The Optimization And Implementation Of AMR-WB Speech Coding Algorithm

With the rapid development of DSP technology, it becomes a powerful tool in the speech signal processing, which makes it possible to implement all kinds of complex algorithms in real time. Based on different applications, many standards of speech compress coding have been established by different international standardization organizations. The AMR-WB speech codec based on ACELP was approved by 3GPP in March 2001 and selected for wideband speech coding by ITU-T.Compared with other speech coding standards, AMR-WB is much more natural and intelligible, so it is widely used in Mobile Communications, ISDN wideband telephone, ISDN video telephone and video conferencing. But its high complexity limits its application in the area with critical hardware platform. The purpose of the thesis is to lower the complexity of AMR-WB, ensure the coding quality and implement the AMR-WB speech coding algorithm in real time on the platform of TMS320C6416.This thesis evaluated the computing complexity, memory space complexity and coding quality of AMR-WB coding algorithm. The results show that the computing complexity of fixed codebook search algorithm is 674.13MIPS, occupying 40% of the whole AMR-WB coding algorithm. This results in the high computing complexity of AMR-WB coding algorithm. In order to reducing the computing complexity of AMR-WB coding algorithm, this thesis proposed a fast fixed codebook search algorithm for AMR-WB coding algorithm on the basis of studying the methods of ACELP fixed codebook search. The results show that the computing complexity of the new algorithm reduces by 53.6% compared with deep first tree search algorithm in AMR-WB,not only reduces the computing complexity of the whole coding algorithm significantly, but also ensures the coding quality. Lastly, this thesis transported and optimized the AMR-WB coding algorithm with improved algorithm based on the platform of TMS320C6416 DSP, completed the optimization of kernal algorithms at the C code level and real-time implementation of the AMR-WB speech coding algorithm.