Abstract: A high-speed search method in a speech encoder using an order character of LSP (Line Spectrum Pair) parameters in an LSP parameter quantizer using SVQ (Split Vector Quantization) used in a low-speed transmission speech encoder, includes the steps of rearranging a codebook according to an element value of a reference row for determining a range of code vectors to be searched; and determining a search range by using an order character between a given target vector and an arranged code vector to obtain an optimal code vector. The method gives effects of reducing computational complexity required to search the codebook without signal distortion in quantizing the LSP parameters of the speech encoder using SVQ, and reducing computational complexity without loss of tone quality in G.729 fixed codebook search by performing candidate selection and search on the basis of the correlation value size of the pulse position index.

Abstract: A method of searching an MP-MLQ fixed codebook through bit predetermination includes the steps of generating a target vector with amplitude, reducing time to search an optimal pulse array through the bit predetermination and searching all of pulses if two errors have an identical value.

Abstract: A high-speed search method in a speech encoder using an order character of LSP (Line Spectrum Pair) counts in a LSP count quantizer using SVQ (Split Vector Quantization) used in a low-speed transmission speech encoder, includes the steps of rearranging a codebook according to an element value of a reference row for determining a range of code vectors to be searched; and determining a search range by using an order character between a given target vector and an arranged code vector to obtain an optimal code vector.

Abstract: A method for improving process time and speech quality of G.723.1 and reducing bit rate in a CLEP (Code Excited Linear Prediction) voice coder (or, called as vocoder) includes: a method of searching MP-MLQ fixed codebook through bit predetermination includes the steps of generating a target vector with amplitude, reducing time to search an optimal pulse array through the bit predetermination and searching all of pulses if two errors have an identical value; a formant post-filtering method of extracting a reflection coefficient of a slope compensation filter to apply a multi-degree slope compensation thereto; a pitch post-filtering method including an energy level standardization step and a step of generating a signal approximate to an average energy level; a VAD algorithm method using an energy, a pitch gain and a LSP distance; and a method of enhancing a processing time of G.723.