A METHOD FOR QUANTIZING COEFFICIENTS OF A FILTER WITH GENETIC ALGORITHM

This paper proposes a new method to quantize coefficients of filters w here frequency-characteristic deterioration is suppressed. When a digi tal filter is realized, quantization errors cannot be avoided because operation circuits and registers have finite word lengths. Generally, filter coefficients are quantized by popular methods, such as rounding and omitting, etc. The pro; posed method obtains the quantized coeffi cients by search. The Genetic Algorithm is used for the search because it needs only objective function information. Further, by using the p roposed method, the filter coefficients can be quantized with the freq uency weight. Therefore, deterioration of the coefficients quantized b y the proposed method is suppressed in the specified frequency region. The effectiveness of this method is shown by some simulations that qu antize the four-line lattice and the direct form filter coefficients.