【作者】 徐乐西；

【导师】 张英海； 王卫东；

【作者基本信息】 北京邮电大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 OFDMA为4G的首选多址技术,严重的小区间干扰(ICI)影响将会大大限制其应用。同时,未来移动通信系统可支持多种类型的业务,它们对QoS的要求各不相同,为此,如何利用有限的资源来满足不同业务的需求成为研究的热点。本文首先介绍了OFDMA系统的原理、关键技术及典型无线资源管理技术。然后分析了现有的OFDMA小区间资源分配策略。第一,这些方案并未考虑多业务QoS对资源分配的需求,而支持多业务是未来通信系统的基本特征。第二,传统方案建立在理想小区结构上,忽视了小区内部规划。实际小区的覆盖往往不规则,干扰与电磁波传播有关,应从电磁波损耗的角度对小区进行划分,并对小区内部进行合理的规划。OFDMA系统中用户具有空间及业务二维属性,不可对两属性孤立对待,若只考虑前者造成的干扰增量,可能会导致高QoS业务得不到较好的服务保障;而只考虑后者需求,可能会造成因资源分配不当而导致较强的干扰,影响系统性能。其次,本文针对传统方案的缺陷提出了新型的资源分配算法:联合位置和业务的资源分配算法(LSA)。该算法定量分析空间区域电磁波损耗引起的ICI特性,对小区内部进行区域划分,并设置区域位置优先级。分析多业务QoS需求设置各个业务的等级,进而确定各区域所有新业务的平均优先级。通过各区域位置优先级及区域的业务优先级计算子载波资源分配指标,并可通过动态调整权重满足实际系统需求。此外,LSA通过设置小区内部及边缘子载波分配列表保证优选子载波所受干扰较少,进而保证了LSA进行资源分配时,实现子载波与各区域资源需求的最优匹配。最后本文通过OFDMA系统级仿真平台对LSA资源分配算法性能进行性能评估。仿真结果表明,新型的资源分配算法可保证不同业务的实际需求,降低干扰,降低新用户阻塞率,提高资源利用率,优化了OFDMA系统的整体性能。更多还原

【Abstract】 Orthogonal frequency division multiple access (OFDMA) is a typical 4G system, which suffers severe Inter-Cell Interference (ICI) and becomes a challenging problem. Meanwhile, future communication system supports various types of services, which have different QoS requirements, how to use the limited resource effectively is an important issue.Firstly, this paper introduces OFDMA system theory, multiple access schemes, key technologies and radio resource management. Secondly, we introduces traditional resource allocation scheme. Traditional schemes always ignore different QoS requirements of multi-service, which is an essential feature of future system; they usually adopt complex cell edge part separation resource allocation scheme, and allocation of cell inner is too simple. But real coverage of cell is irregular, and ICI relates to electromagnetic wave transmits, so cell separation should take into account electromagnetic wave path loss; as system performance, the allocation of inner part areas is of vital importance. Users have location and service dual factors, if we only consider interference increment, high QoS service would not be guaranteed; if we only consider service QoS requirement, it would lead to severe ICI.Thirdly, we present a novel cell-level associated area location and service allocation (LSA) scheme to solve these problems above. LSA analyzes ICI of area location of inner part quantitatively to define area classification, and it sets area priority associated with services QoS requirements of each area. LSA defines inner part and edge part sub-carrier priority list, and LSA guarantees sub-carrier to optimum match with resource requirement of each area, by which to decrease ICI and meet various service requirements. In fact, LSA associated optimize resource allocation among area location and service requirement as well as sub-carrier priority.Last, this paper designs and completes the OFDMA system level simulation platform. Based on the platform, the novel LSA algorithm performance is evaluated by simulation analysis. The simulation results shows that LSA algorithm can decrease system interference and reduce new call blocking probability, improving resource utilization.更多还原