Hello i'm designing a low pass filter windowed sinc in matlab
Fs = 2048; Fc = 250/Fs; % 250hz M=2048 % (to get a 4hz transition bandwidth) sig contains 200hz + 300hz sinusoids, i'm aiming at leaving only the 200hz filt =sinc(2*Fc*((1:length(t))- M/2)).*(0.42-0.5*cos(2*pi*(1:length(t))/M)+0.08*cos(4*pi*(1:length(t))/M))'; filt(M/2)=2*pi*Fc; fsig = sig .* filt;
i understand that the winsinc filter is applied by convolution in the freq domain, so it means a multiplication in the time domain, which i did, but i get an erroneous result, i get a 0 flat frequency everywhere in my frequency plot. what's wrong?