L₁近似による複素係数を有するFIRディジタルフィルタの設計

抄録

In this paper, we propose an L₁-approximation for the design of FIR digital filters with complex coefficients. The L₁-approximation has the advantage of having a flat passband and a small overshoot around the discontinuity point as compared with L₂-approximation and L_∞-approximation. As the obtained filter has complex coefficients, it can be reduced group delay and designed a digital filter with an asymmetric amplitude characteristic with respect to the origin. Algorithm proposed in this paper is based on Newton's method which is an efficient iterative approximation algorithm. We show effectiveness of the proposed method through a design example.