A class of linear-phase FIR filters for decimation, interpolation, and narrow-band filtering

摘要: A new class of linear phase finite impulse response (FIR) digital filters for decimation and interpolation is discussed. The transfer function these the form H(z) = (zD) B(z)where D or ratio realized at lower sampling rate. polynomial adjusted so that overall magnitude presents an equiripple behavior in pass-band, whereas B(z) provides stopband response. An efficient iterative procedure design this type presented optimal selection orders A(zD) considered. Several examples show how decimators interpolators require significantly fewer multiplications per second than equivalent conventional FIR elliptic designs. performance about same as recursive Martinez Parks with only powers zDin denominator. Some characteristics filters, such zero positions, coefficient sensitivity, output noise variance due to roundoff errors, are discussed compared Furthermore, it shown by cascading multistage interpolators, we obtain narrow-band requiring considerably sample