| 摘要 |
PURPOSE:To decide a real assignment bit number of each band area for restricting distortion of the wave form at minimum by truncating a fraction easily on the basis of a computed assignment bit number, and correcting the bit number to maintain the bit number of the whole constant. CONSTITUTION:A decision unit 6 computes a computed assignment bit number R1i on the basis of the data of the power Ui of each band area, and truncates a fraction of the number R1i less than a decimal point to obtain an integral bit number R2i which consists of only integral number. Shortage of the number R2i from the total bit number N - R of the whole is computed to obtain a residual bit number A, and simultaneously, one bit is respectively added to A number of the integral bit number R2i, which correspond to the number R1i and arranged in order of largeness of fraction of the number R1i, to eliminate the shortage on the basis of the number A. The total number of the integral bit number R3i after this addition is equal to the number N - R, and the number R2i is corrected to the number R3i by adding one bit to the number R2i after the truncation to restrict dislocation of the number R1i from the number R3i. The number R3i is thereby decided as a real assignment bit number of each band area, which makes distortion of the wave form minimum. |
