communication Standard (TS) describes the detailed mapping from input blocks of monophonic or stereophonic audio samples in 16 bit uniform PCM format to encoded blocks and from encoded blocks to output blocks of reconstructed monophonic or stereophonic audio samples. The coding scheme is an extensio
37、n of the AMR-WB coding scheme 3 and is referred to as extended AMR-WB or AMR-WB+ codec. It comprises all AMR-WB speech codec modes including VAD/DTX/CNG 2810 as well as extended functionality for encoding general audio signals such as music, speech, mixed, and other signals. In the case of discrepan
38、cy between the requirements described in the present document and the ANSI-C code computational description of these requirements contained in 4, 5, the description in 4, 5, respectively, will prevail. The ANSI-C code is not described in the present document, see 4, 5 for a description of the floati
39、ng-point or, respectively, fixed-point ANSI-C code. 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.)
40、 or non-specific. - For a specific 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
41、the same Release as the present document. 1 GSM 43.050: “ 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 26.194: “AMR wideband speech codec; Voice Activity Detection (VAD)“. 3 3G
42、PP TS 26.190: “ AMR Wideband speech codec; Transcoding functions “. 4 3GPP TS 26.304: “ANSI-C code for the floating point Extended AMR Wideband codec“. 5 3GPP TS 26.273: “ANSI-C code for the fixed point Extended AMR Wideband codec“. 6 M. Xie and J.-P. Adoul, “Embedded algebraic vector quantization (
43、EAVQ) with application to wideband audio coding,“ IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Atlanta, GA, U.S.A, vol. 1, pp. 240-243, 1996. 7 J.H. Conway and N.J.A. Sloane, “A fast encoding method for lattice codes and quantizers,“ IEEE Trans. Inform. Theory,
44、 vol. IT-29, no. 6, pp. 820-824, Nov. 1983 8 3GPP TS 26.193: “AMR Wideband speech codec; Source controlled rate operation“. 9 3GPP TS 26.244: “Transparent end-to-end packet switched streaming service (PSS); 3GPP file format (3GP)“ 10 3GPP TS 26.192: “AMR Wideband speech codec; Comfort noise aspects“
45、 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and apply. ETSI ETSI TS 126 290 V15.0.0 (2018-07)83GPP TS 26.290 version 15.0.0 Release 15adaptive codebook: The adaptive codebook contains excitation vectors that are adapted for every sub
46、frame. The adaptive codebook is derived from the long-term filter state. The lag value can be viewed as an index into the adaptive codebook. algebraic codebook: A fixed codebook where algebraic code is used to populate the excitation vectors (innovation vectors). The excitation contains a small numb
47、er of nonzero pulses with predefined interlaced sets of potential positions. The amplitudes and positions of the pulses of the kthexcitation codevector can be derived from its index k through a rule requiring no or minimal physical storage, in contrast with stochastic codebooks whereby the path from
48、 the index to the associated codevector involves look-up tables. anti-sparseness processing: An adaptive post-processing procedure applied to the fixed codebook vector in order to reduce perceptual artifacts from a sparse fixed codebook vector. closed-loop pitch analysis: This is the adaptive codebo
49、ok search, i.e., a process of estimating the pitch (lag) value from the weighted input speech and the long term filter state. In the closed-loop search, the lag is searched using error minimization loop (analysis-by-synthesis). In the adaptive multi-rate wideband codec, closed-loop pitch search is performed for every subframe. direct form coefficients: One of the formats for storing the short term filter parameters. In the adaptive multi-rate wideband codec, all filters which are used to modify speech samples use direct form coefficient
