An Analytical Approach for Design of Nth-band FIR Digital Filters with Equi-Ripple Passband

Moon, Dong-Wook;Kim, Lark-Kyo;Lim, Cheng-Chew

  • Published : 2009.09.01


In FIR (Finite Impulse Response) filter applications, Nth-band FIR digital filters are known to be important due to their reduced computational requirements. The conventional methods for designing FIR filters use iterative approaches such as the well-known Parks-McClellan algorithm. The Parks-McClellan algorithm is also used to design Nth-band FIR digital filters after Mintzer's research. However, a disadvantage of the Parks-McClellan algorithm is that it needs a large amount of design time. This paper describes a direct design method for Nth-band FIR Filters using Chebyshev polynomials, which provides a reduced design time over indirect methods such as the Parks-McClellan algorithm. The response of the resulting filter is equi-ripple in passband. Our proposed method produces a passband response that is equi-ripple to within a minuscule error, comparable to that of Mintzer's design method which uses the Parks-McClellan algorithm.


Chebyshev polynomials;digital filter design;FIR filter;multi-rate filters;Nth-band filters


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