| 摘要 |
PURPOSE:To obtain superior SN and a distortion characteristic by the small number of bits by dividing a representative value of each block obtained by dividing a PCM code in each fixed period by the difference value of an original signal, then transmitting the compressed value together with the representative value. CONSTITUTION:An A/D converter 1 converts an analog signal AS into a digital signal OP and an RAM 2 stores the digital signal OP. A maximum/minimum detecting circuit 3 detects the maximum and minimum values in the block. A block level calculating circuit 4 finds out a center value BL in the block and a difference detecting circuit 8 finds out the difference value between the center value BL and an original signal. A width detecting circuit 5 detects the variation width in one block and a scale value generating circuit 6 reads out a scale value corresponding to the variation width from a scale reference storage circuit 7 and generates a scale value SL. The difference value is compressed at a data compressing circuit 9 on the basis of the scale value, and synthesized at a synthesizing circuit 10 and the center value BL, and transmitted. |
