LTE-A系统中基于资源利用率的时延优先调度算法

针对现有LTE系统中调度算法在吞吐量、公平性及丢包率性能指标上难以取得性能平衡的问题,提出一种改进算法,在考虑用户时延的前提下还考虑了用户对资源块(RB)的利用率,从实际获得速率的角度来更精确描述用户对资源的利用能力,更加合理地分配资源.仿真结果表明,该算法的丢包率性能有很大改进,同时在吞吐量、公平性方面也有着较好表现,实现了良好的综合性能,能够更好地满足用户的QoS需求.     

Clustering-based adaptive low-power subframe configuration with load-aware offsetting in dense heterogeneous networks

Heterogeneous Networks (HetNets) and cell densification represent promising solutions for the surging data traffic demand in wireless networks. In dense HetNets, user traffic is steered toward the Low-Power Node (LPN) when possible to enhance the user throughput and system capacity by increasing the area spectral efficiency. However, because of the transmit power differences in different tiers of HetNets and irregular service demand, a load imbalance typically exists among different serving nodes. To offload more traffic to LPNs and coordinate the Inter-Cell Interference (ICI), Third-Generation Partnership Project (3GPP) has facilitated the development of the Cell Range Expansion (CRE), enhanced Inter-Cell Interference Coordination (eICIC) and Further enhanced ICIC (FeICIC). In this paper, we develop a cell clustering-based load-aware offsetting and an adaptive Low-Power Subframe (LPS) approach. Our solution allows the separation of User Association (UA) functions at the User Equipment (UE) and network server such that users can make a simple cell-selection decision similar to that in the maximum Received Signal Strength (max-RSS) based UA scheme, where the network server computes the load-aware offsetting and required LPS periods based on the load conditions of the system. The proposed solution is evaluated using system-level simulations wherein the results correspond to performance changes in different service regions. Results show that our method effectively solves the offloading and interference coordination problems in dense HetNets.     

LTE-A系统一种降低复杂度的软球形检测算法

软球形译码算法虽然能接近ML(最大似然)算法的误码性能,但其计算复杂度很高。文章提出了一种降低计算复杂度的SSD(软球形译码)算法,该算法在QR(正交三角)分解算法的反向迭代上三角矩阵R中引入减弱噪声部分以缩小初始搜索半径,然后利用最小距离准则对搜索树进行有效地删减,缩小树搜索空间。MATLAB仿真结果表明,该算法在获得接近传统SSD性能的条件下,能够很大程度地降低系统的计算复杂度。     

一种基于CoMP的随机接入方案

提出了一种新的基于协作多点传输和接收（CoMP）技术的多发随机接入流程,并根据 随机接入的目的和业务类型设计了接入优先级,在此基础上设计了一种新的随机接入方案, 对 不同类型的随机接入请求提供不同的接入机制,以保证边缘用户的接入性能和满足不同业务 的QoS需求。仿真结果表明,与LTE标准随机接入方案相比,该方案对系统整体接入性能略有 提高,且大大提高了边缘高优先级用户的接入性能。     

TD-SCDMA的比较优势及面向未来的发展策略

文章在分析讨论TD的比较优势与面临的主要挑战基础上,重点论述TD—SCDMA面向未来的融合演进发展策略,对全业务环境下双网深度融合及网络优化、低频段的有效利用、飞蜂窝的战略作用、LTE及4G演进的渐进引入策略、TD产业链的国际化、与WiMAX及802,11n等802．11x的关系等关键问题进行了深入探讨。     

LTE-A系统异构网中的定位技术研究

随着全球移动通信技术的迅猛发展,人们对定位业务的需求日益增强,研究无线定位技术具有很强的实际意义。为了达到4G标准中用户上下行峰值速率,带宽等系统性能要求,引入了长期演进项目的后续演进（LTE-A,Long Term Evolution,Advanced）。目前,LTE-A系统的标准制订工作正在稳步进行中,其中包括了无线定位技术的标准制订,涉及定位方法和重要参量的精度要求。这里对LTE-A系统中宏基站和无线中继设备共存的异构网络中的无线定位技术进行了研究,并结合标准进展提出了一种改进方法。     

LTE-A下行CoMP反馈开销减小方案

简单介绍了LTE-Advanced的关键技术之一——协作多点传输技术,通过分析该技术,指出了在下行反馈方面存在的反馈开销巨大的问题。通过对比现有的方案,并在现有方案基础上提出了新的反馈方案,从而在减小反馈开销方面得到很大提升。     

LTE-A载波聚合技术研究及在PDCCH盲检测中的应用

阐述了载波聚合关键技术的最新进展,具体介绍了载波聚合技术在PDCCH盲检测中的应用,以及支持跨载波调度和不支持跨载波调度两种方式下的盲检测方法和各自优缺点。通过C语言搭建链路,对两种调度方式的性能进行了仿真,为LTE-A系统的实现提供了理论依据。     

LTE-A空口监测分析仪中载波聚合的设计与实现

针对载波聚合等关键技术的引入造成通信网络测试及优化困难,长期演进（LTE）网络空口测试仪表国内市场短缺的问题,提出一种支持3GPP R10/11协议标准,LTE演进（LTE-A）载波聚合等关键技术的空口监测分析仪的设计方案。首先,介绍空口监测分析仪整体物理架构及逻辑架构及两者之间的关系,及架构中各模块在监测仪中的功能;然后,设计一种监测仪中载波聚合技术的实现方案,以及一种仪表在多载波多小区情况下对多用户的支持方案,以满足新技术下用户及基站设备测试的需要。方案的应用,可加快载波聚合在网络中的商用进展,加速LTE-A网络部署进程,缩短网络建设周期,并将在网络运行维护中起到不可或缺的作用。     

Radio resource management scheme and outage analysis for network-assisted multi-hop D2D communications

In a cellular network it's very difficult to make spectrum resource more efficiently. Device-to-Device (D2D) technology enables new service opportunities, and provides high throughput and reliable communication while reducing the base station load. For better total performance, short-range D2D links and cellular links share the same radio resource and the management of interference becomes a crucial task. Here we argue that single-hop D2D technology can be used to further improve cellular networks performance if the key D2D radio resource management algorithms are suitably extended to support multi-hop D2D communications. Aiming to establish a new paradigm for the analysis and design of multi-hop D2D communications, We propose a radio resource allocation for multi-hop D2D routes based on interference avoidance approach in LTE-A networks. On top of that, we investigate the outage probability of D2D communication. We first introduce a new definition of outage probability by considering the maximum distance to be allowable for single-hop transmission. Then we study and analyze the outage performance of a multi-hop D2D route. We derive the general closed form expression of outage probability of the multi-hop D2D routes. The results demonstrate that the D2D radio, sharing the same resources as the cellular network, provide higher capacity compared to pure cellular communication where all the data is transmitted through the base station. They also demonstrate that the new method of calculation of D2D multi hop outage probability has better performance than classical method defined in the literature.