A new cascaded modified CIC-cosine decimation filter

This paper presents a new modified multistage CIC-cosine decimation filter. The original CIC filter is replaced by a multistage structure, where each stage is a cascade of simple CIC filters. The number of cascaded filters can be different for different stages. The first section is realized in nonrecursive form. Using the polyphase decomposition, the subfilters of the first section can be operated at a lower rate which depends on the down-sampling factor of the first section. The magnitude response of this filter is improved by using cosine prefilters which can also be moved to a lower rate. The resulting structure does not have any filtering at the high input rate and has an improved magnitude characteristic.