function Pb=Error_Pb(R,S)
%%%本函數用于求誤比特率
x=length(R);
y=length(S);
error_bit=0;
if(x~=y),
    error('There is something wrong with your Receiver')
else
    for iii=1:x,
	if(R(iii)~=S(iii)),
	    error_bit=error_bit+1;
	end
    end
end
Pb=error_bit/x;