1、 ETSI TS 146 008 V14.0.0 (2017-04) Digital cellular telecommunications system (Phase 2+) (GSM); Half Rate Speech; Performance Characterization of the GSM Half Rate speech codec (3GPP TS 46.008 version 14.0.0 Release 14) TECHNICAL SPECIFICATION GLOBAL SYSTEM FOR MOBILE COMMUNICATIONSRETSI ETSI TS 146
2、 008 V14.0.0 (2017-04)13GPP TS 46.008 version 14.0.0 Release 14Reference RTS/TSGS-0446008ve00 Keywords GSM 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
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9、 ETSI TS 146 008 V14.0.0 (2017-04)23GPP TS 46.008 version 14.0.0 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 a
10、nd 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 updates are available on the ETSI Web server (https:/ipr.etsi.org/
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12、ent document. Foreword This Technical Specification (TS) has been produced by the ETSI 3rdGeneration 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
13、references to the corresponding ETSI deliverables. 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“, “wil
14、l not“, “can“ and “cannot“ are to be interpreted 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 146 008 V14.0.0 (2017-04)33GPP TS 46.00
15、8 version 14.0.0 Release 14Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g3Introduction 5g31 Scope 7g32 References 7g33 Abbreviations . 7g34 Quality under error conditions (A-law, IRS), Experiment 1 8g35 Quality under error conditions (UPCM, No IRS), E
16、xperiment 2 . 8g36 Quality under tandeming conditions 9g36.1 Quality under tandeming conditions, Experiment 3 . 9g36.2 Effect of tandeming with other standards, Experiment 7 . 9g37 Quality under background noise conditions . 10g37.1 Experiments 4 and 5 . 10g37.2 Special background noise . 11g37.2.1
17、Introduction. 11g37.2.2 Observations . 11g38 Assessment of equivalent qdu, Experiment 6. 12g39 Talker dependency, Experiment 8 12g310 DTX System . 12g310.1 Assessment of DTX algorithm, Experiment 9 12g310.2 Channel activity in DTX mode . 13g310.2.1 Test procedure 13g310.2.2 Speech channel activity 1
18、3g310.2.3 Level compensation 13g310.2.4 SID update rate . 13g310.2.5 Interleaving compensation 13g310.2.6 Estimated mean TDMA channel activity 13g311 Performance with DTMF tones 14g311.1 Introduction 14g311.2 Test set-up 14g311.3 Results 14g311.4 Conclusions 15g311.5 Result tables of experiments wit
19、h standard and modified DTMF detectors . 15g312 Performance with signalling tones . 15g313 Delay 16g314 Frequency response 16g315 Half Rate codec complexity . 18g316 Summary of results from characterization Phase 1 and 2 18g316.1 Summary of Results From Characterization Phase 1 . 18g316.2 Summary of
20、 Results From Characterization Phase 2 . 20g316.3 Conclusion 20g3Annex A: Bibliography 21g3ETSI ETSI TS 146 008 V14.0.0 (2017-04)43GPP TS 46.008 version 14.0.0 Release 14Annex B: Change history 22g3History 23g3ETSI ETSI TS 146 008 V14.0.0 (2017-04)53GPP TS 46.008 version 14.0.0 Release 14Foreword Th
21、is 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 document, it will be re-rel
22、eased 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
23、 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. Introduction During five years of activity, the Traffic CHannel Half rate Speech (TCH-HS) Experts
24、 Group has produced a number of test plans and experiments to assess the performance of the candidate algorithms submitted for the GSM half rate standardization. An aid in this task was a large knowledge base made available from previous CCITT (now ITU-T) and ETSI activities on codec assessment (see
25、 annex A references 1) 2) 3) 4) 5), plus the use of recommendations in the field (see annex A references 6) 7) 8). Here are reported 3 different phases of the standardization of the GSM half rate codec: Characterization Phase 1, Characterization Phase 2 and Verification phase. The selection of the c
26、odec candidate for the GSM half rate traffic channel was based on the results of the characterization phase 1. Test results reported hereafter are based on version 3.3 of the GSM half rate codec. Characterization Phase 1 (Experiments 1 to 5): For characterization Phase 1, C-simulations of the candid
27、ate codecs were used as hardware implementations were not available at that time. The simulations were produced by MOTOROLA (USA) and Ericsson (Sweden) with support by MATRA (France). The following experiments were carried out: - Experiment 1: Quality under error conditions (A-law, IRS); - Experimen
28、t 2: Quality under error conditions (UPCM, No IRS); - Experiment 3: Quality under tandeming conditions; - Experiment 4: Quality under background noise conditions (ACR); - Experiment 5: Quality under background noise conditions (DCR). Characterization Phase 2 (Experiments 6 to 9): During Characteriza
29、tion Phase 2, a hardware implementation of the candidate algorithm was employed, provided by ANT (Germany). The following experiments were carried out: - Experiment 6: Assessment of equivalent qdu; - Experiment 7: Effect of tandeming with other standards; - Experiment 8: Talker Dependency; - Experim
30、ent 9: Assessment of DTX algorithm. ETSI ETSI TS 146 008 V14.0.0 (2017-04)63GPP TS 46.008 version 14.0.0 Release 14Verification phase: Further tests accompanied characterization Phase 1 and 2 to obtain a better knowledge of the characteristics of the GSM half rate codec and its performance under dif
31、ferent operational conditions: - Special background noise; - Channel activity in DTX mode; - Performance with DTMF tones; - Performance with signalling tones; - Delay; - Frequency response; - Complexity. For the characterization tests, a practical “indirect“ method of performance comparison between
32、different codecs was adopted, that utilizes the Modulated Noise Reference Unit (MNRU) (see annex A reference 7) as a reference degradation in a subjective experiment including the codecs under test. NOTE: The MNRU is a device designed for producing speech correlated noise that sounds subjectively li
33、ke the quantizing noise produced by log-companded PCM codecs. The device is subjectively calibrated for Mean Opinion Scores (MOS) against Q dB (where Q is the ratio of the speech to speech-correlated noise power). The “Equivalent Q“ of the codecs under test can then be found from the corresponding M
34、OS on the calibration curve of the MNRU. It is well known that this procedure works as long as the reference degradation sounds similar to the degradation under test. The MNRU provides the additional function of normalization across laboratories carrying out the same experiment, i.e. all MOS are con
35、verted to Equivalent Q (dB) and the results can be analysed statistically for differences between laboratories. An appropriate analysis of variance (ANOVA) was identified to evaluate the statistical significance of the experimental factors. The aim was to show that the subjective performance of the
36、GSM half rate algorithm is at least as good as that of the full rate codec over a selected set of conditions. To allow for experimental error, the half rate candidate had to perform better than 1 dB below the performance of the full rate (for the overall figure of merit) and better than 3 dB below t
37、he performance of the full rate for individual test conditions. To model its use in a network, the half rate candidate codec had to be placed between either a ITU-T Recommendation G.711 1 PCM coder and decoder, or a Uniform PCM, which provided the necessary A/D and D/A conversions. Source files of s
38、peech, produced either by using an “average“ telephone set (called IRS - Intermediate Reference System) or a microphone showing a “flat“ sending frequency characteristic (No IRS or “flat“), could then be processed through the different experimental conditions, for presentation to subjects in listeni
39、ng experiments. Among the different experimental conditions were error conditions at different input levels under both IRS A-Law PCM and No-IRS Linear PCM audio parts, tandeming conditions for different error patterns and background noise conditions. During all phases of testing, the host laboratory
40、 functions for the processing were provided by Aachen University of Technology (RWTH at Aachen, Germany). The whole set of “individual“ and “global“ data, collected in Experiment 1 to Experiment 9 were extensively analysed and discussed within TCH-HS expert group; for each condition, the MOS (or DMO
41、S for Experiment 5) were computed, separately for male and female speech, as well as averaged together, and the effects of different factors and their interactions were subject to analysis of variance (ANOVA). Within characterization Phase 1, conversion to Q values and weighted averages were calcula
42、ted for the whole set of results, in order to assess that the global figure of merit of the GSM half rate algorithm meets the quality requirement. ETSI ETSI TS 146 008 V14.0.0 (2017-04)73GPP TS 46.008 version 14.0.0 Release 141 Scope The present document gives background information on the performan
43、ce of the GSM half rate speech codec. Experimental results from the characterization and verification tests carried out during the selection process by the Traffic CHannel Half rate Speech (TCH-HS) expert group are reported to give a more detailed picture of the behaviour of the GSM half rate speech
44、 codec under different conditions of operation. 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 no
45、n-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 the same R
46、elease as the present document. 1 ITU-T Recommendation G.711: “Pulse code modulation (PCM) of voice frequencies“. 2 ITU-T Recommendation G.726: “40, 32, 24, 16 kbit/s adaptive differential pulse code modulation“. 3 ITU-T Recommendation G.728: “Coding of speech at 16 kbit/s using low-delay code excit
47、ed linear prediction“. 3 Abbreviations For the purposes of the present document, the following abbreviations apply: A/D Analogue to Digital ACR Absolute Category Rating ANOVA ANalysis Of VAriance C/I Carrier-to-Interferer ratioCEPT Confrence Europenne des Postes et Tlcommunications CNI Comfort Noise
48、 Insertion D/A Digital to Analogue DAT Digital Audio TapeDCR Degradation Category Rating DSP Digital Signal ProcessorDTMF Dual Tone Multi Frequency DTX Discontinuous Transmission for power consumption and interference reduction EID Error Insertion Device ETSI European Telecommunications Standards In
49、stitute GBER Average gross bit error rate GSM Global System for Mobile communications IRS Intermediate Reference System, No IRS= rather flat HLCS Host Laboratory Control System ITU-T International Telecommunication Union - Telecommunications Standardization Sector MNRU Modulated Noise Reference Unit MOS Mean Opinion Score MS Mobile Station OVL Overload pointPCM Pulse Code Modulation Q Speech-to-speech correlated noise power ratio in dB ETSI ETSI TS 146 008 V14.0.0 (2017-04)83GPP TS 46.008 version 14.0.0 Release 14qdu quantization distortion unitRPE-LTP Re
