一种适合于窄过渡带FIR滤波器设计的方法

介绍了一种适合于窄过渡带FIR(有限冲击响应)滤波器设计的方法———频罩法,首先设计一个原型滤波器,将该滤波器每个延迟部分延迟M点可产生尖锐过渡带,对其施加不同中心频率的低阶频罩滤波器,即可得到所需的尖锐带通滤波器,该方法实现窄带FIR滤波器所需的阶数仅为直接设计的50%左右;然后讨论了其VHDL(超高速集成电路硬件描述语言)实现算法,最后介绍了利用FPGA(现场可编程门阵列)实现此系统的设计方案,并分析了实际硬件设计过程中涉及的问题。

A Novel Method for the Design of Narrow Transition-band FIR Filters

In this paper the Frequency-Response Masking technique is introduced which is suitable for the design of narrow transition-band FIR filters.After a prototype filter is designed,M points are delayed so as to generate a narrow transition-band,then low-rank mask filters with different center frequencies are used to obtain the narrow band filuers.Using this method the rank of filters can be reduced to 50% of those needed in the direct method.Finally,the VHDL algorithms and implementation using FPGA are discussed and theproblems occured during the hardware design are also analyzed.