Asymptotic performance of uplink resource allocation for OFDMA-based cognitive radio networks

Cognitive radio and OFDMA attracts a lot of attentions in academic and industry fields. In this paper, the asymptotic performance of an uplink radio resource allocation scheme is investigated for OFDMA-based cognitive radio networks. Considering the characteristics of cognitive radio and OFDMA, in the uplink subcarrier allocation algorithm, the subcarriers are allocated to the users with the best channel quality initially and then adjusted to improve the system performance. A cursory water-filling level estimation method is used to decrease the complexity of the algorithm. To investigate the effect of the rough estimation. By strict theoretic deduction, a lower bound of the stability of the water-filling level estimation is given in this paper. The bound is obtained through analyzing the state transition.