This is another "CELP based fantastic speech coding scheme", and in this case we have solved a problem that will make your speech coding real time implementation really easier. We combine the efficiency of the open loop analysis with the robustness of the closed loop one. In this way, we obtain a significant computational save in the search of the optimum excitation vector with no loss of speech quality. We developed a real time implementation of this coder for low bit rate transmission (from 4.8 to 14.4 KBPS) and for wideband speech coding (from 16.0 to 28.8 KBPS).
Bibliographic reference. Moreno Perez, Sofia / Garcia Gomez, Ramon (1995): "Improved CELP algorithm suited for various speech coding applications", In EUROSPEECH-1995, 699-702.