A candidate coder for the ITU-T's new wideband speech coding standard

This paper presents AT&T's candidate coder for the ITU-T's new wideband speech coding standard at 16, 24 and 32 kb/s. This coder achieves high speech quality with a low coder complexity. The basic idea of the coder is to perform closed-loop pitch prediction on perceptually weighted speech, and then quantize the prediction residual using perceptually based transform coding techniques. A first version of the coder based on DFT was thoroughly tested and submitted to the ITU-T in February 1996, and it was selected as one of two surviving candidates to advance to the next phase. A revised version based on MDCT was later submitted in October 1996. Both versions are described.