Overview of Code Excited Linear Predictive Coder

Advances in speech coding technologies have enabled speech coders to achieve bit-rate reductions at a great extent while maintaining roughly the same speech quality. One of the most important driving forces behind this feat is the analysis-by-synthesis paradigm. Code Excited Linear Predictive coder (CELP) is the quite efficient closed loop analysis-by-synthesis method for narrow and medium band speech coding systems. CELP algorithm can produce lowrate coded speech comparable to that of mediumrate waveform coders thereby bridging the gap between waveform coders and Vocoders. This paper gives the general overview and conceptual literature of this highly proficient speech coder. Keywords— Analysis-by-synthesis, CELP, speech coder, Vocoders, waveform coders.