Some exchange algorithms complementing the Parks-McClellan program for filter design
Ivan Selesnick, C.S. Burrus · 1995
In this paper, several modifications of the Parks-McClellan (PM) program are described that treat the band edges differently than does the PM program. The first exchange algorithm we describe allows (1) the explicit specification of ffi p and ffi s and (2) the specification of the half-magnitude frequency, !o . The set of lowpass filters obtained with this algorithm is the same as the set of lowpass filters produced by the PM algorithm. We also find that if passband monotonicity is desired in the design of filters having very flat passbands it is also desirable to modify the usual way of treating the band edges. The second multiple exchange algorithm we describe produces filters having a specified ffi p and ffi s but also includes a measure of the integral square error. 1 Introduction In this paper, several modifications of the Parks-McClellan (PM) program [11, 13, 17] are described. Recall that in their approach to the design of digital filters, the band edges are specified and the ...