Design of Efficient Polynomial-based Filters Using Discrete-time Opimization

This paper presents several novel structures for conversion between arbitrary sampling rates. The method allows arbitrary number of zeros at multiples of both input and output sampling rates, thus it has both good anti-imaging and good anti-aliasing properties. The novel structures are derived from continuous-time equivalents of CIC and modified comb filters. The implementation can be based on either the modified Farrow or transposed modified Farrow structure. By choosing one of these two alternatives appropriately, it is possible to shift most of the operations to lower sampling rate. Furthermore, it is possible to improve frequency domain performance by choosing continuous-time equivalent of the modified comb filter. In this way, we obtain very efficient filters for arbitrary sampling rate conversion, which are optimized directly in digital domain.