Patent ID: 7496504

Claim:
A combined, fixed codebook searching method used in a code excited linear prediction (CELP) speech codec, the method comprising: searching for a fixed codebook using a full search method that searches for the fixed codebook at all pulse positions; selecting a fixed codebook searching method by counting the number of users who are accessing a gateway, comparing the number of users with a predetermined threshold, and selecting a proper fixed codebook searching method based on the result of comparison; searching for the fixed codebook using the selected fixed codebook searching method; and checking whether the search for the fixed codebook is complete for all tracks of the CELP speech codec, terminating a routine of searching for the fixed codebook when it is determined the search is complete for all the tracks, and selecting a fixed codebook searching method again in consideration of the number of gateway users when there remains a track to be searched for, wherein after said search finds the fixed codebook, using the found fixed codebook as an input to the CELP speech codec.