类梳状补偿滤波器设计与仿真

积分梳状（CIC：cascaded integrator comb）滤波器由于具有运算速度较快，占用资源少等优点，而被广泛应用于多信号抗混叠系统中.针对传统CIC滤波器因简单级联而带来的通带失真增大和阻带衰减减小的缺陷，本文基于CIC滤波器的传递函数以及频谱特性分析，提出了一种类梳状补偿滤波器（SCC_CIC：similar to comb compensation CIC）的设计方案，根据实际需要调整参数和来满足设计要求.同时，利用多相分解技术重构滤波器结构，提升了整个系统的运行效率，且实现复杂度较低.通过MATLAB仿真实验及分析，相比N=2的同级联数的传统CIC滤波器、ISOP_CIC （interpolated second-order polynomials CIC）和SCIC （sharpening to cascaded integrator-comb）滤波器，SCC_CIC滤波器在f_s处的阻带衰减分别增加近了80dB、60dB和70dB，在f_c处分别补偿通带失真97.3%、90.1%和-2%，整个滤波器的运算量减小到1/D，滤波器的精确度基本保持一致，使得SCC_CIC能够较好地应用在抗混叠滤波系统中.

The Designing and the Simulation of the SCC_CIC Compensation Filter

For the advantage of high speed in computing and very limited consumption of resource,CIC (cascaded integrator comb) filter has been widely used in Multi-signal anti-aliasing systems.In this paper,we proposed a SCC_CIC (similar to comb compensation CIC) filter based on the transfer function of CIC filter and the analysis of its spectrum characteristics.The SCC_CIC filter could combat the disadvantage of high pass-band distortion and low stop-band attenuation brought by filter cascading.In practice,we could adjust parameter C1 and K to satisfy the requirement of the system.In addition,by reconstructing the structure of the filter with the aid of poly-phase decomposition technique,the efficiency of the system could be improved evidently.As shown in numerical Montel-Carlo simulation results,compared with the traditional CIC,the ISOP_CIC (interpolated second-order polynomials CIC) and the SCIC (sharpening to cascaded integrator-comb) filters,the advantage of the SCC_CIC for the stop-band attenuation is approximately 80dB、60dB and 70dB,respectively.Compared with the CIC,the ISOP_CIC,and the SCIC filter,the advantage for the pass-band distortion of our method has been improved by approximately 97.3%、90.1% and-2% accordingly.For the SCC_CIC filter,the total computation complexity could be decreased to 1/D the complexity required by the CIC filter.These advantages facilitate the application of the SCC_CIC filter in numeral Multi-signal anti-aliasing systems.