Electronics and Telecommunications Research Institute

Jong Hark Kim

Dae Sik Kim

Song In Choi

Byung Sik Yoon

Man Ho Park

Hyoung Jung Kim

In Sung Lee

The present invention relates to a harmonic-noise speech coder and coding algorithm of the mixed signal of voiced/unvoiced sound using harmonic model. The harmonic-noise speech coder comprises a noise spectral estimating means for coding the noise component by predicting the spectral by LPC analysis method after separating the noise, which is unvoiced sound component from the inputted LPC residual signal using cepstrum. And more improved speech quality can be obtained by analyzing noise effectively using the noise spectral model predicted through cepstrum-LPC analysis method of the mixed signal of voiced/unvoiced sound to the existing harmonic model and then coding the signal.

Harmonic-noise speech coding algorithm and coder using cepstrum analysis method

A time-separated speech coder that codes a transitional signal of voiced/unvoiced sound through harmonic speech coding, the coder including a transitional excitation signal analyzer/synthesizer for coding the transitional signal by extracting the harmonic model parameters of both transitional analyzers after detecting a transitional point and generating sinusoidal waveforms according to a variable transitional point separating both transitional analyzers. By the transitional point at which energy varies abruptly and the time-separated coding based on the transitional point, more improved speech quality than in the general harmonic speech coder can be obtained using the time-separated speech coder by increasing the representation capability of the transitional signal with large energy variation, after adapting it to the variable transitional point.

Speech coding system and method using time-separated coding algorithm

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Chungju, South Korea

Jong Hark Kim