A robust 2400 bps subband LPC vocoder
- 19 November 2002
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 1, 500-503 vol.1
- https://doi.org/10.1109/icassp.1995.479638
Abstract
This paper presents a new voice coder for applications in future low bit rate communication systems. The emphasis has been put on the speech quality, noise robustness and complexity. The coder realizes a multiband+LPC spectral analysis and synthesis of speech. The transmitted information consists of an LPC10 filter, a set of voicing rates, pitch, energies, spectral density of excitation in five subbands, and information about the stationarity of the signal in each half-frame. Depending upon this stationarity, the quantization process is adapted to provide more spectral information (stable speech) or more temporal information (transitory speech). In order to be less sensitive to the surrounding noise, the pitch and voicing rates are first computed in each subband. The final values of these parameters are obtained from the values in the current frame and its neighbours. The excitation signal used at the synthesis side consists of a mixture of isolated pulses, periodic and aperiodic signals of adjustable spectral composition. Tests results are provided.Keywords
This publication has 4 references indexed in Scilit:
- Mixed Excitation Prototype Waveform Interpolation for Low Bit Rate Speech CodingPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- A New Government Standard 2400 bps Speech CoderPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Interpolation of the pitch-predictor parameters in analysis-by-synthesis speech codersIEEE Transactions on Speech and Audio Processing, 1994
- A new mixed excitation LPC vocoderPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1991