water_fill

function Bi = water_fill(ev,r,snr,Nt)
p=1;
Bi=zeros(1,r);
while(p<=r) && (Bi(r-p+1)<=0)
 x=0;
 for j=1:r-p+1
 x=x+(1/ev(j));
 end
 Mu=(Nt/(r-p+1))*(1+(1/snr)*x);
 for j=1:r-p+1
 Bi(j)=Mu-(Nt/(snr*ev(j)));
 end
 if Bi(r-p+1)<=0
 Bi(r-p+1)=0;
 end
 p=p+1;
end