Real-Time Implementation of a 16 Kb/s Low-Delay CELP Speech Coder

Due to the CCITT's intention to standardize a low-delay 16 kb/s speech coder, within the research community there is a great interest in the area of low-delay coding at 16kb/s. In March 1989, AT&T submitted to the CCITT a candidate coding algorithm called Low-Delay CELP (LD-CELP). This coding algorithm achieves speech quality very close to that of the CCITT standard 32 kb/s ADPCM and is much more robust than 32 kb/s ADPCM for noisy channels. However, to implement this complex coding algorithm in real-time and actually achieve a one-way encoder/decoder delay of less than 2 ms remains a major challenge.