1、 STD-ETSI EN 303 703-ENGL 1999 3400855 0483403 T42 ETSI EN 301 703 V7.0.2 (1999-12) European Standard (Telecommunications series) Digital cellular telecommunications system (Phase 2+); Adaptive Multi-Rate (AMR); Speech processing functions; General description (GSM 06.71 version 7.0.2 Release 1998)
2、STD=ETSI EN 30L 703-ENGL 1999 3400855 0483402 989 (GSM 06.71 version 7.0.2 Release 1998) 2 ETSI EN 301 703 V7.0.2 (1999-12) Reference DEN/SMG-110671 Q7 Kevwords Digital cellular telecommunications system, Global System for Mobile communications (GSM) ETSI Postal address F-O6921 Sophia Antipolis Cede
3、x - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistree a la Sous-Prefecture de Grasse (06) N“ 7803/88 Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Internet secretanatetsi.fr Individual cop
4、ies of this ETSI deliverable can be downloaded from http:llwww.etsi.org If yw find errors in the present document, send your comment to: editoretsi.fr Important notice This ETSI deliverable may be made available in more than one electronic version or in print. In any case of existing or perceived di
5、fference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secreariat. Copyright Notification No part may be reproduc
6、ed except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. O European Telecommunications Standards Institute 1999. All rights reserved. - STD.ETS1 EN 301 703-ENGL L999 = 3400855 0483403 8L5 (GSM 06.71 version 7.0.2 Release 1998) 3
7、ETSI EN 301 703 V7.0.2 (1999-12) Con tents Intellectual Property Rights 4 Foreword . 4 1 2 3 3.1 3.2 4 5 5.1 5.2 6 7 8 9 10 5 References 5 Definitions and abbreviations . .6 Definitions . 6 Abbreviations . 6 General . . Adaptive multi-rate speech channel transcoding . 8 Full rate channel . Adaptive
8、multi-rate speech channel discontinuous transmission (DTX) .9 Adaptive multi-rate speech channel Voice Activity Detection (VAD) . 10 Adaptive multi-rate speech channel comfort noise insertion. . -10 Adaptive multi-rate speech channel lost speech hme substitution and muting . 1 1 Adaptive multi-rate
9、codec homing . 1 I History . .12 (GSM 06.71 version 7.0.2 Release 1998) 4 ETSI EN 301 703 V7.0.2 (1999-12) Intellectual 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 publi
10、cly available for ETSI members and non-members, and can be found in SR O00 3 14: “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 updates are available on the ETSI Web s
11、erver (http:/www.etsi .org/ipr) . 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 SR O00 3 14 (or the updates on the ETSI Web server) which are, or may be, or may be
12、come, essential to the present document. Foreword This European Standard (Telecommunications series) has been produced by Special Mobile Group (SMG). The present document introduces the Adaptive Multi-Rate (AMR) speech traffic channels within the digital cellular telecommunications system. The conte
13、nts of the present document is subject to continuing work within SMG and may change following formal SMG approval. Should SMG modi the contents of the present document it will be re-released with an identifjmg change of release date and an increase in version number as follows: Version 7.x.y where:
14、7 indicates Release 1998 of GSM Phase 2+ x the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. y the third digit is incremented when editorial only changes have been incorporated in the specification. National transposition dates Date
15、 of adoption of this EN: Date of latest announcement of this EN (doa): Date of latest publication of new National Standard or endorsement of this EN (dop/e): Date of withdrawal of any conflicting National Standard (dow): 3 December 1999 31 March 2000 30 September 2000 30 September 2000 STD.ETSI EN 3
16、01 703-ENGL 1999 m 3400855 0483405 by8 (GSM 06.71 version 7.0.2 Release 1998) 5 ETSI EN 301 703 V7.0.2 (1999-12) I Scope The present document is an introduction to GSM 04.90 7, GSM 06.91 8, GSM 06.92 9, GSM 06.93 IO and GSM 06.94 1 11 specifications dealing with the speech processing functions in th
17、e adaptive multi-rate channel of the GSM system. A general overview of the speech processing functions is given, with reference to the documents where each function is specified in detail. 2 References The following documents contain provisions which, through reference in this text, constitute provi
18、sions 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 latest version applies. A non-specific reference to
19、an ETS shall also be taken to refer to later versions published as an EN with the same number. For this Release 1998 document, references to GSM documents are for Release 1998 versions (version 7.x.y). Il GSM 01.04: “Digital cellular telecommunications system (Phase 2+); Abbreviations and acronyms“.
20、 GSM 03 SO: “Digital cellular telecommunications system (Phase 2+); Transmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) system“. GSM 05.09: “Digital cellular telecommunications system (Phase 2+); Link adaptation“ GSM 05.03: “Digital cellular telecommunica
21、tions system (Phase 2+); Channel coding“. GSM 06.73: “Digital cellular telecommunications system (Thase 2+); ANSI-C code for the GSM Adaptive Multi-Rate speech codec“. GSM 06.74: “Digital cellular telecommunications system (Phase 2+); Test sequences for the GSM Adaptive Multi-Rate speech codec“. GSM
22、 06.90: “Digital cellular telecommunications system (Phase 2+); Adaptive Multi-Rate speech transcoding“ . GSM 06.91 : “Digital cellular telecommunications system (Phase 2+); Substitution and muting of lost frame for Adaptive Multi-Rate speech traffic channels“. GSM 06.92: “Digital cellular telecommu
23、nications system (Phase 2+); Comfort noise aspects for Adaptive Multi-Rate speech traffic channels“. GSM 06.93: “Digital cellular telecommunications system (Phase 2+); Discontinuous transmission (DTX) for Adaptive Multi-Rate speech traffic channels“. GSM 06.94: “Digital cellular telecommunications s
24、ystem (Phase 2+); Voice Activity Detection (VAD) for Adaptive Multi-Rate speech traffic channels“. i23 i31 41 51 61 71 81 91 IO1 ill STDmETSI EN 301 703-ENGL 1999 - 3400855 O483406 524 (GSY 06.71 version 7.0.2 Release 1998) 6 ETSI EN 301 703 V7.0.2 (1999-12) 3 Definitions and abbreviations 3.1 Defin
25、i tion s Definition of terms used in the present document can be found in GSM 06.90 7, GSM 06.91 8, GSM 06.92 9, GSM 06.93 lo and GSM 06.94 1 I. 3.2 Ab brevi at ions For the purposes of the present document, the following abbreviations apply: ACELP AMR BFI BSS BTS CHD CHE DL DTX ETS GSM ITU-T MS PCM
26、 PLMN PSTN RF RSS Rx SACCH SIDFIRST SID-UPD SPD SPE TC TRAU TX UL Algebraic Code Excited Linear Prediction Adaptive Multi-Rate Bad Frame Indication Base Station System Base Tranceiver Station Channel Decoder Channel Encoder Down Link Discontinuous Transmission European Telecommunication Standard Glo
27、bal System for Mobile communications International Telecommunication Union - Telecommunication standardisation sector (former CCITT) Mobile Station Pulse Code Modulated Public Land Mobile Network Public Switched Telephone Network Radio Frequency Radio Subsystem Receive Slow Associated Control Channe
28、l Speech end marker Silence Descriptor (background descriptor) Speech Decoder Speech Encoder Transcoder TRanscoding and Rate Adaptation Unit Transmit Up Link For abbreviations not given in this subclause, see GSM O1 .O4 I. 4 General Figure i presents a reference configuration where the various speec
29、h processing functions are identified. In this figure, the relevant documents for each function are also indicated. In Figure i, the audio parts including analogue to digital and digital to analogue conversion are included, to show the complete speech path between the audio inpudoutput in the Mobile
30、 Station (MS) and the digital interface of the PSTN. The detailed specification of the audio parts are contained in GSM 03.50 2. These aspects are only considered to the extent that the performance of the audio parts affect the performance of the speech transcoder. Note that the inband STD-ETSI EN 3
31、01 703-ENGL 1999 m 3400855 0483407 460 m (GSM 06.71 version 7.0.2 Release 1998) 7 ETSI EN 301 703 W.0.2 (1999-12) signalling is not shown in Figure 1, refer to Figure 2. The mode indications (UL codec mode and DL codec mode) are used to select the mode of the speech encoder and speech decoder in Fig
32、ure 1. Figure 2 presents a general block diagram of the overall AMR system for uplink and downlink over the same radio interface. Mobile Station (MS), Base Tranceiver Station (BTS) and Transcoding and Rate Adaptor Unit (TRAU) are shown in the figure. The detailed specification of AMR link adaptation
33、, channel quality estimation and inband signalling is given in GSM 05.09 3. The AMR multirate adaptation is based on quality measurements of the radio channel. The measurements are processed to give the UL Quaiity Indicator and the DL Quaiity Indicator. The UL Quality Indicator is mapped to an UL Mo
34、de Command and the DL Quaiity Indicator is mapped to a DL Mode Request in the BTS and MS, respectively. The UL Mode Command and the DL Mode Request are sent to the transmitter using the reverse link. UL codec mode and DL Mode Request are sent as inband signals in the uplink radio channel. DL codec m
35、ode and UL Mode Command are sent as inband signals in the downlink channel. r- _ .- GSM06.94 , GSM 06.93 : 8bit I A-law 13-bit j MS side only GSM03.50 j TRANSMIT SIDE 4 I DTX and Control , ! Info. bits Comfort Noise Fundons SIDframe , GSM06.92 ; GSM06.91 Speech j j info. j _._ GSM 06.90 b frame subs
36、titution j : BSS side only RECEIVE SIDE Figure I: Overview of audio processing functions I) 8-bit A-law or /i -law PCM (ITU-T recommendation (3.71 l), 8 O00 samplesk; 2) 13-bit uniform PCM, 8 O00 samplesh; STD-ETSI EN 302 703-ENGL 1999 3400855 0483408 3T7 m (GSM 06.71 version 7.0.2 Release 1998) 8 E
37、TSI EN 301 703 V7.0.2 (1999-12) 3) Voice Activity Detector (VAD) flag, 4) Encoded speech hme, 50 frames/s, number of bitdame depending on the AMR codec mode; 5) SIlence Descriptor (SID) frame (marked SID-FIRST or SID-UPD); 6) TX-TYPE, 2 bits, indicates whether information bits are available and if t
38、hey are speech or SID information; 7) information bits delivered to the radio subsystem; 8) Information bits received from the radio subsystem; 9) RX-TYPE, the type of frame received quantized into three bits, (classified by the RSS). ., - /- -. I I Figure 2: Block diagram of the AMR system. 5 Adapt
39、ive multi-rate speech channel transcoding GSM 06.90 7 describes the adaptive multi-rate speech codec and GSM 06.73 8 defines the ANSI-C code, thus enabling the verification of compliance to GSM 06.90 7 to a high degree of confidence by use of a set of digital test sequences given in GSM 06.74 6. 5.1
40、 Full rate channel As shown in Figure 1, the speech encoder takes its input as a 13-bit uniform Pulse Code Modulated (PCM) signal either fiom the audio part of the Mobile Station or on the network side, from the Public Switched Telephone Network (PSTN) via an 8-bit A-law or /i -law to 13-bit uniform
41、 PCM conversion. The encoded speech at the output of the speech encoder is delivered to the channel coding function defined in GSM 05.03 4 to produce an encoded block consisting of 456 bits leading to a gross bit rate of 22.8 kbit/s. In the receive direction, the inverse operations take place. GSM 0
42、6.90 7 describes 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 used codec mode) and fiom these to output blocks of 160 reconsructed speech samples. The coding scheme is Multi-Rate Algebraic C
43、ode Excited Linear Prediction. The bit-rates of the source codec for the adaptive multi-rate full rate channel (TCWAFS) are listed in Table 1. An adaptive multi-rate compliant MS shall support all full rate source rates listed in Table 1. STD.ETS1 EN 301 703-ENGL 1999 m 3400855 0483409 233 Channel (
44、GSM 06.71 verslon 7.0.2 Release 1998) 9 Source codec bit-rate 12.2 kbiffs (GSM EFR) 10.2 kbit/s ETSI EN 301 703 V7.0.2 (1999-12) TCHIAHS 5.2 4.75 kbiffs 7.95 kbiffs 7.40 kbis (IS-641) 6.70 kbis Half rate channel As shown in Figure 1, the speech encoder takes its input as a 13-bit uniform Pulse Code
45、Modulated (PCM) signal either from the audio part of the Mobile Station or on the network side, from the Public Switched Telephone Network (PSTN) via an 8-bit A-law or -law to 13-bit uniform PCM conversion. The encoded speech at the output of the speech encoder is delivered to the channel coding fun
46、ction defined in GSM 05.03 4 to produce an encoded block consisting of 228 bits leading to a gross bit rate of 11.4 kbit/s. In the receive direction, the inverse operations take place. GSM 06.90 7 describes the detailed mapping between input blocks of 160 speech samples in 13-bit uniform PCM format
47、to encoded blocks (in which the number of bits depends on the used codec mode) and hm these to output blocks of 160 reconsucted speech samples. The coding scheme is Multi-Rate Algebraic Code Excited Linear Prediction. The bit-rates of the source codec for the adaptive multi-rate half rate channel (T
48、CWAHS) are listed in Table 1. An adaptive multi-rate compliant MS supporting the half rate mode of the adaptive multi-rate speech channel shall support all half rate source rates listed in Table 1. Table 1: Source codec bit-rates for TCHIAFS and TCH/AHS channels I I 7.95 kbiffs TC HIAF S 7.40 kbiffs
49、 (IS-641) 6.70 kbiffs 5.90 kbiVs 5.1 5 kbiffs 5.90 kbiffs 5.1 5 kbiVs I 4.75 kbiffs NOTE: IS-641is the TINEIA 6-641 TDMA Enhanced Full Rate SpeechCodec. 6 Adaptive multi-rate speech channel discontinuous transmission (DTX) During a normal phone conversation, the participants alternate so that, on the average, each direction of transmission is occupied about 50 % of the time. Discontinuous transmission (DTX) is a mode of operat
