NEW NONLINEAR ADAPTIVE FIR DIGITAL-FILTER FOR BROAD-BAND NOISE CANCELLATION

The structure and the adaptive algorithm of a new nonlinear adaptive F IR digital filter, called nonlinear delayed N-path adaptive FIR (NDNAF IR) digital filter, is presented for cancelling broadband noise from s ignals containing sharp edges. The filter structure is obtained by dec omposing a FIR digital filter into N delayed parallel subfilters which facilitates high speed implementation. Adjustable bipolar sigmoid fun ctions are placed at the output of each subfilter as well as after the summation of all subfilter outputs. Simulation results show that the NDNAFIR digital filter outperforms those of the linear adaptive FIR di gital filter and the nonlinear median filter in broadband noise cancel lation in terms of convergence speed and average squared difference be tween original and recovered signals.