Importance

Loading Importance Indicators...

Abstract

A method and implementing apparatus for low-bit rate speech band signal coding. An input signal in the speech band is represented by a pulse excitation sequence and a spectral parameter sequence over a frame of predetermined frame length using a selected one of a plurality of pulse determining processing modes. The selected pulse determining processing mode sequentially determines the amplitudes g.sub.i and locations m.sub.i of the pulses of the pulse excitation sequence on the basis of the amplitudes and locations of pulses in a previous frame. The selection process of determining which of the pulse determined processing modes to be used involves analyzing the input signal to produce a judgment signal d signifying the input signal as a voiced or an unvoiced signal, and selecting the pulse determining processing mode in response to the judgment signal d. The pulse excitation sequence and spectral parameter sequence are coded for transmission to a suitable receiver. The judgment signal d may also be coded and transmitted to the receiver. The receiver reproduces the input signal from the received coded signal.

Loading the Abstract Image...

First Claim