function rct=raisedcos1(fb,fs)
%注意函數名必須與文件名相同
%fb=256000;
%fs=fb*5;
Ts=1/fs;
N=20;
rct=zeros(1,N);
alpha=1;
for i=0:N
    t=i/fs;
    rct(i+1)=sinc(t*fb)*(cos(pi*alpha*t*fb)/(1-4*alpha^2*t^2*fb^2));
end;    
rct1=rct(1:N+1);
rct2=fliplr(rct1);
rct=[rct2(1:N),rct1];