Performance analysis of CELP codec for Gaussian and fixed codebooks

The design of high quality speech coders with low data rate is a very challenging task in speech processing. CELP provides good quality coded speech at a very low bit rate of 4.8kbps. Two types of codebooks namely Gaussian codebook and Fixed codebook are used in this analysis. The changes in the performance of the CELP codec is evaluated for theses two codebooks. Optimization of the codebook can be done by improving the training process in the codebook generation stage. Two different types of codebooks, the Gaussian codebook and the fixed codebook is generated to be implemented in the G723.1 CELP codec and the variation in the performance is evaluated.