METHOD AND APPARATUS FOR SEARCHING VARIABLE FIXED CODEBOOK USED BY CELP VOCODER

摘要

PURPOSE: A method and an apparatus for searching a variable fixed codebook used by a code excited linear prediction(CELP) vocoder are provided to effectively control sound quality and channel capacity. CONSTITUTION: A codebook searching apparatus includes a full searching unit(310), a search method selector(320), and a fixed codebook searching unit(330). Th full searching unit searches a fixed codebook using a full search method that searches the fixed codebook for all of pulse positions. The search method selector reads the number of users currently connected to a gateway and compares the read number with a predetermined value to search a fixed codebook search method. The fixed codebook searching unit searches the fixed codebook using the selected fixed codebook search method.