Abstract
We often encounter with a signal composed of a base level signal slowly varying in time and a relatively fast varying signal of interest, such as electrocardiogram and video signal of cars running on a road. In order to set the base level signal, we usually estimate the base level signal by a lowpass filter using difference of characteristics in frequency domain between these two signals. However, a base level estimator of the linear filter is directly affected by amplitude of the signal of interest.
We propose the new base level signal estimator using a bilateral clamper that consists of two linear filters and a non-linear element, moreover, analyze precisely and give roughly design criteria. This estimator has nice response to the change of the base level signal, and well protects the affection of the signal of interest.
Finally, we demonstrate usefulness of this estimator showing some examples.
