Arrangement having a non-recursive filter and means for weighting a sequence of delayed versions of the input signal in accordance with a sequence of coefficients which are each adjusted iteratively by positive and negative correction steps, respectively, with variable step-sizes, the step-size parameter...http://www.google.com.tw/patents/US4349889?utm_source=gb-gplus-share專利 US4349889 - Non-recursive filter having adjustable step-size for each iteration
