| 摘要 |
PURPOSE:To obtain satisfactory reproduced sound by interpolating at least one parameter in past and future accurate frames when the error of a transmission path which cannot be corrected is detected in a received code. CONSTITUTION:When error detection information is inputted from an error correction decoding circuit 105, an interpolation circuit 110 interpolates delay information showing a pitch period, information showing the power of sound and filter parameter between the parameters of the past and future accurate frames and outputs the interpolated parameter. An adaptive code book 120 inputs delay information, a pitch gain and the output signal of a delay circuit 165 and calculates a prediction signal. A sound source code book 130 inputs a code vector index, reads a corresponding code vector from a code book 135 and outputs a sound source signal. An adder 160 adds the prediction signal from the adaptive code book 120 and that from the sound source book 130 and outputs them to a synthesis filter 170. |
