关键词: 正交频分复用多址接入, 资源分配, 比例公平, 公平度门限

Abstract: For existing algorithms can’t balance system capacity and fairness well, a new adaptive resource allocation algorithm is proposed to maximize the capacity of multiuser OFDMA system under proportional fairness. Firstly, the algorithm selects the appropriate fairness threshold range is selected. Secondly, during sub-carriers allocation stage, the algorithm assigns each sub-carrier to the user with the maximal channel?gain under the constraint of the fairness threshold, and reallocates minimum channel gain sub-carrier of the maximum rate user to achieve a trade-off between sub-carriers utilization and fairness. After sub-carriers allocation, the algorithm allocates the power with water-filling line to adjust user proportional fairness and find the optimum?fairness threshold making the system with maximal capacity finally. Simulation result shows that the algorithm not only guarantees users proportional fairness but also improves system capacity.

Key words: Orthogonal Frequency-Division Multiplexing Access（OFDMA）, resource allocation, proportional fairness, fairness threshold