窄带FIR数字滤波器是滤波器设计的关键课题，利用窄带滤波器可以减少设备的计算量，进而提高速度。本文档的目的是研究性能较好且运算量较小的窄带FIR数字滤波器。实现可以通过DSP编程完成。-Narrow-band FIR digital filter is a key issue in filter design, use of narrow-band filter can reduce the computational device, and then increase speed. The purpose of this document is to study the performance of good and low computational narrowband FIR digital filter. DSP program can be completed to achieve.