| 摘要 |
The present invention provides an apparatus and a method for quantizing the phase of a speech signal using a perceptual weighting function. The apparatus includes a phase information extractor (100) for obtaining the phase of each harmonic frequency in a speech signal represented by the discrete sum of periodic signals having different harmonic frequency components, a quantization noise shaping unit (110) for controlling the amount of quantization noise of each phase using a perceptual weighting function, which makes quantization noise less than a predetermined just noticeable difference (JND) of the phase, a quantization bit assigner (120) for assigning quantization bits to each phase according to the controlled amount of quantization noise, and a scalar quantizer (130) for quantizing each phase by the assigned quantization bits. In an alternative arrangement (fig. 2) for vector quantization, the components (120), (130) are replaced by a comparator, a quantization estimation codebook and a minimum value detector. It is possible to improve the quality of encoded speech by quantizing phase information using a perceptual weighting function. |
