针对IEEE802.16系统中复杂的服务质量(quality of service,QoS)机制,设计了一种统一的效用函数作为资源分配的目标函数以平衡资源分配中的效率和公平性,使资源分配问题转化为基于系统效用最大化的系统优化问题。考虑到对算法的实时性要求和适用于IEEE802.16正交频分复用多址(OFDMA)系统的要求,提出了一种基于效用函数的资源分配(URA)的算法。仿真结果表明,所提出的URA算法在性能上非常接近于最优算法,而计算复杂度却大幅度降低;同时,URA算法能够在频谱效率和公平性之间取得良好的折衷,以满足IEEE802.16系统中各业务类型不同的QoS要求。
A unified utility function was designed as the target function of the resource allocation for the complex QoS mechanism in the IEEE 8002.16 OFDMA systems, and the utility function was used in this study to balance the efficiency and fairness in resource allocation. Thus the resource allocation problem could be described as the problem of optimization of the IEEE 802.16 systems based on maximization of the system utility. According to the real-time requirements of algorithm solution, a suboptimal utility-based resource allocation (URA) algorithm for IEEE 802.16 OFDMA systems was presented. The simulation results show that the proposed URA algorithm can achieve a system performance very close to the optimal solution obtained by the exhaustive method, while the complexity can be greatly reduced. Further, the algorithm can obtain a tradeoff between the spectral efficiency and the fairness through a fair factor and satisfy the different QoS requirements of heterogeneous services in the IEEE 802.16 systems.