| 摘要 |
FIELD: information technology. ^ SUBSTANCE: invention relates to an apparatus for searching in a fixed coding table, which slightly inhibits increase in the volume of operations, even if the filter applied to the drive pulse has a characteristic which cannot be presented by a lower triangular matrix, and realises quasi-optimum search in the fixed coding table. The apparatus for search in a fixed coding table is provided with an algebraic coding table (101) which generates a pulse driving vector; a convolution operation module (151) which performs convolution relative the pulse characteristic of the audio weighted synthetic filter into a pulse characteristic vector, having a value in negative time instants, so as to generate a second pulse characteristic vector, having a value in second negative time instants; a matrix generation module (152) which generates a Toeplitz-type convolution matrix through the second pulse characteristic vector; and a convolution operation module (153) which performs convolution relative the matrix generated by the matrix generation module (152) into a pulse driving vector generated by the algebraic coding table (101). ^ EFFECT: minimising increase in computational load by realising quasi-optimum search of a fixed coding table. ^ 4 cl, 3 dwg |
