The cascaded digital decimation filter based on DMR protocol

This paper gives a research of the cascaded digital decimation filter based on the 12.5kHz channel spacing standard of European ETSI´s DMR which is designed to reduce the sampling rate with a large decimation. Because odd decimations can not be decomposed by 2, the application of HB filter is limited. The Anti-aliasing low-pass FIR decimation filter whose decimations are odd and high level can be instead of half-band filter. The MATLAB simulation result indicates that the cascaded digital decimation filter can not only effectively solve the problem of large and odd decimation, but also gain the signal fitting for the 12.5kHz channel.