Filter enabling decimation of digital signals by a rational factor

摘要

The invention concerns a decimation filter for decimation of a digital signal by a rational decimation factor (R) including: a cascade of integrators ( 12 ), at least a comb branch ( 16 A, 16 B) including a decimator ( 18 A, 18 B), a cascade of differentiators ( 22 A, 22 B), It includes: a first and a second comb branches ( 16 A, 16 B) both adapted to receive the samples from said cascade of integrators ( 12 ), the decimators ( 18 A, 18 B) of the first and second comb branches having a first and a second integer decimation factors (R₁, R₂) which are different, switching means ( 26, 28 ) for delivering at the output of the filter successively a first set of consecutive samples outputted by the first comb branch ( 16 A) and a second set of consecutive samples outputted by the second comb branch ( 16 B). Application to a software defined radio system.