function br = bruitc(f,Fe,n)
% br = bruitc(f,Fe,n)
% bruit centre sur f
%--------------------------

df = .01;
fr = 0:df:1;
H = 1./((fr-f/Fe*2).^2+1e-3);
b = fir2(100,fr,H);

br = randn(1,n);
br = filter(b,1,br);
br = br/max(abs(br));
