Optimization of code excited linear prediction speech coder with PSVQ-genetic codebook

摘要

The development of high quality speech coders at low bit rate and low delay is a challenging task in the field of speech communication, due to ever increasing users in wireless communication networks. CELP codec gives good quality at 4.8 kbps. By optimizing the excitation vectors in the codebook many changes in the performance can be observed to achieve toll quality speech. Codebook optimization can be achieved by improving the training process in the generation process and by using fast searching algorithms. Gaussian (X-means clustering), Fixed (PSVQ) and PSVQ-Genetic codebooks were generated to be included in CELP 4.8. Variations in performance were evaluated using objective and subjective quality measures. Experiments show that CELP 4.8 provides toll quality and reduced delay with PSVQ-Genetic codebook.