基于FPGA的数字滤波器的设计

基于FPGA的数字滤波器的设计Graduation Design(Thesis) of Chongqing University Design of Digital Filter Based on FPGA

Undergraduate: Huang Jianhua

Supervisor: Yang Lisheng

Major: Electronic Information Engineering

College of Communication Engineering Chongqing University

June 2013

摘要

数字信号处理在通信、雷达、声纳等中有着广泛的应用。数字滤波器的设计是数字信号处理的关键技术之一，有着十分重要的理论和实际意义。随着数字技术的不断发展，在许多场合，数字滤波器正在快速取代模拟滤波器。FPGA(现场可编程门阵列）在现代数字电路设计中发挥着越来越重要的作用。从设计简单的接口电路到设计复杂的状态机，FPGA所扮演的角色已经不容忽视。

本论文完成了基于FPGA的FIR和IIR数字滤波器的设计与实现。本论文首先理论分析讨论了数字滤波器的设计方法，并使用MATLAB工具验证采用哪种窗函数来设计FIR数字滤波器，使用哪种模拟滤波器原型映射IIR数字滤波器。然后根据模拟滤波器的技术指标来确定数字滤波器的技术指标，在MATLAB环境下按照数字滤波器的技术指标设计数字滤波器，并得到滤波器系数，编程实现系数量化，并且比较分析量化前后系统响应的差异，由此得到合适的量化等级。然后在ISE软件平台下根据MATLAB工具得到的量化系数，使用VHDL语言进行FIR和IIR滤波器算法模块编程，同时对AMP电路（可编程预放大器）模块、AD电路（模拟到数字转换器）模块和DA电路（数字到模拟转换器）模块分别进行编程配置，并且对各模块进行严格的软件仿真验证，其中AMP电路模块、AD电路模块和DA电路模块必须进行硬件验证。最后将所有软件和硬件验证无误的模块整合，下载到FPGA硬件中，进行功能验证。验证结果符合设计要求。

关键词：FIR滤波器，IIR滤波器，MATLAB，FPGA，VHDL

ABSTRACT

Digital signal processing has been widely used in communications, radar, sonar and many other fields. The design of digital filter is one of the key technologies of digital signal processing, which has a very important theoretical and practical significance. As digital technology continues to develop, on many occasions, the digital filter is rapidly replacing analog filters. FPGA (field-programmable gate array) in modern digital circuit design is playing an increasingly important role. From the design simple interface circuit to the design of the complex state machine, FPGA's role has not been to ignore. This thesis accomplishes a FPGA-based FIR and IIR digital filter design and implementation. This thesis first theoretically analyses the method of digital filter design ,with MATLAB tool verifying which window function is suitable for the FIR digital filter design, which analog filter prototype maps IIR digital filter . And according to the technical specifications of the analog filter the paper determines the specifications of the digital filter. Next in the MATLAB environment in accordance with the technical specifications of the digital filter the paper designs digital filters.And the paper gets the filter coefficients, programming to quantify the coefficients. And the paper has comparative analysis of before and after quantitative differences the system response, thereby obtaining a suitable quantization levels. Then in the ISE software platform according to the obtained quantized coefficients with MATLAB tools, the paper uses VHDL language to program FIR and IIR filter algorithm module. While the AMP circuit (programmable pre-amplifier) module, AD circuit (analog to digital converter) circuit module and DA (digital to analog converter) module are programmed to be configured. And each module has rigorous software simulation, where AMP, AD and DA circuit module must have hardware verification. Finally the paper integrates all the software and hardware verification correct modules, downloading to the FPGA hardware for the functional verification. The Verified result meets the design requirements.

Key words：FIR filter, IIR filter, MATLAB, FPGA, VHDL