N = 3;
T = 10;
t = 0:T;
x1 = randn(N,T+1);
x2 = repmat(randn(N,1), 1, T+1);

figure
subplot(3,1,1); stem(t, x1(1,:));
subplot(3,1,2); stem(t, x1(2,:));
subplot(3,1,3); stem(t, x1(3,:));

figure
subplot(3,1,1); stem(t, x2(1,:));
subplot(3,1,2); stem(t, x2(2,:));
subplot(3,1,3); stem(t, x2(3,:));