混合业务下的宽带电力线通信系统跨层资源分配

Cross-layer Resource Allocation for Broadband Power Line Communication Systems with Mixed Traffics

针对正交频分多址接入(Orthogonal Frequency Division Multiple Access,OFDMA)宽带电力线通信系统资源利用率低的问题,提出一种在混合业务情况下能兼顾用户服务质量(Quality of Service,QoS)要求与用户公平性的跨层资源分配方案。在媒体接入控制(Medium Access Control,MAC)层,根据用户队列状态信息确定用户调度优先级以及用户的最小要求速率和最大许可速率;在物理(Physical,PHY)层,根据用户信道状态信息,为调度用户联合分配子载波-功率资源,以满足用户最小速率要求,若有剩余资源,在满足用户公平性的前提下,以用户最大许可速率为目标分配资源。该算法结合了裕度自适应(Margin Adaptive,MA)和速率自适应(Rate Adaptive,RA)准则,当系统资源充足时,以MA准则为最终目标,否则以RA准则为最终目标。实验结果表明,在典型电力线系统环境下,与现有跨层资源分配算法相比,该算法能利用更少的资源得到更大的系统容量,且能满足用户QoS与公平性等要求。

This paper proposes a novel cross-layer resource allocation scheme that can satisfy the requirements of Quality of Service(QoS) and fairness of users under the mixed traffics, according to the problem of the lower resource utilization ration of Orthogonal Frequency Division Multiple Access(OFDMA) broadband power line communication system. In the Medium Access Control(MAC) layer,we determine the scheduling priority, the rate of minimum requirements and the rate of maximum permission in accordance with the status information queue of users;In the Physical(PHY) layer, we distribute the subcarrier-power resource to users to satisfy the minimum requirements rate, however, we will distribute the resource with the maximum permission rate based on the fairness of user, if there is a surplus resources. The proposed algorithm regards the Margin Adaptive(MA) norm as ultimate goal, in case of the system resource is sufficient, otherwise, it regards the Rate Adaptive(RA) norm as the ultimate goal. The simulation results are comparable with recent result of cross-layer resource allocation algorithm. Under the environment of the typical power line system, the proposed algorithm can obtain larger system capacity by utilizing less resource and satisfy the requirements of QoS and fairness of users.