Abstract:This paper researches the cascade of CIC filter and HB filter, describes the criteria of cascade, simulates cascades of the 2 filters applied in an SDR receiver’s decimating system using Matlab, and the AGWN is also involved in the simulation. The simulation result indicates that the cascading of decimators can effectively solve the problem of the large ratio of decimation with such functions as anti-aliasing, suppression of spurious wave, denoising and decreasing the sampling ratio.