异构网络中用户簇分层组播传输研究

发布时间：2018-05-16 06:35

本文选题：异构网络 + 分层组播　；参考：《重庆邮电大学》2016年硕士论文

【摘要】：如何实现高速视频传输一直是产业界和学术界所追逐的研究热点之一,一方面视频传输速率提高是发展信息服务业务的重要推动力,另一方面业务多样性和网络架构异构化对视频传输的研究提出了新要求。分层组播技术可以较好地解决异构网络中用户对视频流差异性需求,为此论文分别以提高系统吞吐量、系统频带利用率为目标,基于用户簇重点分析分层组播的层速率优化和簇内D2D组播重传算法。具体研究内容如下:1.针对异构网络分层组播的分层速率优化问题是NP-Hard问题,提出一种基于用户簇的分层速率分配优化算法,算法根据用户理论带宽及其用户数进行分层,求出每个分层的分层速率及相应的传输子图,并为每个分层的接收用户分配链路带宽,在充分复用已分配带宽的用户链路基础上,选择具有最大节点度的路径进行合理的链路带宽分配,为更高层接收预留更多资源。进一步结合用户分簇思想,将多个分层合并为预定分层,从全局角度实现分层速率优化并进行链路带宽的分配。仿真实验表明,相比于已有的分层速率优化算法,所提出的基于用户簇的分层速率分配优化算法能改善系统吞吐量等性能指标。2.针对簇内用户丢失数据包的恢复问题,提出一种簇内两级D2D组播重传算法,算法在充分考虑差异性D2D链路质量的基础上,模型化系统链路代价,采用两级组播重传实现簇内用户所有错误包的恢复,从而减少组播次数增加带来的额外信令开销及单播概率,同时定义平均用户链路代价辅助选择组播子簇,排除重复组播,并将一次组播完成后已恢复丢失数据包的用户转化为备选组播发送者,进一步提升系统频带利用率性能。仿真实验表明,与已有D2D组播重传算法相比,所提出的簇内两级D2D组播重传算法可以改善系统链路代价等性能指标。
[Abstract]:How to achieve high-speed video transmission has been one of the hot research topics pursued by industry and academia. On the one hand, improving video transmission rate is an important driving force for the development of information services. On the other hand, the diversity of services and the isomerization of network architecture put forward new requirements for the research of video transmission. Hierarchical multicast technology can solve the different demand of users for video streams in heterogeneous networks. Therefore, this paper aims to improve the system throughput and the system frequency band efficiency. Layer rate optimization and D2D multicast retransmission algorithm are analyzed based on user clusters. The specific contents of the study are as follows: 1. Aiming at the hierarchical rate optimization problem of hierarchical multicast in heterogeneous networks is the NP-Hard problem, a hierarchical rate allocation optimization algorithm based on user clusters is proposed, which is based on the theoretical bandwidth of users and the number of users. The delamination rate of each layer and the corresponding transmission subgraph are calculated, and the link bandwidth is allocated to each layered receiving user, on the basis of fully multiplexing the allocated bandwidth of the user link, The path with the maximum node degree is chosen to allocate the link bandwidth reasonably, and more resources are reserved for the higher level reception. Combined with the idea of user clustering, multiple layers are merged into predetermined layers to optimize the hierarchical rate and allocate the link bandwidth from a global perspective. Simulation results show that compared with the existing hierarchical rate optimization algorithm, the proposed hierarchical rate allocation algorithm based on user clusters can improve the system throughput and other performance indicators. A two-level D2D multicast retransmission algorithm is proposed to recover the lost packets of users in the cluster. The algorithm models the system link cost on the basis of considering the different D2D link quality. Two-level multicast retransmission is used to restore all error packets of users in the cluster, which can reduce the additional signaling overhead and unicast probability brought by the increase of multicast frequency. At the same time, the average user link cost is defined to assist the selection of multicast subclusters, and duplication multicast is eliminated. The users who have recovered the lost packets after a multicast completion are transformed into alternative multicast senders to further improve the bandwidth utilization performance of the system. The simulation results show that compared with the existing D2D multicast retransmission algorithm, the proposed two-level D2D multicast retransmission algorithm can improve the system link cost and other performance indicators.
【学位授予单位】：重庆邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.5

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