Contents
3GPP46.008Half rate speechPerformance Characterization of the GSM Half Rate speech codecRelease 17TS
ContentsForeword 3
Foreword 4
Introduction 4
1 Scope 6
2 References 6
3 Abbreviations 6
4 Quality under error conditions (A-law, IRS), Experiment 1 7
5 Quality under error conditions (UPCM, No IRS), Experiment 2 7
6 Quality under tandeming conditions 8
6.1 Quality under tandeming conditions, Experiment 3 8
6.2 Effect of tandeming with other standards, Experiment 7 8
7 Quality under background noise conditions 9
7.1 Experiments 4 and 5 9
7.2 Special background noise 10
7.2.1 Introduction 10
7.2.2 Observations 10
8 Assessment of equivalent qdu, Experiment 6 11
9 Talker dependency, Experiment 8 11
10 DTX System 11
10.1 Assessment of DTX algorithm, Experiment 9 11
10.2 Channel activity in DTX mode 12
10.2.1 Test procedure 12
10.2.2 Speech channel activity 12
10.2.3 Level compensation 12
10.2.4 SID update rate 12
10.2.5 Interleaving compensation 12
10.2.6 Estimated mean TDMA channel activity 12
11 Performance with DTMF tones 13
11.1 Introduction 13
11.2 Test set-up 13
11.3 Results 13
11.4 Conclusions 14
11.5 Result tables of experiments with standard and modified DTMF detectors 14
12 Performance with signalling tones 14
13 Delay 15
14 Frequency response 15
15 Half Rate codec complexity 17
16 Summary of results from characterization Phase 1 and 2 17
16.1 Summary of Results From Characterization Phase 1 17
16.2 Summary of Results From Characterization Phase 2 19
16.3 Conclusion 19
Annex A: Bibliography 20
Annex B: Change history 21