Analysis-by-Synthesis Speech Coding

Abstract

Since the early 1980s, advances in speech coding speechcoding technologies have enabled speech coders to achieve bit-rate reductions of a factor of 4 to 8 while maintaining roughly the same high speech quality. One of the most important driving forces behind this feat is the so-called analysis-by-synthesis paradigm for coding the excitation signal of predictive speech coders. In this chapter, we give an overview of many variations of the analysis-by-synthesis analysisby synthesis speech coding excitation coding paradigm as exemplified by various speech coding standards around the world. We describe the variations of the same basic theme in the context of different coder structures where these techniques are employed. We also attempt to show the relationship between them in the form of a family tree. The goal of this chapter is to give the readers a big-picture understanding of the dominant types of analysis-by-synthesis excitation coding techniques for predictive speech coding.