CELP coding using trellis-coded vector quantization of the excitation

We analyze the performance of a CELP coder where the vector quantization (VQ) of the excitation is replaced with trellis-coded vector quantization (TCVQ). Our results show that TCVQ performs significantly better than VQ, with reasonable complexity. This makes TCVQ a fair choice for trading quality against complexity and/or delay. We describe a systematic procedure to replace VQ with TCVQ for existing CELP coders. We propose an optimization algorithm to appropriately populate the trellis. We show how pseudo-Gray coding can be applied to the TCVQ codebook to improve intrinsic coder robustness to channel errors. Finally, we evaluate the complexity and performance of the method.

[1]  Gottfried Ungerboeck,et al.  Channel coding with multilevel/phase signals , 1982, IEEE Trans. Inf. Theory.

[2]  Jr. G. Forney,et al.  The viterbi algorithm , 1973 .

[3]  Robert M. Gray,et al.  Finite-state vector quantization for waveform coding , 1985, IEEE Trans. Inf. Theory.

[4]  Thomas R. Fischer,et al.  Trellis-searched adaptive predictive coding of speech , 1993, IEEE Trans. Speech Audio Process..

[5]  D. Lin.  Speech coding using efficient pseudo-stochastic block codes , 1987, ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[6]  Manfred R. Schroeder,et al.  Code-excited linear prediction(CELP): High-quality speech at very low bit rates , 1985, ICASSP '85. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[7]  B. Mazor,et al.  An efficient code structure and search strategy for stochastic coding at 8 kb/s , 1990, International Conference on Acoustics, Speech, and Signal Processing.

[8]  Yair Shoham.  Low Delay Coding of Wideband Speech at 32 Kbps Using Tree Structures , 1993 .

[9]  Min Wang,et al.  Trellis-coded quantization designed for noisy channels , 1994, IEEE Trans. Inf. Theory.

[10]  Robert M. Gray,et al.  The Design of Predictive Trellis Waveform Coders Using the Generalized Lloyd Algorithm , 1986, IEEE Trans. Commun..

[11]  Thomas R. Fischer,et al.  Trellis excitation speech coding at low bit rates , 1994, IEEE Trans. Commun..

[12]  Takehiro Moriya,et al.  4.8 kbit/s delayed decision CELP coder using tree coding , 1990, International Conference on Acoustics, Speech, and Signal Processing.

[13]  G. David Forney,et al.  Convolutional codes I: Algebraic structure , 1970, IEEE Trans. Inf. Theory.

[14]  Michael W. Marcellin,et al.  Trellis-coded vector quantization , 1991, IEEE Trans. Inf. Theory.

[15]  Allen Gersho,et al.  Real-time vector excitation coding of speech at 4800 bps , 1987, ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[16]  Spiros Dimolitsas.  SUBJECTIVE ASSESSMENT METHODS FOR THE MEASUREMENT OF DIGITAL SPEECH CODER QUALITY , 1993 .

[17]  Michael W. Marcellin,et al.  Predictive trellis coded quantization of speech , 1990, IEEE Trans. Acoust. Speech Signal Process..

[18]  Michael W. Marcellin,et al.  Trellis coded quantization of memoryless and Gauss-Markov sources , 1990, IEEE Trans. Commun..

[19]  Allen Gersho,et al.  Pseudo-Gray coding , 1990, IEEE Trans. Commun..