I am getting the matrix dimension error for the following code. What I am trying to do below is modulation of an audio waveform but I could not get passed the error I specified. I have checked the length of the sample.wav and adjusted time axis(t) accordingly but I must have done something wrong. I appreciate if anyone could help. Thanks in advance!.
function [sm]= modulation(ss,fc,mtype)
ss= audioread('C:\Users\furka\Documents\MATLAB\sample.wav'); %audio waveform to be modulated is loaded.
plot(ss)
length(ss)
t=linspace(0,3e6,3161538);
fc= input('Carrier Frequency='); %carrier frequency will be determined by the user
mtype= menu('Modulation type?','dsb','dsbsc','ssb','fm'); %modulation type will be determined by the user
%fs=44100; %sampling frequency is determined for common audio waveform.(44.1kHz)
%t= 0:1/fs:(2e-5)-1/fs;
if mtype==1
ka= 0.7;
sm= ss.*(1+ka*cos(2*pi*fc*t));
plot(t,sm)
elseif mtype==2 %if doublesideband suppress carrier is selected the statements below will be carried out.
y = ss.*cos(2*pi*fc*t);
plot(y)
% sm = fftshift(fft(abs(y)));
% frequency_axis= (-fs/2):(fs/length(sm)):(fs/2-fs/length(sm));
%plot(frequency_axis,sm)
elseif mtype==3
sm=0.5*[ss.*cos(2*pi*fc*t)-hilbert(ss).*sin(2*pi*fc*t)];
plot(t,sm)
elseif mtype==4
kf=0.7; %frequency sensitivity.
sm= cos(2*pi*fc*t+2*pi*kf*int(ss,t,0,t));
plot(t,sm)
end
end
I can't access the link provided for the sound file but a time length of 3e6 seconds seems like a really long sound. I figure that's something around 30 days long.
Using the handel.mat example provided by MathWorks I get this.
load handel.mat
audiowrite('sample.wav', y, Fs);
[ss, Fs] = audioread('sample.wav');
t = linspace(0, length(ss) / Fs, length(ss));
t = t'; % this is important to match ss <-- this is your matrix dimension error I think
fc = 2000;
ka = 0.7
sm = ss .* (1 + ka * cos(2 * pi * fc * t));
The error of mismatched dimensions comes from linspace output being a row vector and audioread output being a column vector. Transpose one or the other. In my case: t = t'