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$$
h_{{{\text{BS}}}}=\left \{{\begin{matrix}1-{\frac  {\Omega _{{c_{2}}}-\Omega _{{c_{1}}}}{\pi }},&n=0\\{\frac  {1}{\pi n}}[\sin (\Omega _{c}_{1}n)-\sin (\Omega _{c}_{2}n)],&n\neq 0\end{matrix}}\right .
$$
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