基于FPGA的IIR数字滤波器实现及其量化字长效应分析

摘要

为了实现音频基带数字信号的提取与杂波信号剔除，提供了一个从MATLAB仿真到FPGA实现的IIR数字滤波器的解决方案，同时对比了由于量化字长的不同对数字滤波器产生的影响。通过MATLAB的FDA Tool产生所需的滤波器构型和SOS系数，由MATLAB量化滤波器系数，将量化后的滤波器系数装载至FPGA板级实现。在Chip-scope中观察实际滤波输出波形，比较滤波器系数量化对滤波效果造成的影响，实验证明，采用级联型结构和较长的量化字长，滤波器输出较为稳定。%In order to realize the extraction of the audio baseband digital signal and the clutter signal elimination, a solution of digital filter from MATLAB simulation to FPGA implementation is provided, while the effects of different quantized word length on the digital filter are compared in this paper. The desired filter configuration and SOS coefficients are produced via the MATLAB FDA Tool, and the digital filter coefficients are quantified by MATLAB computing. Quantized filter coefficients are loaded to the FPGA for board-level implementation. By observing the actual filter output waveform in Chipscope, the effects of the filter coefficient quantization on the filtering effect are compared. The experiment proved that the cascade structure and longer quantitative word length, bring relatively stable filter output.