負の重みを用いたメジアンフィルタによる帯域フィルタの性質

Abstract

Although linear filters show effective performance in many applications, there are certain situations when it is impossible to find an acceptable linear filter. For example, in many applications the spectrum of the desired signal and of the noise overlap and, therefore, frequency selective behavior of linear filters can not produce the desired results. In some of these cases, nonlinear filters can be used. In this paper, weighted median filter admitting negative weights, which is abbreviated as NWMF, is considered. These weights are calculated by using spectral optimization technique and are derived using FIR filter coefficients. Steady state response of NWMF for sinusoidal input signal shows as a notch filter or frequency elimination filter with narrow bandwidth.