Research And Design Of Narrow Band FIR Digital Filters

With the rapid development of software radio techniques, the sampling rate is becoming high. On the condition of high sampling rate, the design of narrow band FIR digital filters by usual ways is impossible. Based on multirate digital signal processing, this paper development a new method to design the narrow band FIR digital filter, which makes the design of narrow band FIR digital filters possible.Firstly, this paper introduces the basic structure of narrow band FIR digital filters. Secondly, it analyses the components of narrow band FIR digital filters, which conclude CIC filter, HBF filter, resampling techniques. Based on these analyses, the paper gives the full structure of narrow band FIR digital filters and analyses its characteristics, which are frequencies response, anti_aliasing and anti_image. Lastly, the paper designs an example and tests its amplitude frequency response.At last, this paper points out that this method can efficiently control the performance of narrow band FIR digital filters. Both test and application indicate that practical performance and ideal performance are almost identical.