Mixed-domain coding of speech at 3 kb/s
Juan Carlos De Martin, A. Gersho · 2002
We present a speech coding algorithm called mixed-domain residual coding (MDRC) wherein a prototype pitch cycle in each frame of the speech residual is coded in the time-domain while interpolation of the residual signal is performed in the frequency-domain. A novel quantization scheme takes into account time scaling and differentially codes successive prototypes with a closed-loop perceptually-weighted search. A fixed-rate (3.15 kb/s) implementation of MDRC achieves quality better or comparable to higher rate coders such as FS 1016 CELP and IMBE.