直接法设计均匀与非均匀滤波器组

摘要

针对滤波器组的重构设计,现有算法只能单独设计均匀或非均匀滤波器组,无法同时设计2种不同类型的滤波器组,不具有灵活性.现提出了一种直接法设计所有滤波器组的新思路,该方法从频域推导出滤波器组的重构条件,并将其表示为矩阵形式.根据给定的频带分布情况,同时设计分析模块中各通道滤波器.然后通过迭代优化的思想,求解重构矩阵方程的最优解,进而得到综合模块各通道滤波系数,设计出需要的滤波器组.通过仿真可知,该设计方法可以同时设计均匀与非均匀滤波器组,实现频带的高效划分,具有很高的灵活性,且可以保证各通道滤波器具有线性相位特性.%As for the reconstruction design of the filter banks, the existing algorithms can only be used to design uniform or non-uniform filter banks, it is hard to design two different types of filter banks at the same time, therefore, the flexibility is not enough. A new method of designing all filter banks directly was proposed in the paper. In the method, the reconstruction conditions of filter banks are derived from the frequency domain and expressed in the form of matrix. According to the distribution of the given frequency bands, all channel filters in the analysis modules are designed simultaneously; then the optimum solution of the reconstruction matrix equation can be obtained by the iterative optimization theory, the filtering coefficients of all passages in the comprehensive modules can be further obtained and the necessary filter banks can be designed. Simulation results show that, the design method can be used to design the uniform filter banks and the non-uniform filter banks simultaneously, realize high-efficiency division of frequency band, the flexibility is high, in addition, the method can ensure the linear phase characteristics of each channel filter.