TD-LTE-Advanced中继系统中的下行资源调度研究

发布时间：2018-04-23 08:24

本文选题：TD-LTE-Advanced + 中继技术　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：近几年中,人们对移动通信的高数据速率、高服务质量、业务多样化的需求日益增长,为了应对这个趋势,第三代合作伙伴计划组织提出了以LTE为基础的LTE-Advanced系统。相对于LTE系统,LTE-Advanced系统中引入了几个关键技术,其中包括能够扩大小区覆盖范围、提高小区边缘吞吐量、增强用户公平性的中继技术。中继具有架设方便、成本低的优点,已经成为目前LTE-Advanced系统中的研究热点。为了更好地利用中继以提升系统的性能,中继系统中的资源调度是至关重要的。目前LTE存在两大主流标准,其中,由我国主导制定的TD-LTE标准也正向TD-LTE-Advanced演进,本文基于TD-LTE-Advanced系统,研究中继系统的资源调度算法。本文首先阐述了TD-LTE-Advanced中继系统的中继分类及架构、物理层相关技术的理论知识,确定了中继系统中下行资源调度的过程。同时研究了中继技术对系统性能带来的影响,在仿真平台上与无中继场景进行对比仿真,结果说明中继技术的引入提升了小区边缘用户性能以及系统的总体性能。然后,本文对TD-LTE-A中继系统的保证Qo S需求的资源调度算法进行了深入的研究。首先设定了传输不同Qo S业务的中继场景,基于对TD-LTE-A标准中规定的Qo S的总结,定义了适用于中继场景的Qo S需求。针对上述场景,本文提出了保证Qo S需求的资源调度算法,分为回程子帧的调度和接入子帧的调度,并在本文搭建的TD-LTE-A中继系统的系统级仿真平台上和现有算法进行对比仿真了,仿真结果表明,所提算法能够实现低丢包率、较好地满足GBR需求,兼顾中继用户和直传用户的性能,实现较高的系统吞吐量和公平性。最后,本文针对TD-LTE-A多天线中继系统的传输场景,研究并确定了各条链路的传输模式以及采用的预编码和检测算法,在搭建的TD-LTE-A多天线仿真平台上验证了结合多天线技术为系统带来的增益。为了进一步提高系统性能,本文提出了低反馈开销并考虑公平性的资源调度算法,算法分为三个子问题求解。仿真结果表明,本文提出的多天线中继系统的资源调度算法在资源划分的过程中能够较好地兼顾用户的公平性和系统吞吐量,在回程链路的调度过程中可以大大减少反馈开销,通过最大化系统的比例公平效用函数值可以同时提高系统的吞吐量和用户的公平性。
[Abstract]:In recent years, the demand for high data rate, high quality of service and diversification of services in mobile communication has been increasing. In order to cope with this trend, the third Generation Partnership Program has proposed a LTE-Advanced system based on LTE. Compared with LTE system, several key technologies are introduced, including relay technology, which can expand cell coverage, improve cell edge throughput and enhance user fairness. Relay has the advantages of convenient installation and low cost, so it has become a research hotspot in LTE-Advanced system. In order to make better use of relay to improve system performance, resource scheduling in relay system is very important. At present, there are two main standards in LTE, among which, the TD-LTE standard, which is developed by our country, is also evolving to TD-LTE-Advanced. This paper studies the resource scheduling algorithm of relay system based on TD-LTE-Advanced system. In this paper, the classification and architecture of relay in TD-LTE-Advanced relay system and the theoretical knowledge of physical layer related technology are introduced firstly, and the process of downlink resource scheduling in relay system is determined. At the same time, the impact of relay technology on the system performance is studied. The simulation results show that the relay technology can improve the performance of the cell edge users and the overall performance of the system. Then, the resource scheduling algorithm for TD-LTE-A relay system to meet QoS requirements is studied. First, the relay scenarios for different QoS services are set up. Based on the summary of QoS specified in TD-LTE-A standard, the QoS requirements for relay scenarios are defined. For the above scenarios, this paper proposes a resource scheduling algorithm to meet the QoS requirements, which is divided into backhaul subframe scheduling and access sub-frame scheduling. The simulation results on the system-level simulation platform of the TD-LTE-A relay system are compared with the existing algorithms. The simulation results show that the proposed algorithm can achieve low packet loss rate and better meet the needs of GBR. The performance of relay users and direct users is taken into account to achieve high system throughput and fairness. Finally, according to the transmission scene of TD-LTE-A multi-antenna relay system, the transmission mode of each link and the precoding and detection algorithm are studied and determined. On the TD-LTE-A multi-antenna simulation platform, the gain of the system is verified by combining the multi-antenna technology. In order to further improve the performance of the system, a resource scheduling algorithm with low feedback overhead and fairness is proposed. The algorithm is divided into three sub-problems. Simulation results show that the proposed multi-antenna relay system resource scheduling algorithm in the process of resource division can better balance the fairness of users and system throughput, in the return link scheduling process can greatly reduce the feedback overhead. By maximizing the utility function of proportional fairness, the throughput of the system and the fairness of users can be improved at the same time.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.5

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