21st International Research/Expert Conference
Decimation is process of decreasing sampling rate by an integer, called decimation factor. This process introduces aliasing which may deteriorate the decimated signal and must be eliminated by a filter, called decimation filter. The most simple decimation filter is a comb filter, which has all coefficients equal to unity, and consequently does not require multipliers for its implementation. However, comb filter does not provide enough aliasing attenuation. This paper presents novel combbased decimation filter with an improved alias rejection in comparison with the original comb filter. This is achieved by rotation of comb zeros from their original position, using simple multiplierless filter. Mathematical background for the design of the filter is provided and explained with one example. The proposed method is illustrated with one example and compared with the original comb filter.