【作者】 刘浩；

【导师】 常永宇；

【作者基本信息】 北京邮电大学 ， 信息与通信工程， 2016， 硕士

【摘要】 目前,移动通信技术飞速发展,对人们的日常生活以及工业生产带来了极大的推动作用。在我国,基本上已经实现了 4G技术的商用。但是同时,人们对于容量与速率日益增长的需求,如何在5G时代实现容量与带宽飞跃性则增长,对于移动通信技术的发展带来了新的挑战。引入低功率节点,与传统的宏基站组成异构网络,成为了目前研究的重点方向。为了应对未来5G时代密集接入的要求,未来的异构网络将向着超密集网络方向发展。在异构网络技术的研究中,无线资源管理技术一直是一个研究的重点。在异构网络的环境下,网络节点将密集部署。如果没有优秀的资源管理机制,将导致严重的干扰,使得整个网络性能下降。此外,在最近的3GPP会议中,为了解决异构网络带来的一些问题,提出了双连接的概念。由于双连接的引入,将给传统的无线资源管理带来新的挑战。基于这种情况,首先,本文在室内部署的异构网络场景中,提出了一种分布式的下行功率分配方案,目的在于减少家庭基站对于室内微小区基站的干扰。通过测量到家庭基站下行对于微小区用户的干扰值,并将其与门限值进行比较,减少造成干扰大的子帧上的功率,适当增大造成干扰小的子帧上的功率。通过这种方法,在不过多影响家庭基站性能的前提下,改善微小区基站用户性能。并在最后给出了系统级仿真,验证了方案的性能。另外,本文讨论了基于双连接技术的切换管理方案。针对在某些场景下,双连接会触发过多的切换事件,造成信令开销过大这种情况,在本文中,我们提出了一种基于小区组的移动性管理方案。切换的执行是基于包含了多个小区所组成的小区组为单位进行的。在小区组内部的小小区的操作,是由用户自主发起的,并不需要RRC配置,所消耗的时间远小于传统切换所需要的时间。本文详细给出了切换的整体流程,并且通过仿真,我们可以看到,小区组切换方案确实可以节省切换时间,提升系统性能。更多还原

【Abstract】 Nowadays,mobility communication technology is developing faster and faster,which brings great advantages on our daily life and industrial manufacture.In China,4th Generation Technology has been applied successfully since 2013.However,with more and more requirements on data rate and capacity,how to make great increases on capacity and data rate in 5G network,brings a great challenge to us.The heterogeneous network,which introduces various kinds of low power nodes and combine with traditional macro node,seems to be a smart solution.To solve the massive connection in 5G network,heterogeneous network will develop into ultra-dense network.Radio resource management technology is an important research area in heterogeneous network.Under heterogeneous environment,cells are deployed densely,which will lead a strong interference between cells.In addition,in recent 3GPP meetings,dual connectivity is introduced to solve problems in heterogeneous network.The introduction of dual connectivity may cause new challenges to radio resource management.In this paper,firstly,we come up with a distributed power allocation scheme under indoor heterogeneous network,in order to decrease micro cell’s interference from femto cells.After comparing interference caused by femto with threshold,this scheme adjusts power allocation of each sub-frame.If one sub-frame causes a great interference,this scheme will allocate it less power.On the other hand,if one sub-frame causes a little interference,this scheme can increase its power.At last,we give a system-level simulation to support this scheme.Secondly,we discuss the mobility management under dual connectivity in heterogeneous network.We come up a cell group handover scheme,which can lead to an improvement in handover time and signaling cost.In this paper,we come up with a mobility management scheme.In this scheme,handover is based on cell groups which contain several small cells.In each cell group,small cell operations are initialed by users,and there are no RRC reconfigurations,so it costs less time than traditional handover.We describe the overall handover procedure in detail,and we also give a system-level simulation.From our simulation,we can see our scheme can decrease average handover time,and improve overall performance.更多还原