Communication system capable of improving a speech quality by a pair of pulse producing units

Abstract From the Canadian patent

In an encoder device which is for use in combination with a decoder device in a communication system and which encodes a sequence of digital speech signals into a sequence of output signals by the use of a spectrum parameter and pitch parameters a primary, pulse producing unit calculates a first set of prediction excitation multipulses by the use of the spectrum parameter and the pitch parameters with respect to a preselected one of subframes which result from dividing every frames and produces the first set of prediction excitation multipulses and a sequence of primary synthesized signals specified by the first set of prediction excitation multipulses and the spectrum parameter and the …