bandstop_50hz.m

%%==================================================================
%
%   IN THE NAME OF ALLAH, 
%
%simple 50hz filter, to remove line noise, implemented in iir band stop
%filter method is butter worth filter
%%


% Aquaire a Clean Workspace;
clear all;
close all;
clc;

%% Simulation Parameters

Fs=1000;
F_org = 5;      %original Signal Frequency
F_noise = 50;   %noise frequency in Hz
T = 1/Fs;       % Time Period

t= 0:T:1;       % time signal to simulate all data

%%   Creating Signals 


org_x  = sin(2*pi*F_org*t);
noise  = sin(2*pi*F_noise*t);
mix_x  = org_x + noise;
figure, plot(org_x),title('Orignial Signal Without Noise');
figure, plot(noise), title('Noise Signal');
figure, plot(mix_x), title('Mixed Signal, Included Noise');

%% Creating Filter

d = designfilt('bandstopiir','FilterOrder',2, ...
               'HalfPowerFrequency1',49,'HalfPowerFrequency2',51, ...
               'DesignMethod','butter','SampleRate',Fs);
           
 % Plot the frequency response of the filter. Note that this notch filter provides up to 45 dB of attenuation.       
 
 %fvtool(d,'Fs',Fs)           


%%  Filter Singal and plot final result;

y = filtfilt(d,mix_x);

figure,
plot(y),title('Filtered Output');