LTE-A系统中D2D资源分配算法的研究

发布时间：2019-04-27 16:43

【摘要】：随着移动通信技术的不断发展,多媒体业务需求的急剧增长,传输速率的不足和频谱资源的稀缺成为目前移动通信领域面临的主要挑战。为此,高级的长期演进技术(LTE-A)系统引入了终端直通技术(D2D)。D2D通信技术的引入,特别是和多播技术结合后,不仅能够提高整个系统的吞吐量和频谱利用率,而且还能极大地改善边缘用户的服务质量。但是D2D通信技术的引入也会给蜂窝系统带来一定的干扰。为了降低干扰,提升系统性能,如何进行资源分配成为研究的重点。通过分析现有的D2D通信文献发现,多数D2D资源分配算法没有考虑蜂窝与D2D混合网络系统公平性的问题。为此,本文研究了一种提升系统公平性的方案。首先,为了降低资源分配算法的复杂度和干扰强度,引入了D2D通信限制区域和D2D用户限制复用蜂窝用户资源区域的概念;其次,为了保证蜂窝系统服务质量(QoS)需求并提升系统性能,提出一种提升蜂窝系统公平性的资源分配算法;最后,使用非线性规划问题中的乘子法来确定D2D用户和蜂窝用户的最佳发射功率。仿真结果表明所提算法与已有方案相比能够显著提升系统的吞吐量和公平性。为了更大程度地利用系统的频谱资源,本文对LTE-A系统中D2D多播资源分配问题进行了研究。考虑到当前文献对D2D多播分簇算法研究较少,本文提出了一种低复杂度的D2D多播分簇算法,以达到进一步提升系统性能的目的。针对现有D2D多播资源分配算法的不足,本文提出了一种基于图论的D2D多播资源分配算法。该算法共分两步完成:首先,使用图论中的着色算法把D2D多播簇划分为若干D2D多播簇集合,同一D2D多播簇集合中的D2D多播簇复用相同的蜂窝用户资源;其次,使用图论中的最优匹配算法为D2D多播簇集合选择合适的蜂窝用户。仿真结果表明,文章所提的D2D多播分簇算法能够有效提高NACK用户的被服务率和小区吞吐量,文章所提的D2D多播资源分配算法能够显著提高小区平均频谱效率和D2D多播用户的被服务率。
[Abstract]:With the development of mobile communication technology, the rapid growth of multimedia service demand, the shortage of transmission rate and the scarcity of spectrum resources have become the main challenges in the field of mobile communication. Therefore, the advanced long-term evolution technology (LTE-A) system introduces the terminal pass-through technology (D2D) and the D2D communication technology, especially when combined with multicast technology, it can not only improve the throughput and spectrum efficiency of the whole system, but also improve the throughput and spectrum efficiency of the whole system. And also can greatly improve the quality of service for edge users. However, the introduction of D2D communication technology will also bring some interference to the cellular system. In order to reduce the interference and improve the performance of the system, how to allocate resources has become the focus of the research. By analyzing the existing D2D communication literature, it is found that most D2D resource allocation algorithms do not consider the fairness of cellular and D2D hybrid network systems. Therefore, this paper studies a scheme to improve the fairness of the system. Firstly, in order to reduce the complexity and interference intensity of resource allocation algorithm, the concepts of D2D communication limiting area and D2D user limiting multiplexing cellular user resource area are introduced. Secondly, in order to ensure the quality of service (QoS) requirements and improve the performance of cellular systems, a resource allocation algorithm is proposed to improve the fairness of cellular systems. Finally, the optimal transmit power of D2D users and cellular users is determined by the multiplier method in nonlinear programming problem. Simulation results show that the proposed algorithm can significantly improve the throughput and fairness of the system compared with the existing schemes. In order to make greater use of the spectrum resources of the system, the problem of D2D multicast resource allocation in LTE-A system is studied in this paper. Considering that there is little research on D2D multicast clustering algorithm in current literature, a low complexity D2D multicast clustering algorithm is proposed to further improve the performance of the system. In view of the deficiency of existing D2D multicast resource allocation algorithms, this paper proposes a graph theory-based D2D multicast resource allocation algorithm. The algorithm is divided into two steps: firstly, the D2D multicast cluster is divided into several D2D multicast cluster sets by using the coloring algorithm in graph theory, and the D2D multicast cluster in the same D2D multicast cluster sets reuses the same cellular user resources; Secondly, the optimal matching algorithm in graph theory is used to select suitable cellular users for D2D multicast cluster set. The simulation results show that the proposed D2D multicast clustering algorithm can effectively improve the serviced rate and cell throughput of NACK users. The proposed D2D multicast resource allocation algorithm can significantly improve the cell average spectrum efficiency and the serviced rate of D2D multicast users.
【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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