数字接收机中CIC滤波器的设计

Application of CIC filter in digital receiver

CIC(cascaded integrator comb)滤波器的结构简单,需要的存储量小,是被证明在高速抽取和插值系统中非常有效的单元。它主要用于采样速率的抽取,同时具有低通滤波的作用。CIC滤波器的主要特点是,仅仅利用加法器、减法器和寄存器,因此占用资源少、实现简单且速度高。介绍了CIC滤波器的基本组成原理,并在此基础上,提出了滤波器的各项参数的选择和设计CIC滤波器的基本方法,用Verilog HDL语言在FPGA和MATLAB上分别进行了仿真,并且验证了设计的可靠性和可行性。

CIC filter is a very effective unit in high-speed extraction and interpolation system, which has simple structure and the small needs of storage. It is used to decimate the sample frequency, and it is can be used as a low pass filter. The CIC filter is a flexible, multiplier-free filter which includes adders, subtracters and registers, so it uses less resources and can play well in high frequency. This paper describes the basic composition principles of CIC filter, Base on the theory of CIC filter, we have proposed the choice of the filter＇s parameters and the basic ways of CIC filter designing. It gives the FPGA and MATLAB simulation results to verify the reliability of the design and feasibility.