Fast FIR Digital Filter Structures Using Minimal Number of Adders and Its Application to Filter Design

Mitsuhiko YAGYU  Akinori NISHIHARA  Nobuo FUJII  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E79-A   No.8   pp.1120-1129
Publication Date: 1996/08/25
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Digital Signal Processing)
FIR digital filter,  CSD expression,  MILP,  

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This paper proposes fast FIR digital filter structures using the minimal number of adders. Filter coefficients are expressed with canonic signed digit (CSD) code and Hartley's technique is used to minimize the number of adders and subtractors. The proposed filters implemented as wired logic are fast because the structure having the shortest critical path is selected. Two algorithms are given to obtain such fast structures. In many examples the critical path length of the filter structures obtained using the proposed method is equal to that of the conventional CSD structures. This paper also presents a new design method of FIR filters using the mixed integer programming (MILP). Utilization of common expressions in Hartley's technique widens the CSD coefficient space. Thus the MILP may lead to better frequency responses. Superior frequency responses are actually obtained in many simulations.