APPARATUS FOR BANDWIDTH EXPANSION OF A SPEECH SIGNAL

摘要

A speech coding method and device for encoding and decoding an input signal, wherein the higher frequency components of the synthesized speech are achiev ed by high-pass filtering and coloring an artificial signal. The processed artificial signal is scaled by a first scaling factor during the active spee ch periods of the input signal and a second scaling factor during the non-activ e speech periods, wherein the first scaling factor is characteristic of the higher frequency band of the input signal and the second scaling factor is characteristic of the lower frequency band of the input signal. In particula r, the second scaling factor is estimated based on the lower frequency componen ts of the synthesized speech and the coloring of the artificial signal is based on the linear predictive coding coefficients characteristic of the lower frequency of the input signal.