Hi, I would like to ask how I can apply the convolution for the following code, rather than applying the filter function (note: for Fourier Transform)
Could please anyone help me.
B=[0.5 0.5]; % coefficient of the x(n), x(n-1)
A= [1 -1 0.5];% coefficient of the y(n), y(n-1), y(n-2)
fs=10000;
n=0:1000;
f1=100;
f2=3000;
x=2*sin(2*pi*f1/fs*n)+4*sin(2*pi*f2/fs*n); % input signal
y=filter(B,A,x);% filter
nfft_of_fft = length(y);% number of samples
yf1 = fft(y,nfft_of_fft);%fourier transform function
yf1_mag = abs(yf1);% to make the y-axis more than 0 (absolute value)
yf1_mag_norm = yf1_mag/max(yf1_mag);%normlized the magnitude
yf1_xaxis=fs/2*(0:nfft_of_fft/2-1)/(nfft_of_fft/2);%frequency
plot(yf1_xaxis,yf1_mag_norm(1:nfft_of_fft/2),'r');% plot DEFT
title('Fourier Transform y(n)')
xlabel('Frequency (Hz)')
ylabel('Magnitude')
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