改进的 IFIR 近似精确重构原型滤波器设计

针对传统内插有限长脉冲响应(interpolated finite impulse response,IFIR)原型滤波器设计时产生镜像部分从而增加设计复杂度的不足,提出一种内插非零值且不产生镜像部分的原型滤波器优化算法.通过对多种非零插值方法得到的滤波器进行仿真及特性分析,揭示出内插零值和内插非零值的内在联系,得到使用一维快速傅立叶内插非零值方法可以设计出符合调制滤波器组要求且设计复杂度降低的高衰减原型滤波器的结论,并给出最优内插模型思路,同时给出设计实例验证了改进方法的性能.理论分析和仿真均可说明,改进方法相对于传统IFIR方法提高了滤波器性能,简化了设计模型,降低了设计复杂度,从而减小了计算量.

Modified IFIR-NPR design of prototype filter

The thesis presents the prototype filter optimization algorithm inserted with a non-zero value to avoid the limitation of design complexity with traditional IFIR prototype filter design mirrored section. The paper reveals the internal relations between the interpolated value of zero and the interpolated value of non-zero by characterization analysis and the filter simulation with a variety of non-zero interpolation method; a high attenuation prototype filter which meets the requirements of the modulated filter banks is designed by using the one-dimensional fast. Fourier nonzero value interpolation method is resulted, and provides on optimal interpolation model and an example to test the performance of new method. It is explained with theory analysis and simulation that the modified method enhances the filter performance, simplifies the design model and reduces design complexity, thus reducing the amount of computation compared to traditional IFIR method.