Low‐sensitivity realization of linear‐phase FIR digital filters using cascade form
Hitoshi Honma, Yukio Mori, Masahiko Sagawa · Electronics and Communications in Japan (Part I Communications) · 1988
Abstract It is important from the viewpoint of economy to realize the digital filter with as little hardware complexity as possible. On the other hand, the theory of low‐sensitivity FIR filter is not advanced, compared with that of the IIR filter. From the viewpoint of minimizing the coefficient word‐length, an investigation of this problem is required. With this as background, this paper aims at the reduction of the coefficient wordlength of the multiplier, and proposes the cascade construction of the FIR filter. First, using the coefficient sensitivity, an evaluation function is defined and used to evaluate the degradation of response due to the coefficient quantization. Then the relation between the locations of zeros and the value of the evaluation function is discussed. It is pointed out that the zeros with relatively remote locations reduce the response degradation. A systematic construction of the low‐sensitivity structure is described, considering the relation between the location of zeros and the evaluation function. Finally, to show its effectiveness, several examples are handled by the proposed method.