function z=mapping(y,NRB,Cell_ID)
k_=(12/2)*(mod(Cell_ID,2*NRB));
k(1)=k_;
k(2)=mod(k_+floor(NRB/2)*12/2,NRB*12);
k(3)=mod(k_+floor(2*NRB/2)*12/2,NRB*12);
k(4)=mod(k_+floor(3*NRB/2)*12/2,NRB*12);

j = 1;
for i=1:4
    Pos = RE_G(k(i)/6,Tx_num,0,Cell_ID,CP_flag);
    z(Pos(1),1,:)=y(:,j);PCFICH_mappingid(Pos(1),1)=2;
    z(Pos(2),1,:)=y(:,j+1);PCFICH_mappingid(Pos(2),1)=2;
    z(Pos(3),1,:)=y(:,j+2);PCFICH_mappingid(Pos(3),1)=2;
    z(Pos(4),1,:)=y(:,j+3);PCFICH_mappingid(Pos(4),1)=2;
    j = j + 4;
end;