SEARCH DEVICE IN FIXED ENCODING TABLES AND SEARCH METHOD IN FIXED ENCODING TABLES

摘要

1. The search device in a fixed encoding table, containing:! a module for generating a pulse excitation vector, which generates a pulse excitation vector; ! a first convolution operation module that performs convolution with respect to the impulse response of the perceptually weighted synthetic filter with an impulse response vector that has one or more values at negative times to form a second impulse response vector that has one or more values at negative times; ! a matrix generating module that generates a Toeplitz-type convolution matrix by a second impulse response vector generated by the first convolution operation module; and! a second convolution operation module that performs convolution processing with respect to the pulse excitation vector generated by the pulse excitation vector generating unit using the matrix generated by the matrix generating unit. ! 2. The search device in the fixed coding table according to claim 1, in which the convolution matrix of the Toeplitz type is shown by the matrix H 'according to the following equation (4):! ! where h0 (n) is the second vector of the impulse response (n = -m, ..., 0, ..., N-1), which has one or more values at negative times. ! 3. The search device in the fixed coding table according to claim 1, in which the energy of the components of the second vector of the impulse response at negative times is less than the energy of the components at non-negative times. ! 4. The search device in a fixed encoding table according to claim 1, in which