So the AM signal has a bandwidth of 5kHz and the carrier signal is 100kHz. I demodulate the AM signal by multiplying it to a sin function (sin(2000000*pi), same frequency with the carrier frequency).
This is my take in Matlab for the ideal:
%read in the audio [y,Fs]=audioread('Signal1.wav'); [gt,fs]=audioread('Signal1_gt.wav'); %demodulation for t=1:1:size(y,1) x=sin(200000*pi*(t/Fs)); y(t,1)=y(t,1)*x; y(t,2)=y(t,2)*x; end %low pass filter h=10*sinc(10*(-10:10)); y1=filter(h,1,y); %down sample y1=downsample(y1,Fs/fs); %plot t=1:size(y1,1); plot(t,y1,t,gt);
But when comparing to the ground truth signal, it's far from correct. Any suggestions?