一种基于功率互补对的混合滤波器组的设计

提出了一种满足近似完全重构的两通道混合滤波器组(HFB)的设计方法.该方法利用由数字共轭正交滤波器组的完全重构特性推导出的功率互补对来分解输入信号带宽,保留了数字共轭正交滤波器组的功率互补特性和无损特性,克服了传统的HFB在0 频率点和低频区域混叠误差较大的缺点.利用遗传算法优化设计模拟滤波器的参数,并利用逆傅里叶变换实现了数字综合滤波器的设计,保证了近似完全重构.仿真结果表明,采用该方法设计的HFB在输入信号带宽内所有频率点上都具有小于-104 dB的混叠误差,能满足16 bit有效位数模数转换系统的需要.

Hybrid Filter Banks Design Based on Power Complementary Pair

A novel approach to two-channel hybrid filter banks satisfying near-perfect reconstruction was presented. The power complementary pair was derived from the perfect reconstruction condition of digital conjugate quadrature filter banks to retain pairwise power complementary property and the lossless property, which could decrease the aliasing error of the 0 frequency and the low frequency region. The parameters of the analog power complementary pair were optimized by genetic algorithm, and the digital synthesis filters were designed by means of the optimization method based on inverse fast Fourier transforms to ensure the near-perfect reconstruction. The simulations show that the aliasing error in the whole frequency region is lower than -104 dB, which satisfies the requirement of analog digital conversion systems with 16 effective bits, 4 bits higher than conventional methods.