提出了一种基于效用函数的应用于多输入多输出正交频分复用接入(MIMO-OFDMA,Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing Access)系统下行链路的分组调度算法.该算法在调度时不仅考虑物理层的信道状况,还利用基站发送缓冲区的状态信息和用户反馈回来的ARQ(Automatic Repeat-request)信息来帮助基站做出调度决策.针对系统中多种业务的不同服务质量(QoS,Quality of Service)要求,分别设计了其效用函数,并将调度决策问题转化成一个系统总效用函数值最大化问题.同时考虑到实际的长期演进计划(LTE,Long Term Evolution)系统中对子载波共享的限制条件,提出了一种可以降低实际复杂度的启发式算法用于求解该最优化问题.仿真结果表明,该算法不但在保证实时业务用户QoS要求方面要好于传统的调度算法,还能获得较好的系统总容量和丢包率性能.
Network selection and resource allocation( NS-RA) are the processes of determining network and radio resource which provide the service to user. Optimizing these processes is an important step towards maximizing the utilization of current and future networks. In this paper,we proposed a preference value-based network selection and resource allocation,in which the NS scheme was performed by the joint radio resource management( JRRM) entity and the RA scheme was performed by the network. In the NS step,the JRRM entity selected the preferable network for users according to the preference value of each network,which took the load balance,the received signal strength( RSS) and the relative position between the user and the network into account. In the second step,the network allocated the optimal sub-carrier to user for the downlink transmission each round according to the preference value of each user and the maximum reachable data rate calculated by users' perceived channel information,maximizing the spectrum efficiency as well as guaranteeing the fairness. The simulation results showed that the proposed NS-RA scheme achieves better performance in terms of load distribution,spectrum efficiency and user fairness,compared to the conventional strategies.
