Content for TS 26.090 Word version: 18.0.0
3 Definitions, symbols and abbreviations
4 Outline description
5 Functional description of the encoder
6 Functional description of the decoder
7 Detailed bit allocation of the adaptive multi-rate codec
8 Homing sequences
9 Bibliography
$ Change history
3 Definitions, symbols and abbreviations p. 7
4 Outline description p. 13
4.1 Functional description of audio parts p. 13
4.2 Preparation of speech samples p. 14
4.3 Principles of the adaptive multi-rate speech encoder p. 14
4.4 Principles of the adaptive multi-rate speech decoder p. 16
4.5 Sequence and subjective importance of encoded parameters p. 17
5 Functional description of the encoder p. 17
5.1 Pre-processing (all modes) p. 17
5.2 Linear prediction analysis and quantization p. 17
5.2.1 Windowing and auto-correlation computation p. 18
5.2.2 Levinson-Durbin algorithm (all modes) p. 19
5.2.3 LP to LSP conversion (all modes) p. 19
5.2.4 LSP to LP conversion (all modes) p. 21
5.2.5 Quantization of the LSP coefficients p. 21
5.2.6 Interpolation of the LSPs p. 23
5.2.7 Monitoring resonance in the LPC spectrum (all modes) p. 24
5.3 Open-loop pitch analysis p. 24
5.4 Impulse response computation (all modes) p. 28
5.5 Target signal computation (all modes) p. 28
5.6 Adaptive codebook p. 28
5.7 Algebraic codebook p. 32
5.8 Quantization of the adaptive and fixed codebook gains p. 38
5.8.1 Adaptive codebook gain limitation in quantization p. 38
5.8.2 Quantization of codebook gains p. 38
5.8.3 Update past quantized adaptive codebook gain buffer (all modes) p. 41
5.9 Memory update (all modes) p. 41
6 Functional description of the decoder p. 41
6.1 Decoding and speech synthesis p. 41
6.2 Post-processing p. 44
7 Detailed bit allocation of the adaptive multi-rate codec p. 46
8 Homing sequences p. 50
8.1 Functional description p. 50
8.2 Definitions p. 51
8.3 Encoder homing p. 51
8.4 Decoder homing p. 51
9 Bibliography p. 55
$ Change history p. 56
