A method and apparatus for performing spectral allocation for a wireless link in a wireless communication system is disclosed. The method determines a distance/range for the wireless link and assigns an optimal sub-carrier frequency to the wireless link based on (1) a higher frequency to lower frequency priority and (2) on the value of the distance/range of the wireless link and (3) on the presence or absence of a primary user in a spectrum of the wireless link. Higher frequency sub-carriers are assigned to wireless links that have a shorter distance/range and lower frequency sub-carriers are assigned to wireless links that have a longer distance/range. The method of the present work increases the spectral efficiency of the wireless communication system and improves system bandwidth.