METHOD AND DEVICE FOR TRANSMITTING SOUND BY NARROW BAND WIDTH CHANNEL, AND METHOD FOR RECEIVING SOUND DIGITIZED FROM NARROW BAND WIDTH CHANNEL

摘要

PROBLEM TO BE SOLVED: To obtain improved and perceived fidelity by using a tautology so called that a signal is predictable as long as the signal is predictable. SOLUTION: An output 122 is a spike gain code 18G, and a spike gain or a scale factor element 126 makes the spike gain reproduce, and the element 126 multiplies the spike gain by a spike signal 130 to generate the scaled spike signal 132. A third minimizer 120 makes the difference between the scaled spike signal 132 and the output 116 of an AF 116 minimum. The operation above mentioned is performed in an LPC remaining area before the scaled spike signal 118 is given to a third SF&PWF 134. A first (pitch) minimizer 78 works after the signal passes through a first SF&PWF 72 just similarly to the case that a second minimizer 96 works after the signal passes through a second SF&PWF 92.