【作者】 张妍；

【导师】 黄永清；

【作者基本信息】 北京邮电大学 ， 电子与通信工程， 2014， 硕士

【摘要】 随着移动通信的迅速发展,移动用户数量一直呈现爆发式增长,对数据业务的需求日益增大,LTE(Long Term Evolution)作为一种革命性的无线技术应运而生,但其在网络容量和频谱效率等诸多方面仍存在提升空间。设备到设备的通信技术(D2D,Device-to-Device)是一种短距离通信技术,可以在基站控制下使数据链路不经过基站而在终端间直接进行传输,提高频率利用率和小区中用户数据传输速率,降低核心网负载和移动终端电池功耗。但资源复用也会带来严重的链路间和小区间干扰。进行合理的无线资源管理来控制链路间干扰,从而保证蜂窝链路的通信质量,成为D2D通信技术中的关键问题。本文的工作是对LTE系统中D2D通信的无线资源管理关键技术展开研究,重点对模式选择、功率控制和资源管理三个模块进行算法的改进设计,减小D2D链路与蜂窝链路之间的干扰,提高系统整体性能。主要研究成果如下：第一,针对模式选择和资源分配模块进行算法改进。模式选择是指D2D终端在D2D模式和小区模式之间选择合适的通信模式,对此本文提出基于D2D链路损耗和D2D到蜂窝链路干扰的模式选择算法。资源分配的目的是选择D2D共享蜂窝链路的资源,减小来自蜂窝通信的干扰,对此提出基于服务质量的干扰受限循环调度资源分配算法,利用资源池进行集中式的资源分配。第二,针对功率控制模块,提出改进算法并进行三种算法比较分析。功率控制模块对蜂窝链路和D2D链路进行功率控制,减小D2D与蜂窝网络间、小区间和小区内的干扰,对此本文提出了基于路径损耗的开环与闭环联合动态功率控制方案,并对固定发送功率的慢功率控制、固定接收功率的快速功率控制和固定信噪比的快速功率控制进行对比分析。第三,完成改进算法的系统级仿真。搭建基于LTE的D2D仿真平台,对模式选择、功率控制、资源分配三个模块的算法进行多小区的系统级仿真。仿真结果显示,在不同链路场景下,通过合理算法设计,可以实现D2D通信系统中无线资源的有效管理。更多还原

【Abstract】 With the rapid development of mobile telecommunication, the number of subscribersis growing explosively, and the requirement of data traffic is improving correspondingly, which both leads to the birth of LTE, a revolutionary new wireless technology. However, considering the network capacity and spectrum efficiency, it is still has room for improvement. As a new telecommunication technology for short distance, Device to Device(D2D) allows the traffic to be transmitted between user equipments directly under the control of base stations, which could improve spectrum efficiencyas well as the transmission data rate of the whole cell, and to reduce the workload of base station and the energy consumption of mobile station.However, the reuse of resources brings in severelyinterference between links and between cells. It is one of the key challenges to manage resources in wireless communication to control the interference between links and assure thecommunication quality of cellular link.This paper focuses on the key technology of D2D radio resource management in LTE system. New algorithms of mode selection, power control and resource allocation are proposed to reduce the interference between D2D and cellular and to improve the performance of system. The key research results are as follows:Firstly, the improved algorithms of mode selection and resource allocation are proposed. Mode selection is to choose the proper communication mode between D2D mode and cellular mode for D2D equipment. Proposed mode selection algorithm is based on the path loss of D2D links and interference between D2D and cellular links. For selecting the sharing resources with low interference from cellular link, we present interference-limit round-robin scheduling resource allocation algorithm based on Quality of Service (QoS), which is controlled centrally by establishing resource pool.Secondly, three improved algorithms of power control are proposed and compared. Power control is to control transmission power of cellular and D2D links in order to limit inter-cell and inner-cell interference between D2D and cellular. Open loop and close loop combined power control algorithm is proposed based on path loss, then three schemes are compared based on the fixed transmission power, the fixed received power and the fixed target SINR (Signal Interference Noise Ratio).Thirdly, system-level simulation of improved algorithms is completed. D2D simulation platform is set up to do system-level simulation of the three algorithms mentioned above with multi-cell topology. The results show that in different link distance scenarios, the radio resource management of D2D can be realized effectively with the well-designed algorithms in this paper.更多还原