An Iterative Approach to Near-Uniform Group-Delay Error Design of FIR Filters
An Iterative Approach to Near-Uniform Group-Delay Error Design of FIR Filters
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DOI：
10.1109/lsp.2010.2099217
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发表时间：
2011-02
影响因子：
3.9
通讯作者：
Xiaoping Lai;Chunlu Lai;Ruijie Zhao
中科院分区：
文献类型：
--
作者：
Xiaoping Lai;Chunlu Lai;Ruijie Zhao
对于极小极大有限脉冲响应滤波器，滤波器带附近的群延迟误差通常比其他地方的误差大得多。最近引入了一个sigmoid函数作为相位误差上界函数，以有效地减小带附近的群延迟误差。然而，手工选择函数参数限制了其在设计中的灵活使用。本文提出了一个迭代过程，利用改进的绝对群延迟误差包络来更新相位误差上界函数，使得到的滤波器具有接近均匀的群延迟误差，从而减小最大群延迟误差。设计实例验证了所提迭代过程的有效性。
For a minimax finite impulse response filter, the group-delay error near the bandedges of the filter is usually much larger than the error elsewhere. A sigmoid function was recently introduced as a phase-error upper-bound function to effectively reduce the group-delay error near the bandedge. However, the manual selection of the function's parameters limits its flexible use in the design. This letter presents an iterative procedure to update the phase-error upper-bound function using a modified envelope of the absolute group-delay error, such that the resulting filter has near-uniform group-delay error, and thus to reduce the maximum group-delay error. Design examples demonstrate the effectiveness of the proposed iterative procedure.