基于中继的蜂窝网络负载均衡与公平性研究

发布时间：2018-07-10 01:57

本文选题：OFDMA + 小区间中继　；参考：《南京邮电大学》2017年硕士论文

【摘要】：基于正交频分复用(OFDM)调制技术的OFMDA技术较传统蜂窝通信网络小区内抗干扰能力更强并且能够提高频谱资源利用率,其通过给小区用户分配子信道的方式获得用户分集效益,为小区内用户提供了更高的数据传输速率。然而,由于严重的小区间干扰(ICI)和系统负载的分布不均衡导致蜂窝小区系统资源利用不平衡以及小区系统公平性和用户的服务质量(QoS)特别是小区边缘用户难以得到有效保证。所以,对OFDMA蜂窝网络的负载均衡的研究也逐渐成为热点问题。在传统蜂窝通信基础上加入中继技术,不仅能够在现有网络架构的基础上实现网络通信系统覆盖范围的拓展以提升小区容量而且能够在高频段有效克服阴影衰落的影响以提升信号质量以及减少网络建设成本。然而,引入中继使得蜂窝网络的拓扑结构和传输时隙发生了变化,并且中继节点也可能为新干扰源。在基于采用小区间中继的下行OFDMA蜂窝网络负载均衡分析中,我们首先提出了一种基于频谱和时隙划分的资源分配方案,并且在该通信模型上分析了干扰情况,从下行链路出发分别分析了基站(BS)和中继(RS)区域的子载波剩余情况及再平均分配后系统吞吐率的变化。最后的仿真表明,该方案可以有效缓解过载小区资源紧张和邻近小区资源利用率低的问题,提升了小区系统的吞吐率。在结合下行OFDMA蜂窝网络的小区间中继负载均衡分析的基础上,我们进一步对该系统下的用户公平性进行了分析。在现有模型下,我们首先提出了基于距离的公平调度算法,分别对BS区域以及RS区域进行了剩余子载波的再分配。其次,我们在保证小区系统公平性尽可能最优时,考虑了中继半径的最优化分析。最后的仿真计算验证了我们的理论正确性,在原系统的基础上进一步提升了系统的用户公平性。
[Abstract]:The OFMDA technology based on orthogonal frequency division multiplexing (OFDM) modulation technology is more powerful than the traditional cellular communication network in anti-jamming ability and can improve the efficiency of spectrum resources. The OFMDA technology obtains the benefits of user diversity by assigning sub-channels to the cell users. It provides higher data transmission rate for the users in the cell. However, due to the severe intercellular interference (ICI) and the uneven distribution of system load, the resource utilization of cellular system is unbalanced, and the fairness of cell system and the quality of service (QoS) of users, especially the edge users, are difficult to be effectively guaranteed. Therefore, the research on load balancing of OFDMA cellular networks has gradually become a hot issue. Adding relay technology to traditional cellular communication, It can not only extend the coverage of network communication system on the basis of the existing network architecture, but also effectively overcome the influence of shadow fading in high frequency band to improve the signal quality and reduce the cost of network construction. However, the introduction of relay makes the topology and transmission time slot of cellular network change, and the relay node may also be a new interference source. In the load balancing analysis of downlink OFDMA cellular network based on inter-cell relay, we first propose a resource allocation scheme based on spectrum and slot division, and analyze the interference on the communication model. Based on the downlink, the sub-carrier residual in the base station (BS) region and the relay (RS) region and the change of the system throughput after redistribution are analyzed respectively. Finally, the simulation results show that the proposed scheme can effectively alleviate the problem of overloaded cell resource shortage and low utilization of adjacent cell resources, and improve the throughput of the cell system. Based on the analysis of inter-cell relay load balancing in downlink OFDMA cellular network, we further analyze the user fairness in this system. Under the existing model, we first propose a distance-based fair scheduling algorithm, which redistributes the residual subcarriers to the BS region and the RS region respectively. Secondly, we consider the optimal analysis of relay radius in order to ensure the fairness of cell system as best as possible. Finally, the simulation results verify the correctness of our theory, and further improve the user fairness of the system based on the original system.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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