On a fast pitch searching by using a simple correlation technique in the CELP vocoder

Code Excited Linear Prediction (CELP) speech coders exhibit good performance at data rates below 4.8 kbps. The major drawback of CELP type coders is the requirement of a lot of computation. In this paper, we propose a new pitch search method that preserves the quality of CELP vocoder with reduced complexity. In the pitch searching, we detect the preliminary pitches of high correlation using a simple correlation technique, and then carry out the pitch searching only for the preliminary pitches. By the proposed method, we can get approximately 77% complexity reduction with 0.8 dB SNR degradation on average due to the pitch search.