Research on Decimation Technique of Digital Downconversion

This paper discusses the theory of CIC decimation filter in digital downconversion processing technique of software radio receiver and analyzed the design technique of CIC filter Cascaded ISOP filters which process decimation filtering. The results validate that ISOP filter can effectively reduce the passband droop caused by CIC filtering with little degradation in aliasing attenuation sand that CIC decimation filter system can largely reduce narrowband FIR filter's lap.