陷波频率可调的线性相位FIR多频陷波滤波器设计方法的研究

发布时间：2018-01-26 12:04

本文关键词： FIR 多频陷波滤波器频率可调线性相位　出处：《南开大学》2015年硕士论文　论文类型：学位论文

【摘要】：数字滤波器具有灵活、快速、精确等优点,广泛应用于通信、控制、生物制药等工业领域。其中数字陷波滤波器,主要用于消除窄带噪声和窄带功率干扰。而频率可调的多频陷波滤波器在应用中具有极大的灵活性,它可以同时消除(或添加)多个指定的频率成分,且不影响其他频率成分。另一方面,具有稀疏性的陷波滤波器,在设计与实现中可以减少加法器的使用量。这不仅能够降低成本、减少功耗、提高运算速度,更可以削弱累计误差造成的影响,提高精确度,增加可靠性。因此,研究低功耗、低复杂度、陷波频率可调的多频陷波滤波器,具有重要的理论和实际意义。本文提出了一种频率可调的多频陷波滤波器的设计方法,该方法利用了窗函数来设计滤波器,并适当地调整滤波器系数,使得设计出来的滤波器具有陷波频率可调、线性相位、FIR、低复杂度等特点。该方法同时适用于均匀(梳状)、非均匀间隔陷波频率的陷波滤波器设计。本文提出的多陷波滤波器设计过程如下：首先,根据给定的通带宽度和阻带纹波要求,利用窗函数设计出一个窄带低通基准滤波器；其次,调整该基准滤波器的系数,使得滤波器的陷波频率满足目标需求,得到最终的多频陷波滤波器。这种调整基准滤波器系数的方法,不仅可以适应不同的陷波频率要求,同时也降低了设计方法的复杂度,还减小了最终滤波器的阶数。仿真结果表明,在相同的设计要求下,对比切比雪夫多项式法,本文设计的均匀陷波滤波器,具有更小的通带纹波；对比级联算法和多重交换算法,本文设计的非均匀陷波滤波器,具有更小的阶数,更小的通带纹波。
[Abstract]:Digital filter is widely used in communication, control, biopharmaceutical and other industrial fields, such as flexible, fast, accurate and so on, among which digital notch filter. It is mainly used to eliminate narrow-band noise and narrow-band power interference. The frequency-adjustable multi-frequency notch filter has great flexibility in application. It can eliminate (or add) multiple specified frequency components at the same time. On the other hand, the notch filter with sparsity can reduce the usage of adder in the design and implementation, which can not only reduce the cost, reduce the power consumption, and improve the operation speed. It can weaken the effect of cumulative error, improve accuracy and increase reliability. Therefore, we study multi-frequency notch filter with low power consumption, low complexity and adjustable notch frequency. It has important theoretical and practical significance. In this paper, a design method of multi-frequency notch filter with adjustable frequency is proposed, which uses window function to design the filter and adjust the filter coefficient appropriately. The designed filter has the characteristics of adjustable notch frequency, linear phase and low complexity, etc. This method is also suitable for uniform (comb). The design process of the multi-notch filter proposed in this paper is as follows: first, according to the given passband width and the requirements of stopband ripple. A narrowband low-pass reference filter is designed by using window function. Secondly, the coefficient of the reference filter is adjusted so that the notch frequency of the filter meets the target requirements, and the final multi-frequency notch filter is obtained. This method adjusts the coefficient of the reference filter. It can not only adapt to different notch frequency requirements, but also reduce the complexity of the design method and reduce the order of the final filter. The simulation results show that under the same design requirements. Compared with Chebyshev polynomial method, the uniform notch filter designed in this paper has smaller passband ripple. Compared with the cascade algorithm and the multiplex switching algorithm, the non-uniform notch filter designed in this paper has smaller order and smaller passband ripple.
【学位授予单位】：南开大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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