| 摘要 |
PURPOSE:To provide a device and a method for controlling adaptation processings capable of suppressing/preventing the generation of noise due to the overflow of updated filter coefficients and in the case of the substantial fluctuation of the level of reference signals in the adaptation processing of an adaptive type noise canceller or the like. CONSTITUTION:A square integration circuit 7 square-integrates reference input signals (b) and calculates energy. A comparator circuit 8 compares an integrated result with a threshold value, turns a step size to '0' and stops the adaptation processing when the integrated result is smaller than a level value and turns the step size to an original value and restarts the adaptation processing when it is larger than the level value. A multiplier 6 multiplies output from the comparator circuit 8 and the output of a subtracter 2 together and inputs the output to a coefficient updating processing circuit 5. The coefficient updating processing circuit 5 executes LMS algorithm by the reference input signals (b) and the output from the multiplier 6. An adaptive type FIR filter 4 performs the adaptation processing to the output of a delay circuit 3 by the output of the coefficient updating processing circuit 5 and obtains adaptation processing signals (d). |
