一种滤除电力线噪声的数字滤波器的设计

Design of Digital Filter for Filtering out Power Line Noise

摘要:

数字滤波是信号处理中滤除噪声干扰的常用方法之一;针对信号通过电力线信道传输后出现严重失真这一问题,基于MATLAB平台的工具箱函数,采用窗函数法(选用哈明窗)设计出一个50阶的数字FIR带通滤波器,借助MATLAB仿真对滤波前后的波形作对比和频谱分析,并通过硬件实现电路测试,结果表明所设计的FIR带通滤波器能够有效地滤除带外信号以及电力线噪声,还原出[0.16,0.24]频带内的有用信号,保证了电力线载波通信的可靠进行。

Abstract:

Digital filter technique is one of the methods that commonly used to filter out noise in the signal processing. The signal often appears serious distortion issue after power line channel transmission. For this problem, based on MATLAB toolbox functions, window function method (Hamming window) is adopted to design a 50-order FIR band-pass filter, and compare the waveform before and after filtering, and spectrum analysis. Through the hardware realizating circuit testing, the results illustrate that the designed FIR band-pass filter can effectively filter out out-of-band signals and power line noise, restoring the useful signal, which provides a strong guarantee for reliable power line carrier communication .