| 摘要 |
<p>PURPOSE:To make the filter adaptive, by detecting the period of noise included in an input signal from the differential signal between the input signal and an output signal and adjusting the moving average width of filter automatically. CONSTITUTION:In a digital moving average filter 1 outputting the moving average of a digital input signal, the moving average width being a parameter of a filter is set so that noise detected in any time can effectively be rejected with a delay element 2 to an observed input signal X. Further, a signal XL giving the phase delay of the moving average width to the input signal X is outputted, and a differential signal E with an estimated output signal Y in moving average is inputted to a moving average width automatic tuner 3, and the period of periodic noise is detected from this signal E and the average width is determined so that the digital filter 1 can interrupt the periodic noise. Thus, the moving average width of the adaptive filter can be changed automatically.</p> |
