down sampling

Illustration of Down-Sampling by an Integer Factor

clf;

n = 0: 49;

m = 0: 50*3 - 1;

x = sin(2*pi*0.042*m);

y = x([1: 3: length(x)]);

subplot(2,1,1)

stem(n, x(1:50)); axis([0 50 -1.2 1.2]);

title(’Input Sequence’);

xlabel(’Time index n’);

ylabel(’Amplitude’);

subplot(2,1,2)

stem(n, y); axis([0 50 -1.2 1.2]);

title(’Output Sequence’);

xlabel(’Time index n’);

ylabel(’Amplitude’);