Modified vector generator

Abstract

A random code vector reading section and a random codebook of a conventional CELP type speech coder/decoder are respectively replaced with an oscillator for outputting different vector streams in accordance with values of input seeds, and a seed storage section for storing a plurality of seeds. This makes it unnecessary to store fixed vectors as they are in a fixed codebook (ROM), thereby considerably reducing the memory capacity.

We claim:  
     
         1 . A modified vector generator used in an excitation vector generator for a speech codec, comprising: 
 a vector providing system that provides an impulse vector;    a waveform providing system that provides a fixed waveform for one processing channel; and    a convoluting system that convolutes said impulse vector with said fixed waveform to modify a waveform of said impulse vector.