Variable fixed codebook searching method in CELP speech codec, and apparatus thereof

The present invention relates to a variable fixed codebook search method and apparatus for use in speech CELP (Code Excited Linear Prediction) encoder. Variable fixed codebook search method in a CELP speech coder according to the present invention includes the steps of: searching a fixed codebook using transmission search method for performing a search of the fixed codebook for all pulse positions; Step of reading the number of users that are currently connected to the gateway by comparing the value with a previously set predetermined value, select the search method of the fixed codebook; The step of using the selected search method to search the fixed codebook; And to determined whether the search is completed for all the tracks, if the search is finished, it stops and a track to be detected yet still includes a step returning to the step of selecting the fixed codebook search method in accordance with the number of users. The present invention has the effect capable of effectively trade-off in sound quality and channel capacity by selecting the appropriate fixed codebook search method in accordance with the number of users.