关键词: 资源分配, 公平度门限, 认知无线电, 正交频分复用

Abstract: Based on the characteristics of cognitive radio and transmission properties of OFDM, an adaptive resource allocation algorithm in OFDM cognitive radio system is proposed. In traditional sub-carrier allocation process, the user with the highest priority can choose sub-carrier first, but the sub-carrier with the best channel gain isn’t always used by the user, which will result in low utilization of sub-carrier. Aiming at this problem, in the proposed algorithm, the priority of the sub-carrier allocation is determined by fairness threshold in order to achieve a tradeoff between capacity and fairness. In addition, by keeping the interference introduced to the primary users within a tolerable range in sub-carrier allocation and power allocation, the algorithm can guarantee communication requirement among secondary users. Simulation results show that the proposed algorithm can not only satisfy the fairness but also improve system capacity.

Key words: resource allocation, fairness threshold, cognitive radio, OFDM