On a time reduction of pitch searching by the regular pulse search technique in the CELP vocoder

Code excited linear prediction (CELP) speech coders exhibit good performance at data rates as low as 4800 bps. The major drawback of CELP type coders is the large amount of computational time. In this paper, we propose a new pitch codebook search method that restricts some range of the pitch searching by using the regular pulse excitation (RPE) searching technique. Applying the proposed method to the 8 kbps CELP vocoder, we can get approximately 48% complexity reduction in the pitch search.