中文摘要：

提出了一种多用户正交频分复用系统的跨层资源分配模型，结合了物理层中信道状态和媒体接入控制层中用户的队列信息，能更好地满足用户的服务质量要求。改进的混合优化算法结合了遗传算法与禁忌搜索算法的优点，并且对遗传算法的交叉因子进行改进，提高了全局搜索能力，能够更好地收敛于全局最优值，这样能更好地解决跨层资源分配问题。仿真结果表明，在此模型下利用改进的混合算法能有效地提高系统吞吐量，减小用户的平均时延，提高服务质量。

英文摘要：

A cross-layer resource allocation model in multiuser OFDM system was proposed, which combined the channel state in physical layer and the user＇s queue in MAC layer. The proposed hybrid optimization algorithm made use of the advantages of genetic algorithm and tabu search algorithm to improve the crossover of genetic algorithm. It would improve the global search ability, converge to the global optimal value faster, solve the cross-layer resource allocation problem more effectively and meet the user＇s quality of service better. The simulation results show that the improved hybrid algorithm increases the throughput, reduces the average delay and improves the QoS of the system.