Patent ID: 6289307
Filing Date: 2001-09-11
Classification: G10L

Abstract:
A codebook preliminary selection device, comprising:a synthesis filter that receives code vectors from a codebook and outputs synthetic signal vectors, respectively;a simple evaluation value deriving section that repeatedly executes matrix calculations based on a simplified calculation equation using an impulse response matrix of said synthesis filter, wherein the code vectors from said codebook and gains of the code vectors are inputted into said synthesis filter, so as to derive simple evaluation values, respectively, for evaluating errors between the synthetic signal vectors outputted from said synthesis filter and a target signal vector, respectively;a grouping section that divides said simple evaluation values into as a number of groups equal to the number of said simple evaluation values to be selected as candidates; anda preliminary selecting section that compares said simple evaluation values mutually in each group to select an optimum value in each group and outputs the optimum values from all the groups as the candidates.