%TCH/FS信道的外編碼解碼
function [d,tag]=T_FS_EX_DE(u)
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%反重排和去尾比特
d2=zeros(1,53);
d2(1:2:49)=u(1:25);
d2(2:2:50)=u(95:119);
d2(51:53)=1;
d2(54:56)=u(92:94); 

d=zeros(1,260);
d(1:2:181)=u(1:91);
d(2:2:182)=u(95:185);
d(183:260)=u(190:267);
rold(1:3)=0;
rnew(1:3)=0;
for i=1:56
   rnew(1)=mod(d2(i)+rold(3),2);
   rnew(2)=mod(rold(1)+rold(3),2);
   rnew(3)=rold(2);
   rold=rnew;
end
p1=rnew;
if(p1==0)
   tag=0;  %沒有錯誤
else
   tag=1;  %有錯誤
end