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

摘要： 针对多用户OFDMA系统资源分配中已有算法对系统容量和公平性兼顾较差的情况，提出了一种满足比例公平性的系统容量最大化资源分配算法。首先选择合适的公平度门限范围，在子载波分配中，先将各个子载波分配给信道增益最大的用户，再在公平度门限约束下重新分配最大速率用户的信道增益最小的子载波，可以实现子载波利用率和公平度的折中。然后采用注水线法分配功率来调整用户间的比例公平性，最终找到使系统容量最大的公平度门限。仿真结果表明，该算法在保证了用户间比例公平性为1的同时提高了系统容量。

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