SIGNAL ENCODING AND DECODING METHODS, DEVICES FOR THE SAME, AND SIGNAL ENCODING/DECODING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a signal encoding method in which a combination of the optimum pulse position and polarity for an excitation source signal can be determined with a small operation quantity. SOLUTION: In the signal encoding method, a sound signal is synthesized by exciting a filter representing the frequency envelope characteristics of a signal with an excitation source signal selected from a noise excitation source code book, a filter coefficient is so quantized that distortion of the composed sound signal based upon an input signal is minimum, and the excitation source signal is selected from the noise excitation source code book. The excitation source signal consists of a string of a specified number of pulses having specified pulse intervals and is represented with quantized amplitudes of the respective pulses and the initial phase of the 1st pulse. COPYRIGHT: (C)2004,JPO&NCIPI