基于MATLAB的Filter使用，低通、带通和高通滤波器的仿真

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %------------------------------------------------------------------------------------% %************************************** Filter **************************************% %------------------------------------------------------------------------------------% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Date:2018.8.25 % Author:flypassion % Version:1.0 clear all close all clc %% Parameter Interface Frequence0 = 60; %单位：Hz Frequence1 = 130; %单位：Hz Frequence2 = 1e3; %单位：Hz SampleFre = 4e3; %单位：Hz SampleLen = SampleFre; %采样点数 %% Main %-------------------产生三路信号 t = 0:1/SampleLen:1/SampleFre*(SampleLen-1); SignalData0 = sin(2*pi*Frequence0*t); SignalData1 = sin(2*pi*Frequence1*t); SignalData2 = sin(2*pi*Frequence2*t); SignalData3 = SignalData0+SignalData1+SignalData2; figure;hold on plot(t(1:150),SignalData0(1:150),'b') plot(t(1:150),SignalData1(1:150),'r') plot(t(1:150),SignalData2(1:150),'k') hold off figure;plot(t(1:150),SignalData3(1:150)) title('三路信号求和') %-------------------频谱分析 FFT_Data = fft(SignalData3); Amplitude = abs(FFT_Data); Amplitude = Amplitude/length(Amplitude); Amplitude(2:end) = 2*Amplitude(2:end); Frequence = (0:(length(Amplitude)/2-1))/length(Amplitude)*SampleFre; figure;plot(Frequence,Amplitude(1:length(Frequence))) title('三路信号叠加频谱') %-------------------低通滤波 LPF_Coe = load('LPF_60M.mat'); LPF_Data = filter(LPF_Coe.LPF_60M,1,SignalData3); figure;plot(t,LPF_Data) title('低通滤波之后的波形') %-------------------低通滤波之后频谱分析 FFT_LPF_Data = fft(LPF_Data); Amplitude_LPF = abs(FFT_LPF_Data); Amplitude_LPF = Amplitude_LPF/length(Amplitude_LPF); Amplitude_LPF(2:end) = 2*Amplitude_LPF(2:end); Frequence = (0:(length(Amplitude_LPF)/2-1))/length(Amplitude_LPF)*SampleFre; figure;plot(Frequence,Amplitude_LPF(1:length(Frequence))) title('低通滤波之后的频谱') %-------------------带通滤波 BPF_Coe = load('BPF_130M.mat'); BPF_Data = filter(BPF_Coe.BPF_130M,1,SignalData3); figure;plot(t,BPF_Data) title('带通滤波之后的波形') %-------------------带通滤波之后频谱分析 FFT_BPF_Data = fft(BPF_Data); Amplitude_BPF = abs(FFT_BPF_Data); Amplitude_BPF = Amplitude_BPF/length(Amplitude_BPF); Amplitude_BPF(2:end) = 2*Amplitude_BPF(2:end); Frequence = (0:(length(Amplitude_BPF)/2-1))/length(Amplitude_BPF)*SampleFre; figure;plot(Frequence,Amplitude_BPF(1:length(Frequence))) title('带通滤波之后的频谱')