Truncation in Decimation Filters with Minimum Number of Additions per Output Sample

Multistage decimation filters allow minimization of number of additions per output sample (APOS), thus reducing the computational complexity. However, the implementation of these filters requires large wordlengths in their internal sections, which increases power consumption. This problem is mitigated by appropriate truncation of filter's adders and registers. In this paper, we consider the truncation in multistage CIC filters. In particular, we present a procedure for the truncation of adders and registers in decimation filters with minimum number of APOS. In addition, we provide an analysis of truncation's influence on the power consumption of these filters.